Malawi - Power system loss reduction study : consultants' report

Q H ESMAP Joint UNDPIWorld Bank Energy Sector Management Assistance Programme (ESMAP) MALAWI POWER SYSTEM LOSS REDUCTION STUDY CONSULTANTS' REPORT November 1992  MALAWI POWER SYSTEM LOSS REDUCTION STUDY CONSULTANTS' REPORT November 1992 This report has been prepartd by Messrs. Kennedy & Donkin Power Systems with the coopaation of the Electricity Commission of Malawi and under the supervision of ESMAP. The report may not be published or quoted as qmsenting the views of the Bank Gioup o r UNDP.  ACROWYMS AND ABBRWIATIOWS AAAC A1 1 aluminium a1 l o y conductor AIC Average incremental cost CADLF Coincident a f t e r d i v e r s i t y load f a c t o r CT Current transformer DPAS D l s t r i b u t l o n Primary Analysl s Software EP&D The Department o f Economlc Planning and Development ESC OH E l e c t r i c i t y Supply Commission o f Malawi ESMAP Energy Sector Management Assistance Programne GDP Gross Domestic Product GH h Giga Watt hours HV High Voltage ICS Interconnected system IERR I n t e r n a l Economlc Rate o f Return IFR R I n t e r n a l Financial Rate o f Return IRR I n t e r n a l Rate o f Return KDP Kennedy & Donkin Power Ltd km K i lometre kV K i lovolt kVAr K i l o v o l t-ampere react1ve kHh K i l o watt hour LF Load f l o w Ln Natural logarithm LRM C Long Run Marginal Cost LV Low vol tage MK Ma1awl Kwacha MV Medi u m Vol tage MVA Mega vol t-ampere MW Mega Watts MW h Mega Watt hour OHL Overhead L i ne SCADA Supervi sory control and data acqui s i t l o n sqmn Square m i 1 1lmetres svs S t a t i c Var System T&D Study Transmission and D i s t r i b u t i o n Study Tambala One hundredth o f One Malawi Kwacha U/G Underground UK United Kingdom UNDP United Nations Development Progranme US$ Dollars - United States EXCHANGE RATE The exchange r a t e used i n the cost estimates presented i n t h i s report i s based on a l a t e 1990 f i g u r e , as follows: 1 Malawi Kwacha (MK) = US$ 2.5 Note: MK1 = 100 Tambala (as defined above)  PAGE0 EXECUTIVE SUMMARY 1. INTRODUCTION 1 2. DISTRIBUTED LOAD FORECAST 3 2.1 General 2.2 Rev1 sed Equatlons for E l e c t r i c 1t y Sales 2.2.1 HIghDenslty 2.2.2 Low Denslty 2.2.3 General 2.2.4 Small Power 2.3 S?!es o f Large Power Consumers 6 2.4 Load Factors, D l v e r s l t y Factors and Coincidence Factors 6 2.5 Losses 7 2.6 Impact o f Improvement I n Voltages 7 2.7 Load Forecast f o r the Interconnected System 8 2.8 Future P a t t e r n o f LoadGrowth 8 3. LONG RUN MARGINAL COST OF POWER AND ENERGY 10 3.1 General 3.2 Capaclty Costs 3.2.1 Generatlon Capacity Costs 3.2.2 TransmlsslonCapacltyCosts 3.2.3 Sumary o f Capac It y Costs 3.3 Marglnal Energy Costs 4. TECHNICAL LOSSES 16 4.1 Introduction 4.1.1 Technical Analysls 4.1.2 EconmfcAnalysls 4.2 132166133 kV System 18 4.2.1 System Losses w i t h o u t Loss Reductton 18 4.2.2 Loss Reductlon S t r a t e g l e s 21 4.2.3 Comnents 28 4.3 11 kVSystems 4.3.1 Introduction 4.3.2 11 kV Feeder Monl t o r i n g 4.3.3 Present Loss Levels 4.3.4 Loss Reductlon S t r a t e g i e s 4.4 1110.4 kV Transformatlon and LV Systems 39 4.4.1 Introductlon 39 4.4.2 11f0.4 kV Transformer Losses 39 4.4.3 C a p l t a l t s a t l o n of Transformer Losses 40 4.4.4 LV Feeder Losses 42 4.4.5 11f0.4 kV Transformer and LV Loss O p t i m l s a t l o n 43 NON-'TECHNICAL LOSSES 5.1 Introductlon 5.2 Meter Accuracy 5.2.1 Generator Meters 5.2.2 Meter1 ng a t I n d u s t r l a l Consumers 5.2.3 Meter Test Bench Accuracy 5.3 B i l l l n g System 5.4 O r g a n l s a t i o n o f Investment and Detection 5.4.1 General ESCOM Organ1 s a t l o n 5.4.2 RevenueSection 5.4.3 Procedures Designed t o Prevent Fraud by Meter Readers 5.4.4 D a l l y I n f o r m a t l o n Report 5.4.5 Consumers Englneer and Meter Englneer 5.4.6 . Results of Meter I n v e s t l g a t l o n s 5.4.7 Data Processing S e c t l o n 5.5 Economfc and F l n a n c l a l A n a l y s f s 5.5.1 F l n a n c l a1 A n a l y s i s 5.5.2 Economl c Analys is CONCLUSIONS AND RECOMMENDATIONS 6.1 E x l s t i n g System Losses 6.2 Losses A f t e r Loss Reductlon 6.3 Recomnendatlons 6.3.1 132166133kV Sys tem 6.3.2 l l k V System 6.3.3 LVSystems 6.3.4 Non-technical Losses 6.3.5 General 6.4 Budgetary Requl rements 6.5 Programne REFERENCES This report discusses the findings o f a Power System Loss Reduction Study whlch was carried out under the supervision o f ESMAP t o establish the present levels o f losses and t o develop loss reductlon strategies f o r the transmission and d l s t r i b u t l o n systems operated by the E l e c t r i c i t y Supply Coninlsslon of Malawi (ESCOM). A package o f loss reductlon measures I s presented, together w l t h estimated budgetary requirements f o r I t s Implementation and a suggested tinescale f o r the execution of each project. Breakdowns o f ex1 s t i n g estimated energy losses associated w l t h each level o f the system and the target loss levels which may be achieved by the Inplenentatlon o f the proposed loss reductlon projects are as follows; these are given as percentages o f the metered net system generatl on : Energy Loss Levels Ex1stlng Target 132/66/33kV Transml sslon System 6.7% 6.7% 1lkV Feeder Losses 1 .OX 0.7% 1110.4kV Transformer 0.9% 0.7% LV Dl s t r l b u t l o n 1.5% 1.OX Non-Technl cal Losses Found 4.0% - Non-Techni cal Losses Remaining 2.9% 0.5% TOTAL SYSTEM ENERGY LOSS 17.0% 9.6% It w i l l be observed t h a t sI.gnlflcant non-technical losses were I d e n t l f 1ed f rom major consumer and generator metering errors. These were found during the measurement work undertaken by E S m and Kennedy & Donkln Power .(KDP) engineers during the course of the study. H h l l s t generator metering errors do n o t r e s u l t I n l o s t revenue to ESO(m, they cause Incorrect figures t o be used I n the basic loss calculations, and w i l l therefore h i s t o r l c a l l y have contributed t o the perceived level of losses on the E SCO M system. The consumer metering errors detected represent some MK413.000 of potential annual Increased revenue t o ESCOM, providing an inmnedlate Indl cation o f the value of undertakl ng non-technl cal loss reductlon. Technical and economic analysl s o f sample areas of the ESO(m system have been undertaken w i t h regard t o technical losses on the basis of a progranme o f measurements carried out I n Malawi t o develop viable loss reduction projects. These have then been extended t o a system-wide package of loss reductlon measures. 'The key reconmendations o f the study are as follows: -The r e s u l t s o f the work c a r r i e d o u t on the transmission system I n d i c a t e t h a t there i s very l i t t l e work which can be j u s t i f l e d i n a d d i t i o n t o the developments which are already programed by ESCOM i n order t o reduce losses. Upgrading o f the Mtunthama 105 33kV c i r c u i t t o 66kV operation I s a j u s t l f l a b l e loss reduction measure due t o the f a c t t h a t the l l n e I s already constructed f o r 66kV operation. The Least Cost Development Plan f o r the ESCOM system Included recommendations f o r the i n s t a l l a t i o n o f s t a t i c compensatlon equipment on the 132kV system. Whilst the c a p i t a l cost o f such equipment i s such as t o make It u n a t t r a c t l v e when viewed s o l e l y f rom the angle o f loss reduction, b e n e f i t s i n terms of reduced losses should be examined i f the current work being c a r r i e d o u t i n the Transmission and D l s t r i b u t l o n Study recommends I t s I n t r o d u c t i o n As p a r t o f the optlmal development o f the system. I t I s recommended t h a t the deslgn loading l e v e l s f o r conductors which have been developed i n t h l s r e p o r t are used as the basis f o r plannlng the transmlsslon system w l t h a view t o minimising losses a t a l l stages of system development. A substantial programme o f feeder reconductoring a t 11kV i s proposed, together w i t h 1i m l ted appl ic a t i o n o f capacl t o r s , on account o f the general l y good system power f a c t o r s . Reconductoring general l y takes the form o f introducing a new conductor slze (150 sq mm) a t 11 kV, together w l t h some cable rep1acement. I t I s recomnended t h a t the o v e r a l l conflguratlon o f the 1lkV system be optlmlsed I n terms o f loss minimisation once the basic system p l a n has been established I n the Transmission and D l s t r i b u t l o n Study. It is a n t l c l p a t e d t h a t the study should include consideration of losses as a matter o f course, b u t I t I s emphasised t h a t f o r f u l l b e n e f i t t o be derived from the design c r i t e r i a presented i n t h l s r e p o r t a co-ordinated approach t o the o p t i n l sation o f t h e . 1lkV system should be adopted. I t i s a l s o recommended t h a t a t an operational l e v e l ESCOM should examine the effects o f switching operations and consequent l o c a l - system r e c o n f i g u r a t i o n i n terms o f losses as p a r t o f t h e i r normal procedures. Proposals have been developed f o r the purchase o f 11/0.4 kV transformers and the execution o f LV reconductorlng p r o j e c t s w i t h a view t o reducing losses associated w l t h d l s t r l b u t l o n transformers and LV systems. The magnitude o f the task o f o p t l m i s i n g the d e t a i l e d investment programne based on these measures i s such t h a t I t can o n l y e f f e c t i v e l y be f i n a l l s e d by means o f a d e t a l l e d LV study whereby transformer placement and LV feeder lengths can be coordinated t o minimlse losses overall.  I t i s envisaged t h a t t h i s work could be c a r r l e d o u t w l t h conslderable Input from ESCOM's Central Planning U n i t I n c o n ~ u n c t i o n w l t h a d l s t r l b u t l o n plannlng s p e c l a l i s t , and a proposal based on t h i s approach has been Included I n the loss reductlon package. Load balanclng on the LV systems has been shown t o p l a y an Important r o l e both i n reduclng loss l e v e l s and I n improving voltages a t remote ends o f the feeders. Thls measure Involves mlnlmal cap1 t a l cost, and I s therefore strongly recommended as a loss reductlon measure. The voltage p r o f l l e across the LV networks I n general would be s u b s t a n t i a l l y improved by changlng the tap s e t t i n g s on a l l of the I l k V l L V and 33 kVILV transformers t o t h e i r +5% levels. Most of t h e d l s t r l b u t l o n transformers are c u r r e n t l y operatlng on nominal tap and n o t therefore u t l l i s l n g the opportunity t o Improve voltages a t consumers' preml ses. hnlcal L o s s 'The key recommendations re1a t l n g t o non-technl cal loss reductlon Involve a number o f c a p l t a l purchases and measures t o Improve organlsational r aspects o f the detection and I n v e s t l g a t l o n o f losses a r l s l n g f om metering e r r o r s and fraud. I n summary, these recomnendatlons are as f o l lows : Implementation o f a new computer b i l l i n g system. I n s t a l l a t i o n of meter boxes a t a l l new consumers' prenlses and r e t r o s p e c t l v e l y a t a l l small power, high denslty, low density and general consumers. Purchase o f two meter t e s t benches and constructlon o f a new meter t e s t room I n Blantyre. Purchase o f f i f t y p a i r s o f meter p l l e r s Purchase o f f l f t e e n s o l i d s t a t e kHh meters f o r use by the ESCOM meter1ng department I n carry1 ng o u t on-sl t e meter accuracy checks. A number o f detal 1ed recommendatlons are made regardl ng organ1 s a t l m a l aspects o f the meterlng and b i l l l n g operatlons whlch should be Implemented by ESCOM t o reduce the scope for non-technlcal losses a r i s l ng in these processes. 'These Include recommendations o f increased rewards f o r meter readers discovering abnormalltles a t consumers' premises, modlflcatlons t o the r e p o r t i n g and recordlng procedures for detect! ng and investi g a t i ng I 1 legal abstract lons, and s p e c l f 1c d e t a i l s whlch should be recorded I n the computer b i l l l n g system. I t I s a l s o recomnended t h a t continued monltorlng o f loss l e v e l s be c a r r l e d out by ESCOM t o ensure t h a t the effectiveness of l o s s reductlon p r o j e c t s can be measured and the i d e n t i f l c a t i o n o f p a r t l c u l a r sources of losses be contlnued. The budgetary requlremnts f o r carrylng out the above technlcal and technl ca.1 loss reductlon pro3ects are as f o l lows : Non-Technl cal Loss Reductlon 6.56 Technical Loss Reduction 4.90 Physlcal Contlngencles (10) 1.15 Engineetlng Contlngencles (5%) 0.57 TOTAL 13.18 13.75 Thls gives an overall t o t a l f o r the package of USS19.1 n, based on an exchange r a t e o f MK 2.5 = US$ 1 .O. A more detal l e d summary o f the reconnendatlons w l 11 be found . I n Sectlon 6 of t h l s report. I t I s proposed t h a t . a l l the measures to reduce losses should be Implemented over a f l v e year perlod, with the exceptlon of the i n s t a l l a t l o n o f meter boxes, whlch, glven the number consumers to be addressed, i t I s intended should be carrled out over f l f t e e n years. I n addltlon to speclflc recomendatlons for loss reductlon proJects, a number o f deslgn c r l t e r l a have been produced whlch I t I s ' r e c m n d e d t h a t E S W adopts I n carrylng o u t f u t u r e plannlng I n such a way as to reduce system losses t o ecororlc levels. The measurement work and associated technlcal and econocnlc analysls performed I n the course of t h l s study has been undertaken w l t h a hlgh degree o f Involvement of counterpart teams of E S W engineers. The degree of cawnltnent and enthuslasn demonstrated by these teams has to a large extent contributed t o the sound base of a n a l y t l c a l r e s u l t s used I n the study, whlch has enabled the compllatlon o f the loss reductlon package. KDP would I l k e to acknowledge w l t h thanks the considerable assistance recelved fr o m E S W I n the executlon of the study phases I n Malawl . T h l s r e p o r t d e s c r i b e s t h e work whlch has been undertaken i n c a r r y i n g o u t a Loss Reduction Study f o r t h e system o p e r a t e d by t h e E l e c t r i c i t y Supply Commission o f Malawi (ESCOM). Thls comprised p e r i o d s o f measurement and in v e s t l g a t i o n work c a r r i e d o u t i n Malawi by engineers and economists f r o m Kennedy & Dankin Power (KDP) and ESCOM, t o g e t h e r w i t h a n a l y s i s of r e s u l t s and I d e n t i f i c a t i o n o f loss reduction s t r a t e g i e s c a r r i e d o u t both i n Malawi and i n t h e UK. T h i s work has c u l m i n a t e d I n t h e recommendation o f a number of measures t o reduce t h e e x i s t i n g l e v e l s o f b o t h t e c h n i c a l and n o n - t e c h n i c a l losses i n t h e ESCOM system. The s t u d y was performed under t h e s u p e r v i s i o n of t h e Energy S e c t o r Management Ass1 stance Program (ESMAP) , which is a j o i n t program sponsored by t h e World Bank, UNDP and B i l a t e r a l A i d agencies. The key o b j e c t i v e s o f t h e s t u d y were defined by ESMAP a t t h e o u t s e t t o ( a ) i d e n t i f y t h e v a r i o u s sources o f energy losses on t h e ESCOM t r a n s m l s s i o n and d i s t r i b u t l o n systems, ( b ) q u a n t i f y t h e c o n t r i b u t i o n o f each of t h e s e sources t o o v e r a l l losses, and ( c ) develop a program of d i s c r e t e , m o n i t o r a b l e and phased p r o j e c t s t o reduce losses t o economic levels. The economi c and t e c h n i c a l assessment of l o s s r e d u c t i o n s t r a t e g i e s depends upon t h e c a l c u l a t i o n o f m a r g i n a l power and energy c o s t s and t h e ex1 stence o f an up t o d a t e l o a d f o r e c a s t f o r t h e system under i n v e s t i g a t l o n . Both o f t h e s e areas have been addressed as t h e s t a r t i n g p o l n t for t h e a n a l y s i s phase of t h e Loss Reduction Study, and a r e d e s c r i b e d i n ' t h e opening s e c t i o n s of t h e r e p o r t . The r e p o r t summarises t h e measurement and a n a l y s l s techniques which have been a p p l i e d I n o r d e r t o assess t h e scope for r e d u c i n g t e c h n i c a l l o s s e s a t a l l v o l t a g e l e v e l s on t h e transmi s s i o n and d l s t r i b u t i o n systems. Thl s Is t h e n expanded i n t o a programne o f system-wide measures t o reduce t e c h n i c a l losses, on t h e b a s i s o f d e t a i l e d t e c h n i c a l and economic a n a l y s i s of t y p i c a l s e c t i o n s o f t h e system. The a n a l y s i s which has been performed on t h e accuracy o f g e n e r a t o r and consumer m e t e r i n g and t h e procedures adopted by ESCOM f o r d e t e c t i n g and i n v e s t i g a t i n g n o n - t e c h n i c a l losses I s a l s o presented and developed i n t o a s e r i e s o f f i n a n c i a l l y and e c o n o m l c a l l y j u s t i f i a b l e measures t o reduce n o n - t e c h n i c a l system l o s s e s . The r e p o r t concludes w i t h t h e recommendation of measures t o be implemented t o reduce t h e p r e s e n t l e v e l o f system l o s s e s , I n c l u d i n g budgetary e s t i m a t e s of t h e c o s t a s s o c i a t e d wi t h t h e s e t o f measures and t h e suggested programme for t h e i r Implementation. A t t e n t i o n i s drawn t o t h e need for l o s s m i n i m l s a t l o n t o be a t t h e f o r e f r o n t of t h e p l a n n i n g and d e s i g n strategies used by ESCOM, with reconrnendatlons which w i l l ensure that losses can be maintained a t economic levels during the expansion o f the system I n response t o Increasing demand. Many o f the key ESCOn system parameters are introduced i n the naln body o f the report. Table 1.1 gives an overview o f the t o t a l equl pment i n s t a l led i n the transmi sslon and d l strlbutlon systems f o r reference purposes; copies o f World Bank Map IBRO 23398 and ESCOM Drawing No. 7.03/108A are Included a t the end of the report for reference and indicate the extent of the ex1st1ng and proposed transmi sslon systems.  SECTIOW 2 DISTRIBUTED LOU) FORECAST 2 DISTRIBUTED U)AD FORECAST 2,1 General 'The ESCOM l o a d f o r e c a s t i n g model has been d e s c r i b e d I n v a r i o u s documents I n c l u d i n g a manual and users guide produced a t t h e end o f t h e Power System P l a n n i n g t r a i n i n g programme conducted by Kennedy & Donkin w i t h t h e l a s t phase completed I n May 1990. The mode1 used I n t h i s Loss Reduction Study i s an updated v e r s i o n o f t h i s e a r l i e r model, t h e s t r u c t u r e o f which was c r e a t e d I n 1985. I n p a r t i c u l a r , t h e e q u a t i o n s d e s c r i b i n g t h e r e l a t i o n s h i p between e l e c t r i c 1 t y s a l e s and e x t e r n a l v a r i a b l e s have been r e v l s e d and re-estimated. The f o r e c a s t has been m o d i f i e d t o I n c o r p o r a t e t h e l a t e s t macroeconomi c p r o j e c t i o n s f r o m The Department o f Economl c P l a n n i n g and Development, (EP&D), a department o f t h e Malawi Government. The Energy P l annl ng Unl t wl t h i n EP&D p r o v l ded government In f o r m a t i o n r e 1e v a n t t o t h e l o a d f o r e c a s t . The p r o j e c t l o n s t h a t were p a r t 1 c u l a r l y r e l e v a n t were t h e r e v 1 sed GDP f i g u r e s which were p r o v i d e d I n 1978 p r i c e s . The f o r e c a s t d e s c r l bed below t h e r e f o r e , uses t h e l a t e s t GDP p r o j e c t l o n s , however these were n o t s u b s t a n t i a l l y d i f f e r e n t from the projectlons used i n t h e 1988 "Least Cost Development Programme", which was developed by KDP and o t h e r c o n s u l t a n t s . F u r t h e r macroeconomic d a t a was a l s o p r o v i d e d by t h e N a t i o n a l Statist! cal Office. 'The e s t i m a t e d r e l a t i o n s h i p s d l scussed below a r e t h e f i n a l ' versions. A number o f a1 t e r n a t l v e s p e c i f i c a t i o n s , l a g s and p r o x y v a r i a b l e s have been t r i e d and r e j e c t e d 'for v a r i o u s reasons. These a1 t e r n a t l ves are n o t d l scussed. 2*2 Revlsed Equations for Electrlci t y Sales ESCOM's t a r i f f s t r u c t u r e s p l l t s consumers I n t o f o u r c a t e g o r i e s , t h e d e f i n i t i o n s o f which a r e as f o l l o w s : Domestic (High D e n s i t y ) : f o r t h e s u p p l y o f e l e c t r i c i t y t o premises used s o l e l y f o r r e s l dent1 a1 purposes be1 ng preml ses o f a t y p e approved by ESCOM as a h i g h d e n s i t y r e s i d e n t i a l area f o r t h e purposes of e l e c t r i c i t y supply. Domestic (Low D e n s i t y ) : . f o r t h e s u p p l y o f e l e c t r i c i t y t o premises used s o l e l y f o r r e s i d e n t i a l purposes b e i n g premises o t h e r t h a n those s p e c l f i e d i n t h e High D e n s i t y category, i n c l u d i n g motors up t o a t o t a l of 1.5kW. n o r m a l l y used f o r such preml ses. General: f o r t h e s u p p l y o f e l e c t r i c i t y t o premises, o t h e r t h a n premises used s o l e l y f o r r e s l d e n t i a l purposes, b e i n g premises I n r e s p e c t o f which t h e chargeable maximum demand I s l e s s t h a n 25 kVA.  Maxlmum Demand: f o r the supply o f e l e c t r l c l t y t o a consumer w l t h a chargeable maxlmum demand o f 25 kVA o r more. Thls category I s sub-dlvlded f o r reference purposes as follows: Larger Power - the f o l l o w l n g major I n d u s t r l a l consumers: SUCOHA Blantyre Water Board Portland Cement Davl d Whl tehead V l phya Saw M i 11 Small Power t a r l f f band. - the rernalnlng consumers I n the Maxlmum Demand Hlgh denslty sales represent only 2.4% o f t o t a l kWh generatlon. I n vlew o f t h l s f a c t and I n the context o f t h l s study, the r e l a t l o n s h l p establlshed I n the 1985 study has not been revlsed. The short and long run e l a s t l c l t l e s are as f o l lows : Consumer nos: 0.61 *Government Employment : 0.85*Prlvate Employment kwh sales per consumer: 0.35*Income The use o f employment as the Independent v a r l a b l e I n these equations was establlshed I n 1985 based on the c o r r e l a t l o n between l e v e l s o f employment and proper houslng. The l a t t e r I n t u r n I s a pre-requl s l t e f o r e l e c t r l c l t y connectlon. The equattons f o r low denslty consumptlon have been rev1 sed. The growth I n the number o f consumers was n o t found t o be stat1 s t l c a l l y dependent on any o f the external varlables. Thls I s not particularly s u r p r l s l n g slnce the connectlon o f consumers I n the large p a r t has generally been d i c t a t e d more by the development o f the Interconnected g r l d system and I n t h e l a t e 19708s, the development o f Lllongwe r a t h e r than any Increases t n income o r changes I n e l e c t r l c l t y prlces. It appears t o have followed a r e l a t i v e l y smooth p a t t e r n of annual Increases a t 7.5% per annum. ESCW I s contlnulng t o extend electricity supplles both w i t h i n urban centres and t o r u r a l areas. Thls trend I s therefore extrapolated l n t o the f u t u r e . The equatlon f o r low denslty consumptlon per consumer has been re-estimated as shown I n Table 2.1. Lag r e l a t l o n s h l p s have been lntroduced t o allow f o r delays between Income Increases o r p r l c e decreases and changes l n spendlng patterns o r appliance ownershlp. Analysls showed t h a t Income (GDP) Increase I n one year does not s l g n l f l c a n t l y a f f e c t e l e c t r l c l t y usage I n t h a t same year. The Impact I s delayed t o the f o l l o w l n g year. The  Income v a r i a b l e chosen was GDP for the economy as a whole. No data are a v a l l a b l e on the d i s t r l b u t i o n o f Income i n Malawi. However, I t I s c l e a r t h a t the 18,000 households I n the low-density category r e c e i v e Income dlsproportlonate t o t h e i r numbers. A useful Independent v a r l a b l e would be a measure o f the I n e q u a l l t y o f Income d l s t r l butlon. Whilst GDP per c a p l t a might be considered t o be the normal v a r i a b l e , I n Malawl the d i s t r l b u t l o n of Income I s such t h a t t o t a l GDP r e f l e c t s more accurately the Income o f low dens1 t y consumers. Consumer numbers were entered I n t o the equatlon t o r e f l e c t the tendency for average consumptlon per consumer t o be depressed as new consumers w l t h low consumption l e v e l s j o l n t h e ranks of the e l e c t r i f i e d . I n most power systems i n developlng countrles there I s a strong tendency for the wealthler consumers t o connect f i r s t followed by the less wealthy consumers over tlme. The wealthy consumers have r e l a t l v e l y h l g h l e v e l s of consumptlon and the average l e v e l o f consumptlon s t a r t s o f f a t a r e l a t l v e l y hlgh l e v e l . Over tlme, a l l else belng equal, the connectlon of new consumers w i l l d l l u t e the average l e v e l of consumptlon. . Table 2.1 a l s o shows the long run s t a b l e r e l a t i o n s h l p when the dynamlc effects have died down. Thls shows t h a t the long term e l a s t i c i t y between income (GDP) and kWh sales I s 0.45. For every 1% Increase I n Income, consumptlon Increases by 0.45% I n the long run. The long term e l a s t l c l t y w i t h respect t o r e a l e l e c t r l c l t y prlces I s -0.2. W 1 t h consumer numbers the e l a s t l c l t y I s -0.28. Thls l a t t e r r e s u l t , taken I n conjunction w l t h the e x t r a p o l a t i o n o f consumer numbers o f 7.5% per annum Implies t h a t I n the absence of Income growth or decreases i n p r i c e s then the average kWh sales per consumer would decline I n the long r u n by 2.1% per annum. Thls I s the r e s u l t of the d l l u t l o n effect d l scussed above. General The two equatlons f o r the general consumer category have been amalgamated I n t o only one whlch descrlbes the t o t a l kWh sales. Thls has been done for simp1 i c l t y and because, glven the d l v e r s l t y o f types of consumers I n t h l s consumer category, the split I s arbltrary. The estlmated equatlon I s shown I n Table 2.1. A dynamlc r e l a t l o n s h l p has agaln been adopted s l g n l f y l n g t h a t there are lags Involved here. The GDP v a r i a b l e used f o r t h l s consumer category I s t h a t o f the d i s t r l b u t i o n a l and f i n a n c i a l services category of economic output. Thls I s regarded as belng the most representative of a c t l v l t y among these consumers. A p o s l t l v e tlme trend was a l s o found t o be s t a t l s t l c a l l y s l g n l f l c a n t . Thls Implies t h a t these consumers are tending t o become more dependent on e l e c t r l c l t y over tlme. This I s consistent w l t h the expectatlon t h a t shops, o f f l c e s and workshops w l l l tend t o become more mechanlsed and automated w l t h tlme.  The l o n g term r e l a t i o n s h i p s a r e a l s o shown I n Table 2.1. An increase I n t h e o u t p u t (GDP) o f t h e d i s t r i b u t i o n a l and f i n a n c i a l services s e c t o r leads, i n t h e long run, t o a 0.8% increase I n e l e c t r l c i t y sales i n t h i s sector, le., an e l a s t i c l t y o f 0.8. The l o n g r u n e l a s t i c i t y w l t h r e s p e c t t o e l e c t r i c i t y p r i c e s i s -0.87. The l o n g r u n t r e n d increase i n e l e c t r i c i t y sales i s 5.3% per annum. Small Power consumers are, i n terms o f e l e c t r l c l t y sales, t h e l a r g e s t and most important s e c t o r f o r ESCOM. Corresponding a t t e n t i o n has t h e r e f o r e been devoted t o t h e f o r e c a s t for t h i s sector. U n f o r t u n a t e l y , t h e Small Power category c o n t a l ns a l a r g e m i x t u r e o f o r g a n i s a t i o n s r a n g i n g f r o m l a r g e shops and o f fices to relatively large scale manufacturers and processors. Given t h e r e l a t i v e l y small number o f customers (approximately 450) and the d i s t o r t i o n s caused by t h e l a r g e r o f these, t h e e s t i m a t i o n of a s t a t i s t i c a l r e l a t i o n s h i p is fraught w l t h d i f f i c u l t y . Nevertheless, a r e l a t i v e l y good equation has been derived, as demonstrated by t h e a n a l y s i s shown i n Table 2.1. The s p e c i f i c a t i o n o f t h e equation i s based on t h e r a t i o o f e l e c t r i c 1t y consumption t o t h e o u t p u t of t h e manufacturing s e c t o r o f t h e economy, i n c l u d i n g a g r i c u l t u r a l processing. T h i s i s shown I n Table 2.1. There a r e two d r i v i n g f o r c e s behind t h e equation. The f i r s t I s GDP; i n t h e l o n g r u n e l e c t r i c i t y sales increase' one f o r one w l t h t h e o u t p u t o f t h i s s e c t o r (as measured by GDP). The second f a c t o r i s a t i m e t r e n d ; each year, i n t b e absence o f any o t h e r e f f e c t s , sales would Increase by 3%. This i s again t h e phenomenon o f Increased mechanlsatlon and use o f e l e c t r i c i t y . Dynamic r e l a t i o n s h i p s a r e a l s o e v i d e n t i n t h e equatlon s p e c i f i c a t i o n . 2.3 Sales t o Large Power C o n s u ~ r s P r o j e c t i o n s o f sales t o the l a r g e consumers, i n c l u d i n g SUCOMA, David Whitehead, B l a n t y r e Hater Board (Chileka and Halkers F e r r y ) , P o r t l a n d Cement (Blarityre and Changalume) and Viphya Saw Mi 11, a r e l a r g e l y based on t h e r e s u l t s o f i n t e r v i e w s conducted w i t h these consumers I n 1987188, however i n some cases these have been r e v i s e d on t h e b a s i s o f t h e 1989 survey o f l a r g e consumers. I n p a r t i c u l a r t h e f o r e c a s t s f o r B l a n t y r e Water Board, David Hhitehead and Viphya Saw M i 11 have been changed i n o r d e r t o r e f l e c t t h e i r r e v i s e d loads and investment programnes. 2.4 Load Factors. D l v e r s l ty F a c t o r s and C o l ncldence F a c t o r s The r e l a t i o n s h i p s between e l e c t r i c 1 t y sales and maximum demand were d e r i v e d I n t h e e a r l i e r model f r o m a n a l y s i s o f t h e l o a d shape f r o m feeder m o n i t o r i n g exercises. I t has n o t been necessary t o update these f o r consumer c a t e g o r i e s I t o IV. For t h e l a r g e power consumers some r e v i s i o n has been undertaken t o  take account o f actual r e l a t i o n s h i ps observed between 1986 and 1989. For SUCOMA t h e on-peak coincident load f a c t o r has v a r i e d between 63% and 85%. Assuming an average o f 67.5% and an average d i v e r s i t y f a c t o r o f 0.9 gives a colncldent, a f t e r d i v e r s i t y load f a c t o r (CADLF) o f 75%. Thls I s a reductlon from the previous 85%. For David Whltehead a f a i r l y consistent p a t t e r n emerges w l t h colncldent load f a c t o r s between 61% and 67%. An average o f 65.25% has been assumed together w l t h a d i v e r s i t y f a c t o r o f 90%. Thls increases the CADLF s l i g h t l y from 69% t o 72.5%. The demand f o r e c a s t has been s l l g h t l y modified s l nce David Whltehead have expressed the I n t e n t i o n t o c a r r y o u t f u r t h e r expansion o f t h e i r operation. The maximum demand f o r e c a s t f o r Blantyre Water Board was o r 1g l nal l y produced f o r the 1987 Capacl t y U t l 1 1s a t l o n Study and updated f o r the Least Cost Development Programme. Thls has now been updated again I n order t o take account o f the progressive increase I n the demand f o r water, thus r e q u i r i n g more pumping capacl t y than was o r 1 g l nal l y envl saged. The Portland Cement colncldent load f a c t o r has remained r e l a t i v e l y s t a b l e w l t h a s l i g h t upward trend. This I s projected t o continue, r i s i n g from 42.1% I n 1990 t o 46.6% I n 2005. A 90% divers1t y demand f a c t o r has a1 so been assumed. Viphya Saw M i l 1 began operation I n June o f t h l s year. I t s peak demand, colncldent w l t h the J u l y peak, was 1500 kVA. The r o r i g i n a l f o r e c a s t o f demand f om the saw mi 11 has been r e t a i n e d w l t h .a one year delay I n reaching f u l l production. Thls I s now assumed t o occur I n 1992 w l t h a colncldent, a f t e r d i v e r s i t y o f 2.14 MW. 2.5 Losses The purpose o f t h l s study I s t o prepare recommendations t o reduce losses t o an optlmum l e v e l . The optlmum l e v e l w l l l be determined f o l l o w i n g a f u l l analysis o f the r e s u l t s of feeder monl t o r i ng exercl ses and exam1n a t i o n o f the options aval l a b l e . Nevertheless, a load f o r e c a s t I s necessary t o undertake t h l s analysls and a p r o v i s i o n a l estlmate o f loss l e v e l s I s required f o r t h l s . On the basis o f the e x i s t i n g loss l e v e l , a t a r g e t o f 10% energy losses by 1994 has been adopted, as a f l g u r e i n d l c a t l v e o f the l e v e l which may be achleved by the 1ntroductlon o f loss r e d u c t l o n measures. 2.6 I l p a c t of Ilprcwemnt I n Voltages The Improvement I n supply voltages t o w i t h i n ESCOM technical standards (plus and minus 6% d e v i a t i o n from the 400/230 V nominal f l g u r e a t the consumers' terminals) w l l l r e s u l t I n an Increase I n demand and energy. The impact d i f f e r s between  power and energy and between the short term and the long term. I n the short term l l g h t bulbs, for example w l l l burn more b r i g h t l y . I n the longer term some consumers may declde t h a t they can make do w l t h lower wattage 1i g h t bulbs. As another example, f r l d g e s may have b u r n t o u t more f r e q u e n t l y because of low voltage. I n the s h o r t term, the energy consumption of f r l d g e s w i l l not increase because of the r e t u r n to standard voltages. I n the longer term, the f a c t t h a t fewer f r i d g e s burn o u t w l l l lead t o a longer term increase i n energy consumption. Experlence elsewhere shows t h a t the suggested improvements may lead to a 7.5% Increase i n kWh consumption for domestic consumers and shops and o f f i c e s leading t o an o v e r a l l 2.5% increase i n t o t a l energy consumption and t h a t demand nay increase t o a greater extent. This has now been incorporated i n t o the forecast. Evidence o f t h i s I s provided I n Appendix A. 2.7 Load Forecast for the Interconnected Systea The load f o r e c a s t i s presented i n Table 2.2 showlng energy and maxlmum demand. The maximum demand f o r e c a s t f o r 1990 has n o t been adjusted t o show what i s l i k e l y t o be the actual peak for t h i s year o f 119.4 Ctn a t 18:OO hours on J u l y 4th. .'rhls i s d e l i berate t o emphasl se t h a t the f o r e c a s t I s o n l y expected t o be accurate t o perhaps +I- 5 X . The expectation i s t h a t , on average over a number of years, the over p r e d i c t i o n s w i 11 match the under-predictions. One, two or even three years i n which the model consistently over or under p r e d i c t s does n o t necessarily mean t h a t the model I s wrong. The growth r a t e of maximum demand shown i n Table' 2.2 s e t t l e s down to between 6 . S and 7.0% per annum beyond 1995. This i s scmtewhat lower than presented i n the Least Cost Oevelopnent P r o g r a m . On t h i s basis Kapichira F a l l s would n o t be r e q u i r e d unti.1 two years l a t e r than o r i g l n a l l y expected. 2.8 Future Pattern of Load Grmth The broad p a t t e r n o f f u t u r e growth I n the country has teen derlved using the same basic equations described above b u t t a k i n g account of known development (eg, the Vlphya Saw Mi 111. The r e s u l t i n g annual average growth r a t e s for the three areas are as f o l l o w s : Southern 5.4% 7.4% Central 7 .Ox 7.6% North 8.8% 5.6% The Interconnected system forecast has now been d l s t r l buted I n t o three reglons above. This was achleved by t a k l n g actual demands I n the Blantyre, Lilongwe and Mzuzu reglons f o r 1990 and p r o j e c t l n g them forward uslng the average growth r a t e s above t o 2005. I n each area the demands o f the h i g h denslty, low densl t y , general and small power categorles were assumed t o remaln the same proportion o f the t o t a l demand as calculated I n the forecast f o r the Interconnected system slnce no data was a v a l l a b l e t o I n d l c a t e the actual proportlons. I t I s not a n t l c l p a t e d t h a t t h l s w i l l Introduce any s l g n l f l c a n t e r r o r s t o the o v e r a l l analysis. The demands o f the large power consumers have been a l l o c a t e d t o the reglons I n which the consumer I s a c t u a l l y located. The load forecasts f o r the reglons are presented I n Tables 2.3 t o 2.5. They are a l s o shown g r a p h l c a l l y I n Flgures 2.1 and 2.2. For the analysls of non-technical losses I t was necessary t o derlve, f rom the load forecast, growth r a t e s f o r I n d u s t r l a l feeders and f o r general feeders. General feeders were t o Include domestic, general and small power categorles. The r e s u l t l n g annual growth r a t e s f o r the three areas . a r e as f o l lows: 1990 - 1999 2000 - 2005 Average Industrlal : Southern 3.5% 1.2% 3.0% ' Central 14.9% 0 9.6% Northern 5.2% 0 ' 3.4% Other: Southern Central Northern  SECTIOn 3 L m RUN HARGIWAL a K T S OF FWER AND ENERGY The methodology adopted for estlmatlng long run marglnal costs o f power and energy follows t h a t o f the Coopers & Lybrand T a r l f f Study o f 1985. For the purposes o f t h l s study m r g l n a l costs can be separated I n t o two types: (1) capaclty costs ( 11 energy costs Capaclty costs are lncurred a t around the tlm o f systen peak, uhen the systen I s under s t r a l n . Sustalned Increases I n demand a t t h l s time would create a need f o r lnvestment t o provide more power. Energy costs may vary u l t h the amount o f consumption. Both capacl t y and energy cost may vary by t lme o f day, by day o f week and by season. I n Malawl, the system I s largely hydro powered and thus there are r e l a t l v e l y high levels o f Investment and low operation costs. I n deternlnfng the capaclty costs the cost o f provldlng an extra k l l o w a t t I n each f u t u r e proJect has been determined. The sequence o f generation proJects I s as I n the "Least Cost Development P r o g r a m " , 1988, and the t l n l n g I s deternlned by the load forecast I n Sectlon 2 o f t h l s report as follows. 1991 Nkula B 5 1994 Tedzanl 111 2000 Kaplchlra I 2003 Kaplchlra I 1 The development program3 I s optlmlsed t o match the type o f capaclty Increment w i t h the energy o r power defects on the system. Nkula B Unlt 5 I s currently belng I n s t a l l e d t o meet a . capacl t y s h o r t f a l l rather than an energy def lc l t Tedanzl 111, although It I s the t h i r d . phase a t t h a t locatfon, w l l l meet power and energy def lc lt s . The optlnun development p r o g r a m I n Halawl I s a function o f both the shape o f the load and the hydro resources. Malawf has a substantlal base-load I n d u s t r i a l demand plus a s l g n l f lcant cunmerclal load. The cmblnatlon o f these two glves the system a f a i r l y hlgh load f a c t o r and a hlgh day-tfme plateau. Thfs I s I l l u s t r a t e d i n Flgure 3.1. The peak generally occurs a t around mid-day but the evenlng peak I s close to, and scnnetlmes exceeds, the day peak. The r e l a t i v e l y hlgh load f a c t o r and the a v a l l a b l l l t y o f abundant run-of-river resources Imp1l e s t h a t optlnntn developments w f l l tend t o be new statlons I n cascade rather than mu1t l p l e extenslons t o ex1s t i n g statlons.  AnalysIs o f the long-run costs o f supply under the load forecast for the Inter-connected system (ICS), presented In Sectlon 2, Is descrlbed below. 3.2 Capacity Costs Increases in demand at t l m of system peak will In the long run requlre: more generatl ng capac 1 ty ; more HV transnl sslon/dl strl butlon capacl ty ; more MV transmlsslon/dlstrlbutIon capacl ty; and flnal ly, more LV dlstrlbutlon capacl ty. The tlmlng o f new projects Is discussed In Sectlon 3.1, from whlch It Is clear that new hydro Investment would be the response to Increased demand rather than thermal peak1 ng plant. The only conmltted Investment In the Least Cost Development Progranmne Is In Nkula B unlt 5, on whlch work Is proceedlng. The cost o f thls unlt has therefore not been Included In the analysis slnce It can nelther be advanced nor delayed In response to Incremental demand. All o f the other projects are Included. Table 3.2 shows for each project the capltal cost and the annultlsed cost per kW assumlng: (1) a dlscount rate of 10% (11) an exchange rate of MK2.56 - $1 (111) phaslng of expend1 ture and spll t between forelgn and local cost as gIven in the Least Cost Development Programme. (iv) economlc lifetime of generatlng plant of 40 years. At Kapichira, phase one Is consldered to provlde both capacl ty and energy, and phase two Is for peaklng capaclty. In general, inltial unlts at a statlon tend to be used to meet energy requlrements whllst later unl ts are for peaklng capacl ty. Thls assuntptlon may be tested by comparing the loss of energy expectation and the loss of load expectatlon with and wlthout Kapichlra 11. Thls however Is beyond the scope of thls study. The LRMC of power on the ICS Is therefore consldered to be 175 W/kW per annum before adjustment for statlon use, flxed O&M and Incremental reserve margl n.  S t a t l o n use I s equlvalent t o around 0.7% and annual f l x e d O&M t o around 1% o f unannul t l s e d cap1 t a l cost. The requlred percentage reserve marglns whlch r e s u l t from t h e l e a s t cost development programne range from 25% t o 30X. The annultlsed costs are t h e r e f o r e Increased o v e r a l l by 30X t o 227.2 MKlkW per annum t o g l v e the LRMC o f generatlon f o r the ICS. 3.2.2 Transml ssion C a ~ a ct lv Costs Transml sslon capacl t y costs are c a l c u l a t e d us1ng an average I ncremental cost (AIC) methodology. Transml sslon p r o j e c t s are t y p l cal l y undertaken for t h e purposes of system extenslon, replacement and reinforcement and It I s d l f f l c u l t t o separate these Items. The c a l c u l a t l o n s have been based on average incremental cost derlved from t o t a l planned expendlture over the p e r l o d 1990 t o 2005 a t each voltage l e v e l and t o t a l annual demand growth a t each voltage l e v e l ( l e , demand growth o f e x l s t i n g consumers plus t h a t due t o demands o f new consumers). Thls may overstate the A I C . However, replacement costs represent o n l y ' a small p r o p o r t l o n o f o v e r a l l expend1 t u r e and the overstatement I s l l k e l y t o be modest. Capital expendlture has been determlned on a cost per MW growth basis I n the MV and LV categorles as f o l l o w s : MV 0.23 MKIMW growth LV 1 .15 MKIMW growth Thls approach has been made necessary because no Investment programme f o r these categorles e x l s t e d a t the time of the study. I n the HV category sane investment plans f o r the 132kV system were a v a l l a b l e and these a r e shown I n Table 3.1. However no such plans were a v a l l a b l e f o r the 66kV and 33kV systems. A cost o f 0.23MKlMW growth was t h e r e f o r e assumed. The H V system i s consldered t o be the 132166133 kV system. Changes I n HV demand were calculated by t a k i n g changes I n t o t a l demand slnce a l l voltage l e v e l s has t o pass through the H V system. These assumptions y l e l d an average cost of 975.8 MKlkW. Annul tl slng over the expected 1l f e o f transml sslon p r o j e c t s , taken t o be 25 years, and addlng O&M gives a cost o f 110.7 MKlkW per annum f o r H V transmlsslon and a t o t a l cost o f 353.8 MKlkW per annum I n c l u d i n g losses. The M V system was consldered t o be the 11 kV system. Changes I n the M V demand were c a l c u l a t e d from the load forecast by t a k l n g t o t a l demand and s u b t r a c t i n g from i t the . l a r g e power demand which i s assumed t o be supplled a t HV. Applying the same process as f o r the H V system y l e l d s a cost o f 786.1 MKlkW and a t o t a l cost o f 445.3 MKlkW per annum I n c l u d i n g O&H and losses.  Changes i n demand a t the LV l e v e l are calculated from the low densl t y , high dens1t y and general consumer categories i n the load forecast. Again applying the same methodology as f o r the HV system r e s u l t s i n a t o t a l capacl t y charge o f 527.98 MK/kW per annum Including O&M and losses. Calculation o f Transmission AIC I s shown I n Table 3.3. 3.2.3 -acit~ Costs I n order t o calculate the long run costs a t the HV, W and LV l e v e l s then losses must be included. The following i s considered t o be an achievable l e v e l o f power losses I n the long run, a f t e r the Implementation o f l o s s reduction measures: 132/66/33 kV Transml sslon and transformation 11 kV feeder losses 11 kV/LV transformer losses LV system losses Non technical losses Total This produces t o t a l long run capacity costs a t the generation and a t each voltage l e v e l as follows: Generation 227.24 MK/kW per annum HV Transml sslon 353.77 MK/kW per annum MV Transml ssion/dl s t r l butlon 445.28 MK/kW per annum LV D i s t r i b u t i o n 527.98 MK/kW per annum 3.3 Hargl nal Energy Costs The gas turbine a t Blantyre i s used o n l y i n emergencles o r m n t h l y t o keep It i n running order. The v a r i a b l e cost i s not therefore included i n the average 'incremental cost of energy. I n Section 3.2, the marginal cost o f capaclty a t Kaplchira I 1 was estimated, however a t Tedanzl I11 and Kaplchlra I I t was decided t h a t the p r o j e c t costs should be a l l o c a t e d t o both capacity and energy. I n t h i s respect costs should be allocated t o the peak period energy made a v a l l a b l e by those projects, because It i s demand f o r energy w l t h l n the daytime plateau (0600 t o 2030) which causes hydro p l a n t t o be the response t o Incremental demand r a t h e r than the cheaper peaking p l a n t . The cost of each p r o j e c t a t t r i b u t a b l e t o peak period energy made a v a i l a b l e I s calculated by subtracting from the t o t a l annual cost a credt t equal t o the cost of capaci t y suppl l e d by the p r o j e c t . For example, the annual cost o f capacity a t Tedzani I11 i s :  U n i t slze LRHC capacity Thls I s then subtracted from the t o t a l annual cost of Tedzani I11 calculated as f o l l o w s : U n i t slze Annuitised cost per k i l o w a t t 50,000 376 MK/kW per annum = 18.8 m MK per annum The annual cost o f energy i s therefore 18.8 m MK per annum mlnus 11.36 m MK per annum, which gives a t o t a l f l g u r e of 7.44 mM K per annum. The cost per k l l o w a t t hour a t peak I s calculated by d l v l d l n g the annual cost o f energy by the peak G Wh calculated by assuming the daytime plateau Prom 0600 t o 2030, a load f a c t o r o f 60% and 92% a v a i l a b l l it y t o give 174 GWh per annum I n the peak. The cost per k i l o w a t t a t Tedzanl I11 I s therefore 4.3 tambala/kHh. The annual cost o f energy a t Kapichira I i s calculated as above g l v i n g a cost per k l l o w a t t hour o f 13.1 tambala/kWh. I n order t o estlmate the system energy costs a welghted average o f the costs of Kapichira I and Tedzani I11 has been formed. As the p r o j e c t s w i l l be c m i ssloned approximately f l v e years apart a weight o f u n i t y has been applied t o Tedzani I11 and a weight o f 1/1 .15 t o the Kapichira cost, hence welghting more heavlly the p r o j e c t which occurs sooner. Thls y i e l d s a cost of 6.2 tambala/kHh f o r peak period energy. An average energy charge was a l s o adopted since I n the off-peak periods energy I s v i r t u a l l y f r e e o f charge. We have therefore adopted a welghted average o f the calculated long run peak energy charge o f 6.2 tambala/kHh and the o f f peak cost o f zero. Thus the long run marglnal cost o f energy i s taken t o be 4.1 tambala/k#h on average. Losses are then added a t the t a r g e t level o f 10% per annum g i v i n g a t o t a l LRMC o f 4.5 tambala/kWh. An o f f peak energy charge o f zero has been assumed since Malawl has e s s e n t i a l l y a run-of r i v e r hydro system backed up by d l urnal storage. Seasonal storage capacl t y , other than Lake Malawi i s nel ther required nor contemplated. The cost o f providing dlurnal storage I s a very small p o r t l o n o f the cost of the complete power. s t a t l o n . Since .water i s s p i l l e d throughout each day o f the year, and has done f o r several years and I s expected t o contlnue t o do so, and the cost o f pondage I s very low, I t i s reasonable t o assume t h a t the o f f peak LRMC of energy Is negl 1g l b l e. An average LRMC o f energy has been adopted since analysis I s n o t c a r r i e d o u t on a system basis, b u t on a feeder by feeder basis. 'Thus a feeder may peak a t a d i f f e r e n t time from system peak and i t would n o t be appropriate t o apply the system peak energy charge t o the analysls o f t h a t feeder.  SECTION 4 TECHNICAL LOSSES 4 . TECHNICAL B S E S Technlcal losses may be sumnarlsed as those a r l s l n g from power losses occurring I n c u r r e n t c a r r y l n g conductors, transformers and other Items of equlpment connected t o the transmlsslon and dlstrlbutlon systems. Non-technical losses are those assoclated w l t h e r r o r s I n power and energy meterlng and consumer f r a u d whlch r e s u l t I n a mlsmatch between generated and sold power, and energy whlch cannot be accounted for by the technlcal loss component. The development of s t r a t e g l e s for reduclng technlcal losses on the ESCOM system has been based on an exhaustlve programme of system measuremnts assoclated w l t h the varlous voltage l e v e l s I n the system. The analysls was s p l l t I n t o three sectlons, concentratf ng on the transml sslon system (132/66/33 kV voltage l e v e l s ) , 11 kV systems I n Blantyre and Lllongwe and LV systems I n the two c l t l e s . The s t a r t l n g p o i n t for the analysls o f the 132/66/33 kV transml sslon and subtransml sslon systems was the load flow study developed f ro m system records f o r the 1990 peak demand experlenced on 4 t h J u l y 1990. The analysls performed on 11 kV feeders I n Blantyre and Lllongwe, and on LV systems, was c a r r l e d o u t on the basls of d l r e c t system measurements made w l t h the a l d o f the "Dranetz" power demand analysers and cllp-on a m e t e r checks t o e s t a b l i s h the d l s t r l b u t l o n o f loads on these systems. These system measurements were then scaled to produce estimates of the load d l s t r l b u t l o n on the feeders a t tlmes o f peak demand by a process descrlbed I n more d e t a l l be 1ow. The system measurements were s t a r t e d d u r l n g the f l r s t v l s i t by KDP englneers t o Malawl I n August 1990. 'These were then contlnued by ESCOM englneers u n t l l the beglnnlng of November 1990, when the second s l t e v l s l t by KDP took place, durlng which much of the analysls of present system l o s s l e v e l s and the technl cal assessment of a1t e r n a t l v e loss reductlon s t r a t e g l e s was c a r r l e d o u t . A v a r l e t y o f t o o l s have been used I n the assessment o f technlcal loss r e d u c t l o n measures. The KDP LF software package, whlch has already been wldely used by ESCOM and KDP, was u t l l l s e d for load flow a n a l y s l s of . the 132/66/33 kV systems. For some o f t h e 11 kV feeders analysls has a l s o been performed on the D l s t r l b u t l o n Plus (DPAS) software package suppled by ESMAP f o r use I n t h l s p r o j e c t . Durlng the p e r l o d between the two KDP v l s l t s , ESCOM englneers were engaged I n the preparatlon o f data bases for a number o f feeders on DPAS, t o f a c l l l t a t e t h e l r analysls once the r e s u l t s o f feeder loadlng surveys became aval l a b l e . The LV survey r e s u l t s have been processed using a spreadsheet t o perform d l s c r e t e t h r e e phase a n a l y s i s o f voltage drops and losses. I n order t o compare the t e c h n i c a l v i a b i l i t y o f a l t e r n a t i v e l o s s r e d u c t l o n s t r a t e g i e s , load f l o w a n a l y s l s has been performed t o c a l c u l a t e power losses on the transmission and d i s t r i b u t i o n systems b e f o r e and a f t e r t h e Implementatlon o f l o s s r e d u c t l o n measures. This enables annual energy losses t o be c a l c u l a t e d f o r use I n c o n j u n c t i o n w i t h t h e power losses I n t h e economlc a n a l y s i s o f a1 t e r n a t l v e p r o j e c t s . The s i z e o f t h e ESCOM system I s such t h a t , p a r t i c u l a r l y a t 11 k V and below, I t I s Impossible I n a p r o j e c t of t h i s type t o c a r r y o u t an exhaustive a n a l y s i s o f l o s s r e d u c t l o n measures on each c i r c u i t. The emphasis of t h e work undertaken on t e c h n l c a l losses has from t h e o u t s e t stressed t h e need f o r a sampled approach covering as much of t h e system as I s p r a c t i c a l l y possible, and ensuring t h a t a r e p r e s e n t a t i v e cross-section o f feeders and LV systems a r e analysed I n formul a t 1 ng system-wide loss reductlon strategies. To t h i s end, the a n a l y s i s has concentrated on e s t a b l l s h i n g t h e v i a b i l i t y of s p e c l f l c p r o j e c t s which then form t h e basis of a wlder programne of measures a p p l i e d across the system, f o r which r e s o u r c i n g and budgetary requirements have been formulated. ESCOM engineers I n the Central Planning U n i t have been f u l l y i n v o l v e d w l t h a l l stages of the t e c h n l c a l l o s s a n a l y s i s , from the p r e p a r a t i o n o f system models through t o t h e assessment o f a l t e r n a t i v e l o s s r e d u c t l o n schemes, t o ensure t h e maximum degree of t r a i n i n g and technology t r a n s f e r i n t h e p r o j e c t . The economic a n a l y s i s o f t e c h n l c a l l o s s r e d u c t l o n measures has been c a r r l e d o u t by i d e n t i f y i n g a l l o f the costs and b e n e f i t s a t t r l butable t o a p a r t i c u l a r p r o j e c t . The methodology f o r studylng t h e 132166133 k V system, the 11 k V system, and t h e LV systems i s t h e same I n a l l cases, however t h e Marginal Costs o f Capacity vary a t each l e v e l o f transmission and d i s t r i b u t i o n as described I n Sectlon 3. For each feeder under c o n s l d e r a t l o n the losses have been c a l c u l a t e d over t h e p e r i o d 1990 t o 2005 assuming f i r s t l y t h a t l o s s r e d u c t l o n measures are Implemented and secondly t h a t no l o s s r e d u c t l o n I s c a r r l e d o u t . The stream o f b e n e f l t s a r i s e s p r i m a r i l y from a savlng i n the generatlon and transmission costs due t o the lower l e v e l of losses on the system. There may a l s o be an increase i n revenue t o ESCOM.due t o t h e e f f e c t s o f Improved voltages on demand, through the mechani sm d e s c r l bed I n s e c t i o n 2.6. This would however accrue a t t h e d l f f e r e n c e between t h e consumers' w i l l lngness t o pay f o r t h e add1 t i o n a l energy and t h e marginal c o s t of generatlon and would t h e r e f o r e be a second order e f f e c t by comparison w l t h the benefl t s due t o  reduced g e n e r a t l o n and t r a n s m i s s i o n c o s t s . For t h l s reason, coupled w l t h t h e f a c t t h a t any I n c r e a s e I n demand I s h l g h l y dependent o n t h e f e e d e r l o a d t y p e , o n l y t h e b e n e f l t s of reduced g e n e r a t l o n and t r a n s m l s s l o n c o s t s have been q u a n t i f i e d , u s i n g margl n a l c o s t s a t t h e a p p r o p r i a t e v o l t a g e l e v e l . The c o s t s a r i s i n g f r o m each p r o j e c t a r e a t t r l b u t a b l e w h o l l y t o t h e c a p i t a l c o s t o f l o s s r e d u c t l o n measures f o r t h e feeder under examination. For each p r o j e c t considered an I n t e r n a l Rate o f R e t u r n has been c a l c u l a t e d , i n o r d e r t o examine t h e v l a b l l l t y of t h e p r o j e c t i n economl c terms. The need t o c a l c u l a t e streams of l o s s e s f o r elements o f t h e system b o t h w l t h and w i t h o u t l o s s r e d u c t l o n o v e r a f i f t e e n y e a r p e r i o d has n e c e s s i t a t e d an approach t o be adopted t o c a t e r f o r cases where, f o r example, a c l r c u l t o r network of c l r c u i t s I s unable t o supply t h e 2005 l o a d w i t h o u t some form o f reinforcement. I n many cases such reinforcements w l 11 i n e v l t a b l y be considered as p a r t of t h e ESCOM Transmlsslon and D i s t r i b u t i o n Planning Study, and as such a r e beyond t h e scope o f t h e p r e s e n t study, o t h e r t h a n I n t h e e x t e n t t o which t h e y should be based on t h e p l a n n i n g s t r a t e g i e s f o r loss m l n l m i s a t i o n which a r e h i g h l i g h t e d I n l a t e r s e c t i o n s of t h l s report. For t h e a n a l y s l s of l o s s e s i n 2005 t o be p o s s i b l e however, a l l t h e p r e s e n t ESCOM proposals for t r a n s m i s s i o n system r e i n f o r c e m e n t have been i n c o r p o r a t e d as I n t e n d e d system developments, and the minimum additional relnforcement necessary t o enable r e a l i s t i c o p e r a t i o n of t h e system i n 2005 has been added. A t t h e d i s t r i b u t i o n l e v e l , t h e e f f e c t s of l i m l t l n g growth I n e x l s t l n g f e e d e r demand on t h e v i a b i l i t y o f l o s s r e d u c t l o n measures have been examined. T h i s has enabled t h e assessment o f t h e s e n s l t l v I t y of t h e proposed measures t o demand growth v a r i a t i o n s and t h e e f f e c t s of d l s t r l b u t i o n system enhancement I n t h e form of p o t e n t i a l new l i n e s and s u b s t a t l o n s r e s t r i c t i n g t h e growth on e x l s t l n g c l r c u i t s . The t e c h n i c a l and economic analys 1s of t e c h n l c a l l o s s r e d u c t l o n measures a t t h e v a r i o u s l e v e l s of t h e ESCOM system a r e d l scussed I n d e t a l 1 below. 4.2 132166133 kV System 4.2.1 es W l t h o u t Loss Reduction The e x i s t i n g ESCOM l o a d flow model for t h e p r e s e n t 132166133 kV system was used I n c o n j u n c t l o n w l t h SCADA o u t p u t t o f o r m u l a t e a model of t h e o p e r a t i o n of t h e system a t t h e peak 1990 demand l e v e l of 119 MW, experienced d u r i n g t h e evening of 4 t h J u l y 1990. The r e s u l t s o f t h i s load flow are presented I n Table 4.1 and show a peak net power loss of 8.0% based on n e t generated power. When the power losses assocl ated w l t h transformer core loss are taken I n t o conslderatlon t h l s f l g u r e Increases t o 8.4%. The load forecast glves an annual load f a c t o r of 62.3% f o r the system I n 1990, whlch, uslng the f o l l o w l n g formula for c a l c u l a t i n g loss f a c t o r : Loss f a c t o r = 0.7 x (Load actor)^ + 0.3 x Load Factor glves a loss f a c t o r o f 45.8%. Applylng t h l s f l g u r e t o the load dependent losses, and addlng I n the transformer core losses, glves an o v e r a l l annual n e t energy loss o f 6.7% assoclated w l t h the transrnisslon system, based on the 1990 peak demand. I n order t o assess the f u t u r e v a r l a t l o n o f losses on the transml sslon and subtransml sslon systems, load f l o w studles were performed' for key stages I n the planned development o f the ESCOM system, r e f l e c t l n g the f o l l o w l n g modlflcatlons: - f l r s t 132kVNkula-Lilongwe l l n e ; - u p r a t l n g o f the northern backbone l i n e and substatlons from 66 kV t o 132 kV, Including Lllongwe B a n d Sallma; - Kwacha, Sunnyslde and Llmbe B substatlons; - Zomba 66 kV 1lne; - r u p r a t l n g Nkhotakota-Htunthama fom 33 kV t o 66 kV; - Golomotl -Monkey Bay 33 kV l l n e ; - Nkula B 5 t h machlne; - Fundls Cross u p r a t l n g from 5 MVA t o 12.5 MVA; - second 132 kV Nkula - Lllongwe l l n e ; - Tedanzl 111 Power Station; - Tedanzl - Kapl chl r a interconnector ; - Blantyre West 132166 kV substatlon; ' - Golomot1 - Mlangenl 66 kV 1lne; - Kaplchlra Phase 1 (2 x 25 MW); - B l a n t y r e West - Mapanga 66 kV l i n e ; - K a p l c h l r a Phase I1 ( 3 x 25 MW); - B l a n t y r e West - Kaplchlra 11; Table 4.2 shows a summary o f t h e power and energy losses assoclated w l t h t h e 132166133 kV systems I n t h e years 1990, 1991, 1994 and 2005, whlch I n d i c a t e s t h a t a f t e r an I n l t l a l Increase I n losses I n 1991, the transmlsslon system Improvements proposed by ESCOM c o n t r o l t h e l o s s l e v e l such t h a t I t I s back t o 6.7% o f n e t energy by 1994. A t t h e end o f t h e p l a n n l n g horizon, i n 2005, however, t h e energy l o s s e s have Increased t o 9.0%. A more d e t a i l e d a n a l y s i s , l o o k l n g f i r s t a t t h e 132/66 kV losses, i s shown I n Table 4.3, and demonstrates t h a t t h e power and energy losses a s s o c l a t e d w l t h t h l s s e c t l o n o f system c o n t i n u e t o reduce u n t i l 1999 due t o system Improvements, ' b u t t h a t an Increase then occurs o v e r t h e f o l l o w l n g f i v e years. There I s r e l a t l v e l y l i t t l e Impact on losses a t 33 kV over t h e p e r i o d 1990 - 2005, as shown I n Table 4.4, due t o t h e 1l m l t e d 33 kV system enhancements proposed by ESCOM a t t h l s stage. As a consequence, t h e losses on t h e 33 kV system Increase f r o m 2.1% t o 3.0% by 2005. F i g u r e 4.1 shows a breakdown of t h e power losses o c c u r r l n g o n t h e t r a n s m l s s l o n system a t peak demand i n 1990. T h l s I n d l c a t e s t h a t t h e 66 kV system c o n t r l b u t e s t h e l a r g e s t amount t o t h e o v e r a l l l o s s l e v e l (39%). w l t h t h e 132 kV system accounting for 26%. F i g u r e 4.2 shows t h e component o f t h e l o s s e s a s s o c l a t e d w l t h t h e 132/66/33 kV t r a n s m l s s l o n l l n e s , broken down t o I n d i c a t e those c o n t r l b u t l n g t h e g r e a t e s t l e v e l o f l o s s e s t o t h e overall total. T h l s I n d l c a t e s t h a t t h e 132 kV c l r c u l t from Nkula t o Sallma a l o n e c o n t r l b u t e s n e a r l y one q u a r t e r of t h e t o t a l l o s s e s o c c u r r l n g on t h e t r a n s m l s s l o n system, w l t h t h e 66 kV c l r c u l t s f r o m Nkula t o Lllongwe, Mapanga and C h l c h l r l c o n t r l b u t l n g t h e h i g h e s t l o s s e s of t h e remaining l l n e s . A number o f t h e measures a l r e a d y proposed by ESCOM f o r t h e development o f t h e transmf s s l o n system w i l l have a d i r e c t Impact on t h e losses on these c i r c u i t s , most n o t a b l y as a consequence o f t h e I n t r o d u c t i o n of t h e f i r s t 132 kV c i r c u i t r u n n i n g d l r e c t l y f r o m Nkula t o Lllongwe. The r e s u l t o f I n t r o d u c i n g t h e v a r i o u s upgrades in d i cated above between 1990 and 1994 I s t o reduce t h e p r o p o r t i o n of transmission system losses a s s o c l a t e d w i t h t h e 132 kV and 66 kV l i n e s , w l t h Increases I n losses, due t o t h e Increased system demand, o c c u r r l n g on t h e 33 kV 1l n e s and I n t h e t r a n s f o r m e r wlndlngs, as shown I n F i g u r e 4.3.  The above observations I n d i c a t e a hlgher l o s s l e v e l a t present associated w l t h t h e ESCOM transmlssion system than would normally be expected i n a 132166133 kV system. I t i s clear, however, t h a t many o f t h e proposed m o d l f l c a t i o n s t o the present system already programmed f o r I n t r o d u c t l o n by ESCOM w l 11 c o n t r l b u t e t o an I n l t l a l r e d u c t l o n I n losses, although an o v e r a l l increase I s Indicated over t h e p e r l o d f r o m 1990 t o 2005 from 6.7% o f n e t generated energy l o s t t o 9.0%. The e v a l u a t l o n o f a number o f p o t e n t l a l methods o f reducing losses on t h e transmission system I s considered below. 4.2.2 Lass Reductlon S t r a t e a l e s (a) Reconductorlng: 66 kV & 33 kV lines The p o t e n t l a l f o r reconductorlng e x l s t l n g 66 kV c l r c u l t s has been examined as a p o s s l b l e means o f reduclng t h e losses on the ESCOM transmlsslon system. Thls a n a l y s l s I s based on t h e p r l n c l p l e s o f conductor o p t l m l s a t l o n , whereby t h e c o s t o f losses I s evaluated over a number o f years f o r d l f f e r e n t conductor slzes, and the present values o f these costs plus the c a p l t a l costs associated w l t h t h e c o n s t r u c t i o n o f l i n e s o f each conductor type a r e compared t o o b t a l n t h e optlmum conductor t o be used f o r a glven I n i t l a l loadlng c o n d i t i o n on t h e 1lne. Thl s technlque gives I n d l c a t l v e loading l e v e l s f o r planning purposes; r l g o r o u s a n a l y s l s o f . I n d t v l d u a l p r o j e c t s I s a l s o performed t o ensure t h e economl c v l abl 11t y o f t h e proposal S f o r l o s s reductlon. Flgure 4.4 shows the deslgn l o a d l n g ranges which apply t o t h e c o n s t r u c t i o n o f new 66 kV wood p o l e l l n e s I n Malawi, based on t h e f o l l o w i n g c r l t e r l a : Analysis perlod: 15 years Annual Demand Growth Rate: 7.2% Load Factor: 62.3% Loss Factor: 45.8% Marglnal Power Cost: 353.8 MKlkW Marglnal Energy Cost: 0.045 MKIkWh Discount Rate: 107. The demand growth r a t e i s based on the average f i g u r e f o r the Increase i n demand i n the ESCOM system over the p e r l o d 1990 t o 2005. The curves shown i n t h e dlagram i n d i c a t e t h a t for peak demand a t p r e s e n t i n excess of 8 MVA, a 175 sq mm conductor r e p r e s e n t s t h e optimum s i z e f o r t h e use on 66 kV wood p o l e s i n g l e c l r c u i t I l n e s . T h l s I s based o n t h e f o l l o w i n g c o n s t r u c t i o n c o s t s f o r 66 kV wood p o l e l l n e s , o b t a i n e d from t h e KDP d a t a base of i n t e r n a t i o n a l transmission costs: 75 sq mm MK 70,000 p e r km 100sqmm MK78,OOOper km 125 sq mm MK 85,000 per km 175 sq mm MK 96,000 p e r km F i g u r e 4.5 shows t h e l o a d i n g l e v e l s which a p p l y f o r t h e r e c o n d u c t o r l n g of e x i s t i n g 75,100 and 125 sq m c i r c u i t s t o become v i a b l e , on t h e b a s i s o f upgrading t o a 175 sq m m conductor. The c a p i t a l c o s t of r e c o n d u c t o r l n g I s t a k e n t o be 50% o f t h e c o n s t r u c t l o n c o s t of a new l i n e , t o r e f l e c t t h e component due t o t h e c o s t o f t h e conductor i t s e l f p l u s an a1 lowance for t h e replacement o f p o l e s , I n s u l a t o r s , e t c which may be found necessary. The curves in d i c a t e t h e f o l low1 ng t h r e s h o l d s f o r c i r c u i t reconductorlng: From 75 sq m m t o 1 7 5 sq mm : 9 MVA From 100 sq mn to 175 sq mm : 12 MVA From 125 sq mm t o 175 sq m m : 16.5 MVA 'The l o a d flow r e s u l t s for t h e peak 1990 system demand were examined i n t h e c o n t e x t of these loading levels, from which two potential reconductorlng projects were Identified, on c i r c u i t s u s l n g 100 sq mm ACSR conductors a t p r e s e n t , w i t h demands i n excess of 12 MVA. These p r o j e c t s were t h e n assessed us1 ng economic a n a l y s i s based on t h e c a l c u l a t i o n of i n t e r n a l r a t e s o f return. T h i s n e c e s s i t a t e d . t h e c a l c u l a t i o n of streams of l o s s e s w i t h and w i t h o u t r e c o n d u c t o r i n g o v e r a f i f t e e n y e a r a n a l y s i s p e r l o d , which was performed on t h e b a s i s of a d d i t i o n a l l o a d f l o w s t u d i e s t o o b t a l n l o s s l e v e l s on t h e f e e d e r s w i t h r e c o n d u c t o r l n g i n 1991 ( t h e e a r l i e s t t i m e by which r e c o n d u c t o r i n g c o u l d be achieved) and i n 2005, and a 2005 s t u d y w i t h o u t r e c o n d u c t o r i n g . The r e s u l t s o f t h i s a n a l y s i s were used t o g e t h e r w i t h t h e c a p i t a l c o s t s for r e c o n d u c t o r l n g and t h e m a r g i n a l c o s t s o f power and energy t o c a l c u l a t e an i n t e r n a l r a t e of r e t u r n for each p r o j e c t . Table 4.5 summarlses the I R R c a l c u l a t l o n f o r 66 kV reconductorlng on the Nkula A B - - C h l c h l r l and Nkula Mapanga 1 lnes. These I n d l c a t e r a t e s o f r e t u r n o f -1.3% f o r each p r o j e c t , whlch c l e a r l y shows t h a t n e l t h e r p r o j e c t represents an economlcally v l a b l e loss reductlon measure. Thls I s due t o the f a c t t h a t I n n e l t h e r case I s the average annual demand Increase as great as the 7.2% f l g u r e used I n d e r l v l n g the o p t l m l s a t l o n curves, whlch are a gulde based on system-wlde flgures. Thl s I 1 l u s t r a t e s the Importance of c a r r y l n g o u t d e t a l l e d economic analysls on speclflc l o s s reductlon p r o j e c t s I n para1 l e l w i t h examlnl ng trends from system-wlde statlstlcs. A s e n s l t l v l t y analysis was performed t o examlne the effect of reduclng the capltal cost of r e c o n d l t l o n l n g from 50% o f the new l l n e cost to 30%. Thls has the e f f e c t o f decreasing the thresholds for c i r c u l t recondl t l o n l n g t o the followlng levels: From 75 sq mn t o 175 sq mm : 7 M VA From 100 sq mn t o 175 sq mn : 9 M VA From 125 sq mn t o 175 sq mm : 13 MVA The r e d u c t l o n I n reconductorlng thresh01 d t o these l e v e l s does n o t I n p r a c t l c e l n d l c a t e t h a t any f u r t h e r reconductorlng schemes should be consldered I n the ESCOM transmlsslon system. The e f f e c t o f reduclng the c a p l t a l costs o f reconductorlng on the I R R calculations c a r r l e d o u t f o r the Nkula A - C h l c h l r l and Nkula B - Mapanga c l r c u l t s I s t o Increase the r a t e s of r e t u r n t o 5.2% and 4 . a respectlvely. These represent marglnal l e v e l s of r e t u r n , and these reconductorlng p r o j e c t s are n o t therefore recommended f o r I n c l us I o n In the l o s s reductlon package. I t I s recommended t h a t 50% o f the new l l n e cost be adapted I n cons1 d e r l ng reconductorl ng schemes, t o ensure t h a t a l l costs l l k e l y t o be I n c u r r e d are represented I n the assessment o f alternatives. Figures 4.6 and 4.7 show sets o f conductor o p t i m i s a t i o n curves r e l a t i n g t o s t e e l tower l i n e s using the same analysls c r l t e r l a as f o r the wood pole cases, except t h a t the c a p t t a l costs of s t e e l tower construction are somewhat hlgher than for wood pole, as f o l lows : 75 sq mm MK 95,000 per km 100 sq mm m MK 105,000 per k 125 sq mm MK 115,000 per km 175 sq mm MK 130,000 per km This r e s u l t s I n hlgher loadings belng j u s t i f i a b l e a t the design stage f o r new Iines and hlgher reconductorlng thresholds. as demonstrated from the diagrams, whlch show t h a t the 175 sq mm conductor should be used on new l l n e s w l t h demands o f over 9.5 MVA and i n d l cate the f o l l o w l n g reconductoring levels: From 75 sq mn t o 175 sq mm : 10.5 MVA From 100 sq mn t o 175 sq mn : 14 MVA From 125 sq mn t o 175 sq mn : 19.5 MVA Whllst none o f the other 66 kV c i r c u i t s r e q u i r e reconductori ng In terms of these thresholds, the new l l n e loadlng l e v e l s should be u t l l l s e d by ESCOM I n planning transmlsslon system developments. Slml l a r l y , the reconductori ng l e v e l s should be appl l e d as p a r t of a contlnulng programne o f loss m n I t o r 1 n g and r e d u c t i o n as the system demand Increases. Figures 4.8 and 4.9 show the new l i n e design load1 ngs and reconductorl ng load1 ng 1eve1 s whi ch apply f o r 33 kV feeders on the ESCOM system. These were calculated uslng the same economic and f i n a n c i a l parameters as f o r the 66 kV l i n e s , b u t w i t h the following cap1 t a l costs f o r llne constructlon, obtained from the ESCOM data base: 50 sq m n s l n g l e phase l l n e : MK 17,657 per km 50 sq nun three phase l l n e : MK 22,'970 per km 100 sq mn three phase 1l n e : MK 32,747 per km 150 sq m three phase 1l n e : MK 39.538 per km The ' f u l l l l n e c o n s t r u c t i o n cost was used I n the analysis o f reconductorlng a t 33 kV, t o a1 low f o r s l g n l f l cant pole and I n s u l a t o r replacement as p a r t o f the reconductorl ng exercl se. The new l i n e loadings show t h a t f o r c l r c u l t loads above 2500 kVA a 150 sq m conductor should be used a t 33 kV, as compared w l t h the present ESCOM p r a c t i c e o f using a 100 sq mm conductor as the l a r g e s t s l z e a t 33 kV. The reconductorl ng 1oadl ng ranges indl cate the f o l l o w l n g load l e v e l s a t which t r a n s f e r r l n g t o a 150 sq mn conductor i s l i k e l y t o be deslrable: These reconductoring l e v e l s were appl l e d t o the 33 kV system I n order t o i d e n t i f y c i r c u i t s which would b e n e f i t from reconductoring, on the basis of t h e i r present peak loading conditions . The c i r c u l t s from C h i c h i r l t o Customs and Fundi's Cross t o 'Thy010 were both found t o be close t o o r exceeding the threshold associated w i t h 75 sq mm conductors, havlng peak demands I n 1990 o f 3.82 HVA and 4.92 MVA r e s p e c t i v e l y . (The f i g u r e f o r the Fundi's Cross t o Thyolo c i r c u i t was obtained assuming t h a t the switching c o n f i g u r a t i o n was such as t o supply Thyolo B from C h i c h i r i and Thyolo A from Fundl's Cross). Table 4.6 shows a summary o f the l o s s l e v e l s associated w i t h the key years required f o r the i n t e r n a l r a t e of r e t u r n analysis o f the two reconductoring schemes, f o r whlch 4 km o f 150 sq mm reconductorlng would be required on the C h i c h l r i - Customs c i r c u l t and 35 km on the Fundl's Cross - Thyolo l i n e . The analysis based on the ESCOM c a p i t a l cost estimates given above I s shown i n section (a) o f Table 4 . 6 , and shows r a t e s o f r e t u r n o f 4.3% and 6.9% r e s p e c t i v e l y f o r the two p r o j e c t s . On t h l s basis, reconductoring o f n e i t h e r would be recommended f o r I n c l u s i o n i n the loss reduction package. A f u r t h e r a n a l y s i s was performed whereby the costs o f reconductoring were increased t o a l e v e l more I n 1lne w l t h i n t e r n a t i o n a l budgetary p r i c e s than those provided by ESCOM. Whilst I t I s l i k e l y t h a t ESCOM can themselves undertake reconductoring work f o r the cost l e v e l s i n d i c a t e d e a r l i e r , I t i s considered appropriate t o assess such p r o j e c t s on the basis o f i n t e r n a t i o n a l cos ti ngs; t o ensure t h a t the possi b l e need f o r contractors from outslde ESCOM t o c a r r y o u t some o f the p r o j e c t s I s f u l l y r e f l e c t e d i n the analysl s. The constructlon cost for a 150 sq mm three phase l i n e , from the KDP data base o f i n t e r n a t i o n a l cost estimates, I s MK 57,300 per km, which gives the c a p i t a l costs and I R R f i g u r e s shown i n s e c t i o n (b) o f Table 4.6. These I n d i c a t e r a t e s o f r e t u r n o f 0.2% f o r the reconductoring o f the C h i c h i r i - Customs l l n e and 2.3% f o r the Fundi's Cross - Thyolo l i n e .  From these r e s u l t s , n e i t h e r p r o j e c t would appear justlflable In financial terms based on i n t e r n a t l o n a l o r ESCOM c o n s t r u c t l o n costs. Table 4.7 summarl ses t h e t e c h n i c a l parameters and constructlon costs of e x i s t i n g and proposed conductor s i z e s used i n t h e above a n a l y s i s of t h e 132166133kV systems. ( b) Vol tage Upgrad ing Voltage upgradiug from 33 kV t o 66 kV h a s been l d e n t l f l e d by ESCOM as a s t r a t e g y t o reduce t h e problems o f v o l t a g e r e g u l a t i o n I n some o f t h e .long r u r a l 33 kV feeders on t h e system. The e x t e n t t o which t h i s can be j u s t i f l e d as a l o s s r e d u c t i o n measure has been examined, as d e t a l l e d below for t h e case o f t h e Mtunthama 105 feeder. T h l s feeder 1s a t present o p e r a t l n g w l t h some 74 km o f 75 sq mm AAAC overhead l l n e r u n n l n g a t 33 kV f r o m Nkhotakota t o Mtunthama, f r o m where a c l r c u l t runs t o Kasungu and a number o f d l s t r ! b u t l o n transformers a r e s u p p l i e d a t b o t h 33 and 11 kV. Load flow s t u d i e s were performed for t h e present o p e r a t l n g conf l g u r a t l o n and then f o r t h e s f t u a t l o n w l t h the 74 km s e c t i o n of t r a n s m l s s l o n l l n e o p e r a t l n g a t 66 kV I n s t e a d o f 33 kV. The power losses on t h e feeder were c a l c u l a t e d I n each case, and t h e energy losses were obtalned u s l n g t h e l o a d f a c t o r and l o s s f a c t o r c a l c u l a t e d f r o m "Dranetz" measurements o f t h e feeder demand. I n t e r n a l r a t e o f r e t u r n c a l c u l a t l o n s were c a r r l e d o u t based on these r e s u l t s and u s i n g two d i f f e r e n t approaches t o t h e c a p i t a l costs I n v o l v e d w l t h t h e v o l t a g e upgrade. I n the f l r s t case, t h e f a c t t h a t t h i s p a r t i c u l a r 1l n e was o r l g l n a l l y c o n s t r u c t e d f o r 66 kV o p e r a t l o n b u t i s a c t u a l l y r u n n i n g a t 33 kV was taken i n t o c o n s l d e r a t l o n . Consequently t h e r e i s no c o s t associated w i t h l l n e c o n s t r u c t l o n t o be considered, b u t o n l y t h a t o f t h e s u b s t a t i o n work r e q u l r e d a t Nkhotakota and Mtunthama. 'The cap1t a l c o s t associated w l t h t h i s , f r o m ESCOM's c o s t estimate f o r t h e p r o j e c t . i s M K 1.05 m. Table 4.8 shows a summary of t h e c a l c u l a t i o n , i n d i c a t i n g an i n t e r n a l r a t e o f r e t u r n o f 16.8% for t h e p r o j e c t as a l o s s r e d u c t i o n measure. The remainder o f t h e t a b l e shows t h e r e s u l t s o f a n a l y s i s on t h e b a s i s o f c o s t s associated w i t h t h e s u b s t a t i o n works and c o n s t r u c t i o n o f a new 66 kV l l n e , which would be necessary i n t h e case of a 1i n e l n l t l a l l y c o n s t r u c t e d f o r 33 kV o p e r a t l o n . This shows an I n t e r n a l r a t e o f r e t u r n o f -2.3%. whlch Is clearly indicative that in this situation the project would not be viable as a loss reductlon strategy. These results indlcate that even In the case of a feeder wl th a relatlvely high load factor (75.5%), If capltal costs o f constructlng a new 66 kV llne are assoclated wlth converslon to 66 kV operation, such a project Is unllkely to be viable for loss reductlon. In the case of the Mtunthama 105 line, upgradlng Is justifiable as a loss reductlon measure, due to the reduced cap1 tal costs Involved wI th the project. This measure has therefore been Included in the programne presented at the end of thl s report. The Least Cost Development Plan for the ESCOM system Included In its recommendatlons the Instal latlon of statlc compensatlon to be located at Lilongwe in order to Improve the power transfer capablllty of the 132 kV clrcults running north from Nkula. Whilst the capltal cost assoclated wi th SVS equipment is such as to make its Introductlon an uneconomic proposltlon when vlewed solely from the loss reductlon angle, there wlll clearly be a benefit In terms o f reduced losses assoclated wlth Its Introductlon as part of the development of the transmission system. In view of the work currently being carrled out In the Transmission and Dlstrlbutlon Study belng performed for ESCOM, detalled analysls of the effects of compensatlon on the losses on the transmission system has not been performed. Any recommendatlons for the I ntroductlon of compensation whlch are made In the T&D study should however be consldered wlth a view to the potentlal beneflt to be galned by acceleratlng the tlmescale for Its Installation to gain from the effects of loss reductlon. The precise nature of the compensation should also be consldered i n detall, to ensure, for example, that the approprlate combination of dl strl buted swl tched capacl tors and ful ly control led compensatlon equipment Is used to mlnlmlse losses on the system whllst maintalnlng satlsfactory reactive power flows and voltage profiles at tlmes of mi n 1 mum demand. 4.2.3 Comments I t i s c l e a r from t h e work described above t h a t t h e r e a r e very few l o s s r e d u c t i o n p r o j e c t s whlch may be economically undertaken on the ESCOM transmission system t o reduce losses below t h e l e v e l s which w i l l be achieved f o l l o w i n g t h e In t r o d u c t i o n o f the transmi s s i o n p r o j e c t s a1 ready programmed by ESCOM as p a r t o f t h e i r system development proposals. The emphasis o f such s t u d i e s as t h e present Transmission and D i s t r i b u t i o n Study must be t o ensure t h a t losses a r e maintained a t an economic l e v e l , which would appear t o be i n the r e g i o n o f t h e 6.7% energy l o s s l e v e l e x i s t i n g on t h e system a t present. Careful m o n i t o r i n g and a n a l y s i s o f losses i n t h e c o n t e x t o f t h e design and reconductoring loadings discussed above w i l l enable ESCOM i t s e l f t o ensure t h a t I t s p l a n n i n g p o l i c i e s a r e developed i n l i n e w i t h loss minlmisatlon strategies. 4.3 11 kV Systems 4.3.1 Introduction I n o r d e r t o assess the scope f o r l o s s r e d u c t i o n on t h e 11 kV sections o f the ESCOM system, a sampling approach was adopted whereby as l a r g o a number o f 11 kV feeders as possi b l e I n t h e study p e r i o d were analysed t o produce r e s u l t s from whlch a wider programme o f l o s s r e d u c t i o n measures could be developed. This necessitated d e t a i l e d measurements o f l o a d d l s t r i b u t i o n s on the 11 kV systems i n B l a n t y r e and Lilongwe, f r o m which load f l o w models were produced t o enable e x i s t i n g feeder l o s s l e v e l s t o be c a l c u l a t e d . Loss r e d u c t i o n measures were then appl l e d t o these feeders and analysed from both t e c h n i c a l and economi c v i ewpol n t s t o e s t a b l i s h v i a b l e s t r a t e g i e s f o r reducing 11 kV losses. These were then appl l e d a t a wider s c a l e over t h e 11 kV systems as a whole t o produce a programne o f measures t o be included i n t h e f l n a l l o s s r e d u c t i o n package. Extensive programmes o f feeder monitoring were c a r r i e d o u t on the 11 kV systems i n B l a n t y r e and Lilongwe t o p r o v i d e t h e basic data necessary t o c a r r y o u t load f l o w a n a l y s i s o f i n d i v i d u a l feeders and groups o f feeders t o assess l o s s r e d u c t i o n strategies. The m o n i t o r i n g comprised measurements o f power demand, power f a c t o r and sending end 11 kV v o l t a g e obtained us! ng "Dranetz" power demand anal ysers , together w i t h physi c a l surveys o f feeder lengths and conductor sizes, and t h e measurement o f transformer LV c u r r e n t s , voltages and power factors. The process whereby these measurements a r e combined t o enable l o a d f l o w a n a l y s i s t o be performed I s described below f o r a t y p i c a l feeder. F i g u r e 4.10 shows t h e power demand p r o f i l e o b t a i n e d f o r B l a n t y r e Main s u b s t a t i o n feeder 5L5 o v e r a t w e n t y - f o u r hour p e r i o d from Thursday 9 t h t o F r i d a y 1 0 t h August 1990. The "Dranetz" averages t h e power demand on t h e f e e d e r o v e r a 10 m i n u t e I n t e r v a l , so t h a t a smooth demand p r o f il e Is o b t a i n e d , r a t h e r t h a n t h e f l u c t u a t i n g p r o f i l e which would o t h e r w i s e r e s u l t from t a k i n g 1nstantaneous demand measurements. From t h i s p l o t i t can be seen t h a t t h e peak demand on 5L5 i s j u s t under 2 MW, and t h a t t h i s demand c o i n c i d e s w i t h t h e system peak a t a p p r o x i m a t e l y 18: 30. The demand gradual l y decreases t h r o u g h t h e evening, r e a c h i n g a steady minimum l e v e l d u r i n g t h e small hours o f t h e morning, and t h e n b u i l d s up f r o m about 05:00 onwards, r e a c h i n g a morning peak o f about 1.6 MH. The l o a d l e v e l decreases s l i g h t l y through t h e morn1 ng u n t i 1 lunchtime, when t h e r e i s another c l e a r l y d e f i n e d i n c r e a s e i n demand t o around 1.5 MW, a f t e r which t h e l o a d decreases b e f o r e b u i l d i n g up f o r t h e evening peak a g a i n . T h i s f e e d e r demand p r o f i l e i s c h a r a c t e r i s t i c o f a feeder s u p p l y i n g a predominantly domestic l o a d , w i t h some commercial l o a d c o n t r i b u t i n g t o t h e morning and a f t e r n o o n demands. F i g u r e 4.11 shows t h e corresponding power f a c t o r p r o f i l e f o r feeder 5L5, once a g a i n g i v i n g t h e average power f a c t o r o v e r a t e n minute p e r i o d . T h i s shows a s t e a d i l y i n c r e a s i n g power f a c t o r up t o an average o f 0.98 a t t h e peak f e e d e r demand, f o l lowed by a gradual decrease towards 0.91 t h r o u g h t h e evening and i n t o t h e n i g h t . T h i s r e f l e c t s t h e gradual d i s c o n n e c t i o n of r e s i s t i v e domestic loads such as e l e c t r i c cookers, 1 i g h t s , water heaters, e t c , so t h a t i n t h e m i d d l e of t h e n i g h t t h e c o m p a r a t i v e l y poor power f a c t o r r e s u l t s from such l o a d s as a i r c o n d i t i o n e r s and r e f r i g e r a t o r compressor motors which r u n throughout t h e n i g h t , t o g e t h e r w i t h t h e low power f a c t o r a s s o c i a t e d wl t h t r a n s f o r m e r I r o n losses on t h e f e e d e r . The power f a c t o r b u i l d s up a g a i n d u r l n g t h e e a r l y morning as domestic and c o n e r c i a l consumers t u r n on more r e s i s t i v e loads, and t h e n decreases d u r l n g t h e a f t e r n o o n b e f o r e t h e evening peak b u i l d up. The 11 kV v o l t a g e v a r i a t i o n a t B l a n t y r e Main d u r i n g t h i s p e r i o d I s shown i n F i g u r e 4.12, from which t h e a c t i o n of manual and automatic t a p changers on t h e system can be c l e a r l y observed w i t h sudden increases I n v o l t a g e d u r i n g t h e evening around t h e peak l o a d p e r i o d , f o l l o w e d by t a p p i n g down d u r i n g t h e n i g h t and t a p p i n g up a g a i n i n t h e morning. The v o l t a g e l e v e l on t h e 11 kV busbars i s g e n e r a l l y m a i n t a i n e d a t a h e a l t h y l e v e l between 1 .O1 and 1.05 pu t o ' m a i n t a i n t h e system v o l t a g e a t t h e remote ends o f t h e I 1 kV f e e d e r s . The 'peaky' n a t u r e o f t h e v o l t a g e profile reflects the f a c t that t h e "Dranetz" records instantaneous v o l t a g e v a l u e s as opposed t o average v a l u e s , w i t h t h e consequence t h a t l o c a l l o a d v a r i a t i o n s w i l l show up more c l e a r l y as f l u c t u a t i o n s on t h e o v e r a l l v o l t a g e waveform.  During t h e p e r i o d f o r which t h e "Dranetz" was connected t o m o n i t o r feeder 5L5, measurements o f t r a n s f o r m e r c u r r e n t s and, where p o s s i b l e , v o l t a g e s and power f a c t o r were made a t each 11 kVl400 V t r a n s f o r m e r . The r e s u l t s a r e summarised i n Table 4.9, I n which t h e t o t a l demand I s c a l c u l a t e d f r o m t h e c u r r e n t measurements and e i t h e r measured v o l t a g e s and power f a c t o r s or assumed values based on t h e peak l o a d c o n d i t i o n s o f t h e transformer. The a p p r o p r i a t e f a c t o r i s then used t o m u l t i p l y t h e measured load up to what i t would be a t t h e f e e d e r peak l o a d l n g c o n d i t i o n , by o b t a i n i n g t h e r a t i o o f t h e monitored feeder load a t t h e time each t r a n s f o r m e r was measured t o t h e peak load recorded by t h e "Dranetz". This s c a l i n g technique i s o n l y appl l e d t o those t r a n s f o r m e r s f o r which s p e c l f l c "Dranetz" measurements have n o t been made as p a r t of t h e LV system survey work discussed i n S e c t i o n 4.4, and t o those t r a n s f o r m e r s s u p p l y i n g loads which a r e t y p i c a l o f those s u p p l i e d by t h e feeder as a whole. I n t h e case o f I n d u s t r i a l o r pumping loads, together w i t h maize m i l 1s. for which t h e l o a d l n g i s dependent upon s p e c i f i c items of p l a n t b e i n g on o r o f f , e s t i m a t e s a r e based on t h e l i k e l y r u n n i n g c o n d i t i o n of t h e p l a n t a t t h e t i m e o f feeder peak. Using t h i s method i t may be observed t h a t t h e t o t a l predlcted l o a d i n g on t h e transformer peak comes o u t t o 1989.9 kW, which compares f a v o u r a b l y w i t h . t h e "Dranetz" recorded peak demand o f j u s t under 2 MW. The Y e s u l t i n g transformer loads were then used as t h e b a s i s for a l o a d f l o w of t h e 11 kV f e e d e r . 3 Present Loss L e v e l s Load flow s t u d i e s were performed for a number of t h e 11 kV feeders i n B l a n t y r e and Lilongwe for which l o a d measurements had been obtained, u s i n g b o t h t h e KDP LF software, w i t h which ESCOM engineers were a l r e a d y f a m l l j a r , and t h e DPAS package, which was i n t r o d u c e d as p a r t o f t h e Loss Reduction Study. The use o f b o t h packages enabled as l a r g e a number o f feeders as p o s s i b l e t o be analysed d u r i n g t h e study p e r i o d by b o t h KDP and ESCOM engineers. Table 4.10 shows a summary o f t h e r e s u l t s o f these s t u d i e s , i n d i c a t i n g f o r each f e e d e r t h e peak demand, l o a d f a c t o r and l o s s f a c t o r , together w l t h t h e percentage peak power and energy losses. The load f a c t o r i s c a l c u l a t e d from t h e "Dranetz" demand measurements as t h e r a t i o of t h e average demand t o t h e peak demand over twenty-four hours. The l o s s f a c t o r i s s i m i l a r l y o b t a i n e d f r o m these r e s u l t s as t h e r a t i o o f t h e average o f t h e squares o f t h e demand t o t h e square o f t h e peak demand. The peak percentage power l o s s 1s. o b t a i n e d from t h e feeder l o a d f l o w r e s u l t s and converted I n t o a percentage energy l o s s by m u l t i p l y i n g by t h e r a t i o of t h e l o s s f a c t o r t o t h e l o a d factor. The r e s u l t s obtalned I n d l c a t e an average 1.5% energy loss assoclated w l t h the range o f feeders analysed, whlch Included some c i r c u l t s such as Lilongwe B 3L5, supplylng predomlnantly I n d u s t r i a l loads, as well as those supplylng more general loads. The assessment o f a l t e r n a t l v e strategles f o r reduclng the losses on the 11 kV systems I s dlscussed below. A number o f p o t e n t l a l loss reductlon s t r a t e g l e s ,have been Investlgated w l t h regard t o the losses on the 11 kV system. These have been examlned both w i t h regard t o t h e l r technlcal v l a b l l l t y and t h e l r r e l a t l v e economlc merl t s . 'The a p p l l c a t l o n o f capacltors a t 11 kV I s a strategy whlch, w h i l s t on many systems being l l k e l y t o represent an economlcally a t t r a c t l v e p r o p o s l t l o n due t o the r e l a t l v e l y low cost o f 11 kV capacitor banks, has I l m l t e d scope f o r appl l c a t i o n I n the ESCOM system due t o the generally good power f a c t o r s a t 11 kV. Thls I s p a r t l c u l a r l y c l e a r when I t I s borne i n mind t h a t I t I s undeslrable t o compensate t o a l e v e l greater than t h a t requlred t o glve u n i t y power f a c t o r on the feeder a t perlods o f mlnlmum demand, t o avoid problems o f overvoltages occurring I f the capacltors are t o remaln I n servlce permanently. Switchable capacitors are an o p t l o n whlch could be consldered If there were s l g n l f l c a n t dlfferences between power f a c t o r s a t maxlmum and mlnlmum demand l e v e l s , although there I s a cost penalty assoclated w l t h t h l s e x t r a degree of sophlstlcatlon. Feeder reconductorl ng Is a loss reduction a1t e r n a t l ve whlch has far greater scope for a p p l l c a t l o n on the 11 kV system, p a r t l c u l a r l y given the e x l s t l n g maxlmum 11 kV overhead l l n e condu.ctor slze u t l l l s e d by ESCOM o f 100 sq mm. I t I s proposed t h a t a new 150 sq mm conductor slze be Introduced a t 11 kV on feeders whlch are runnlng a t load l e v e l s above the optlmum f o r 100 sq mn conductors; d e t a l l e d technlcal .and economlc analysl s o f t h l s and the other loss reductlon measures consldered on the 11 kV system are glven below. (a) 11 kV Reconductoring The starting polnt for the analysls of reconductorlng optlons a t 11 kV i s the examlnatlon of conductor o p t i m i s a t l o n curves as i n the transml ssion system analysi s descrl bed e a r l ier. A serles o f curves were produced based on the f o l lowlng data: Analysis Perlod: 15years Annual Demand Growth Rate: 8.5% - Southern Reglon 7.6% - Central Region  Load F a c t o r ) Loss Load F a c t o r ) Feeder dependent Margi n a l Power Cost: 445.28 MKIkW Margi n a l Energy Cost: 0.045 MKIkWh The growth r a t e s shown a r e average annual values obtained from the load f o r e c a s t f o r feeders s u p p l y i n g a m i x t u r e o f l o a d types, i e , combinations o f small industrial, commercial and domestic premises. The l o a d f a c t o r s and l o s s f a c t o r s observed f o r t h e feeders which were analysed u s i n g "Dranetz" measurements and l o a d f l o w a n a l y s l s v a r i e d q u i t e widely,as shown i n Table 4.10, and i n d i v i d u a l o p t l m i s a t i o n curves were thus generated t o examlne t h e sensi t i v i t y o f r e c o n d u c t o r i ng t h r e s h o l d s t o l o a d and l o s s f a c t o r s . The f o l l o w i n g c a p i t a l c o s t s f o r l i n e c o n s t r u c t i o n , o b t a i n e d f r o m t h e ESCOM c o s t database, were used i n g e n e r a t i n g t h e o p t i m i s a t i o n curves: 50 sq mm MK 18,924 p e r km 100 sq mm MK 28,561 p e r km 150 sqmm MK32,280 p e r km Reconductoring c o s t s a t 11kV have been taken as 100% o f t h e new 1i n e c o s t , t o a l l o w f o r such c o n t l n g e n c l e s as p o l e and I n s u l a t o r replacement whlch may be necessary t o accompll sh r e c o n d u c t o r i n g successfully. Table 4.11 shows t h e r e s u l t s of o p t i m i s a t 1 o n s t u d l e s I n terms o f t h e l o a d i n g on 50 sq m m and 100 sq mn conductors a t which i t becomes v i a b l e t o t r a n s f e r t o a 150 sq mm conductor t o minim1 se n e t present value operating costs. These l o a d l n g l e v e l s a r e shown for a number o f l o a d f a c t o r s , u s i n g t h e Southern Region average growth r a t e I n s e c t i o n (a) o f t h e t a b l e , and f o r a number o f growth r a t e s w i t h t h e l o a d f a c t o r f i x e d a t t h e o v e r a l l system value o f 62.3% i n s e c t i o n ( b ) . These r e s i l l t s show an i n c r e a s e o f 18% i n t h e r e c o n d u c t o r i n g t h r e s h o l d s o v e r a range o f l o a d f a c t o r s from 48.4% t o 90.1%. t h e extremes o f the sample o b t a i n e d f r o m "Dranetz" measurements. This suggests 1 i m i t e d s e n s i t i v i t y o f .the l o a d i n g l e v e l s a t whlch r e c o n d u c t o r i n g should be u t i l i s e d t o l o a d f a c t o r v a r i a t i o n s , p a r t i c u l a r l y i n view o f t h e r o l e o f t h i s type of o p t l m i s a t i o n technique as a t o o l i n t h e p r e l i m i n a r y I d e n t i f i c a t i o n of p o t e n t i a l l o s s r e d u c t i o n p r o j e c t s , which a r e t h e n s u b j e c t e d t o more d e t a i l e d economic a n a l y s i s t o e s t a b l i s h t h e i r viability.  S e c t i o n (b) t o Table 4.11 shows a d l f f e r e n c e o f some 65% between t h e l o a d l e v e l s a t whlch r e c o n d u c t o r l n g t o a 150 sq m m conductor becomes v l a b l e o v e r a range o f annual growth r a t e s f r o m 8.5% t o 2.0% o v e r t h e f i f t e e n y e a r a n a l y s l s perlod. T h i s r e p r e s e n t s a much more s i g n i f i c a n t s e n s l t l v l t y t o growth r a t e than was t h e case w l t h l o a d f a c t o r , and suggests t h a t g r e a t c a r e needs t o be taken when a p p l y i n g t h e r e g l o n a l l o a d growth f a c t o r s t o s p e c l f l c f e e d e r s as t h e b a s l s f o r conductor o p t l m l s a t l o n . F l g u r e 4.13 shows I n graphlcal form t h e I m p l l c a t l o n s o f these r e s u l t s I n terms o f t h e bands I n whlch r e c o n d u c t o r l n g should be performed w l t h r e g a r d t o b o t h conductor l o a d l n g and l o a d growth r a t e , and I n d i c a t e s t h e l o w e r i n g o f t h e r e c o n d u c t o r l ng t h r e s h o l d s as t h e annual l o a d growth v a r i e s from 0 t o 10%. The Impact o f growth rate varlatlons on the speclflc 11 kV r e c o n d u c t o r l ng p r o p o s a l s developed f o r t h e ESCOM system I s discussed I n more d e t a i 1 below. F u r t h e r a n a l y s l s was performed t o examlne t h e sensl t l v l t y o f t h e r e c o n d u c t o r l ng t h r e s h o l d s t o a d i f f e r e n t f o r m o f l o a d growth v a r i a t i o n , whereby an 8.5% annual growth was a p p l l e d o v e r a seven y e a r p e r i o d , and t h e f e e d e r l o a d l e v e l h e l d c o n s t a n t t h e r e a f t e r f o r t h e remalnder o f t h e f l f t e e n y e a r analysls. T h i s growth p a t t e r n c o u l d r e f l e c t t h e posslble Introductlon of other llnes and s u b s t a t l o n s due t o system enhancement whl ch would t e n d t o 1l m l t t h e growth o f demand o n ' an ex1 s t l n g c l r c u l t. The r e s u l t s o f t h l s a n a l y s l s a r e s u m a r l s e d below, w l t h f l g u r e s from the analysls w l t h f u l l f l f t e e n y e a r growth shown f o r r e f e r e n c e . The t h r e s h o l d s a r e g l v e n I n kVA, and percentage o f t h e r a t l n g of t h e l l n e w l t h t h e s m a l l e r cross-sectional area, and a r e based on an 8.5% annual growth r a t e a t t h e system l o a d f a c t o r o f 62.3%. LUL 15 Year Growth S r o w th These show an lmcrease I n t h e t h r e s h o l d l e v e l s a t whlch r e c o n d l t l o n l n g would become v l a b l e t o l e v e l s whlch a r e a p p r o p r i a t e f o r a d o p t i o n as t h e s t a r t l n g polnt for Identlflcatlon of potential loss reduction projects. Sample reconductoring projects were initially identified on the basis of the 8.5% and 7.6% growth rates for the Southern and Central regions, and then examined in terms o f economic viability. Having performed detailed analysis for the sample projects, a wider programme of reconductori ng was prepared based on the same selection criteria that yielded sample projects givl ng acceptable economl c rates o f return. 'rhi s necessitated exam1 nation o f each feeder t o determine its peak demand, from "Dranetz" measurements, its conductor sizes and lengths from the physical line surveys and its approximate load distribution. 'The latter factor was assessed from load flows, in the case of the detailed sample analyses, and from an assessment o f transformer sizes and locations from single line diagrams for the remaining cases. As part of this analysi s, cable reconductoring has been considered in cases where the thresholds for reconductori ng i ndi cated in Figure 4.14 are exceeded. These levels have been prepared on the basis o f ESCOM cost estimates for 3 core copper XLPE cables, o f which the details are as follows: It may be observed from Flgure 4.14 that for the case o f replaclng exlstlng cables by a 2 4 0 sq m size, the loadlngs at which this becomes justified are very close to, o r in excess of, the cable thermal ratings. In uprating cable capacity for loss reductlon purposes, the normal procedure t o be adopted would be t o Install a second cable In parallel with the existlng cable t o obtain the desired overall cable cross-section. In many o f the cases observed on the ESCOM system however, cables that would justify action t o reduce losses are already overloaded or will be by the time reconductorl ng can be Implemented . It is thus proposed that in these cases a single replacement 240 sq mm cable is installed t o avoid potential operational problems that may result from continuing to use a cable that has already suffered the stresses associated with operating under overload conditions.  Hhi 1s t the replacement o f overloaded cables could be viewed as a t e c h n i c a l necessity the costs o f which should n o t e n t i r e l y be borne by l o s s r e d u c t i o n p r o j e c t s , i n p r a c t i c e , as i s demonstrated below, the r a t e s o f r e t u r n f o r most o f t h e proposed p r o j e c t s are s u f f i c i e n t l y h i g h n o t t o be affected by the i n c l u s i o n of t h e f u l l cable replacement cost where necessary. I n one case however a p r o j e c t becomes v i a b l e through the apportionment of p a r t o f the cable cost t o system development. Table 4.12 shows a summary o f i n t e r n a l r a t e o f r e t u r n c a l c u l a t i o n s which have been performed f o r reconductorlng p r o j e c t s I d e n t i f i e d on the basis o f the technlques described above. The costs used I n the I R R c a l c u l a t i o n have been increased over those provlded from t h e ESCOM data base t o a l l o w f o r i n t e r n a t i o n a l tendering I n the event, as d i scussed e a r l i e r , of e x t e r n a l agencies being r e q u i r e d t o undertake the work due to ESCOM resource constraints. Table 4.13 summarises the ESCOM and KDP international budgetary p r l ces for reconductoring, together w i t h the r e s i s t a n c e values f o r the a l t e r n a t i v e conductor sizes. This gives the f o l lowing In t e r n a t l o n a l component costs f o r reconductori ng : 150 sq mn AAAC overhead 1 i n e : 47,600 MK/km 240 sq mm Cu XLPE cable: 354,000 MK/ km Table 4.12 i n d i c a t e s the g e n e r a l l y very good r a t e s o f r e t u r n associated w i t h reconductoring p r o j e c t s i d e n t i f i e d from o p t l m l s a t i o n o f conductor sizes and confirms the value of . undertaking 1lkV reconductoring as a l o s s r e d u c t i o n s t r a t e g y on the ESCOM system. .These have been assessed u s i n g q u i t e stringent analysl s c r lterla, whereby the appropriate annual growth r a t e (7.9% f o r the Southern Region f r o m 1991 t o 2000 and 7.6% f o r the Central Region over the same period) was a p p l i e d u n t i 1 the ex1 s t i n g feeder under examination reaches I t s thermal r a t l n g . The same amount o f growth was then a p p l i e d t o the reconductored Ilne, and the b e n e f i t s c a l c u l a t e d over a f i f t e e n year p e r i o d as sum1 ng no f u r t h e r load growth beyond the t herma 1 r a t i n g o f t h e l l n e before reconductoring. This method i s somewhat p e s s i m i s t i c , since i t takes no account o f the a b i l i t y o f the reconductored c i r c u i t t o supply g r e a t e r demand l e v e l s than t h e e x i s t i n g llne. The r a t e s o f r e t u r n c a l c u l a t e d i n d i c a t e however t h a t from consideration o f losses alone the p r o j e c t s are v i a b l e .  I n the case of Group feeder 202, I n whlch t h e e x i s t i n g 70 sq mm cable I s exceeding I t s thermal r a t i n g a t present peak demand l e v e l s , benefl t s have been c a l c u l a t e d u s l n g a p r o p o r t i o n o f t h e c a p i t a l c o s t f o r i n s t a l l a t l o n o f a 240 sq mm cable equal t o t h e d i f f e r e n c e between t h e c o s t o f a 240 sq mm cable and t h a t of a 120 sq mm s i z e , t h e minimum r e q u i r e d t o r e l i e v e t h e e x i s t i n g cable overload. Table 4.14 l i s t s t h e wider programme o f 11 kV reconductorl ng p r o j e c t s i d e n t l f l e d f o r the system as a whole, d e t a i l i n g the feeder names, t h e i r peak demands, the length of lines requiring reconductoring, together w l t h d e t a i l s o f the sections t o be replaced and t h e t o t a l c o s t f o r each feeder. From t h i s i t may be seen t h a t a t o t a l 11 kV reconductorlng package o f MK 3.9 m Is recommended f o r implementation as p a r t o f t h e l o s s reduction project. Examlnlng these p r o j e c t s I n t h e c o n t e x t o f t h e v a r i a t i o n o f reconductorlng thresholds shows t h a t t h e v a s t m a j o r i t y o f feeders on the l i s t are o p e r a t i n g a t l o a d l e v e l s above those whlch a t OX growth r a t e would s t i l l show b e n e f i t s from reconductoring over a f l f t e e n year p e r l o d . I n the f o l l o w i n g f o u r cases, reconductorlng would show marginal benefl t s I f an annual growth r a t e o f below 5% were sustained: B l a n t y r e Main 5L5 Chlleka 3L0 Limbe 5L5 L I longwe B 4L5 I n o n l y one case ( t h a t o f Lilongwe B feeder 2L5) would reconductoring become u n j u s t i f i e d I f the f o r e c a s t annual growth r a t e o f 6.7% were n o t mai n t a l ned. On t h i s b a s i s , i t I s n o t considered t h a t t h e 11 kV reconductorlng programme as a whole Is s l g n l f l c a n t l y I n f l u e n c e d by v a r l a t i o n s I n load growth r a t e , and t h e package should be Implemented I n i t s e n t i r e t y as p a r t o f the l o s s r e d u c t i o n project. Figures 4.15 and 4.16 show the conductor o p t l m l s a t l o n curves based on the ESCOM l i n e costs and u s l n g an 8.5% growth r a t e a p p l l e d over seven years and a f l f t e e n year e v a l u a t i o n p e r i o d t o determlne design loadings f o r overhead l i n e s and underground cable c l r c u l t s a t 11 kV. These should be used as a gulde i n t h e design o f f u t u r e system expanslon p r o j e c t s t o ensure t h a t these a r e c a r r i e d o u t I n accordance w l t h l o s s m i n l m i s a t i o n s t r a t e g i e s . (b) Capacitor Placenent Capacitor placement o f f e r s 1i m i t e d scope for implementation as a l o s s r e d u c t i o n s t r a t e g y on t h e ESCOM system, due t o t h e g e n e r a l l y good power f a c t o r s o c c u r r i n g across t h e system. The o n l y feeder 1i k e l y t o b e n e f l t from t h e a p p l i c a t i o n o f c a p a c l t o r s i s Lilongwe B feeder 6L5. T h i s has a power f a c t o r a t peak o f 0.9 a t p r e s e n t , and feeds a predominantly i n d u s t r i a l load, having a l o a d f a c t o r of 84.6%. The e x i s t i n g energy l o s s l e v e l o f 1.2% I s s l i g h t l y lower than t h e average f o r t h e 11 kV system. A t o t a l o f 600 kVAr o f capacitance should be a p p l i e d t o t h e feeder by 2005, w l t h 200 kVAr b e i n g i n s t a l l e d I n 1991. These l e v e l s were d e r i v e d f r o m t h e r e s u l t s o f t h e "Dranetz" measurements which i n d i c a t e d t h a t a maximum o f 200 kVAr o f compensation c o u l d be accommodated on t h e feeder I n i t i a l l y t o g i v e a u n i t y power f a c t o r a t minimum feeder demand. This value should be Increased t o 600 kVAr on a p r o - r a t a b a s i s w l t h t h e I n c r e a s i n g feeder demand, p r o j e c t e d f r o m t h e C e n t r a l Reg'lon annual growth r a t e o f 7.6%. I n general, t h e benef it s o f capaci tor placement a r e s l g n i f l c a n t l y a f f e c t e d by t h e p o s i t i o n i n g o f t h e c a p a c i t o r s on t h e l i n e ; f o r maximum b e n e f l t a d i s t r i b u t e d approach i s necessary t o ensure a u n i f o r m r e d u c t i o n i n t h e r e a c t l v e power f l o w a l o n g t h e f e e d e r and a consequential l o w e r i n g o f t h e l o s s l e v e l . I n t e r n a t l o n a l experlence shows t h a t p l a c i n g o f capaci t o r s a t approximately one-thl r d and t w o - t h i r d s o f t h e t o t a l f e e d e r l e n g t h r e p r e s e n t s an e f f e c t i v e d l s t r i b u t l o n o f r e a c t l v e power support. I n t h e case of Lilongwe B 6L5 these p o s i t i o n s c o l n c i d e w l t h t h e main t e e - o f f s supplying the i n d u s t r i a l loads on t h e feeder, and these t h e r e f o r e r e p r e s e n t optimum p o s i t i o n s for t h e c a p a c i t o r s . Table 4.15 shows t h e d e t a i l s o f i n t e r n a l r a t e o f r e t u r n calculations for t h e r e c o n d u c t o r i n g proposal f o r 6L5 shown i n Table 4.14, t h e I n s t a l l a t i o n o f c a p a c i t o r s w i t h o u t r e c o n d u c t o r l n g and t h e e x e c u t i o n o f b o t h r e c o n d u c t o r i n g and c a p a c i t o r placement. The c a p a c l t o r c o s t s were c a l c u l a t e d on t h e b a s i s o f c u r r e n t i n t e r n a t i o n a l budgetary e s t i m a t e s of MK 3,400 per 100 kVAr s t a t i c c a p a c l t o r bank. The r a t e s o f r e t u r n f o r these measures a r e c a l c u l a t e d u s i n g seven y e a r s ' l o a d growth, b r i n g i n g t h e f e e d e r l o a d l n g t o I t s thermal l i m i t , a t which stage t h e feeder demand I s h e l d c o n s t a n t f o r e i g h t f u r t h e r years. I n seven y e a r s o f l o a d growth, o n l y 2 x lOOkVAr c a p a c i t o r s would be r e q u i r e d , and c o s t s f o r  these a r e t h e r e f o r e shown i n the a n a l y s i s . The r e s u l t s c l e a r l y demonstrate t h a t b o t h t h e l o s s r e d u c t i o n p r o j e c t s proposed f o r t h i s feeder a r e v i a b l e , g i v i n g an o v e r a l l r a t e o f r e t u r n o f 12%. Both a r e t h e r e f o r e i n c l u d e d i n t h e f i n a l l o s s r e d u c t i o n package. (c) 11 kV System R e c o n f i g u r a t i o n R e c o n f i g u r a t i o n o f t h e 11 kV system t o mlnlmlse losses w i l l i n e v i t a b l y be i n f l u e n c e d t o a l a r g e e x t e n t by t h e i n t r o d u c t i o n o f new b u l k supply p o i n t s , new feeders and t h e u p r a t l n g o f feeders t o higher o p e r a t i n g v o l t a g e s , a l l o f which w i l l undoubtedly f o r m p a r t o f t h e Transmission and Di s t r i b u t i o n Study c u r r e n t l y be1 ng performed f o r t h e ESCOM system. U n t i l such plans a r e f i n a l i s e d i t i s d i f f i c u l t t o optimlse the c o n f i g u r a t i o n o f t h e system i n such a way as t o ensure t h a t losses a r e minimised. A case I n p o i n t i s t h a t o f Lilongwe B feeder 2L5, which a t p r e s e n t has a h i g h l o s s l e v e l o f 7.7%. p r i m a r i l y caused by i t s s u p p l y i n g a r e l a t i v e l y remote l o a d which i s due t o be catered f o r by a new 33/11 kV s u b s t a t i o n proposed by ESCOM, which w l l l presumably be viewed i n t h e c o n t e x t o f the recommendations of t h e Transmi s s i o n and D i s t r i b u t i o n Study. W h i l s t t h e Loss Reduction Study can s t r o n g l y recommend t h a t t h i s a c t i o n should be taken t o a l l e v i a t e an e x i s t i n g h i g h l o s s s i t u a t i o n , such c o n s i d e r a t i o n s as t h e s i z i n g o f , and p o s s i b l e i n t e r c o n n e c t i o n o f o t h e r feeders t o , t h e new s u b s t a t i o n can o n l y be assessed as p a r t o f o v e r a l l system development p l a n , which should i n c o r p o r a t e loss minimisation as one of its primary objectives. I t i s thus recommended t h a t such techniques as o p t i m i s i n g t h e open p o i n t s between feeders by a n a l y s i s o f t h e power f l o w s o c c u r r i n g on adjacent 1i n e s i n a closed mode o f system o p e r a t i o n should be i n c l u d e d i n t h e a n a l y s i s f o r m i n g t h e basis o f t h e development p l a n f o r t h e ESCQM system, and t h a t ESCOM should themselves examine t h e e f f e c t s o f s w i t c h i n g o p e r a t i o n s on l o s s e s as p a r t o f t h e i r normal o p e r a t i o n a l p l a n n i n g procedure. The use o f these techniques coupled w i t h t h e design g u i d e l i n e s developed i n t h i s r e p o r t w l l l ensure t h a t t h e l o s s r e d u c t i o n achieved by t h e s p e c i f i c projects proposed here is extended in it s e f f e c t i v e n e s s i n t o t h e p l a n n i n g and o p e r a t i o n a l aspects o f t h e ESCOM system. 4.4 11/0.4 kV Transfomatlon and LV Systems 4.4.1 Introduction D e t a i l e d a n a l y s i s has been performed f o r sample 11 kV and LV networks i n t h e ESCOM system, t o evaluate e x i s t i n g l e v e l s o f losses associated w i t h 11/0.4 kV transformers and LV distribution. Methods o f reducing these losses have been examined u s i n g transformer and conductor o p t i m i s a t i o n , t h e l a t t e r i n terms o f conductor s i z e s e l e c t i o n on t h e b a s i s of both l o s s l e v e l s and v o l t a g e performance, i n o r d e r t o e s t a b l i s h design r u l e s f o r t h e p l a n n l n g of t h e d i s t r i b u t i o n system and t o develop cost estimates for programmes of transformer replacement and LV reconductoring across t h e system. W h i l s t a1 1 o f these measures w i 11 reduce losses, and a r e shown t o do so I n an economically v i a b l e way, i t i s c l e a r t h a t t o f u l l y o p t i m i se the performance and development of t h e ex1 s t 1 ng LV systems and t h e i r associated transformers n e c e s s i t a t e s a coordinated approach t o t h e a d d i t i o n o f new transformers and t h e extension o r r e c o n f i g u r a t i o n o f t h e LV systems. The importance o f I n t e g r a t i n g s p e c i f i c l o s s r e d u c t i o n p r o j e c t s w l t h t h e p l a n n i n g o f t h e d l s t r i b u t l o n system I s such t h a t I t can o n l y be f u l l y assessed by means o f a d e t a i l e d study, as p a r t o f which a complete data base o f a l l t h e LV systems s u p p l i e d from a number o f 11 kV feeders is formulated, which can then be used t o o p t l m i s e t h e p o s i t i o n i n g of transformers and open p o i n t s between LV systems. The magnitude o f t h e t a s k r e q u i r e d t o achieve t h i s i s such t h a t i t cannot be f u l l y addressed I n a system wide l o s s r e d u c t i o n study o f t h l s type. One o f t h e recommendations d e t a i l e d below t h e r e f o r e Includes f o r t h e e x e c u t i o n of such a study, whlch would n e c e s s i t a t e a s i g n i f i c a n t e x e r c i s e I n d a t a c o l l e c t i o n of t h e type which was v e r y e f f e c t i v e l y s t a r t e d by ESCOM i n f o r m u l a t i n g the data base f o r t h e sample s t u d i e s c a r r i e d o u t I n t h l s project. F u r t h e r d e t a i l s of t h l s and t h e o t h e r l o s s r e d u c t i o n s t r a t e g i e s examined for t h e LV d i s t r i b u t i o n systems and associated t r a n s f o r m a t i o n are g i v e n below. The losses associated w l t h 11 kV/LV transformers were evaluated e x p l i c i t l y f o r a number o f feeders i n B l a n t y r e and Lilongwe f o r whlch d e t a i l e d surveys had been performed as p a r t of t h e 11 kV feeder a n a l y s i s . The d a t a base used I n the c a l c u l a t i o n of losses f o r transformers o f d i f f e r e n t r a t i n g s i s shown I n Table 4.16. The core and winding l o s s f i g u r e s were o b t a i n e d from tendered values f o r transformers s u p p l i e d t o ESCOM, w l t h t h e exception o f those f o r t h e 15 kVA and 400 kVA sizes, f o r whlch t h e same percentage impedances were used as for t h e 25 kVA and 500 kVA s i z e s r e s p e c t i v e l y . For each f e e d e r t h e t o t a l t r a n s f o r m e r core energy losses were c a l c u l a t e d as t h e sum o f t h e core power losses a s s o c i a t e d w i t h each t r a n s f o r m e r on t h e f e e d e r mu1t i p 1 l e d by twenty-four hours, t o o b t a l n a d a l l y core energy l o s s f i g u r e . For t h e windlng losses, t h e peak l o a d i n g on each t r a n s f o r m e r was o b t a i n e d from t h e l o a d d i s t r i b u t i o n used as t h e b a s i s f o r t h e 17 kV l o a d f l o w studies, t h e associated peak windlng power l o s s was c a l c u l a t e d , and then m u l t i p l i e d by the t r a n s f o r m e r l o s s l o a d f a c t o r and twenty-four hours t o o b t a i n a d a i l y windlng energy l o s s f i g u r e . The transformer l o s s l o a d f a c t o r was assumed equal t o t h e feeder l o s s l o a d f a c t o r unless . t h e t r a n s f o r m e r had been s p e c i f l c a l l y monitored w i t h t h e "Dranetz" analyser . The t o t a l o f t h e two energy l o s s f i g u r e s was then compared w i t h t h e energy s u p p l i e d t o t h e f e e d e r over twenty-four hours t o o b t a i n a percentage transformer l o s s f i g u r e f o r each f e e d e r . The r e s u l t s o f t h i s a n a l y s i s f o r t h e sample feeders s t u d i e d a r e shown i n Table 4.17. Thls i n d i c a t e s an average energy l o s s l e v e l o f 1.8% associated w i t h 1110.4 kV t r a n s f o r m a t i o n , w i t h an average transformer u t l l i s a t i o n f a c t o r o f 46%. I n general i t w i l l be observed from t h e t a b l e t h a t as t h e t r a n s f o r m e r u t i 11s a t i o n f a c t o r Increases, t h e balance s h i f t s f r o m core losses t o winding losses, r e f l e c t i n g t h e i n c r e a s i n g e f f e c t o f the load c u r r e n t on the t o t a l losses i n t h e t r a n s f o r m e r . The optimum u t i l i s a t i o n f a c t o r f o r a d l s t r i b u t i o n t r a n s f o r m e r o f a g i v e n s l z e may be o b t a i n e d by c a l c u l a t l n g t h e annual c o s t o f losses based on a g i v e n peak demand and l o s s f a c t o r , and I n c l u d i n g a component f o r t h e a n n u i t l s e d c a p l t a l c o s t o f t h e t r a n s f o r m e r . Figure 4.17 sh6ws a s e t o f curves i n d i c a t i n g t h e annual o p e r a t l ng c o s t f o r a v a r i e t y o f t r a n s f o r m e r ' s i z e s I n use on t h e ESCOM 11 kV system, based on the c a p l t a l c o s t s and percentage losses shown I n Table 4.16. The system l o a d f a c t o r o f 62.3% ( w i t h a corresponding l o s s f a c t o r of 45.8%) was used i n c a l c u l a t l n g t h e c o s t o f losses, t o g e t h e r w i t h t h e marginal power c o s t o f 527.98 MK/kW which a p p l i e s f o r losses as f a r as t h e LV system. The a n a l y s i s was performed u s i n g a 15 year period f o r the a n n u l t i s a t i o n o f the transformer c a p i t a l costs. These curves show t h a t f o r each t r a n s f o r m e r s i z e It I s p r e f e r a b l e i n terms o f m i n i m i s i n g o p e r a t i o n a l c o s t s t o supply loads o f up t o t h e transformer r a t i n g b e f o r e s w i t c h i n g t o a l a r g e r s l z e u n i t . Thls I m p l i e s t h a t f o r l o s s m i n l m i s a t i o n i t is p r e f e r a b l e t o rep1ace t r a n s f o r m e r s progress1v e l y as l o a d i ng increases, r a t h e r than t o use a transformer s i z e d f o r the maximum p r o j e c t e d demand which w i l l be experienced i n a number o f y e a r s ' time f r o m t h e s t a r t i n a p a r t i c u l a r l o c a t i o n . The curves i n d i c a t e t h a t t h e r e i s i n f a c t n o t h l n g t o be gained by i n t r o d u c i n g an i n t e r m e d i a t e s i z e between 200 kVA and 500 k V A i n terms o f losses; indeed i t i s general l y advantageous t o minimi se t h e number o f t r a n s f o r m e r swaps t h a t a r e r e q u i r e d t o c a t e r f o r l o a d growth, w h i l s t aiming t o mlnimise t h e annual o p e r a t i n g c o s t o f t h e transformers, so as t o a v o i d unnecessary work being programmed i n t o t h e u t i 11t j l ' s o p e r a t i o n .  Figures 4.18 and 4.19 show s i m i l a r curves p l o t t e d f o r t h e cases o f 90i6 and 40% l o a d f a c t o r s r e s p e c t i v e l y . These I n d i c a t e very l i t t l e v a r i a t i o n I n t h e t r a n s f o r m e r l o a d i n g l e v e l s a t which u p r a t i n g i s recommended over t h i s range o f load f a c t o r s . Thls i n s e n s i t i v i t y t o l o a d f a c t o r v a r i a t i o n demonstrates t h a t t h e o v e r a l l p r l n c l p l e o f t r a n s f o r m e r u p r a t i ng o n l y when t h e transformer r a t l n g I s reached I s s u i t a b l e f o r a p p l i c a t i o n on a system wide b a s l s . A number o f sample t r a n s f o r m e r o p t i m i s a t l o n s t u d i e s were c a r r i e d o u t i n o r d e r t o a l l e v i a t e overloads i d e n t i f i e d f r o m t h e load d i s t r i b u t i o n s used f o r feeder l o a d f l o w s t u d i e s , and t o improve u t l 1is a t i o n factors by removl ng over-rated transformers, t o be redeployed elsewhere on t h e f e e d e r , and r e p l a c i n g them w i t h s m a l l e r u n i t s . I n p r a c t i c e , accurate measurements o f i n d i v i d u a l transformer peak demands would be examined p r i o r t o r e p l a c i n g them; g i v e n t h e accuracy o f t h e measttremeilt and s c a l i n g process used t o e s t i m a t e feeder l o a d d l s t r i b u t i o n s however, a reasonable o v e r a l l t r e n d may be expected t o emerge f rom t h i s s o r t o f a n a l y s i s , t o enable budgetary estimates o f transformer replacement c o s t s t o be prepared. Table 4.18 shows transformers which would be r e p l a c e d on Group Substation Feeder 202, on t h e b a s l s o f t h e e s t i m a t e d l o a d distribution. Thls ill u s t r a t e s cases such as t h a t o f transformer number 30, which would be uprated t o 200 kVA, having reached i t s 100 kVA r a t i n g a t peak demand, t o g e t h e r w i t h examples such as number 10, where a 200 kVA u n i t would be replaced by a 100 kVA s i z e , I n t h e presence o f a peak demand o f 57 kVA. The f i r s t o f these examples would r e l e a s e a 100 kVA transformer which c o u l d be swapped w i t h t h e 200 kVA r e l e a s e d I n t h e second case, thereby a v o i d i n g t h e purchase o f an add1 t i o n a l u n l t .. Table 4.19 extends t h i s p r i n c i p l e f o r t h e remal n i n g t r a n s f o r m e r replacements I d e n t i f l e d , f r o m which i t I s concluded t h a t t h e twelve changes recommended r e s u l t I n t h e need f o r f b ~ rnew transformers, w l t h f o u r u n i t s o f d i f f e r e n t r a t i n g s be1 ng placed I n t h e s t o r e s f o r f u t u r e use, assuming t h a t t h e i r c o n d i t i o n i s such as t o make t h i s a v i a b l e o p t i o n . The c a p i t a l c o s t s assoclated w i t h purchasing t h e new t r a n s f o r m e r s a r e based on i n t e r n a t i o n a l budgetary f i g u r e s , and t h e labour charges f o r each replacement a r e based on ESCOM's c u r r e n t r a t e s f o r t h e r e q u i r e d teams. A t o t a l c o s t o f some MK 49,000 i s a s s o c i a t e d w i t h t h e transformer replacements on Group Feeder 202. I n c a l c u l a t i n g the I n t e r n a l r a t e o f r e t u r n assoclated w l t h t h i s work, streams o f losses were c a l c u l a t e d based on t h e use o f transformer s i z e s determined from t h e o p t i m i s a t i o n curves, compared w l t h a s l t u a t i o n i n which transformers a r e r e p l a c e d I f they a r e overloaded by more than 20%, and then r e p l a c e d w l t h t h e n e x t standard s i z e . No r e s i d u a l value i s a t t a c h e d t o  transformers which a r e r e l e a s e d t o go i n t o t h e s t o r e , t o t a k e i n t o account t h e f a c t t h a t some such u n i t s w i l l be beyond t h e end o f t h e i r economic 1i v e s , o r have problems which may present them from being worth r e - i n s t a l 1 i n g on t h e system. On t h e b a s i s o f these assumptions an i n t e r n a l r a t e o f r e t u r n o f 17% was c a l c u l a t e d f o r t h e proposed t r a n s f o r m e r replacement programme. This r e p r e s e n t s a w o r t h w h i l e p r o j e c t t o pursue, and v a l l d a t e s t h i s approach t o transformer s i z i n g as a p p r o p r i a t e f o r a p p l i c a t i o n on a system-wide s c a l e . Table 4.20 shows t h e r e s u l t s of s i m i l a r replacement e x e r c i s e s implemented on a sample o f 11 kV f e e d e r s i n B l a n t y r e and Lilongwe, i n terms of t h e number o f t r a n s f o r m e r s t o be purchased f o r each f e e d e r and l e a d i n g t o t h e development o f an o v e r a l l percentage o f t h e i n s t a l l e d c a p a c i t y on t h e sample feeders whlch needs t o be purchased, s p l i t i n t o 50 kVA, 100 kVA, 200 kVA and 500 kVA u n i t s i z e s . These percentages a r e then a p p l i e d t o t h e t o t a l e x i s t i n g 1110.4 kV t r a n s f o r m e r c a p a c i t y on t h e i n t e r c o n n e c t e d system, t o produce e s t i m a t e s o f the number o f u n i t s f o r each s i z e r e q u i r e d f o r budgeting purposes. This r e s u l t s i n an estimated M K 2.8 m requirement f o r new d l s t r i b u t i o n transformers, whlch i s I n c l u d e d i n t h e t o t a l package summarised a t the end o f t h e r e p o r t . 4.4.3 C a o i t a l i s a t i o n o f Transformer Losses The t r a n s f o r m e r c a p i t a l i s a t l o n f o r m u l a used by ESCOM t o assess a l t e r n a t i v e transformer s i z e s I n terms o f losses r e q u i r e s some m o d i f i c a t i o n i n view o f t h e l o n g r u n marginal c o s t s o f power and energy which have been c a l c u l a t e d as p a r t o f t h i s study. The present formula used by ESCOM i s as f o l l o w s : ' Ck + Cw Top (MklkH y e a r ) (MklkH y e a r ) where a = assessment o f l o s s e s per year PO - no l o a d losses P1 P load losses Ck P W demand c o s t , Mk 333.00lkH k cw I kwh energy c o s t , Mk 0.07lkWh  CV = cash value f a c t o r , based on 25 years a t 15% Top = o p e r a t i n g hours, 8760 per y e a r 0 = coincidence f a c t o r , 0.95 S E kwh l o s s f a c t o r , 0.33 Mr = capac It y f a c t o r , 0.65 I t i s recommended t h a t the f o l l o w i n g values are used f o r analyslng 1110.4 kV transformers: Marglnal c o s t o f power: 527.98 MKlkH Marginal c o s t o f energy: 0.045 MK/kWh I n a d d l t l o n i t I s f e l t t h a t f o r long term a n a l y s i s the discount r a t e o f 15% p r e s e n t l y used I s somewhat t o o h i g h , and t h a t a value o f 10% would be more appropriate, as used I n t h e economic analysis performed i n t h i s study. 4.4.4 LV Feeder Losses (a) Present Losses A number o f sample LV systems were monitored i n B1antyre and L i longwe, us ing "Dranetz" demand analysers mounted alongside the 11 kVl0.4 kV transformer supplying t h e system, I n order t o measure d i r e c t l y the LV phase voltages and c u r r e n t s . H h l l s t the "Dranetz" was connected a t each transformer under i n v e s t i g a t i o n , measurements o f currents and voltages a t various p o i n t s on t h e LV systems suppl !ed from the transformer were recorded, together w l t h d e t a i l s o f feeder lengths and conductor sizes obtained by a l i n e crew carry1ng o u t a physical survey. Thi s Informatlon was used as the basis o f a f u l l t h r e e phase l o a d f l o w , t o determine e x l s t l n g l o s s l e v e l s , and t o ' assess l o s s r e d u c t i o n measures. Figure 4.20 shows the demand p r o f i l e obtained f o r the 315 kVA Browns Road transformer, which i s s u p p l i e d from the B l a n t y r e Main feeder 5L5. The p l o t shows t h a t the Browns Road transformer i s not I n f a c t t y p i c a l of t h e 5L5 feeder as a whole, i n t h a t I t suppll es a predoml n a n t l y commercl a1 load which peaks a t about 10:00, w i t h no significant load Increase a t the time o f the o v e r a l l system peak. The power f a c t o r p r o f i l e o f Figure 4.21 shows siml l a r character1 s t ics t o those observed f o r o t h e r commerci a1 feeders, w i t h I n c r e a s i n g power  f a c t o r d u r l n g t h e evening, b u t w i t h lower power f a c t o r s d u r l n g t h e day due t o a i r condl t i o n l n g and o t h e r motor loads a s s o c i a t e d w i t h some v e r y small I n d u s t r i a l consumers. The average phase v o l t a g e p r o f l l e shown i n F i g u r e 4.22 shows I n d i c a t i o n s o f t a p c h a n g i n g f u r t h e r up i n t h e system, coupled w l t h t h e e f f e c t s o f l o c a l l o a d changes. The v o l t a g e a t t h e t r a n s f o r m e r end o f t h e LV system I s m a i n t a i n e d between 226 and 237 V, whlch I s w l t h i n t h e t o l e r a n c e p e r m i t t e d by ESCOM o f p l u s and-minus 6% on t h e noml n a l 230 V supply. F i g u r e 4.23 shows a p l o t of. t h e demand on each phase o f t h e Browns Road t r a n s f o r m e r d u r l n g t h e m o n i t o r i n g p e r i o d , and I n d i c a t e s q u i t e s l g n l f l c a n t Imbalance between t h e t h r e e phases I n terms o f 1oadi ng , p a r t 1c u l a r l y around t h e peak demand p e r i o d s , when t h e b l u e phase I s loaded t o t y p i c a l l y o n l y 60 - 70% o f t h e l o a d on t h e o t h e r two phases. T h i s I s r e f l e c t e d i n t h e v o l t a g e s measured a t t h e ends o f t h e LV feeders, whlch showed d l f f e r e n c e s o f up t o 17 V between t h e v o l t a g e on t h e r e d and y e l l o w phases and t h a t on t h e b l u e phase, r e s u l t i n g I n phase v o l t a g e s t o consumers which a r e o u t s l d e t h e ESCOM s t a t u t o r y 1 l m l t. D e t a l l e d three-phase a n a l y s i s has been performed f o r four LV systems u s i n g a computer spreadsheet model t o c a l c u l a t e t h e power l o s s I n each s e c t i o n o f t h e c i r c u i t between s e r v i c e s , and t o assess t h e approximate losses occurring In the services themselves. The percentage energy l o s s e s c a l c u l a t e d f r o m t h e a n a l y s i s o f two 'average' LV systems and two ' p o o r ' LV systems a r e shown i n Table 4.21. These i n d i c a t e a range o f values f r o m 3.6% t o 7.8% l o s s e s , t o g e t h e r w l t h mlnimum f e e d e r v o l t a g e s whlch a r e I n a l l cases below t h e s t a t u t o r y 6% d e v i a t i o n f r o m 230 V perm1 t t e d by ESCOM. (b) Loss Reduction The maln l o s s reduction s t r a t e g i e s whlch have been cons1 dered f o r Imp1ementation on t h e sys tem LV systems comprlse t h e b a l a n c i n g of LV l o a d s t o reduce t h e l a r g e d i f f e r e n c e s i n c u r r e n t s between t h e phases, which a r e observed I n many g f t h e LV systems, and t h e i n t r o d u c t i o n o f a new 150 sq mm conductor a t l o w v o l t a g e on t h e overhead l i n e l e n g t h s c a r r y i n g t h e maln feeder c u r r e n t s . In a d d i t i o n , d e s i g n guldes f o r t h e selection o f LV conductor s l z e s have been prepared, b o t h i n terms of l o s s e s and o f v o l t a g e performance o f each conductor a g a l n s t power t r a n s f e r 1eve1 and f e e d e r 1ength.  Figures 4.24 and 4.25 show conductor o p t l m l s a t l o n curves which have been developed f o r t h e 400 V systems on t h e ESCOM network, based on t h e f i f t e e n year a n a l y s i s o f losses and using t h e Southern Region average annual demand growth r a t e o f 8.5%. together w i t h t h e marginal costs o f energy and power, the l a t t e r being t h e 527.98 MKIkW f l g u r e which a p p l i e s a t LV. These I n d l c a t e t h a t f o r new l i n e s , loads above approximately 28 kVA should be suppl l e d using a 150 sq mm conductor. I n t h e case o f reconductoring, thresholds a r e i n d i c a t e d a t 27 kVA f o r r e p l a c i n g 50 sq m m conductors by the 150 sq mm s i z e and 56 kVA f o r upgrading f r o m 100 sq mm t o 150 sq mm. Table 4.22 s u m a r i s e s the conductor parameters and c o n s t r u c t i o n costs whl ch apply a t LV. The f u l l l i n e construction costs have been assumed for reconductoring, t o a l l o w f o r any p o l e / l n s u l a t o r replacement t h a t may be necessary i n t h e reconductoring process. These reconductori ng and design load1 ng thresholds a r e sumnarised below, together w i t h t h e r e s u l t s of f u r t h e r a n a l y s i s which was performed t o examine the e f f e c t o f a p p l y i n g seven y e a r s ' l o a d growth and then h o l d i n g t h e load l e v e l constant f o r a f u r t h e r e i g h t years, t o r e f l e c t t h e p o s s i b l e i n t r o d u c t i o n of addl t i o n a l transformers (LV systems whl ch would tend t o l i m i t the growth of e x i s t i n g systems. L ~ z Year 7 15 Year Growth Growth I V Reconduc t o r 1ng 7 Year 15 Year Growth Growth I t i s considered t h a t t h e 7 year growth f i g u r e s represent a more r e a l i s t i c load growth scenario, and should therefore be adopted as design thresholds. Figures 4.26 t o 4.28 show power c i r c l e diagram p l o t s f o r 50, 100 and 150 sq m m conductors which represent t h e maximum l o a d t h a t could be supplied a t 0.95 power f a c t o r ( a t y p i c a l power f a c t o r a t peak load associated w i t h the ESCOM LV systems) over 1 km f o r each conductor size. The l e v e l s may be e s t a b l i s h e d from t h e intersection of t h e 0.95 power factor line and the power circles corresponding t o t h e d e s i r e d maximum v o l t a g e drop  which may be t o l e r a t e d i n t h e l i n e . A l l of the curves assume a maxlmum v o l t a g e o f 105% o f nominal a t t h e t r a n s f o r m e r LV t e r m l n a l s , so t h a t a 10% v o l t a g e drop over t h e l e n g t h of t h e 1 l n e may be accepted w h i l s t e n s u r i n g t h a t t h e 6% s t a t u t o r y 1 l m l t on undervol tage a t t h e consumers ' preml ses i s not Infringed. W - km 1i m i t s a p p l y f r o m these The f o l l o w i n g k curves for t h e t h r e e conductors considered assuming a 0.95 power f a c t o r and a 10% maximum v o l t a g e drop. These 1i m l t s may be a p p l i e d t o determine t h e t e c h n i c a l l o a d i n g l i m i t f o r conductors I n terms o f v o l t a g e drop, i n o r d e r t o d e f i n e maxlmum LV system l e n g t h s f o r s p e c i f i c l o a d i n g s . For example, a 100 sq mm conductor may be used t o supply up t o 42 k W over 1 km, or 84 k W over 500 m y 168 k W o v e r 250 my etc. I t should be noted t h a t these f i g u r e s r e p r e s e n t t e r m i n a l l o a d i n g l e v e l s , l e . loads lumped a t t h e remote end o f a g i v e n l e n g t h o f l i n e . I n t h e case o f d i s t r l b u t i o n 11nes these t h r e s h o l d s a r e usual l y a p p l i e d I n c o n j u n c t i o n w i t h t h e l o a d moment o f t h e feeder, i e . t h e sum o f t h e p r o d u c t s o f loads and d i s t a n c e s f r o m t h e t r a n s f o r m e r , t o produce an e q u i v a l e n t d i s t a n c e a t which t h e t o t a l t r a n s f o r m e r l o a d may be appl l e d t o g i v e an i n d i c a t i o n of t h e v o l t a g e performance o f t h e l i n e . LV r e c o n d u c t o r l n g a n a l y s i s has been performed f o r sample LV systems on the basis of the reconductor ing curves and t h e c l r c l e diagrams t o i d e n t i f y cases where 150 sq m m c o u l d be used t o reduce losses and improve t e c h n i c a l performance o f LV c i r c u i t s . Table 4 . 2 3 shows the d e t a i l e d r e s u l t s of technical and economical analysis of r e c o n d u c t o r i n g i n accordance w i t h t h e conductor o p t i m l s a t i o n curves c a r r i e d o u t on t h e Browns Road LV c i r c u i t which was analysed i n t h e assessment o f e x i s t i n g l o s s l e v e l s . This i n d i c a t e s t h a t 390 ffi o f 100 sq m m conductor should be r e p l a c e d by t h e new 150 sq m m size. 'The t a b l e shows t h e losses and minimum v o l t a g e s a s s o c i a t e d w i t h o p e r a t i o n i n t h e y e a r s 1990, 1991 and 2005. I n o r d e r t o r e p r e s e n t a r e a l i s t i c s i t u a t i o n , i t has been assumed t h a t t h i s LV feeder would be used t e supply a l o a d up t o a p r o p o r t i o n o f t h e t r a n s f o r m e r r a t i n g equal t o t h e p r e s e n t p r o p o r t i o n of t h e t r a n s f o r m e r maximum demand which i t c a r r i e s . I t i s t h e n assumed t h a t f u t u r e demand growth beyond the transformer r a t i n g would be catered f o r by a separate LV system and transformer. Thls prevents a n a l y s i s I n 2005 from being c a r r i e d o u t on a scenario I n whlch the feeder would n o t be capable of operation. These r e s u l t s show an i n i t i a l r e d u c t i o n I n energy losses from 4.7% t o 3.1% f o l lowing reconductoring, w i t h an improvement i n the minimum feeder voltage t o 202 V . This minimum voltage would be f u r t h e r Improved by a d j u s t i n g the transformer t a p t o i t s +5% s e t t i n g Instead o f i t s nominal s e t t i n g as a t present. Thls i s a measure which i s recommended f o r implementation across the whole system, as during the survey work i t was discovered t h a t t h e vast major1 t y o f the d l s t r i b u t i o n transformers are o p e r a t i n g a t nominal t a p i n s i t u a t i o n s where low LV voltages are nevertheless a problem and the cause o f complaints f r o m consumers. By 2005 the losses on the Browns Road c i r c u i t under i c v e s t l g a t i o n w i l l have d e t e r i o r a t e d t o 4.8%. w i t h a minimum voltage o f 188 V. Economic a n a l y s i s using streams o f losses based on these r e s u l t s show an I n t e r n a l r a t e o f r e t u r n o f 19.3% f o r t h l s reconductorfng p r o j e c t , assessed I n terms o f an i n t e r n a t i o n a l budgetary c o s t of MK 46,105 per km for the c o n s t r u c t i o n o f a 150 sq mm LV l l n e . Thls demonstrates t h a t reconductoring c a r r i e d o u t on the bas1 s o f the conductor o p t i m i s a t i o n techniques described above represents an economically v i a b l e approach t o loss r e d u c t i o n on the LV systems. Reconductorlng requirements have been assessed f o r a number o f sample feeders on the LV systems, i n order t o e s t a b l i s h an approximate percentage o f t h e overall LV feeder lengths which should be reconductored, and t o c a l c u l a t e a budgetary allowance f o r such an undertaking i n the loss reduction project. The r e s u l t s o f t h l s a n a l y s i s are shown i n Table 4.24, i n d i c a t i n g an average figure of 34% o f the LV network t o be reconductored. The t o t a l LV length i n the interconnected system i n 1990 was 1597 km, reconductorl ng 34% o f whi ch represents a budgetary expenditure o f MK 24.9 m, whlch has been included I n the o v e r a l l budget presented a t the end o f t h i s report .  A f i v e y e a r programme is proposed f o r t h e assessment of the detai led r e c o n d u c t o r l ng requirements o f each LV system and c a r r y i n g o u t t h e r e c o n d u c t o r l n g work. 'The "Dranetz" a n a l y s e r r e s u l t s o b t a i n e d d u r i n g t h e measurements c a r r i e d o u t on t h e Browns Road LV system in d l c a t e d t h a t a t peak t r a n s f o r m e r load1 ng t h e c u r r e n t d i s t r i b u t i o n between t h e r e d , y e l l o w and b l u e phases on c i r c u i t 1 was 224A, 226A and 155A r e s p e c t i v e l y . Thi s phase imbalance I n e v i t a b l y c o n t r i b u t e s b o t h t o t h e l e v e l of l o s s e s on t h e f e e d e r and t o t h e e f f e c t o f reduced s u p p l y v o l t a g e a t t h e remote ends o f t h e system. I n order t o q u a n t i f y t h e r e d u c t l o n I n l o s s e s and Improvement I n minimum v o l t a g e whlch c o u l d be achieved by b a l a n c l n g t h e phase c u r r e n t s , t h e t h r e e phases l o s s calculation whlch was carried out for the reconductored system In 1991, as summarl sed above, was repeated assuming an equal s h a r i n g o f t h e l o a d c u r r e n t between t h e phases. The r e s u l t s o f t h l s Indlcate the following: A d d i t i o n a l r e d u c t l o n I n energy l o s s e s from 3.1% t o 2.9%. Improvement I n minimum v o l t a g e f r o m 202 V t o 207 V. Thl s c l e a r l y demonstrates t h e degree of Improvement which may be o b t a i n e d by addressing t h e b a l a n c l n g of loads on t h e LV system, an e x e r c i s e whlch I s q u l t e s t r a i g h t f o r w a r d t o implement, as i t g e n e r a l l y o n l y r e q u i r e s t h e t r a n s f e r o f consumer s e r v i c e s f r o m one phase t o a n o t h e r on t h e overhead LV systems I n order t o o b t a i n a more equal d i s t r l b u t l o n o f . l o a d between t h e phases. It I s recommended t h a t ESCOM should address t h l s measure as a h i g h p r i o r i t y , g i v e n t h a t i t I n v o l v e s minimal cap! t a l expend1 t u r e and c o u l d be e f f e c t i v e l y Implemented by one l i n e crew addresslng each o f t h e LV systems i n t u r n . 4.4.5 1110.4 kV Transformer and LV Loss O o t i m l s a t l o n The measures dlscussed above a l l r e p r e s e n t t e c h n i c a l l y and e c o n o m i c a l l y v i a b l e ways of r e d u c i n g t h e l e v e l o f losses a s s o c i a t e d w i t h 11 kV/LV t r a n s f o r m a t i o n and LV d i s t r i b u t i o n , which c u r r e n t l y account f o r some 6% o f t h e energy d e l i v e r e d t o t h e 11 kV/LV t r a n s f o r m e r s . The sample s t u d i e s performed I n d l c a t e t h a t t h l s l o s s l e v e l can be reduced t o n e a r e r 4% by t h e I n t r o d u c t i o n o f 150 sq mn overhead conductors on t h e e x i s t i n g LV networks, t h e b a l a n c i n g o f LV l o a d s and t h e replacement o f t r a n s f o r m e r s I n accordance w i t h o p t i m a l l o a d i n g . strategies. I n o r d e r t o f i n a l i s e i n d e t a i l t h e l o s s r e d u c t i o n investment programme based on these measures, as we1 1 as t o o b t a i n f u r t h e r r e d u c t i o n s i n losses and t o f u l l y implement t h e d e s i g n c r i t e r i a which have been presented f o r t h e r e d u c t i o n of v o l t a g e drops on the LV system, a fully c o o r d i n a t e d approach t o t h e r e c o n f i g u r a t i o n o f each 11 kV feeder and i t s a s s o c i a t e d LV networks i s r e q u i r e d . T h i s should I n c l u d e t h e o p t i m i s a t i o n o f d i s t r i b u t i o n t r a n s f o r m e r placement, LV f e e d e r l e n g t h s and t h e open p o i n t s between LV systems. I t sho~bld a l s o i n c l u d e d e t a i l e d assessment for each LV feeder i n terms of how much of t h e f e e d e r i s t o be reconductored. A l l o f t h e above r e q u i r e t h e c o m p i l a t i o n o f t h e comprehensive model of each 11 kV feeder, i n c l u d i n g 11 kV/LV t r a n s f o r m e r s and LV networks, which can then be examined I n t h e c o n t e x t of a detailed d i s t r i b u t e d load forecast t o e s t a b l i s h the technical and economic v i a b i 1 i t y of techniques t o be used i n p l a n n i n g t h e development o f t h e system a t t h i s l e v e l i n such a way as t o ensure t h a t losses c o n t i n u e t o be minimised. I t i s envisaged t h a t t h e most e f f e c t i v e way o f o r g a n i s i n g t h i s r e v i e w would be by means of an i n i t i a l p e r i o d of c o n t i n u e d d a t a c o l l e c t i o n which would be c a r r i e d o u t by ESCOM i n e x a c t l y t h e same way as has been s u c c e s s f u l l y used i n o b t a i n i n g t h e necessary i n f o r m a t i o n for t h e sample a n a l y s i s c a r r i e d o u t f o r t h e Loss Reduction Study. The DPAS s o f t w a r e which has a l r e a d y been i n s t a l l e d i n ESCOM's o f f i c e s would be used for t h e a n a l y s i s , which would be s t a r t e d by means, o f a d e t a i l e d examination o f t h e measures r e q u i r e d t o o p t i m i s e t h e LV networks associated w i t h a number o f 11 kV f e e d e r s s u p p l y i n g d i f f e r e n t l o a d types. T h i s would be undertaken d u r i n g a p e r i o d of approximately one month, d u r i n g which a d i s t r i b u t i o n p l a n n i n g e x p e r t would work w i t h ESCOM's C e n t r a l P l a n n i n g U n i t i n Malawi s p e c i f i c a l l y on t h i s area of system o p t i m i s a t i o n . This would e s t a b l i s h t h e process f o r e n s u r i n g t h a t n o t o n l y a r e t h e requirements for each LV system f u l l y defined, b u t t h a t a1 so these measures a r e combined w i t h o p t i m a l t r a n s f o r m e r placement and LV system reconf ig u r a t i o n c o n s i d e r a t i o n s t o f u r t h e r reduce losses and d e f i n e system p l a n n i n g procedures a t t h i s l e v e l w i t h a view t o c o n t i n u e d l o s s r n i n l m i s a t l o n . The l e v e l o f s k i l l i n ESCOM's C e n t r a l P l a n n i n g U n i t i s such t h a t b o t h these areas o f work can undoubtedly be completed independently, once procedures f o r so d o i n g have been established. A b r i e f v i s i t from the d i s t r i b u t i o n planning s p e c i a l i s t , eg approximately one week, would then t a k e p l a c e t o r e v i e w and summarise the f i n d i n g s o f t h e d e t a i l e d s t u d y i n such a way as t o enable t h e d e t a i l s o f t h e .LV l o s s r e d u c t i o n p r o j e c t s t o be d e f i n e d . A budget a l l o c a t i o n o f US$ 45,000 i s I n c l u d e d I n t h e package of l o s s r e d u c t i o n measures t o enable t h i s stage of t h e p r o j e c t d e f i n i t i o n t o be completed on t h e b a s i s described above. Some p r e l i m i n a r y a n a l y s i s has been c a r r i e d o u t t o examine t h e comparison between LV r e c o n d u c t o r i n g and the r e d u c t i o n o f LV feeder lengths through the placement of additional t r a n s f o r m e r s , i n terms o f t h e r e l a t i v e c o s t e f f e c t i v e n e s s o f the two approaches. Studies have been performed on t h e bas1 s o f an ex1 s t i n g 315kVA I l k V / L V transformer s u p p l y l n g a 145kW l o a d w i t h a l o a d f a c t o r o f 54% and a l o s s f a c t o r of 37%, s u p p l y i n g two LV systems w l t h 100 sq mm AAC conductors. Figures 4.29 and 4.30 show t h e r e s u l t s o f a f i f t e e n year a n a l y s i s w i t h a growth r a t e of 8.5%. F i g u r e 4.29 shows t h a t t h e lowest o p e r a t i n g c o s t s r e s u l t from 50% r e c o n d u c t o r i n g on LV feeders w l t h no cons1 d e r a t i o n o f add1 t l o n a l t r a n s f o r m e r s . F i g u r e 4.30 demonstrates t h a t 50% r e c o n d u c t o r i n g r e s u l t s i n t h e lowest o p e r a t i n g costs on LV l i n e s of up t o 550 m l e n g t h , b u t t h a t a t t h i s l e n g t h i t i s m ~ r eeconomic t o i n t r o d u c e a second transformer, w i t h t h r e e transformers being t h e cheapest o p t i o n f o r a l e n g t h o f g r e a t e r than 800 m. A n a l y s i s o f t h e s c e n a r i o w i t h seven years l o a d growth i s shown I n Figures 4.31 and 4.32 i n d i c a t i n g t h a t 25% I s t h e optlmum r e c o n d u c t o r i n g l e v e l , and t h a t r e c o n d u c t o r l n g represents the most economlc o p t i o n f o r LV f e e d e r s o f up t o 750 m I n length. These r e s u l t s show t h a t f o r LV feeders con'structed i n accordance w l t h ESCOM's p o l i c y of 500 m maximum LV feeder l e n g t h s , r e c o n d u c t o r l n g I s l l k e l y t o p r e s e n t t h e most economlc l o s s r e d u c t i o n measure. For l o n g e r feeders t h e i n t r o d u c t i o n o f a d d i t i o n a l transformers should be considered on a feeder by feeder b a s i s , u s i n g l e n g t h g u i d e l i n e s produced from a n a l y s i s such as t h a t shown here. I t I s t h i s t y p e o f e x e r c i s e which I t I s envisaged should f o r m p a r t of t h e LV system study recommended above. For t h e m a j o r i t y o f LV feeders on t h e ESCOM system however, I t i s l i k e l y t h a t r e c o n d u c t o r i n g w i l l prove t h e optimum l o s s r e d u c t i o n method.  SECTION 5 KIM-TECHNICAL LOSSES 5. WOW-TECHNICAL LOSSES 5.1 Introduction The i n v e s t i g a t i o n o f non-technical losses has concentrated on I d e n t i f y i n g sources of e r r o r s i n t h e ESCOM system whlch r e s u l t I n I n c o r r e c t records of generated and s o l d e l e c t r i c a l power and energy being o b t a i n e d . These can r e s u l t from s t r a i g h t f o r w a r d i n a c c u r a c i e s i n kwh and kW/kVA metering, problems o f i n c o r r e c t m e t e r i n g i n s t a l l a t l o n , o r , I n some cases, d e l l b e r a t e tamperlng w l t h connections by consumers. S i m i l a r l y , i n t h e event o f t h e r e b e i n g any confusion o v e r , f o r example, t h e appl l c a t l o n o f meter f a c t o r s by meter readers o r w l t h l n t h e b i l l i n g system, t h i s could I n t r o d u c e p o t e n t i a l sources o f b i l l l n g Inaccuracy. The In v e s t i g a t l o n s o f non-technl c a l losses i n c o r p o r a t e d in t h l s p r o j e c t commenced w l t h a comprehensive s e r i e s of checks on t h e m e t e r l n g i n s t a l l a t l o n s a t the major consumers I n B l a n t y r e and Lilongwe c a r r l e d o u t by a KDP m e t e r i n g s p e c i a l l s t and h i s ESCOM c o u n t e r p a r t d u r i n g t h e f i r s t f o u r week KDP s l t e v l s l t . ThIs work was then continued by ESCOM d u r l n g t h e p e r i o d p r i o r t o t h e second s l t e v l s l t , t o enable a l a r g e r sample of consumer i n s t a l l a t i o n s t o be checked. Each major consumer's premises was v i s i t e d and a "Dranetz" power demand analyser was connected t o t h e Incoming v o l t a g e and c u r r e n t s u p p l i e s t o t h e kwh meter. The "Dranetz" was a b l e t o r e c o r d a c c u r a t e l y t h e energy s u p p l i e d over a g l v e n p e r i o d t o t h e consumer, t a k l n g due cognlsance o f c u r r e n t and v o l t a g e t r a n s f o r m e r r a t l o s , i f appl l c a b l e . This measurement was then compared w i t h t h e energy recorded by t h e consumer's meter. Each t e s t was c a r r i e d o u t over a p e r i o d o f t y p i c a l l y several hours, t o ensure t h a t any s l l g h t e r r o r I n t h e p h y s i c a l r e a d l n g o f t h e kwh meter would n o t have a s i g n i f i c a n t e f f e c t on t h e c a l c u l a t i o n o f t h e meter accuracy. W h i l s t t h e "Dranetz" m o n i t o r i n g was i n progress, a number o f checks r e l a t i n g t o t h e consumer's meter i n s t a l l a t i o n were c a r r i e d o u t , t o i d e n t i f y any obvlous signs o f tamperlng, connection e r r o r s e t c . whlch would l n d l c a t e p o t e n t l a l non-technical losses. Where p o s s l b l e , t h e "Dranetz" connections a t each meter1 ng i n s t a l l a t l o n were made I n such a way as t o g i v e a m e t e r i n g check whlch was Independent of c u r r e n t transformer accuracy, so t h a t as much of t h e i n s t a l l a t i o n as p o s s l b l e was t e s t e d f o r sources o f e r r o r . 'The r e s u l t s o f , the "Dranetz" checks were used t o c a l c u l a t e an o v e r a l l percentage accuracy f o r t h e kwh meter, which was compared w i t h t h e s t a t u t o r y accuracy l i m i t s o f p l u s and minus 2 . 5 % permi t t e d by ESCOM.  S i m i l a r accuracy checks were c a r r i e d o u t on t h e energy meters a t the Nkula and Tedzanl power s t a t i o n s , t o a u d l t the figures f o r t o t a l annual generated MWh and auxl 1i a r y energy consumption which are used as t h e basis f o r the annual energy l o s s calculation. D e t a i l s o f the r e s u l t s o f t h e i n v e s t i g a t i o n s o f both consumer and generator meterlng accuracy are given below. Tests were a l s o c a r r i e d o u t on t h e accuracy o f the meter t e s t and c a l i b r a t i o n f a c i l i t i e s used by ESCOM, as these are c l e a r l y o f c r i t i c a l importance I n determining the accuracy o f meters whlch are i n s t a l l e d i n the power s t a t i o n s and a t consumers' premises throughout the system. I n para1 l e l w i t h the metering checks which were performed, the I n v e s t i g a t i o n and d e t e c t i o n procedures employed by ESCOM i n l o o k i n g f o r sources o f non-technical losses i n the system have been examined. The r e s u l t s o f t h i s analysis a r e described below, together w i t h recommendations f o r reducing non-techni c a l losses and the associated f i n a n c i a l and economic a n a l y s l s o f t h e measures proposed. 5.2 H e t e r i ng Accuracy 5.2.1 Generator Meters Table 5.1 shows t h e r e s u l t s o f generator metering accuracy checks whlch were c a r r i e d o u t d u r i n g the course o f t h e p r o j e c t . I t w i l l be observed from t h i s t h a t the accuracy o f the meters on a number of the generator u n i t s was found t o be o u t s i d e the s t a t u t o r y 2.5% t o l e r a n c e . The o v e r a l l e r r o r on generator metering a t Nkula and Tedzani was found t o be an over-read o f 2.7%. 1 .e. the generator metering i s I n d i c a t i n g t h a t more energy I s belng generated than I s i n f a c t the case. This w i l l lead t o an a r t l f l c l a l l y h i g h estimate o f the losses associated w i t h the r e s t o f t h e system when t h e generator meterlng f i g u r e s are used as the basis f o r comparing generated energy w i t h sold energy. I t i s recommended t h a t those meters whlch are o u t s i d e the s t a t u t o r y accuracy l i m i t s be replaced and r e c a l i b r a t e d i n t h e meterlng s e c t i o n p r i o r t o belng placed elsewhere on t h e system, and t h a t f o r the o t h e r meters readings a r e c o r r e c t e d before being used as the i n p u t t o l o s s c a l c u l a t i o n s . A1 1 the generator kwh meters should be checked and r e c a l ibrated f r e q u e n t l y , t o ensure t h a t c o r r e c t metered energy f i g u r e s are included i n the system s t a t i s t i c s . 5.2.2 Meterina a t I n d u s t r i a l Consumert The r e s u l t s o f the summary o f metering a t i n d u s t r i a l consumers' premises are shown I n Table 5 . 2 .  The r e s u l t s may be considered b o t h I n terms o f t h e accuracy o f t h e meter and t h e o v e r a l l m e t e r i n g system accuracy, which I n c l u d e s c u r r e n t t r a n s f o r m e r s , i n t e r p o s i n g transformers and voltage transformers. The general philosophy of t h e meter accuracy t e s t s was t o m o n i t o r t h e complete m e t e r i n g system o f t h e i n s t a l l a t i o n wherever p o s s i b l e and t o e s t a b l i s h c o r r e c t CT and VT r a t i o s wherever access i s 1 i m i t e d . The i n d u s t r i a l consumer meters were g e n e r a l l y found t o be o p e r a t i n g w i t h i n s t a t u t o r y accuracy l i m i t s , as can be seen f r o m Table 5.2. The l a r g e e r r o r s shown were due t o o t h e r reasons, as discussed below f o r t h e i n d i v i d u a l cases. The d i s c u s s i o n i s Intended t o p o i n t o u t some o f t h e problems i n m e t e r i n g and h e l p t o e l i m i n a t e such occurrences i n m e t e r i n g systems i n f u t u r e instal lations. A a r l c u l t u r e Research O f f i c e (LV m e t e r i n a ) 'The m e t e r i n g system was found t o be o p e r a t i n g w i t h one o f t h e v o l t a g e leads disconnected from t h e fuse h o l d e r which was sealed. Loose connections were a l s o found i n other I n s t a l l a t i o n s b u t t h e v o l t a g e leads were i n p o s i t i o n . For an LV I n s t a l l a t i o n t h i s could r e s u l t i n an e r r o r i n t h e r e g i o n o f 113 under-read. For an l l k V i n s t a l l a t i o n t h e discrepancy would depend on t h e disconnected phase, as t h e power f a c t o r s could v a r y w i d e l y between phases. Extruders L t d (LV meterina) P i ~ e The m e t e r l n g e r r o r was due t o a reversed CT connection. This would n o r m a l l y r e s u l t I n t h e m e t e r i n g system r e c o r d i n g about 113 of t h e t r u e energy f o r a balanced load. I f the load I s unbalanced t h e e r r o r c o u l d be more o r l e s s than t h i s depending on t h e r e l a t i v e phase l o a d i n g . The Staae Coach (LV meterina) A t t h l s i n s t a l l a t i o n I t was found t h a t t h e b l u e phase was by-passlng t h e meter. The f i g u r e o f 19.3% under-read i n d i c a t e s t h a t t h i s phase was c a r r y l n g l e s s load than t h e o t h e r phases. There were two metering s e t s f o r t h i s i n s t a l l a t i o n , one f o r each s i d e o f t h e s e c t i o n a l i s e d busbar. One side o f t h e busbar was comparatively h e a v i l y loaded w h i l e t h e o t h e r was c a r r y i n g a f r a c t i o n o f t h e load. Meter No. 1 was monitoring t h e m a j o r i t y of t h e load w h i l e t h e d l s k of meter No. 2 .was j u s t creeping. I t I s understood t h a t t h i s i s t h e normal o p e r a t i n g mode o f t h e a i r p o r t system.  Tests c a r r i e d o u t on Meter No.1 revealed a 47.5% meterlng system under-read e r r o r . The t r u e energy u n i t s were t h e r e f o r e 1.89 times t h e metered values. A p o s s i b l e reason f o r t h l s could be a wrong CT r a t i o o r t a p p o s i t i o n i n s i d e t h e meter. The kVAh meter was w l t h i n accuracy. Tests on meter No.2 under f u l l a l r p o r t load revealed a metering e r r o r o f 46.14% comparable t o t h a t of meter No.1. 'The kVA meter e r r o r was w i t h i n l l m l t s . During normal o p e r a t l ng condi t l o n s however Meter No.2 I s suppl l e d w l t h very I 1t t l e CT secondary c u r r e n t , o p e r a t l ng o u t s l d e guaranteed accuracy 1 lmi t s . Thl s r e s u l t s I n f u r t h e r accuracy e r r o r s . For c l a r i f i c a t i o n consider t h e energy recorded between August 1989 and August 1990. k Wh kVAh kWh/kVAh Meter No. 1 2005900 4685300 0.43 The power f a c t o r o f t h e load according t o measurements was 0.99 and f o r t h e purposes of t h l s exercise we w i l l consider it as 1. As can tie seen, w h i l e f o r Meter No. 1 t h e kWh meter recorded approximately h a l f of t h e kVAh f i g u r e , Meter No. 2 recorded 0.13 times the kVAh f i g u r e . This t r a n s l a t e s i n t o an even higher under-reading e r r o r d u r i n g normal o p e r a t i n g procedures. I t I s recommended t h a t t h e metering system should be changed t o a one meter system w i t h a summation CT. L l mbe Leaf Tobacco Com~any (HV mete r l na) The I n l t l a l meter m o n l t o r l n g t e s t s , which i n c l u d e d the meter and t h e I n t e r p o s i n g CT, revealed a meter accuracy of 1.1% over-read. Fol lowing In v e s t l g a t l o n s I n t o primary transformer and secondary CT c u r r e n t I t was considered necessary t o monitor t h e supply a t t h e 11 kV s l d e . o f the transformers i n o r d e r t o e l i m l n a t e any e r r o r s introduced by the CTs. The o v e r a l l meter t e s t i n g revealed t h a t t h e metering system was under - readlng by 24.5%. The c o r r e c t reading was t h e r e f o r e 1.32 tlmes t h e metered value. A p l a u s i b l e reason f o r t h l s could be t h a t t h e CTs I n one o f t h e phases is 150/5 A as opposed t o 100/5 A as per t h e declared CT nameplate I n s i d e t h e r e l a y panel.  I t I s recommended t h a t t h e CTs be changed as t h e p r e s e n t accuracy o f t h e c a l c u l a t e d c o r r e c t i o n f a c t o r I s dependent o n l o a d balance. Mount Soche Hotel and B l a n t v r e N e t t i n g Both o f these i n s t a l l a t i o n s have meter under-reads o f t h e o r d e r o f 50%, which a r e suspected t o be due t o I n c o r r e c t connections between t h e c u r r e n t transformers and t h e meters. It I s recommended t h a t b o t h o f these i n s t a l l a t i o n s be t h o r o u g h l y examined as a m a t t e r of h i g h p r i o r 1 t y . Table 5.3 summarises t h e r e s u l t s of b o t h t h e g e n e r a t o r and consumer meterlng checks, In d l c a t l n g that the total non-technical losses measured by t h e end o f t h e second s i t e v i s i t accounted f o r n e a r l y 4% of t h e 1989-90 metered energy generation. The revenue which would have been recovered i n 1989-90 by t h e c o r r e c t i o n of t h e major consumer m e t e r i n g e r r o r s shown i n Table 5.2 amounts t o some MK413,OOO. 'This c l e a r l y demonstrates t h e v a l u e of t h e meter checking e x e r c i s e which was c a r r i e d o u t d u r i n g t h e l o s s r e d u c t i o n study, t o g e t h e r w l t h t h e importance t o ESCOM of m a i n t a i n i n g such a programme of checks i n conjunction w i t h the analysis of b i l l i n g information. A f t e r d i s c u s s i o n s w i t h ESCOM concerning t h e l e v e l s o f consumer f r a u d o c c u r r i n g on t h e system, i t was concluded t h a t one method of r e d u c i n g t h e scope f o r making i l l e g a l connections t o t h e meter t e r m i n a l s o r tampering w l t h t h e meter i t s e l f would be t o i n t r o d u c e meter boxes a t each consumer's premises i n t h e domestic, general and small power c a t e g o r i e s . These would be sealed, w l t h a perspex f r o n t t o enable t h e meters t o be read w i t h o u t opening t h e box, and would make tampering i n t h e v l c l n ! t y o f t h e meter e x t r e m e l y d i f f i c u l t . I n t h i s respect the a p p l i c a t i o n of meter boxes r e p r e s e n t s a more e f f e c t i v e s t r a t e g y than t h a t o f u s i n g , for example, socket t y p e meters, s i n c e a1 though t h e l a t t e r a v o i d t h e ease of access t o t e r m i n a l s which I s a problem w i t h c o n v e n t i o n a l meters, i t i s s t i l l p o s s i b l e t o I n t e r f e r e w l t h t h e meter i t s e l f . D e t a i l s o f t h e c o s t s a s s o c i a t e d w l t h meter boxes and t h e proposed method f o r t h e i r i n t r o d u c t i o n a r e g i v e n i n s e c t i o n 5.5 below. I n summary however, t h e e s t i m a t e d c o s t s o f meter boxes and socket type meters, I n c l u d i n g t h e sockets, a r e : Meter Box ( s i n g l e phase) Mk 60 (Local Malawi) Meter Box ( t h r e e phase) Mk 140 (Local Malawi) Socket Type Meter ( s i n g l e phase) Mk 100 (FOB USA) Socket Type Meter ( t h r e e phase) Mk 650 (FOB USA) There I s l i k e l y t o be an a d d i t i o n a l c o s t p e n a l t y I n t h e case o f socket t y p e meters r e s u l t i n g f r o m I n c r e a s e d I n s t a l l a t i o n t i m e as compared w i t h t h e meter boxes, e s p e c i a l l y g i v e n t h e I n t e n t i o n t h a t new consumers should I n s t a l l t h e i r own boxes p r i o r t o h a v i n g a supply connected by ESCOM.  I t I s considered t h a t a more immediate and c o s t e f f e c t i v e r e d u c t i o n I n non-technical losses w i l l be achieved u s i n g t h e meter box approach, whlch w l l l p r o v i d e a v i s i b l e d e t e r r e n t as we1 1 as a reasonable degree o f s e c u r l t y a t t h e most v u l n e r a b l e p o i n t o f t h e metering process. I n addltlon it o f f e r s the a t t r a c t i o n o f u s i n g l o c a l m a t e r i a l s and l a b o u r i n t h e p r o d u c t i o n o f t h e boxes, whlch w l l l be r e q u i r e d I n c o n s i d e r a b l e quantl t y . F i n a n c i a l r a t e s o f r e t u r n f o r t h e a l t e r n a t i v e schemes a r e g l v e n i n s e c t i o n 5.5. 5.2.3 Meter Test BenchAccuracv The r e s u l t s o f t e s t s c a r r i e d o u t t o I n v e s t i g a t e t h e accuracy o f t h e two meter t e s t benches I n B l a n t y r e a r e shown I n Tables 5 . 4 (a) and ( b ) . Tests were c a r r i e d o u t on t h e F o s t e r t e s t bench by connecting t h e "Dranetz" t o t h e bench o u t p u t and r e q u e s t i n g t h e o p e r a t o r s t o s e t t h e bench t o g l v e o u t p u t s o f s p e c i f i e d c u r r e n t s , voltages and power f a c t o r s over a range t h a t would n o r m a l l y be used i n meter t e s t i n g . T h l s bench i s used f o r checklng energy meters by s e t t i n g known values of power as I n p u t t o t h e meters under t e s t , and t h e n t i m i n g t h e d u r a t i o n o f t h e t e s t u s i n g a s t o p watch. The t i m e and power f i g u r e s a r e then used t o c a l c u l a t e t h e energy s u p p l i e d , whlch i s compared w i t h t h e r e a d i n g on each meter. The accuracy o f t h l s procedure I s c r l t l c a l l y dependent on t h e o p e r a t o r ' s s k i l l i n s e t t l n g t h e power l e v e l s , and t h e accuracy of t h e wattmeters and t h e t i m i n g device. With r e g a r d t o s e t t i n g t h e power f a c t o r o f t h e bench o u t p u t , t h e Power f a c t o r meter on t h e bench does n o t f u n c t l o n c o r r e c t l y , so t h a t t h e o p e r a t o r has t o c a l c u l a t e t h e power f a c t o r f r o m r e a d l n g s on v o l t m e t e r s an ammeters, t o e s t a b l i s h t h e power f a c t o r b e i n g used; The r e s u l t s o f t e s t s c a r r i e d o u t on t h i s bench a r e shown i n Table 5 . 4 (a). They i n d i c a t e accuracles o f between 0.4% and 1.6% on t h e I n d l v l d u a l meters o n t h e bench, t o g e t h e r w i t h a range o f accuracles f r o m +1.12% t o -2.74% I n t h e accuracy o f t h e s t a t e d power o u t p u t o f t h e bench I n t h e v a r i o u s t e s t modes. T h l s represents an unacceptably wlde range o f accuracles f o r t e s t l n g purposes, s i n c e t h e p e r m i t t e d meter t o l e r a n c e o f p l u s or minus 2.5% c o u l d p o t e n t i a l l y be added o n t o these f i g u r e s and considered acceptable f o r p l a c i n g o f t h e meter on t h e system. The s k i l l of t h e o p e r a t o r s i n o b t a i n i n g t h l s range o f accuracies i s to be commended however, g i v e n t h e range of accuracies o f t h e Instruments w i t h which they a r e work1 ng . The normal accuracles expected o f t e s t bench equipment a r e as f o l lows: Active Energy Measurements: 0.2%, i .e. c l a s s 0.2 R e a c t i v e Energy Measurements: 0.5%, i . e . c l a s s 0.5 Currents, Voltages, e t c . 1.0%, i .e. c l a s s 1 . 0 I t w l l l be observed t h a t most of t h e r e s u l t s l i s t e d i n Table 5.4(a> exceed these 1 i m i t s . These f a c t o r s coupled w l t h t h e f a c t t h a t t h e bench was purchased secondhand i n 1954 and i s no l o n g e r s u p p o r t e d by t h e m a n u f a c t u r e r i n d i c a t e t h a t a replacement bench s h o u l d be purchased i n t h e l o s s r e d u c t i o n p r o j e c t . The second meter t e s t bench I s a L a n d i s and Gyr model manufactured i n 1972, and i s used I n c o n j u n c t i o n w l t h a r o t a t i n g substandard k i l o w a t t - h o u r meter f o r c a r r y i n g o u t meter checks. The accuracy o f t h i s s t a n d a r d i n s t r u m e n t was checked u s i n g t h e "Dranetz" a n a l y s e r o v e r a range o f t e s t l o a d i n g s . The r e s u l t s o f t h e s e checks a r e shown I n T a b l e 5.4 ( b ) , I n d i c a t i n g a range o f a c c u r a c i e s between 1.19% and 2.66% over-reading on t h e s t a n d a r d meter. Whi 1 s t cons1 s t e n t over-reading w l l l n o t r e s u l t i n increased non-technical losses, i t does r e p r e s e n t p o t e n t i a l use o f meters which a r e o u t s i d e t h e s t a t u t o r y accuracy 1 i m i t s . I t i s t h e r e f o r e recommended t h a t t h i s t e s t bench a l s o be r e p l a c e d . The new t e s t benches s h o u l d be l o c a t e d I n a new meter t e s t room w i t h c a r e f u l l y c o n t r o l l e d e n v i r o n m e n t a l c o n d i t i o n s so t h a t t h e equipment I s n o t s u b j e c t e d t o wide t e m p e r a t u r e ranges, v i b r a t i o n s , d u s t e t c . . t h e r e b y e n s u r i n g t h a t i t s accuracy i s maintained. F u l l t r a i n i n g i n t h e use o f t h e equipment by i t s m a n u f a c t u r e r should a l s o be i n c l u d e d when I t i s i n s t a l l e d . I t i s proposed t h a t t h e e x i s t i n g p o r t a b l e t e s t m e t e r s which a r e used by t h e m e t e r i n g s e c t i o n be r e p l a c e d by e l e c t r o n i c u n i t s . which w i l l have a s t r o n g e r r e s i s t a n c e t o t h e e f f e c t s o f b e i n g t r a n s p o r t e d t o consumer i n s t a l l a t i o n s t h a n i s t h e case w i t h t h e existing rotary units. I n c l u s i o n o f f i f t e e n meters i s recommended, t o be s p l i t between bases i n B l a n t y r e , L i l o n g w e and Mzuzu. The meter t e s t benches which s h o u l d be purchased as p a r t o f t h e l o s s r e d u c t i o n package s h o u l d each be capable o f h a n d l i n g up t o t e n s i n g l e phase o r polyphase meters, and s h o u l d i n c o r p o r a t e a s o l i d s t a t e r e f e r e n c e s t a n d a r d meter which meets t h e a c t i v e and r e a c t i v e energy' c l a s s e s d e t a i l e d above. The r e f e r e n c e s t a n d a r d s h o u l d be capable o f r u n n i n g meter checks e i t h e r by measuring impulses d e t e c t e d by a p h o t o e l e c t r i c head from t h e d i s c o f a s i n g l e m e t e r , o r by s u p p l y i n g a pre-determined amount o f energy t o a b a t c h c f up t o t e n m e t e r s . The bench s h o u l d i n c o r p o r a t e a console o n wh'ch phase c u r r e n t s and v o l t a g e s a r e d i s p l a y e d , t o g e t h e r w i t h t h e necessary c o n t r o l s t o o b t a i n t h e f u l l range o f t e s t c u r r e n t s , v o l t a g e s and power f a c t o r s r e q u i r e d f o r c a r r y t n g o u t meter t e s t s .  The s o l i d s t a t e t e s t meters should be s u f f i c i e n t l y rugged t o enable frequent t r a n s p o r t a t i o n , and should be s u i t a b l e for t e s t i n g both s i n g l e phase and t h r e e phase meters. They should be suppl l e d w i t h sui t a b l e c u r r e n t clamps and voltage connectors t o enable them t o be conveniently connected t o t h e range of meters used by ESCOM. The emphasis of these and t h e t e s t benches should be on t h e p r o v i s i o n o f re1 l a b l e , rugged i n s t r u m e n t a t i o n which performs the basic functions required, r a t h e r than i n c o r p o r a t i n g l a r g e numbers o f unnecessary o p t i o n a l e x t r a s . Manual t e s t benches r a t h e r than f u l l y automati c computer! sed u n l t s a r e reconmended, t o a v o i d unnecessary complication of the meter t e s t i n g procedure. Budgetary amounts have been included I n the l o s s reduction package t o cover the above equipment, as f o l l o w s : - 2 Meter Test Benches : MK 333,000 Meter Test Room MK 80,000 15 S o l i d State Meters : MK 75,000 An a d d i t i o n a l MK 30,000 has been Included t o cover a one week p e r i o d o f t r a i n i n g t o be provided by t h e t e s t bench manufacturer, t o ensure t h a t the ESCOM metering t e c h n l c l a n s a r e f u l l y versed i n the o p e r a t i o n a l procedures r e q u i r e d t o o b t a i n accurate r e s u l t s from the benches. 5.3 B i l l i n g System The mainframe ICL ME29 computer used f o r b i 1l i n g i s l o c a t e d I n ESCOM House, B l a n t y r e and was Introduced here I n 1983. I t has 1MB o f RAM memory, two f i x e d d i s k s of 120 MB each and two exchangeable d l s k d r i v e s w i t h a d l s k c a p a c i t y o f 80 MB each. A d i r e c t data e n t r y and v e r i f i c a t i o n system I s I n o p e r a t i o n through terminals i n B l a n t y r e . I n Lilongwe data i s entered t o the B l a n t y r e mainframe v i a a modem l i n k . Elsewhere data forms are completed by the D i s t r i c t o f f i c e s and sent t o B l a n t y r e Data Processing Section. The computer b i l l i n g system i s designed by a South A f r i c a n company c a l l e d Jack C u r t i s Computer Systems. I t was i n s t a l l e d i n 1983 and covers a l l b i l l i n g a c t i v i t i e s from the e n t r y and v e r i f i c a t i o n o f meter consumption data t o t h e p r i n t i n g o f invoices and the p r o v i s i o n o f management i n f o r m a t i o n r e p o r t s . The main f i l e used for the b i l l i n g system i s the Customer Master F i l e containing records f o r n e a r l y 40,000 consumers. This alone accounts f o r between 60 MB and 70 MB o f d i s k space. Slnce t h e f i e l d work f o r t h i s study was c a r r i e d o u t I t i s understood t h a t ESCOM has purchased two ICL DRS 3000. One I s s l t e d i n Lilongwe and t h e o t h e r i n B l a n t y r e t o r e p l a c e t h e ME29. They a r e t o be used f o r b i l l i n g , s t o c k c o n t r o l , t r a n s p o r t management and p a y r o l l . F u r t h e r t o t h i s a number o f PC's have been purchased o f which n i n e a r e be1 l e v e d t o be f o r b i l l i n g . Given t h e r e c e n t hardware purchases i t I s n o t thought necessary t h a t any f u r t h e r hardware w i l l be necessary t o c a r r y o u t t h e b i l l i n g f u n c t l o n o f ESCOM, and no c o s t f o r hardware has t h e r e f o r e been i n c o r p o r a t e d I n t o t h e f l nanci a1 and economic a n a l y s i s a t t h i s stage. Remote d a t a e n t r y s t a t i o n s i n t h e r e g i o n s would speed t h e p r o c e s s i n g o f b l l l i n g c o n s i d e r a b l y and would a l s o a v o i d t h e need t o complete d a t a e n t r y forms thus p o s s i b l y a v o i d i n g e r r o r s i n t r a n s c r i b i n g t h e d a t a . The s u i t a b i l l t y o f remote d a t a e n t r y s t a t i o n s would depend on t h e a v a i l a b i l i t y o f a r e l i a b l e telephone network and b e f o r e proceeding w i t h t h i s programme ESCOM should ensure that an adequate communciations i n f r a s t r u c t u r e for the t r a n s f e r o f data i s i n place. New b i 11 l n g s o f t w a r e i s a l s o r e q u i r e d t o c a r r y o u t b o t h t h e f u n c t i o n s o f t h e c u r r e n t s o f t w a r e t o g e t h e r w l t h some a d d i t i o n a l f u n c t i o n s t h a t have been i d e n t i f i e d t o be necessary, i n connection with the detection and investigation of non-technical losses. F i r s t l y t h e a b l l i t y t o e n t e r kVAh as w e l l as kwh I s e s s e n t i a l so t h a t t h e b f l l l n g system may a l s o c a l c u l a t e power f a c t o r . T h i s would a c t as a check on t h e m e t e r i n g accuracy o f l a r g e consumers, I d e n t i f y i n g p o t e n t i a l problems w i t h e i t h e r t h e kVAh meter o r w l t h t h e kwh meter. Secondly, simple e n q u i r y f u n c t i o n s need t o be improved. A t t h e moment, f o r example, i t I s o n l y p o s s i b l e t o t r a c e a consumer's account on t h e computer w i t h t h e account number. Tracing a consumer by name I s c a r r i e d o u t by searchlng t h r o u g h p r i n t e d r e c o r d s I n o r d e r t o f i n d t h e account number. New b l l l l n g s o f t w a r e can p r o v i d e a1 1 o f t h e f a c i 11t i e s c u r r e n t l y a v a i l a b l e t o ESCOM and i n a d d i t i o n t o t h i s can p r o v i d e a l l o f t h e f u n c t i o n s necessary t o a modern b l l l l n g system. It i s recommended t h a t a d e t a i l e d s p e c i f l c a t i o n o f t h e b l l l l n g s o f t w a r e be c a r r i e d o u t , however, a budget p r i c e o f MK 1,082,005 has been o b t a i n e d and has been i n c o r p o r a t e d i n t o t h e economic and f i n a n c i a l a n a l y s i s . 'This p r i c e I s based on an e s t a b l i s h e d b l l l i n g package b e i n g t a l l o r e d t o t h e s p e c l f l c needs o f ESCOM and would be undertaken as a c o n s u l t a n c y p r o j e c t i n c l u d i n g progtam development, i n s t a l l a t i o n , t e s t i n g , support and s t a f f t r a i n i n g . O f f - t h e - s h e l f b i l l i n g packages a r e a v a i l a b l e a t a b a s i c c o s t o f a p p r o x i m a t e l y MK 65,000. However, these a r e n o t 11k e l y t o meet a1 1 of ESCOM's requirements and bespoke software would need t o be w r i t t e n . I n a d d i t i o n t o t h i s ESCOM would r e q u i r e i n s t a l l a t l o n , t e s t i n g , d a t a conversion, support and t r a l n i n g .  The t o t a l c o s t i s l i k e l y t o approach t h a t g i v e n above. The c o s t of t h e consul t a n c y p r o j e c t has t h e r e f o r e been i n c l u d e d I n t h e economic and f i n a n c i a l a n a l y s i s a l t h o u g h I t may be a l i t t l e pessimistic. 5.4 Organisation o f Investigation and Detection 5.4.1 General ESCOM Oraani s a t i o n The o r g a n i s a t i o n of ESCOM i n so f a r as i t a f f e c t s t h e d e t e c t i o n and c o r r e c t i o n o f n o n - t e c h n i c a l l o s s e s , b r o a d l y c u t s a c r o s s f o u r sections. Meter r e a d i n g f a l l s under t h e Revenue s e c t i o n . Readings a r e passed t o t h e Data P r o c e s s i n g s e c t i o n where customer r e c o r d s a r e updated and i n v o i c e s produced. Meter r e a d e r s a l s o n o t e any problem meters o r s u s p i c i o u s s u p p l i e s and r e p o r t s a r e passed t o engineers f o r j n v e s t i g a t i o n . I n Blantyre the Meterlng section under t h e Commercial Manager i n v e s t i g a t e s t h e s e cases. E l sewhere t h e y a r e i n v e s t i g a t e d by t h e Consumers Engl neer, t h e D i s t r i c t Engineer or O f f i c e r - i n - C h a r g e . I n cases where suppl ies have been o b t a i n e d i 1 1egal l y , t h e Area Manager, D i s t r i c t Engineer or O f f i c e r - i n - C h a r g e e s t i m a t e s t h e v a l u e o f that theft. The consumer e n g i n e e r s a r e r e s p o n s i b l e f o r i n s t a l 1 i n g new meters and p a s s i n g t h e docurnentatlon back t o t h e Revenue s e c t i o n . Meter r e a d e r s d i sconnect suppl i e s . The Data process1 ng s e c t i o n produces except I o n r e p o r t s , which a r e passed t o t h e Revenue s e c t i o n , and o t h e r statistics for ESCOM management. For o p e r a t f o n a l and a d m i n i s t r a t i v e purposes Malawi i s d i v i d e d i n t o t h r e e 'Areas' c o m p r i s i n g t h e South ( B l a n t y r e ) , C e n t r e (Lilongwe) and N o r t h (Mzuzu), each under an Area Manager. I n the Southern Area there are currently two smaller a d m i n i s t r a t i v e ' D i s t r i c t s ' under a D l s t r l c t Engineer. These a r e t h e Thyolo D l s t r l c t and t h e Zomba D i s t r i c t . Thc l o w e s t o r g a n i s a t i o n a l l e v e l i s t h a t of t h e ' O f f i c e ' under t h e c o n t r o l o f an ' O f f i c e r - i n - C h a r g e ' . There a r e c u r r e n t l y s i x t e e n O f f i c e s w i t h t h r e e more planned. TWO o f these O f f i c e s (Liwonde and Mangochi) r e p o r t t o t h e Zomba D i s t r i c t and one ( M u l a n j e ) t o t h e Thyolo D i s t r i c t . The o t h e r O f f i c e s r e p o r t d i r e c t l y t o t h e Area. The s t a f f i n g o f t h e O f f l c e s v a r i e s depending on t h e i r s i z e . The O f f i c e r - i n - C h a r g e i s g e n e r a l l y t e c h n i c a l l y w e l l q u a l i f i e d b u t may n o t be q u a l i f i e d or e x p e r i e n c e d a t t h e a d m i n i s t r a t i v e o r managerial l e v e l . As a minimum t h e O f f i c e w i l l i n c l u d e a cashierlmeter reader, ltnesmen and s u p p o r t staff. The cashierlmeter readers r e p o r t to the 0ff.icer-in-Charge for a d m i n i s t r a t i v e purposes b u t t o t h e Area Branch Accountant for f u n c t i o n a l purposes.  The D i s t r i c t o r g a n i s a t i o n i n c l u d e s a D i s t r i c t A c c o u n t a n t who again r e p o r t s t o the D i s t r i c t O f f i c e r f o r a d m i n i s t r a t i v e m a t t e r s and t o t h e Area Branch A c c o u n t a n t on f u n c t i o n a l m a t t e r s . 5.4.2 Revenue S e c t i o n There a r e c u r r e n t l y 62 meter r e a d e r s i n ESCOM as shown i n Table 5.4.1. The m a j o r i t y o f t h e s e a r e c e n t r e d i n B l a n t y r e (25) and i n L i l o n g w e (15). Zomba has a f u r t h e r f o u r and Mzuzu a n o t h e r t h r e e . The r e m a i n i n g f i f t e e n o p e r a t e i n i s o l a t i o n o u t s i d e t h e main c e n t r e s . I n B l a n t y r e and L i l o n g w e t h e m e t e r r e a d e r s a r e d i v i d e d i n t o s e c t i o n s w i t h f o u r o r f i v e I n each. One o f t h e s e s e c t i o n s compri ses ' S p e c i a l Meter Readers' who have motor1 sed t r a n s p o r t i n the f o r m o f cars o r motorbikes. These r e a d e r s o p e r a t e on t h e o u t s k i r t s of t h e c i t y ; t h e y r e a d t h e meters o f t h e 'Small Power' and 'Large Power' consumers and t h e y u n d e r t a k e d i s c o n n e c t i o n s and r e c o n n e c t l o n s . The s e c t i o n s a d d i t i o n a l l y have ' S e c t i o n L e a d e r s ' . I n t h e s m a l l e r areas, o u t s i d e o f t h e main c e n t r e s , t h e meter r e a d e r s may d o u b l e as c a s h i e r s . There a r e no vacancies f o r meter r e a d e r s a t p r e s e n t . I n the near f u t u r e t h e r e a r e p l a n s t o r e c r u i t f u l l t i m e s t a f f f o r Mzimba, Nkhata Bay and Chinteche. A t Mzuzu t h e numbers a r e planned t o I n c r e a s e by one, b r i n g i n g t h e complement t o f o u r . A t Nchalo t h e d u t i e s o f t h e c a s h i e r l m e t e r r e a d e r a r e t o be s p l i t between two p e o p l e . D u r i n g p e r i o d s of annual l e a v e or s i c k n e s s f o r meter r e a d e r s I n t h e more i s o l a t e d areas i t i s ESCOM p o l i c y t o use r e 1 l e f meter readers. These a r e t a k e n f r o m among t h e normal r e a d e r s i n B l a n t y r e and L i l o n g w e . I n some cases, m o n t h l y consumption d u r i n g these periods I s estimated. The procedures f o r meter r e a d e r s a r e n o t f o r m a l l y documented i n a s i n g l e procedural guide. Nevertheless, a brief job d e s c r i p t i o n t o g e t h e r w i t h v a r i o u s memoranda d e s c r i b e s t h e d u t i e s and t a s k s expected o f meter r e a d e r s . New meter r e a d e r s l e a r n t h e j o b by shadowing t h e o l d e r , more e x p e r i e n c e d r e a d e r s f o r a p e r i o d o f one month. New meter r e a d e r s a r e c o n f i r m e d i n t h e i r j o b s a f t e r a s a t 1 s f a c t o r y s i x month p r o b a t i o n a r y p e r i o d . A seminar f o r meter r e a d e r s and m e t e r i n g t e c h n i c i a n s was h e l d I n 1988. S p e c i a l meter r e a d e r s would b e n e f i t g r e a t l y f r o m more s p e c i a l 1sed t r a i n i n g . The t u r n o v e r o f meter r e a d e r s i s s a i d t o be h i g h w i t h a s t a y o f above t h r e e y e a r s r e g a r d e d as v e r y good. I n Blantyre the m a j o r i t y o f r e a d e r s have been i n t h e j o b f o r l e s s t h a n t w o y e a r s . Two or t h r e e have been w l t h ESCOM f o r a b o u t t e n y e a r s . The s t a r t i n g pay for a new meter r e a d e r i s K2208 ( $ 8 0 0 ) l y e a r . D l s c l p l l n a r y a c t l o n takes the form o f d e n i a l o f annual increments i n pay, suspension o r dismissal. Over the one year period, J u l y 1989 t o June 1990, some s l x d i s c i p l i n a r y a c t i o n s were taken against meter readers throughout the country. Four of these were r e l a t e d t o t h e use o f ESCOM v e h i c l e s , one t o poor work performance and one r e l a t i n g t o missing cash f o r a meter readerJcashier. (1) Meter Reading and Recording Meter readers c a r r y a 'meter book' together w i t h a notebook. The meter book contains a double page e n t r y f o r each meter. He enters t h e new meter reading and s u b t r a c t s the o l d reading from the new t o g i v e a monthly consumptlon. These e n t r l e s are repeated I n the house card which accompanies the meter. The meter reader does n o t ad3ust t h e reading t o take account o f any m u l t l p l y l n g factors. For the very l a r g e consumers, meters are read on the l a s t working day o f the month. Other meters are supposed t o be read f a i r l y c l o s e t o an i n t e r v a l o f one month. A memo dated March 1988 t o s e c t i o n leaders asks them t o ensure t h a t readings are taken monthly w l t h i n p l u s o r minus f o u r days. This p r a c t i c e I s n o t g e n e r a l l y adhered t o . For t h e very l a r g e consumers, meters a r e read on t h e l a s t working day o f the month. The adoption of a c o n s i s t e n t p a t t e r n f o r meter reading would have the unfortunate disadvantage t h a t tamperers may easl l y a n t i c i p a t e these v i s i t s , thus making t h e task o f d e t e c t i o n more d l f f l c u l t . The element o f randomness has an advantage i n t h i s respect, although I t i s recognised t h a t I t may cause payment d i f f i c u l t i e s f o r some customers. The meter books are passed t o t h e s e c t i o n leaders ( i n Blantyre, L l longwe, Mzuzu and Zomba) . The s e c t i o n 1eader checks the meter books t o ensure t h a t the reader has n o t skipped p r o p e r t i e s and t o estimate the consumptlon o f those meters where t h e reader was unable t o g a i n e n t r y . This estimate i s based on t h e average o f the l a s t three months consumption. (Where a meter reader f a i l s t o gain e n t r y f o r t h r e e consecutive months then the householder I s n o t i f i e d t h a t f a i l u r e t o permit e n t r y on t h e next v i s i t by t h e meter reader w i l l r e s u l t i n disconnection). I n Blantyre, the meter books are passed t o the data-processing section. Outside Blantyre slightly d i f f e r e n t procedures operate. I n L i longwe the metering records a r e entered I n t o the computer ( i n B l a n t y r e ) d i r e c t l y v i a a modem l l n k . Elsewhere, t h e metering records are t r a n s c r i b e d o n t o a form which I s then sent t o B l a n t y r e f o r data e n t r y .  The b i l l i n g system reports all 'rotas' which remain unprocessed. The ' S p e c i a l Meter Readers' undertake t h e readings f o r t h e 'Small Power' consumers. The kVAh a r e recorded f o r most o f these consumers b u t t h e i n f o r m a t i o n i s n o t t r a n s c r i b e d o n t o t h e computer and I s n o t t h e r e f o r e r e p o r t e d t o t h e Comnerci a1 Manager. 'The kVAh read1 ngs, In conjunction w i t h kwh, w l l l enable power f a c t o r s t o be c a l c u l a t e d . This n i l 1 a c t as a cross check on t h e accuracy of t h e two meters. Should t h e power f a c t o r f a l l below, say 80%. t h e computer should Issue a warning which w l l l t r i g g e r an I n v e s t i g a t i o n by t h e Commercial Manager. (ii)Defective Meters and T h e f t The meter readers a r e a l s o r e q u i r e d t o note any problems w l t h t h e meters o r suppl l e s I n t h e i r notebook. This w l l l i n c l u d e broken seals. broken meters, tampering, meters n o t o p e r a t i n g and signs o f t h e meter being by-passed. They a r e I n s t r u c t e d t o pay a t t e n t i o n t o t h e appliance ownership i n a p r o p e r t y i n r e l a t i o n t o t h e monthly consumption levels. The notebooks i n B l a n t y r e and Lilongwe a r e passed t o t h e s e c t i o n leaders who w r i t e s a memo t o t h e Branch Accountant n o t i n g any problem meters. I n B l a n t y r e t h e Branch Accountant w r l t e s a f u r t h e r memo t o t h e Commercial Manager a s k i n g him t o i n v e s t i g a t e . I n Lilongwe these cases a r e r e p o r t e d t o t h e Consumer Engineer f o r I n v e s t i g a t i o n . Outside the main c i t i e s , r e p o r t s o f meter problems a r e r e p o r t e d t o t h e D l s t r i c t Engi neer o r O f f 1cer-1 n-Charge who niay r e f e r t h e m a t t e r t o t h e Area Engineer. If it i s confirmed t h a t an i l l e g a l connection has taken p l a c e t h e n t h e meter reader r e c e i v e s a K5 reward. Memoranda t o t h e Commercial Manager a r e r e l a t i v e l y i n f r e q u e n t . I n t h e two month p e r i o d i n February and March 1990 t h e r e were 13 cases r e p o r t e d f o r S e c t l o n I11 I n B l a n t y r e and 43 cases f o r S e c t i o n 11. Payments t o meter readers under t h e reward scheme a r e r e l a t i v e l y r a r e , approximately two per reader per y e a r . The reward appears t o be on t h e low s i d e . A t two f i n d i n g s per year it amounts t o l e s s than 0.5% o f t h e annual pay o f t h e new s t a r t e r (K2208Iyear). Moreover, i t i s a small sum compared w i t h t h e ' f i n e ' f a c i n g t h e tamperer (K110 t o K130 p l u s estimated l o s t u n i t s ) . For t h e Special meter readers t h e divergence between t h e value of t h e reward and t h e value o f t h e t h e f t i s even g r e a t e r . The i n c e n t i v e t o e n t e r i n t o c o l l u s i o n , e i t h e r through casual f a v o u r s f r o m customers o r through b r i b e r y , I s g r e a t . An i n c r e a s e i n t h e reward t o c o r r e c t t h i s Imbalance would seem t o be I n order. However, t h e r e I s a danger t h a t t h e balance c o u l d  swing t o o f a r i n f a v o u r of r e p o r t i n g incidences such t h a t t h e meter1 ng s e c t i o n or consumers engi neers a r e inundated w i t h cases t o i n v e s t i g a t e . I f t h e reward i s t o o g r e a t t h e r e I s a l s o t h e danger t h a t t h e meter reader w i l l f a b r i c a t e evidence. An increment to, say, K20 f o r o r d i nary meter readers p e r proven i1 1egal customers woul d seem reasonable and c o u l d e a s i l y be recovered i n t h e customer's 'fine'. For t h e Special meter readers o p e r a t i n g i n t h e Small Power category, an automatic f i g u r e o f K50 might be a p p r o p r i a t e w i t h a d i s c r e t i o n a r y a d d i t i o n a l reward f o r c a t c h i n g t h e e x t r a b i g and s o p h i s t i c a t e d tamperers. A l l of these payments c o u l d be recovered i n t h e ' f i n e ' . The rewards should be indexed a g a i n s t annual average pay r i s e s . Approximately 20% o f soppl i e s i n v e s t i g a t e d a r e general l y shown t o be I 1 l e g a l and an unknown p r o p o r t i o n of those r e p o r t e d a r e i n v e s t i g a t e d . The meter readers may r e p o r t f i f t y consumers per year, of whom o n l y two may be found t o be p l l f e r l n g . 'rhi s does n o t seem unreasonable and t h e system o f rewarding readers only for successful i n v e s t i g a t i o n s appears t o work w e l l . No r e c o r d I s maintained w i t h t h e customer f i l e o f r e p o r t s made by meter readers nor of cases where t h e consumer was found t o have been a c t i n g i l l e g a l l y . I n o r d e r t o check a consumer's p a s t h i s t o r y t h e Revenue o r Branch Accountant would need t o read through t h e book o f memos. A r e c o r d should be k e p t i n t h e customer f i l e thus p e r m i t t i n g easy access t o b o t h p a s t consumption and t o p a s t r e p o r t s . Meter readers a r e r e q u i r e d t o check a1 1 meters, i n c l u d l n g those of properties where the supply has been , disconnected. They a l s o l o o k o u t f o r p r o p e r t i e s which have a supply b u t no account. (1 I 11 Procedures for Hew Connectlons New consumers pass through t h r e e stages b e f o r e they a r e connected. F i r s t o f these i s t h e connection a p p l i c a t i o n and connectlon f e e , second i s t h e I n s p e c t i o n and i n s p e c t i o n fee, and t h e t h i r d i s t h e payment o f a d e p o s i t and connectlon. Consumers may, however, pay a l l t h r e e fees i n one go. Upon payment o f t h e d e p o s i t they a r e issued w i t h a r e c e i p t and a l l o c a t e d an account number by t h e Revenue s e c t i o n , b o t h of which are entered i n a 'new connections' book. The Consumers s e c t i o n informs t h e Revenue s e c t i o n o f t h e connection and. the opening meter reading. The date a t whlch t h i s occurs I s noted i n t h e New Connectlons book. The Revenue s e c t i o n then completes a form whlch they submit t o d a t a processing t o open a new r e c o r d f o r t h i s customer. A new e n t r y i s a l s o made i n t h e meter book.  There i s no s y s t e m a t i c check t h a t a l l customers who have been p r o v i d e d w l t h a supply ever have t h e i r meters r e a d and a r e b i l l e d . T h i s i s discussed f u r t h e r i n S e c t i o n 5 . 4 . 7 below. (I v ) Procedures for D i sconnections/Reconnections ' A consumer w i s h i n g t o d i s c o n t i n u e h i s supply completes a f o r m i n d i c a t i n g t h e d a t e and t i m e a t which he wishes t h e supply t o be disconnected. ESCOM then sends a meter reader t o t h e p r o p e r t y a t t h a t t i m e t o read t h e meter. I n B l a n t y r e and Lilongwe o n l y t h e s p e c i a l meter r e a d e r s were, a t one stage, s e l e c t e d f o r t h i s t a s k . This precaution would appear t o have been d i s c o n t i n u e d a t t h e p r e s e n t t i m e and normal meter r e a d e r s a l s o undertake d i s c o n n e c t i o n s and r e c o n n e c t i o n s . S p e c i a l meter r e a d e r s a r e r o u t i n e l y i s s u e d wlth sealing p l l e r s . Normal meter readers a r e i s s u e d w i t h p l i e r s on an as-needed and a s - a v a i l a b l e b a s i s . A shortage o f p l i e r s has e x i s t e d and p l i e r s have been l o s t o r m i s l a i d . T h l s has meant t h a t s u p p l i e s have been d i s c o n n e c t e d o r reconnected w i t h o u t t h e f u s e b e i n g r e s e a l e d . T h l s i n t u r n has b r o u g h t i n t o q u e s t i o n t h e v a l u e o f evidence p r o v i d e d by a broken s e a l . Outside o f B l a n t y r e and Lilongwe, normal meter readers a r e supposed t o be i s s u e d w l t h s e a l i n g p l l e r s . The shortage o f p l i e r s has a g a i n meant t h a t meters and fuses have n o t always been sealed. T h l s s i t u a t i o n may be r e c t i f i e d w i t h t h e purchase o f f i f t y new p l i e r s . The p r a c t i c e o f a l l o w i n g s u p p l i e s t o remain unsealed should be s t r o n g l y discouraged. P l i e r s should I d e a l l y be issued o n l y t o S p e c i a l meter r e a d e r s I n B l a n t y r e and L l longwe. P l l e r s i ssued I n t h e o u t s t a t i o n s should always be signed o u t . The Revenue s e c t i o n submits a closedown f o r m t o t h e Data Processing s e c t i o n when t h e supply has been disconnected. A customer who wishes t h e supply t o be r e s t o r e d t o a p r o p e r t y t o which he has j u s t moved w i 11 a g a i n complete a f o r m and t h e meter r e a d e r w i l l v i s i t t o r e a d t h e meter and reconnect s u p p l y . ' He w i l l a t t h i s t i m e n o t e any discrepancy between t h i s and t h e c l o s i n g r e a d i n g p r i o r t o disconnection. A f o r m i s then submitted t o t h e Data Processing s e c t i o n t o open a new account. The f o r m w i l l i n c l u d e t h e opening meter r e a d i n g (as noted below t h e r e I s no cross-check t o ensure t h a t c l o s i n g r e a d i n g s a r e equal t o open1 ng r e a d i ngs) .  There i s no systematic r e p o r t i n g o f numbers, names and addresses o f premises which have been disconnected and not reconnected. A q u a r t e r l y management Informatlon r e p o r t showing the addresses o f those properties which have not been reconnected a f t e r s i x , nine and twelve months should serve t o warn ESCOM o f p o t e n t i a l problem supplies. It would a l s o be useful Information f o r other purposes. 5.4.3 Procedures Desianed t o Prevent Fraud bv Meter Readers The rotas f o r meter readers are a l l o c a t e d by the section leaders. I n Blantyre, Lilongwe, Mzuzu and Zomba the meter readers are, I n p r i n c i p l e , not supposed t o be a1 located t o the same area f o r two months i n succession. I n p r a c t i c e they may take the same r o t a f o r several months consecutively. However, the meter readers do generally r o t a t e f r e q u e n t l y w i t h i n each sectlon. Moreover, there I s no evidence o f systematic patterns i n v o l v i n g combinations o f two readers always v i s i t i n g the same areas. Rotation o f meter readers between sections i s said t o be practised i n Blantyre but t h i s i s not borne out by the evidence. I n Blantyre, f o r example, four readers stayed i n Section I f o r over f i v e years between 1982 and 1987. One o f these f o u r st1 11 remains i n t h a t Section w h i l s t none o f the new readers who joined ESCOM over a year ago have been r o t a t e d . Notwi thstandlng the above, there i s no evidence o f any c o l l u s i o n between meter readers and customers t o defraud ESCOM. Moreover, given the r e l a t i v e l y high turnover r a t e amongst meter readers the need f o r r o t a t i o n between sections i n Blantyre and Lilongwe i s less pressing. Outside o f the main centre.^, where there i s o n l y one meter reader there i s a need f o r some form o f checking. I t I s Important t h a t d u r i n g periods o f annual leave, consumption should n o t be estimated but a r e l i e f meter reader be c a l l e d i n t o a c t as an a u d i t o r o f the primary reader. 5.4.4 Dai 1y Information R e ~ o r t The d a i l y information r e p o r t i s received by the Revenue Accountant and contains information re1 at1 ng t o : deleted accounts accounts where consumption i s +I- 50% o f the previous month negatl ve consumption The bulk o f the reports r e l a t e t o accounts where consumption exceeds +I- 50% o f the previous month. The 'deleted accounts' are Ignored by the Revenue section. These r e f e r t o accounts which have been closed and the f i n a l invoice s e t t l e d . Since no a c t i o n i s taken t h i s r e p o r t serves no purpose and adds t o the volume o f Information passed t o the Revenue section.  Negative consumption r e l a t e s t o accounts where an adjustment has been a p p l i e d t o compensate for erroneous e n t r i e s i n p r e v i o u s months. These r e p o r t s a r e r e l a t i v e l y i n f r e q u e n t and no a c t i o n g e n e r a l l y appears t o be taken. The Assi s t a n t Accountant (Revenue) scans t h e r e p o r t and places a t l c k a g a l n s t those accounts which e i t h e r show gross v a r i a t i o n o v e r t h e p r e v i o u s month (eg, a f a c t o r o f 10 g r e a t e r o r l e s s ) . A d d i t i o n a l l y he marks w i t h a t l c k those accounts f o r which t h e minimum charge has been a p p l i e d ( i e , K10.25). The i n v o i c e s f o r these a r e t h e n e x t r a c t e d and passed t o t h e Revenue Accountant. For B l a n t y r e t h e I n v o l c e s may be passed t o t h e S e c t l o n Leaders t o be checked and a d j u s t e d If necessary. For o t h e r accounts t h e Revenue Accountant a d j u s t s t h e i n v o i c e s . A c r o s s i s marked on t h e d a i l y i n f o r m a t i o n r e p o r t a g a i n s t those accounts where t h e I n v o i c e has been e x t r a c t e d . The d a i l y i n f o r m a t i o n r e p o r t o f t h e 11t h August 1990 c o n t a i n e d 15 pages and a p p r o x i m a t e l y 750 r e c o r d s t o be scanned. 'This was, a p p a r e n t l y an e x c e p t i o n a l l y l a r g e r e p o r t b u t n e v e r t h e l e s s i n d i c a t e s t h e volume of i n f o r m a t i o n f a c i n g t h e Revenue section. On t h i s o c c a s i o n 90 i n v o i c e s were e x t r a c t e d f o r c l o s e r examination. The I n f o r m a t i o n c o n t a i n e d i n t h i s r e p o r t I s n o t passed t o t h e Commercial Manager o r Consumer Englneers and I s n o t used t o d e t e c t tamperers. I t I s recommended t h a t t h e D a l l y I n f o r m a t i o n Report a l s o be passed t o t h e a p p r o p r i a t e ' i n v e s t l g a t l o n personnel. The volume o f i n f o r m a t i o n i s g e n e r a l l y t o o g r e a t t o enable t h e Revenue s e c t i o n t o adequately m o n i t o r r e c o r d s . A t t h e same t i m e t h e q u a l i t y o f I n f o r m a t i o n c o u l d be improved t o t a r g e t problem accounts more u s e f u l l y . The problem I s compounded by t h e absence o f a system for t h e maintenance and easy r e t r i e v a l of I n f o r m a t i o n on a consumer's p a s t . T h i s i s d i s c u s s e d f u r t h e r i n S e c t i o n s 5.4.5 (111) and 5.4.7 below. 5.4.5 Consumers Enai neer and Meter Engi neer (1) Organisation I n t h e p a s t y e a r t h e s m a l l e r i s o l a t e d O f f i c e s and D i s t r i c t O f f i c e s have taken r e s p o n s i b i 11t y f o r t h e c o n n e c t i o n and meter investlgatlon f o r the domestic and general consumers : However, r e s o u r c e s and s k i 11 s a r e general l y l a c k i n g i n these o f f i c e s and more c o m p l i c a t e d t a s k s a r e passed t o t h e Area Consumer Engineers o r t o t h e M e t e r i n g sectlon I n Blantyre. The O f f i c e s a r e r e s p o n s i b l e f o r Imposing ' f i n e s ' on consumers found t o be 11 l e g a l l y t a k i n g s u p p l i e s . The D i s t r i c t o f f i c e s and t h e o u t s t a t i o n s do n o t read meters f o r t h e 'Small Power' consumers. It Is c u r r e n t l y ESCOM p o l i c y t o t r a i n s t a f f i n t h e s e o f f l c e s and  t o provide equipment ( i n c l u d i n g check meters) i n order t o devolve as much o f the connection and i n v e s t i g a t i o n work as p o s s i b l e . The Commercial Manager has responsi b i 1it y f o r a1 1 consumer matters and i s a l s o responsible f o r consumers above 500 kVA o r i n v o l v i n g l a r g e c a p i t a l costs (above K100,OOO) o r those metered a t HV. The metering s e c t i o n u ~ d e r the Commerci a1 Manager undertakes a form o f trouble-shooting. They undertake ad-hoc meter i n v e s t i g a t i o n s , extensive i n v e s t l g a t i o n s o f meters over given areas and meter t e s t i n g . The meter t e s t bench i n Blantyre i s under the c o n t r o l of t h i s section. I n Blantyre, the task of I n v e s t i g a t i n g suspect meter tamperers i s undertaken by the Commercial Manager. Elsewhere, i t i s undertaken by Consumers Engineer. The o r g a n i s a t i o n o f the Metering s e c t i o n i s c u r r e n t l y under review. I t i s headed by a Meter Superintendent under whom i s nominal l y a Meter Technician Englneer (vacant) w i t h a Senior Meter Technician below t h i s . The l a t t e r post i s a l s o vacant. There are two meter technicians who now undertake the meter i n v e s t i g a t i o n s and three ' a r t i s a n s ' o r meter mechanics who t e s t , r e p a i r and overhaul meters. One o f the l a t t e r posts i s vacant. In the near f u t u r e , w i t h the r e t i r e m e n t o f the c u r r e n t occupant, the post o f .Meter Superi ntendent w i l l d l sappear. The Consumer Engineer under the Area Manager undertakes the l a r g e s t p r o p o r t i o n o f the connection' work. In Blantyre the section i s headed by the Consumer Englneer followed by an A s s i s t a n t Consumer Englneer. Under him I s a Senior I n s t a l l a t i o n Inspector and two Installation Inspectors. Below these are Consumers c l e r k s , etc. The section is responsible for connecting consumers, i n s p e c t i n g i n s t a l l a t i o n s , i n v e s t i g a t i n g suspected cases o f tampering, imposing ' f l n e s ' and e s t i m a t i n g adjustments t o accounts. (ii Equlpment and Resources The meter t e s t bench f a c i l i t i e s and the o t h e r equipment t o enable meters and supplies t o be i n v e s t i g a t e d are discussed elsewhere i n the main t e x t . The Commercial Manager has i d e n t i f i e d t r a n s p o r t as one o f the major c o n s t r a i n t s on the Metering section. This I s a l s o the case w i t h the Consumers s e c t i o n where three Inspectors have the use o f o n l y two v e h i c l e s . (III) Procedures The Commercial Manager checks t h e readings taken f o r a l l Small Power consumers. I n v e s t i g a t i o n o f problem meters i n t h i s category i s always undertaken by the M e t e r i n g s e c t i o n under t h e Commercial Manager. A1 1 meters whlch a r e new o r have been overhauled o r t e s t e d have s h e l l a c a p p l i e d t o t h e v o l t a g e t e r m i n a l s . The use o f seals f o r t h e meter and f u s e i s discussed i n S e c t i o n 5.4.2 above. Shellac has n o t always been a p p l l e d . Only where i t has been a p p l i e d and the v o l t a g e t e r m i n a l s a r e found t o be loose i s i t taken t o be evidence o f tampering, When meters a r e r e p l a c e d a meter o r d e r f o r m i s completed and a new meter drawn from s t o r e s . The r e a d i n g o f t h e o l d meter taken o u t I s noted on t h e f o r m as i s t h e i n i t i a l r e a d i n g on t h e new meter. These readings a r e entered i n t h e meter books by a c l e r k . ( I v ) I m p o s i t i o n o f ' F i n e s ' and t h e Deterrence of Offenders Consumers found t o have f a u l t y o r broken meters a r e charged a MKlO meter t e s t i n g charge. I n cases where meters have been by-passed o r tamperlng i s proven then t h e consumer I s ' f i n e d ' an amount whlch i s c a l c u l a t e d according t o an e s t l m a t e o f t h e costs o f t h e I n v e s t i g a t i o n including transport, a d m i n l s t r a t i o n , overheads, meter I n v e s t i g a t i o n , s t a f f time, revenue s t a f f time and a meter t e s t i n g fee. This Ss estimated t o be MKlOO f o r labour, MKlO per i n s p e c t i o n v i s i t ( n o r m a l l y x2) and, 'if t h e meter I s f a u l t y , MKlO f o r r e c a l i b r a t i o n . A d d i t i o n a l l y an e s t l m a t e i s made by t h e Officer-in-Charge, t h e D i s t r i c t Engineer o r t h e Consumers Engineer o f t h e amo~~n ot f u n i t s which ESCOM has l o s t as a r e s u l t of t h e i l l e g a l abstractions. I n t h e o r y consumers may a l s o be charged w i t h t h e c o s t o f a new meter, which c o u l d be o f t h e o r d e r o f K100. Consumers i n f i n a n c i a l d i f f i c u l t i e s may be g i v e n t h e chance t o pay t h e ' f i n e ' i n i n s t a l m e n t s . Consumers a r e sent a standard l e t t e r which b r i n g s t o t h e i r a t t e n t i o n S e c t i o n 36 o f the E l e c t r i c i t y Act and Rule 4 o f t h e ESCOM By-laws under which " . . . i f any person w i t h o u t l a w f u l j u s t i f i c a t i o n o r excuse i n j u r e s o r i n t e r f e r e s w i t h o r damages o r permits o r s u f f e r s t o be i n j u r e d , i n t e r f e r e d with or damaged any ESCOM e l e c t r i c apparatus o r I n s t a l l a t i o n o f any k i n d whatsoever, he s h a l l be g u i l t y of an offence". No mention i s made o f t h e f t . I n t h e event t h a t a consumer commits an o f f e n c e t w i c e i t i s ESCOM p o l i c y t o take t h a t person t o c o u r t . The one i n s t a n c e noted by t h e team I n whlch two offences were committed d i d not involve court action.  I t would appear t h a t ESCOM have o n l y taken a very 1 l m i t e d number o f cases t o c o u r t and t h a t these involved a l o t of time and e f f o r t and were not successful. Consequently, ESCOM decided t o adopt the approach o u t l i n e d above of charging tamperers and il 1 egal abstractors w l t h the cost o f detection and I n v e s t l g a t i o n . ESCOM has no l e g a l powers t o impose f i n e s and I s therefore constrained t o asking consumers t o reimburse these costs. They cannot set the ' f l n e ' a t any a r b i t r a r y l e v e l . The fmposltlon o f the charge has not been tested I n the courts. For the smaller consumers I n the h i g h density areas the ' f i n e ' may appear t o be p u n i t i v e , equivalent t o the cost o f u n i t s f o r up t o two years f o r a normal household. However, o f the 42 i l l e g a l cases i n the high density area o f Bangwe i n MayIJune, only three o f the ' f i n e s ' remain unpaid a t t h i s date (August). For the consumers I n low density areas o r f o r 'General ' consumers the s i z e o f the f i n e I s n e g l i g i b l e . This may be equivalent t o o n l y one t o three months supply. As a general legal p r i n c i p l e the f i n e f o r a misdeed I s t a i l o r e d t o the income o f the miscreant and t o the s i z e o f the misdeed. The size o f the ' f i n e ' should I d e a l l y be increased s u b s t a n t i a l l y f o r the l a r g e r consumers. An argument could e a s i l y be made t h a t the d e t e c t i o n and i n v e s t i g a t i o n systems are designed t o catch and deter the l a r g e r c u l p r i t s and t h a t the costs should be shared i n p r o p o r t i o n t o the scale o f the abstraction. This I s s i m i l a r t o the p r i n c i p l e o f marginal cost p r i c i n g . A d i f f e r e n t scale should be charged f o r each' of the low densl t y and high densl t y areas and for the 'General ' consumer category. 'Small Power' consumers could be charged on a per kVA basis. The average cost o f d e t e c t i o n and I n v e s t i g a t i o n i s a l s o thought t o be somewhat understated. Account should be taken of a l l costs i n c l u d i n g p a r t o f the c a p i t a l costs o f vehicles, p a r t o f the c a p i t a l cost o f the meter t e s t i n g bench and other t e s t i n g equipment, t r a i n i n g costs, the meter readers' reward, p a r t o f the cost o f the b i l l i n g system and a more s u b s t a n t i a l p a r t o f the cost o f supervisory and management s t a f f . I t should ' a l s o be remembered t h a t one o f the p r i n c i p l e purposes of a system o f p e n a l t i e s i s n o t j u s t i c e but deterrence. Maximum pub1 ic i t y should be given t o programmes designed t o catch I l l e g a l -tapping. I n t h i s respect the Commercial Manager's preferred approach i n v o l v i n g high p r o f i l e sweeps of an area may be more e f f e c t i v e than occasional ad-hoc v i s i t s t o suspect propert 1es.  (v) Records of Offences Correspondence r e l a t i n g t o r e p o r t s o f broken seals, broken meters o r consumers f o r meter tampering o r by-passing supplies i s malntalned I n a f l l e w i t h the Commercial Manager in Blantyre. The current file contains correspondence since the beginning o f 1989. The correspondence f i l e does n o t c o n t a i n records o f a1 1 cases reported. Separate f i l e s a r e maintained by t h e Consumers Engineer, D i s t r i c t Engineers and Officer-in-Charge. A r a t h e r haphazard system o f r e c o r d i n g p e r t a i n s I n t h e outstations. Meter readers' r e p o r t s o r records of mls-deeds a r e n o t k e p t i n the consumer's f i l e i n the Revenue s e c t i o n . I n t h e event t h a t the Commercial Manager o r Area Manager should wish t o check the p a s t consumption behaviour of a consumer he would need t o search t h e correspondence f i l e and a l s o go t o the consumer f l l e ( h e l d by t h e Revenue s e c t i o n ) o r meter books t o f i n d the p a s t p a t t e r n o f consumption. As discussed above I n Section 5.4.2 above and I n Section 5.4.7 below t h e r e I s a very s t r o n g case t o be made f o r keeplng a r e c o r d w i t h the customer f l l e and on computer o f any previous r e p o r t s and f i n d i n g s . The monthly r e p o r t i n g t o t h e Commercial Manager o f meter investigations, meter replacements and cases o f i l l e g a l supplies has r e c e n t l y been introduced. A t t h e 'same time a r e p o r t on the same t o p i c has been requested covering t h e p e r i o d 1986 t o 1989. The s t a t i s t i c s have been complled f o r B l a n t y r e b u t n o t f o r Lilongwe. The B l a n t y r e r e s u l t s a r e shown below: Investigations 1162 1472 359 563 578 I 1l e g a l - 63 85 47 106 (Note: I n 1986 ESCBM was o n l y concerned w i t h t h e condl t i o n o f t h e meters and the meter seals, hence no a c t l o n was taken a g a l n s t suspected consumers). I n 1990 t h e f o l l o w i n g monthly s t a t i s t i c s have been compiled: Investigations I 1l e g a l Meters Changed March 186 Apr i1 56 May 132 June 109  (Note: Not a l l those w i t h i l l e g a l s u p p l i e s r e q u i r e d new meters). I n t h o s e cases where meter s e a l s a r e found t o be broken o r t h e meter i s broken b u t t h e r e i s no evidence o f meter t a m p e r i n g or by-pass t h e n a warning s t i c k e r i s p l a c e d o n t h e meter which i s then resealed. I n most a l l o f t h e cases found t o be i l l e g a l t h e meter had been by-passed. I n t h e remainder t h e v o l t a g e 1 i n k had been opened. The l a r g e number of cases i n March were due t o t h e sweep o f Bangwe ( d i s c u s s e d below). The low number o f cases i n A p r i l were due t o problems o f s i c k n e s s i n t h e meter i n v e s t i g a t i o n team. Some f o u r major in v e s t i g a t i o n e x e r c i ses o r meter r e s e a l i n g programmes have been undertaken t o d a t e . The two most r e c e n t l y were f o r B a ~ g w e and Chi lomoni . B o t h of these a r e h i g h d e n s i t y areas i n B l a n t y r e . The Chilomoni o p e r a t i o n t o o k p l a c e i n J u l y 1990 and n e t t e d a p p r o x i m a t e l y 35 cases o f meter by-pass. The Bangwe o p e r a t i o n t o o k p l a c e o v e r a one week p e r i o d i n l a t e May and e a r l y June and n e t t e d a p p r o x i m a t e l y 42 meter by-passers. The l a t t e r o p e r a t i o n was c o - o r d i n a t e d by t h e M e t e r i n g s e c t i o n under t h e Commercial Manager b u t i n v o l v e d s t a f f f r o m t h e Consumers s e c t i o n . 'The premises were t a r g e t e d I n advance by t h e Commercial Manager f r ~ m t h e r e p o r t s by meter r e a d e r s . The success r a t e i n f i n d i n g by-passers was 23% of those investigated. O t h e r areas i n B l a n t y r e whlch a r e l i k e l y t o have s i m i l a r problems i n c l u d e Ndi rande, Chi lombwe, Zingwangwa, Soche, Chi t a w i r a , Chinyonga, Njamba and Kanjedza. Nkolokosa was a l s o i n v e s t i g a t e d i n 1986 s o l e l y for t h e purpose of r e s e a l i n g meters. Of these areas, Ndirande i s t h e l a r g e s t . The l a s t t h r e e a r e r e l a t i v e l y small and o f medium to h i g h d e n s i t y . 5.4.7 Data Processlnu S e c t i o n Meter consumption i s e n t e r e d and v e r i f i e d as d e s c r i b e d i n S e c t i o n 5.4.2 and 5 . 4 . 7 ( i ) above. An i n i t i a l v e t t i n g r u n f u r t h e r checks t h e v a l i d i t y o f t h e e n t r i e s and r e p o r t s e r r o r s . These a r e passed back t o t h e Revenue s e c t i o n for c o r r e c t i o n . The data e f i t e r e d i n c l u d e s t h e o l d meter r e a d i n g , t h e new r e a d i n g and t h e consumption. The o l d meter r e a d i n g e n t e r e d i n t h e t r a n s a c t i o n i s compared w i t h t h e meter r e a d i n g on t h e f il e . Discrepancies are reported. The meter readers' c a l c u l a t i o n s a r e a l s o checked by t h e system. The master customer r e c o r d s a r e updated upon r e c e i p t o f a p p r o v a l by t h e Revenue s e c t i o n . C o r r e c t e d transactions a r e r e - e n t e r e d a t a l a t e r time.  Management r e p o r t s and i n v o i c e s a r e produced d a i l y . The d l s t r l b u t l o , and c o n t e n t of management i n f o r m a t i o n r e p o r t s is described i n S e c t i o n 5.4.4 above. Suggestions for t h e Improvement I n t h e r e p o r t i n g system a r e g i v e n below. Accounts a r e closed a t month end, which, for t h e Data processing s e c t i o n , occurs a t t h e end o f t h e 9 t h day o f t h e f o l l o w i n g month. Thus t h e sales recorded for t h e month o f J u l y a r e closed on t h e 9 t h o f August. Accounts f o r which a c l o s i n g t r a n s a c t i o n has been e n t e r e d a r e n o t d e l e t e d u n t i l t h e f i n a l i n v o i c e has been s e t t l e d . U n t i l t h l s happens t h l s becomes a suspense account. The meter readers ' S e c t i o n Leaders general l y e s t i m a t e t h e consumption f o r unread meters as d e s c r i b e d i n S e c t i o n 5.4.2(1) above. Accounts where t h i s has n o t happened and for which no consumptlon has therefore been e n t e r e d a r e known as 'presumptive'. The consumption i s e s t i m a t e d by t h e computer as equal t o t h e l a s t months consumptlon. This p r a c t i c e d i f f e r s f r o m t h a t o f t h e S e c t i o n Leaders who base t h e i r e s t i m a t e on t h e average o f the p a s t t h r e e months consumptlon. Presumptive b i l l s a r e r e p o r t e d I n an Exceptions Report. A t month end a l i s t i s compiled o f a l l books for which no t r a n s a c t i o n s have been r e c e i v e d . Account numbers a r e generated by t h e Data p r o c e s s i n g s e c t i o n and passed t o t h e Areas and D i s t r i c t s i n batches. Suaaested Improvements i n Computerised Svstems New Connections The procedures f o r t h e r e c o r d i n g of t h e connection o f new consumers before a supply i s given, as d e s c r i b e d i n S e c t i o n 5.4.2(1) above, a r e manual. No checks e x i s t , o u t s i d e t h e o b s e r v a t i o n of t h e meter readers, t o p r e v e n t consumers being connected and n o t b i l l e d . T h i s c o u l d be by o v e r s i g h t or d e l i b e r a t e . I t w i l l be a r e l a t i v e l y minor procedural change t o open a master customer r e c o r d as soon as a f o r m I s completed by a customer r e q u e s t i n g a connection. Upon completion of t h e connectlon t h e r e c o r d would be updated and b i l l s sent. The system should r e p o r t those Instances where delays of t h r e e , s i x , n i n e and' t w e l v e months occur between t h e r e q u e s t and connection. The r e p o r t would add v a l u a b l e management information i n a d d i t i o n t o i t s r o l e i n reducing the r i s k o f losses. 5.5 E c o m l c and F i n a n c i a l A n a l y s i s 5.5.1 Financial Analvsif The financial a n a l y s i s of non-technical losses i s ~ a s e d on determining t h e I n t e r n a l f i n a n c i a l r a t e o f r e t u r n . To t h i s end, a l l of t h e f i n a n c i a l c o s t s and b e n e f i t s a t t r i b u t a b l e t o  t h e r e d u c t i o n o f non-technical losses were c a l c u l a t e d . I t was f i r s t necessary t o estimate the l e v e l of non-technical losses on the system. As was d e t a i l e d i n Section 5.2 losses t h a t were found as a r e s u l t of measurement and meter checking are as f o l l o w s : Metering e r r o r s a t power s t a t i o n s 2.7% Metering e r r o r s i n the small and l a r g e power categories 1.x F u r t h e r t o t h i s i t i s estimated t h a t some 2 . n of non-technical losses s t i l l e x i s t on the system these may be s p l i t i n t o categor ies as f o l 1ows : Small power losses Domestic General I n the small power category, losses were c a l c u l a t e d from the I n d u s t r i a l Consumer Meter Accuracy Results Table 5.2.2 from which a l l those consumers t h a t could be considered t o be l a r g e power were e l i m i n a t e d ( l e , SUCOMA, David Whitehead). The l o s s i n t h i s category i s c a l c u l a t e d from the remaining consumers, which was consldered t o be a reasonable sample o f some 8% o f the small power consumers selected a t random. I n the domestic category a n a l y s i s of t h e b i l l s of those consumers found t o be t a k i n g i l l e g a l supply was undertaken. This showed t h a t where a consumer was found t o be t a k l n g i 1l e g a l supply i n the h i g h d e n s i t y and low d e n s i t y categorles some 202 kwh were s t o l e n on average. This represents some 7% o f average consumption per consumer i n the domestic category. I t i s assumed t h a t 5% o f domestic c0nsumer.s a r e t a k l n g I l l e g a l supply, whlch I s consldered a reasonable estimate s i n c e I t i s known t h a t f r a u d i s f a i r l y common I n t h e domestic s e c t o r . I n t o t a l some 3.9% o f t h e energy i n t h i s category I s estlmated t o be l o s t through non-techni c a l losses, g i v l ng an o v e r a l l system l o s s o f 0.6%. I n the general category i t i s assumed t h a t a consumer who i s s t e a l i n g e l e c t r i c i t y w l l l o n l y pay for 25% o f h i s a c t u a l consumption. I t i s f u r t h e r assumed, I n the absence of any o t h e r data, t h a t some 10% of consumers I n t h i s category a r e s t e a l l n g energy. This I s considered a reasonable estimate since the general category and I n p a r t i c u l a r t h e maize m i l l s and garages are n o t o r i o u s f o r t h i s k i n d o f t h e f t . Losses I n t h i s category are t h e r e f o r e estlmated . t o be 7.5% o f consumption, r e p r e s e n t l n g 6 G W h and 1 .O% losses on t h e system. I n c a l c u l a t i n g streams o f non-technical losses I t I s assumed t h a t the o v e r a l l non-technical losses I n t h e small power domestic and general c a t e g o r i e s w i l l f a l l t o 0.5% by t h e end o f 1995, whlch i s consldered a reasonable t a r g e t f o r t h e measures proposed, and w l l l be maintained a t t h l s l e v e l t h e r e a f t e r .  Losses are valued using the current average t a r i f f i n each category and the b e n e f i t s are determined i n the loss reduction by assuming the reduction t o 0.5% by 1995, and I n the case w i t h no loss reduction by assuming t h a t the current losses remain constant over tlme. This i n r e a l i t y represents a somewhat pessimistic view I n c a l c u l a t i n g r a t e s o f r e t u r n , as I n general i f no a c t i o n were taken against non-technical losses they would Increase over tlme ( I n terms o f Kwh) r a t h e r than remaining constant . The costs o f reducing non-technical losses Include a b i l l i n g system software, meter boxes socket o r type meters, meter p l i e r s , two meter t e s t benches I n Blantyre and a meter t e s t room. The requirements o f the b l l l i n g system are d e t a i l e d I n Section 5.3. The cost o f the b i l l i n g system software I s estlmated t o be MK1,082,005 plus an annual software r e n t a l and maintenance charge o f MK166,740. Software MK 1,082,005 Q u a r t e r l y Software - r e n t a l /ma1 ntenance MK 166,740 H l t h regard t o meter boxes there are a number o f options. F i r s t l y i t I s envisaged t h a t i n the long term a l l meters should be placed i n sealed boxes, and t h a t these should have a transparent f r o n t so t h a t the meter may be read without having t o open the box. I n t h i s way any person w l shlng t o access the meter box would have t o f i r s t break the seal. I t I s , however, d i f f i c u l t t o e s t a b l i s h the benefits t h a t are d i r e c t l y a t t r i b u t a b l e t o i n s t a l l i n g meter boxes since w h i l s t meter tampering would be immediately evident, meter by-passes would st11 1 be possible. A c r u c i a l requirement t o prevent tampering I s t h a t meter p l i e r s are under s t r i c t l y c o n t r o l l e d issue, and are o n l y a v a i l a b l e t o those peo,ple who are empowered t o seal both meters and boxes. I t I s therefore recommended t h a t f i f t y p a i r s o f meter p l i e r s are purchased a t M K 173 per p a i r . I t i s assumed t h a t a l l new connections would be c a r r i e d o u t using the meter boxes and t h a t t h l s would be a t the expense o f the consumer and would be I n s t a l l e d by the consumer. ESCOM would I n s t a l l and seal the meter i n the normal way. The meter box would a l s o be sealed by ESCOM. There would therefore be negl l g i b l e addi'tional cost t o ESCOM. I n the case of e x i s t i n g consumers i t I s envisaged t h a t a l l meters I n the Small Power, High Density, Low Density and General categories could be placed I n sealed boxes w i t h i n a period o f f i f t e e n years. The e n t i r e cost o f t h l s would be borne by ESCOM. The cost of meter boxes I s estimated t o be M K 60 f o r a s i n g l e phase box and M K 140 f o r a three phase box. The cost of labour t o I n s t a l l these I s estlmated t o be M K 100 per day f o r a three man team comprising a meter f i t t e r , an a s s i s t a n t and a d r i v e r . I t i s estlmated t h a t a s i n g l e phase  box would r e q u i r e one day t o f i t and t h a t a three-phase box would r e q u i r e two days t o f i t . The l e v e l o f commitment r e q u i r e d t o complete t h l s p r o j e c t would be e i g h t teams f o r f i f t e e n years. The cost of e i g h t vehicles has a l s o been Included. A second approach, I n the l i g h t of 'the d i f f i c u l t y I n assigning b e n e f i t s t o the I n s t a l l a t i o n o f meter boxes, would be a t h r e e stage p r o j e c t . (i) r e q u i r e t h a t a l l fiew meters are placed i n sealed boxes. (11) f o r c e a l l consumers found s t e a l i n g t o have sealed boxes. Thfs could be added t o the ' f i n e ' Imposed on meter tamperers by ESCOM as f o l l o w s : Box MK 60 F it t l n g MK 100. I t could t h e r e f o r e increase the p e n a l t y f o r meter f r a u d by MK 160 for s i n g l e phase consumers. (111) assess the l e v e l o f benefits t o be obtained by i n s t a l l i n g meter boxes by r e p l a c i n g a l l o f the boxes in a particular area and a c c u r a t e l y m o n i t o r i n g the r e s u l t s . Even though the l e v e l o f b e n e f i t s a r i s i n g from i n s t a l l i n g meter boxes i s somewhat indeterminate, i t i s expected t h a t t r i a l s w i l l show t h a t the f u l l programme o f I n s t a l l a t i o n I s f i n a n c l a l l y v i a b l e and i t I s t h l s programme t h a t has t h e r e f o r e been included i n the f i n a n c i a l a n a l y s i s . As a l t e r n a t i v e a n a l y s i s has a l s o been considered f o r the I n s t a l 1a t i o n o f socket-type meters, a slmi l a r programme of i n s t a l l a t i o n should be c a r r i e d o u t as d e t a l l e d above f o r meter boxes. Thus the b e n e f i t s can be assessed. For the purposes of t h i s analysi s the benef it s obtained from i n s t a l 1i n g socket-type meters are considered t o be the same as from i n s t a l l i n g meter boxes. Whll s t socket-type meters prevent tampering w i t h the connections t o the meter, they do n o t prevent tampering w l t h the meter I t s e l f . Conversely sealed meter boxes w i l l prevent tampering w i t h the meter b u t n o t the connections t o i t . The c o s t of socket type meters i s as follows: Single Phase MKlOO Three Phase MK650 Plus I n s t a l l a t l o n as d e t a l l e d f o r the meter boxes, giving a t o t a l i n s t a l l e d c o s t as follows:  S i n g l e Phase MK200 Three Phase MK850 W h i l s t a n a l y s i s was c a r r l e d o u t on t h i s b a s i s , i t was considered 1 ik e l y t h a t i n s t a l l a t i o n c o s t s f o r socket-type meters would be h i g h e r than f o r meter boxes. A f u r t h e r s t u d y was t h e r e f o r e c a r r l e d o u t w l t h I n s t a l l a t i o n c o s t mu1 t i p l l e d by a f a c t o r o f 1.75. The c o s t o f two meter t e s t benches and a meter t e s t room have been i n c l u d e d t o r e p l a c e t h e two meter t e s t benches i n B l a n t y r e . These a r e a t an estimated cost o f M K 170,000 each f o r t h e t e s t benches and M K 80,000 f o r t h e t e s t room. The c o s t of f i f t e e n s o l i d s t a t e t e s t meters has a l s o been i n c l u d e d a t MK 5,000 each. A l l of t h e above c o s t s a r e based on budget p r i c e s o b t a i n e d f r o m recognised suppliers o f the products. The r e s u l t s o f t h e a n a l y s i s a r e presented i n Tables 5.6 t o 5.8. Table 5.6 shows t h e a n a l y s i s I n c l u d i n g meter boxes, g i v i n g an I n t e r n a l F i n a n c i a l Rate o f Return (IFRR) o f 37.6%. Table 5.7 shows t h e analysls i n c l u d i n g socket t y p e meters w i t h the lower I n s t a l l a t i o n c o s t , g i v i n g an IFRR o f 31.3%. F i n a l l y Table 5.8 shows a n a l y s i s w i t h socket t y p e meters and t h e h l g h e r i n s t a l l a t i o n c o s t , g i v i n g an IFRR o f 24.76%. Thus w h i l s t a l l t h r e e o p t i o n s a r e v i a b l e t h e i n s t a l l a t l o n o f meter boxes r e p r e s e n t s t h e most f a v o u r a b l e IFRR. 5.5.2 Economi c Anal vs is The economic a n a l y s i s i s c a r r l e d o u t u s i n g t h e same methodology as f o r t h e f l n a n c l a l a n a l y s i s . The c o s t s and b e n e f i t s d e t a i l e d above a r e a l l r e l e v a n t t o t h e economlc a n a l y s i s w i t h t h e e x c e p t i o n t h a t o n l y 30% o f t h e c o s t o f t h e b i l l i n g system has been i n c l u d e d . T h i s r e f l e c t s t h e l o s s r e d u c t i o n purpose o f t h e b i l l i n g system. There i s a l s o an a d d i t i o n a l b e n e f i t i n t h e form of resource c o s t savings. Resource c o s t savings a r i s e f r o m t h e f a c t t h a t t h e consumer wl11 use more e l e c t r i c i t y I f he I s n o t b e i n g charged f o r I t than he w i l l i f he has t o pay t h e f u l l p r i c e f o r e v e r y u n i t consumed. T h i s may be r e p r e s e n t e d as t h e area BCD i n F i g u r e 5.1. The r e s o u r c e c a s t saving i s s i m p l y c a l c u l a t e d i n t h e domestic c a t e g o r i e s by assuming t h a t each consumer has two c i r c u i t s - l i g h t i n g and sockets and t h a t where t h e meter i s by-passed i t w i l l be t o a v o i d p a y i n g f o r t h e consumption on t h e sockets. The average domestic consumer i n Malawi consumes 2918 kwh p e r year. A n a l y s i s o f t h e b i l l s o f t h o s e consumers caught w i t h meter by-passes r e v e a l s t h e f o l low1 ng In f o r m a t l o n : (1) assuming t h a t a l l u n i t s consumed for t h e purposes o f 1 i g h t i ng a r e metered, t h e annual consumption p e r consumer f o r l i g h t i n g i s 1284 kwh.  (11) on average, a consumer caught with a meter by-pass consumes 3660 kwh per annum. I n Figure 5.1 consumptlon on the socket when t h e consumer i s paying f o r a1 1 the energy he consumes, i s represented by p o i n t A. Thls i s c a l c u l a t e d as f o l l o w s . Average consumption by consumer not by-passing meter - consumption f o r l i g h t i n g : P o i n t B i s the consumption on the socket when the consumer i s by-passing the meter. Thls i s c a l c u l a t e d as f o l l o w s : Average consumptlon by consumer by-passing meter - consumptlon f o r lighting: The resource c o s t savings i n t h i s category are shown i n Figure 5.1 and assuming an average t a r i f f o f 0.15 MK/kWh these a r e equal t o 0.075 MK/KIJh. This i m p l i e s t h a t the average meter bypasser i n t h e domestic sector i s s t e a l i n g e l e c t r i c i t y t o the value o f 55.6 M K per annum. Resource cost savings I n the small power and general category have not been c a l c u l a t e d due t o i n s u f f i c i e n t data, however, i t has been assumed t h a t t h e Resource Cost Savings I n these sectors are 0.075 MK/kWh. I t I s n o t expected t h a t t h l s w l l l have any s u b s t a n t l a l e f f e c t on t h e economic v l a b l l l t y o f t h e p r o j e c t . I n the general category i t i s we1 1 known and accepted t h a t t h e f t i s hlgh, e s p e c i a l l y among t h e maize m l l l s and garages. I n the small power category i t appears t h a t fraud i s n o t so hlgh, however there a r e s t 1 11 metering e r r o r s t o be detected. I n c o r r e c t meter readings and lower b i l l s may encourage consumers I n t h l s sector t o be more p r o f l i g a t e than they otherwise would be and thus resource cost savings have been Inc 1uded . The costs f o r the economic a n a l y s i s a r e t h e same as f o r the f i n a n c i a l a n a l y s i s except t h a t o n l y 30% o f the b l l l l n g system cost has been taken t o be a t t r i b u t a b l e t o l o s s r e d u c t i o n . The b i l l i n g system has a v a r i e t y o f purposes o t h e r than l o s s reduction. For example, i t w i l l speed and ease t h e b i 11 l n g process and the hardware w l l l need t o be s p e c i f i e d n o t o n l y t o r u n the b i l l i n g system, b u t a l s o programme such stock c o n t r o l and p a y r o l l . The r e s u l t s o f the analysls are I n d i c a t i v e only o f the economlc r a t e o f return. Tables 5.6, 5.7 and 5.8 show Economic Rates o f Return f o r meter boxes. socket-type meters and socket-type meters w l t h a higher i n s t a l l a t i o n cost o f 16.4%. 8.78% and 0.19% respectively. I t i s therefore I n d i c a t i v e t h a t only the i n s t a l l a t i o n o f meter boxes i s economically vlable.  SECTION 6 CONCLUSIONS AND RE-ENDATIONS 6. CONCXUSIONS AND RECOWENDATIONS 6.1 E x l s t i n g System Losses The measurement and a n a l y s i s work d e s c r l b e d above has enabled an e s t i m a t e t o be produced of t h e e x i s t i n g t e c h n i c a l losses associated w i t h t h e v a r i o u s v o l t a g e l e v e l s on t h e ESCOM system, t o g e t h e r w i t h t h e non-technical losses which have been accounted f o r t o date, and those whlch a r e e s t l m a t e d t o be remaining on t h e system. I n producing the t e c h n i c a l l o s s estlmate, i t I s tmportant t o take due cognlsance o f loads which a r e s u p p l i e d from each v o l t a g e l e v e l and the losses a s s o c i a t e d w i t h each l e v e l and t o s u b t r a c t these from t h e energy whlch I s s u p p l i e d through t h e lower l e v e l s , i n o r d e r t o a v o i d c a l c u l a t i n g an unduly p e s s i m i s t i c l o s s e s t i m a t e . F i g u r e 6.1 shows the assessment o f t e c h n i c a l losses performed I n t h i s way, working on the assumption t h a t l a r g e power consumers are s u p p l i e d f r o m t h e 132166133 kV system, small power f r o m t h e 11 kV system and domestic and general consumers f r o m t h e LV network. The t e c h n i c a l energy l o s s percentages used a r e taken f r o m t h e r e s u l t s of t h e a n a l y s i s d e s c r i b e d i n S e c t i o n 4 f o r each o f t h e elements o f the transmission and d i s t r l b u t l o n systems.. For t h e case o f the small power consumers, h a l f o f t h e l o a d i s shown s u p p l l e d from the 11 kV system d i r e c t l y and h a l f through 11 kVlLV t r a n s f o r m e r s . This makes an allowance f o r t h e f a c t t h a t some of t h e l a r g e s t small power consumers a r e HV metered, and t h e losses a s s o c i a t e d w i t h t h e i r t r a n s f o r m e r s do n o t t h e r e f o r e appear as a l o s s t o ESCOM. The r e s u l t s o f t h i s a n a l y s i s i n d i c a t e t e c h n i c a l losses o f 10.1% and i n i t i a l non-technical losses o f 6.911, g i v i n g an e s t l m a t e d t o t a l energy l o s s f i g u r e o f 17% o f n e t generated energy f o r t h e system a t the s t a r t o f t h e study. This compares q u l t e favourably w i t h t h e ESCOM f i g u r e o f 16.3% whlch a p p l i e d f o r 1989. The non-technical losses found d u r l n g t h e p e r l o d of t h l s study account f o r 4% o f t h e n e t generated energy, suggesting t h a t o v e r a l l the remaining system l o s s l e v e l I s r u n n i n g a t approximately 13%. 6.2 Losses A f t e r Loss Reductlon Indicative l e v e l s o f losses a f t e r t h e i n t r o d u c t i o n of t h e v a r i o u s l o s s r e d u c t i o n measures whlch have been discussed above have been c a l c u l a t e d t o g i v e an e s t l m a t e of t h e t a r g e t l o s s l e v e l whlch should be o b t a l n a b l e f o l l o w l n g ' t h e implementation o f t h e recommendations contained I n t h l s r e p o r t .  Figure 6.2 sumarises the predicted l e v e l s o f losses a f t e r the 1ntroduction of loss reduction measures, based on the reduction i n losses observed from the sample studies performed a t each voltage l e v e l . I t i s assumed t h a t the percentage loss l e v e l s calculated a f t e r the i n t r o d u c t i o n o f loss reduction measures on the system i n 1991 are malntalned as t a r g e t l e v e l s durlng the development o f the system, and t h a t the goal of achieving 0.5% non-technical losses by 1995 I s maintained as the t a r g e t level f o r non-technical losses t h e r e a f t e r . The r e s u l t s of t h i s analysis show a t a r g e t technical energy loss l e v e l of 9.1% o f net generation, which, when combined w i t h 0.5% non-technical losses, gives an o v e r a l l f i g u r e o f 9.6%. This i s considered a r e a l i s t i c t a r g e t l e v e l on the basis o f foregolng analysis, and i s i n l i n e w i t h the i n i t i a l estimate used i n preparing the load forecast a t the outset o f the study. The recommendatlons f o r loss reduction projects which have been described i n the main body o f the r e p o r t are summarised below. 6.3.1 132166133 kV Svstem The r e s u l t s o f the work c a r r i e d out on the transmission system Indlcate t h a t there i s very l i t t l e work which can be j u s t i f i e d i n add1 t i o n t o the developments which are already programmed by E SCOM i n order t o reduce losses. Upgrading of the Mtunthama 105 33 kV c i r c u i t t o 66 kV operatlon I s a j u s t i f i a b l e loss reductlon measure due t o the f a c t t h a t the l i n e I s already constructed f o r 66 kV operation ( s e c t i o n 4.2.2). The Least Cost Development Plan f o r the E SCOM system Included recommendations f o r the I n s t a l l a t i o n o f s t a t i c compensation equipment on the 132 kV system. H h l l s t the c a p i t a l cost o f such equlpment I s such as t o make I t u n a t t r a c t l v e when viewed s o l e l y from the angle o f loss reductlon, b e n e f i t s I n terms o f reduced losses should be examined If the current work being c a r r i e d o u t i n the Transmlsslon and D l s t r i b u t l o n Study recommends it s I n t r o d u c t i o n as p a r t of the optlmal development o f the system. I t i s recommended t h a t the design loading levels f o r conductors whlch have been developed I n t h l s r e p o r t are used as the basis for planning the transmission system w i t h a view t o mlnimislng losses a t a l l s.tages o f system development ( s e c t i o n 4.2.2). 6.3.2 I 1 kV Svstem A substantial programme o f feeder reconductoring a t 11 kV i s proposed, together w i t h l i m i t e d a p p l i c a t i o n of capacitors, on account of the generally good system power factors. Reconductorlng generally takes the form o f i n t r o d u c i n g a new 150 sq mm conductor slze a t 11 kV, together w i t h some cable replacement (section 4.3.4).  I t I s recommended t h a t t h e o v e r a l l c o n f i g u r a t i o n of t h e 11 kV system be o p t i m l s e d I n terms o f l o s s m l n j m i s a t i o n once t h e b a s i c system p l a n has been e s t a b l i s h e d I n t h e Transmlsslon and D i s t r i b u t i o n Study. I t i s a n t i c i p a t e d t h a t t h e study should I n c l u d e c o n s i d e r a t i o n o f losses as a m a t t e r o f course, b u t I t i s emphasised t h a t f o r f u l l b e n e f i t t o be d e r i v e d f r o m t h e design c r i t e r i a presented i n t h i s r e p o r t a c o o r d i n a t e d approach t o t h e o p t i m l s a t i o n o f t h e 11 kV system should be adopted. I t i s a l s o recommended t h a t a t an o p e r a t i o n a l l e v e l ESCOM should examine t h e e f f e c t s o f s w i t c h i n g o p e r a t i o n s and consequent l o c a l system r e c o n f i g u r a t i o n i n terms o f losses as p a r t o f the1 r normal procedures. Proposals have been developed f o r t h e purchase o f 11/0.4 kV transformers (section 4.4.2) and the execution o f LV r e c o n d u c t o r l n g p r o j e c t s ( s e c t i o n 4.4.4) w i t h a view t o r e d u c i n g losses associated w i t h d i s t r l b u t 1 o n t r a n s f o r m e r s and LV systems. The magnitude o f t h e t a s k o f o p t i m i s i n g t h e d e t a i l e d investment programme based on these measures I s such t h a t i t can o n l y e f f e c t i v e l y be f i n a l l s e d by means of a d e t a i l e d LV study whereby t r a n s f o r m e r placement and LV feeder l e n g t h s can be c o o r d i n a t e d t o mlnimlse losses o v e r a l l . I t I s envisaged t h a t t h i s work c o u l d be c a r r i e d o u t w i t h c o n s i d e r a b l e i n p u t from ESCOM's C e n t r a l Planrling U n i t I n c o n j u n c t i o n w i t h a d l s t r l b u t i o n p l a n n i n g s p e c i a l i s t , and a proposal based on t h i s approach has been included. I n the l o s s r e d u c t l o n package and i s discussed I n more d e t a i l I n t h e e a r l i e r s e c t i o n s of t h i s r e p o r t ( s e c t i o n 4.4.51. Load b a l a n c i n g on t h e LV systems has been shown t o p l a y an I m p o r t a n t r o l e b o t h I n r e d u c i n g l o s s l e v e l s and I n Improving v o l t a g e s a t remote ends o f t h e .feeders. This measure I n v o l v e s minimal c a p i t a l c o s t , and i s t h e r e f o r e s t r o n g l y recommended as a l o s s r e d u c t l o n measure ( s e c t i o n 4 . 4 . 4 ) . The v o l t a g e p r o f 1 l e across t h e LV networks i n general would be s u b s t a n t i a l l y improved by changing t h e t a p s e t t i n g s on a l l o f t h e 11 kV/LV and 33 kV/LV transformers t o t h e i r +5% l e v e l s . Most o f t h e d i s t r i b u t i o n t r a n s f o r m e r s are c u r r e n t l y o p e r a t i n g on nominal t a p , and n o t t h e r e f o r e u t i l i s i n g t h e o p p o r t u n i t y t o improve v o l t a g e s a t consumer's premises. 6.3.4 Non-technical Losses The key rec~mmendations r e l a t i n g t o non-techni c a l loss r e d u c t i o n i n v o l v e a number o f c a p i t a l purchases and measures t o Improve organisational aspects of the detection and i n v e s t i g a t i o n o f losses a r i s i n g f r o m m e t e r i n g e r r o r s and fraud. I n summary, these recommendations a r e as f o l l o w s :  Implementation o f a new computer b i l l i n g system ( s e c t i o n 5.3). v I n s t a l l a t i o n o f meter boxes a t a l l new consumers' premises and r e t r o s p e c t i v e l y a t a1 1 small power, high densl t y , low densl t y and general consumers (sections 5.2, 5 . 5 ) . Purchase o f two meter t e s t benches and c o n s t r u c t i o n o f a new meter t e s t room I n Blantyre ( s e c t i o n 5 . 2 ) . Purchaseofflftypairsofmeterpliers. Purchase o f f i f t e e n s o l i d s t a t e kWh meters f o r use by the ESCOM metering department I n c a r r y i n g o u t on-site meter accuracy checks. The organ1 satlonal recommendations r e l a t i n g t o non-technical loss reduction may be sumnarlsed as f o l l o w s and are d e t a i l e d i n section 5.4 o f the r e p o r t : - The incentive f o r c o l l u s i o n between meter readers and tamperers i s considerable. The reward f o r o r d i n a r y meter readers should be r a i s e d to. say, K20 per proven i l l e g a l customer. For speclal meter readers ( d e a l i n g w l t h Small Power customers) the reward should be considerably more a t , say, K50. Addl t i o n a l l y , a d i scretionary payment could be made f o r b i g discoveries o r offences which are c l e v e r l y disguised. The cost o f t h i s could be recovered I n the customer's ' f i n e ' . Rewards should be Index-linked t o annual average pay increases; - Meter readers i n o u t s t a t i o n s should always be replaced by outside r e l i e f readers d u r i n g periods o f leave t o a c t as auditors of the primary reader; - The meter readers reports and deta.11~ o f any i n v e s t i g a t i o n s c a r r i e d o u t against a p a r t i c u l a r customer should be systematlcally malntalned and c i r c u l a t e d t o a l l s t a f f charged w l t h detecting and I n v e s t i g a t i n g I l l e g a l abstractions ( i e , Commercial Manager. Consumers Engineer, D i s t r i c t Engineers and Officers-in-Charge). The f i l i n g should be such as t o enable s t a f f t o q u l c k l y and e a s i l y check on a customer's past mls-deeds and past consumption h l story; - An account number should be a l l o c a t e d and a record entered on the computer as soon as a request I s made f o r a new connectlon. The system should r e p o r t accounts which are experiencing long delays I n connectlon.: These should then be investigated; - Sealing p l i e r s should only be Issued t o Special Meter Readers i n Blantyre and L I longwe. No disconnections o r  reconnections should be made w l thout seal l n g p l i e r s . A l l p l i e r s should be f u l l y accounted for and signed for when they are Issued; - Special meter readers should be given more s p e c l a l i s e d t r a i n i n g t o r e f l e c t the s o p h i s t i c a t i o n o f the meters and customers I n the Small Power category. Speclf l c t r a i n i n g should be Included on current transformer metering methods and the p o t e n t i a l e r r o r s which can r e s u l t from I n c o r r e c t connections I n three phase. metering. - Meter readings should continue t o be undertaken a t random i n t e r v a l s t o prevent consumers becoml ng f a m l l ia r w l t h a r o u t i n e and a n t i c i p a t i n g v i s i t s ; - Opening meter readings should be checked by the b i l l i n g system against the previous closing reading for dlsconnectlons/reconnectlons. - Premises which have been disconnected b u t f a l l t o be reconnected w i t h i n a reasonable period o f time should be reported by the b i 11ing system and Investigated; - 'The ' f i n e ' f o r I l l e g a l abstractors should be t a i l o r e d t o the size o f the consumer. A l i t t l e c r e a t l v l t y could be used t o e a s i l y j u s t i f y the r a i s i n g of the ' f i n e ' t o a l e v e l which might a c t as a r e a l deterrent; - 'The E S C OM p o l i c y o f high p r o f i l e and concentrated I n v e s t i g a t i o n s o f areas should be continued t o reap the maximum pub1 1 c i t y and deterrence value; - The Abnormal Consumption Variations r e p o r t should be made more informative and should be c i r c u l a t e d t o a l l persons responsible f o r detecting and i n v e s t i g a t i n g non-technical losses. The r e p o r t should look f o r both changes I n trend and monthly dips o r splkes r e l a t i v e to 'normal' v a r i a t i o n s . Seasonal v a r i a t i o n s should a l s o be taken i n t o account. Abnormal v a r i a t i o n s I n kVA readings should a l s o be reported; - Customer master records should include a record o f past mlsbehaviour. This should a l s o be reported I n the event ' o f an Abnormal Vari at1 on; - The ~bnormal Variation Report should Include the customer's consumption h i s t o r y over the past 14 months; - The kVAh readings taken for Small Power consumers should be entered on the customer master record on the computer. The power f a c t o r should be calculated t o a c t as a cross-check on the accuracy o f the kwh and kVA meters. I f the power f a c t o r f a l l s below, say, 0.8 a warning r e p o r t should be sent t o the Commercial Manager f o r f u r t h e r Investigation. 6.3.5 General Contl nued monl toring of both techni cal and non-techni cal losses Is important both in terms o f enabling the finalisation o f the LV loss reductlon programme and in terms of tracing sources of meter errors and consumer fraud. In order to facil itate this It is strongly recommended that two "Dranetz" power demand analysers and accompany1 ng personal computers and software be purchased for ESCOM aa part o f the loss reduction package, particularly in view of the experience which has been gained in effectively using thls equipment by engineers In both the metering and planning functions of ESCOM. 6.4 Budgetary Requirements Budgetary requirements for each loss reduction project have been given in the main text expressed in Malawi Kwacha. These are now summarised in Table 6.1, split into foreign and local cost components, based on constant 1990 costs. The overall budgetary requirements identified including contingencies, amount t o US$ 13.8 m o f foreign costs, with an associated MK 13.2 m local component. The overall package is equivalent to US$ 19.1 m. The significance o f the LV system component in the overall budget, together with the sum for distribution transformer replacement, reinforces the need for further attention to be paid to the overall optimisatlon o f the LV systems prior to the implementation of a large scale reconductoring and transformer replacement programme at thls level. The fact that overall the loss reduction budget is lower than would be expected in some situations reflects the findings of the study with regard t o economic loss levels, particularly relating t o the transmission system. It is also indicative of the ' relatively small investment required t o attack non-technical losses, which form a significant component of the existing loss level on the ESCOM system and which have already been substantially reduced simply by monl toring consumers' ' Instal latlons and makl ng straightforward corrections o f metering errors. Through thls process alone, over MK 0.4 m o f annual revenue has already been recovered. Subject to the observations made regarding the need for further work on the L V systems, these investment levels may be viewed as adequate t o bring losses on the ESCOM system down t o an economic level. 6.5 Program The programme proposed for the execution o f the various loss reductlon projects is designed t o enable the various recommendations to be implemented within five years. This Is considered a reasonable timescale in which t o attain the target loss level of 10% for the system as a whole. The exception to t h e f i v e year implementation p e r i o d i s t h e scheme for I n s t a l l i n g meter boxes, which i s i n t e n d e d t o r u n through a f i f t e e n year p r i o r due t o t h e number o f consumer I n s t a l l a t i o n s requiring modification. The r a t e s o f r e t u r n a s s o c i a t e d w i t h l l k V r e c o n d u c t o r i n g and non-technical l o s s r e d u c t i o n a r e such t h a t they r e p r e s e n t t h e p r o j e c t s which should be undertaken as t h e h i g h e s t p r i o r i t y . They a r e a l s o q u i t e s e l f - c o n t a i n e d , as s u b s t a n t i a l changes to r e c o n d u c t o r i n g recommendations a r e u n l i k e l y t o r e s u l t f r o m o p t i m i s a t i o n of t h e l l k V d i s t r i b u t i o n systems. On t h e assumption t h a t one gang i s dedicated t o t h e t a s k o f r e c o n d u c t o r i n g t h e 59km o f 11kV feeders identified for I n c l u s i o n i n the p r o j e c t , a t i m e a l l o c a t i o n o f approximately s i x months i s i n c l u d e d i n t h e programme f o r t h i s a c t i v i t y . This a l l o w s some contingency f o r such items as p o l e replacement which may be found necessary d u r i n g t h e course of t h e p r o j e c t . With r e g a r d t o non-technical l o s s e s , t h e most t i m e consuming a c t i v i t y i s l i k e l y t o be t h e i n t r o d u c t i o n of a new b i l l i n g system. This w i l l necessitate periods o f s p e c i f i c a t i o n , software p r e p a r a t i o n , t e s t i n g and t r a i n l n g p r i o r t o handing o v e r , and i s thus l i k e l y t o t a k e up t o e i g h t e e n months f o r completion. Shorter p e r i o d s a r e envisaged f o r t h e procurement o f t h e meter t e s t benches and t h e o t h e r items; c l e a r l y t h e new meter t e s t room would need t o be complete b e f o r e t h e t e s t benches a r r i v e , b u t since a p e r i o d o f some t w e l v e months i s l i k e l y t o be r e q u i r e d f o r the benches t o be s p e c i f i e d , tenders t o be r e c e i v e d and the benches t o be supplied, t h e b u l l d i n g should e a s i l y be complete w i t h i n t h i s p e r i o d . Before work can be c a r r i e d o u t on LV system r e c o n d u c t o r i n g and t r a n s f o r m e r replacement, f u r t h e r study w i 11 be needed t o o p t l m l s e t h e p o s i t l o n i n g o f d i s t r i b u t i o n t r a n s f o r m e r s and t h e c o n f i g u r a t i o n o f LV c i r c u i t s . I t i s envisaged t h a t t h i s would be performed a t the s t a r t o f t h e f i v e year programme, and would comprise a one month p e r i o d o f works undertaken by a d i s t r i b u t i o n p l a n n i n g s p e c l a l i s t working w i t h t h e ESCOM c e n t r a l p l a n n i n g u n i t , f o l l o w e d by a p e r i o d o f approximately s i x months d u r i n g which ESCOM would a p p l y t h e techniques e s t a b l i s h e d I n t h e f i r s t v l s i t t o o p t l m i s e t h e LV systems across t h e network. The r e s u l t s of t h i s a n a l y s i s would thus be combined i n t o a r e v i s e d statement o f t h e LV d l s t r l b u t l o n system requirements and budget assessment. On t h e b a s i s o f t h e work c a r r i e d o u t t o d a t e , i t i s l i k e l y t h a t some 500km o f t h e LV system would r e q u i r e r e c o n d u c t o r l n g , w i t h over two hundred new transformers t o be purchased and t h r e e times t h a t number o f replacements and swaps. This amount o f work, coupled w i t h t h e b a l a n c i n g of LV l o a d s , would r e q u i r e t h e resources o f a t l e a s t t h r e e gangs of linesmen, w i t h one o v e r t o c a r r y o u t t h e transformer replacements s i m u l t a n e o u s l y w i t h t h e reconductoring work on each feeder, t o minimise load i n t e r r u p t i o n s , I f i t I s t o be achieved w i t h i n t h e f o u r years remaining a f t e r t h e LV o p t i m i s a t i o n study.  The 33kV t o 66kV upgrading o f Mtunthama 105 feeder i s the l a s t .project t o be implemented on the basis of loss reduction, and i s programed f o r i n c l u s i o n i n the f i n a l year o f the f i v e year period. Figure 6 . 3 summarises the above programme i n the form o f a bar chart I n d i c a t i n g the r e l a t i o n s h i p between the p r o j e c t s i n terms o f t h e i r execution times. SECTION 7 REFERENCES 7. REFERENCES Power System Loss R e d u c t i o n Study f o r t h e E l e c t r l c l t y Supply Commlsslon of Malawl - I n t e r l m Reports Nos. 1 and 2 (KDP, August and December 1990). Study t o update ESCOM's L e a s t Cost Development Programme - F l n a l Report (KDP/HLPU A p r l l 1988). Load R e p r e s e n t a t i o n i n Power System S t a b i 1 it y Studies, Concordla & I h a r a , I E E E PAS-101 No. 4, 1982.  APPENDIX A EFFECT O M MIMESTIC ELECTRICITY COWSUUPTIOW F VOLTAGE C  EFFECT OF CHANGES IN VOLTAGE ON ELECTRICITY CONSUMPTION Change in Voltage from 219 to 230 Volts ie 5.0% APPLIANCE % OF SHORT TERM LONG TERM TYPE TOTAL Power Energy Power Energy Incandescent Lighting 15% 8% 8% 4% 4% Fluorescent Lighting 15% 3% 3% 12% 12% Water Heaters 15% 10% 0% 5% 0% Refrigerators & Freezers 40% 4% 0% 12% 0% Fans & Air Conditioners 10% 0% 0% 10% 0% Televisions 5% 10% 10% 20% 20% Induction Motors 0% -0% -0% 10% 10% Computers & Electronics 0% 0% 0% 10% 10% OVERALL EFFECT 5% 2% 10% 3% Notes: Short Term Thermostatic Failure if Consumer Variation Control Voltage low Compensation Idp%/dW Incandescent Lighting 1.6 No No Yes Fluorescent Lighting 0-7 No Yes Yes Water Heaters 2.0 Yes No No Refrigerators & Freezers. 0.8 Yes Yes No Fans & Air Conditioners 0.0 Yes Yes No Televisions 2.0 No Yes No Induction Motors -0.1 No Yes No Computers & Electronics 0.0 No Yes No Load Representation in Power System Stability Studies Concordia & hara, IEEE PAS-101 No.4 1982 (56 refr) TJW / 28-Mar-91  EFFECT OF CHANGES IN VOLTAGE ON ELECTRICITY CONSUMPTION Change in Voltage from 190 to 230 Volts ie 21.1% APPUANCE %O F SHORT TERM LONG TERM TYPE TOTAt Power Energy Power Energy Incandescent Lighting 15% Fluorescent Lighting 15% Water Heaters 15% Refrigerators & Freezers 40% Fans & Air Conditioners 10% Televisions 5% Induction Motors 0% Computers & Elechonio 0% 096 0% 10% 10% Notes: Short Term 'Thermostatic Failure if Consumer Va riotion Control Voltage Low Compensation ldp%/dV%l Incandescent Lighting 1.6 No No Yes Fluorescent Lighting 0.7 No Yes Yes Water Heaters 2.0 Yes No No Refrigerators & Freezers 0.8 Yes Yes No Fans & Air conditioners 0.0 Yes Yes No Televisions 2.0 No Yes Induction Motors -0.1 No Yes Computers & Electronics 0.0 No Yes No Reference : Lwd Representation in Power System Stability Studies bncordia & Ihara, IEEE PAS-101 No.4 1982 (56 refs)  132 k v O r m h # d u r w , b w l t 4 132 k ~ O m h r o d h m ( d p d a ) 66 k V 0mh.ad LLwr 33 k V O d m d U n r 11 kVc4uhwdUnr 400/230 V O d d Linr 33 W U n d a g d 6bk 11 kV U n b r g d 6bk 400/230 V U n d r g d 6bh sc.puP 11/132 kVSllbrtdPclc Step-up 11/66 k VShahn shpup 11/33 kV Subatbu Strpup 0.4/3.3/11 kV Subotkro Shp-dom, 33/11 kV Substation, skpdoum 33/0.4/0.23 kV Su&dion, skpdoum 1 1/0.4/0.23 kV S d n m i i Skp-dorm 66/11 kV Subatitnu Skpdom, 66/33 kV Subdion, Shpdcmn 1 32/ 1 1 kV S u b d i SkpAmn 132/66/11 kV S u b a t h I~J& Trondomwn 132/66 W Table 2.1 : Resuhr 0 1 Econometric Analysis LOW DENSIW DOMESTIC: Where: kwh =kwh sales per consumer kwh-1 =kwh lagged one period real pice =averqge price/composite retail price index nos. =consumer numbers RA2=0.913 long Term Relationship: GENERAL: Where: MWh =total MWh sales real prim =average price/GDP deflator RA2=0.994 long Term Relationship: Ln(MWh)=3.32 1+0.804' ln(GDP)-0.874' Ln(real prices)+0.053 'Trend SMALL POWER: Where: GWh =total GWh soles Rh2=0.967 long Term Relationship: Ln(GWh)=-0.411 +LnlGDP)+0.03 'Trend NOTE: Figures in parentheses represent standard errors.  Table 2.2 (Sheet 1 of 21 : ESCOM Load Forecasting MdeC (Author : Kenwdy & Donkin Power Systems, At gust 19901 Lor D" .* Kwh mnrt" Lor Rnu'ty 4500 4614 4527 4dOB 4697 4471 4703 4404 4291 4258 4247 4240 4234 4228 4223 42ii 4212 4207 4201 4156 dl90 -p.--....----..-...---p--..-p-..--------- mn.;cl %US [Cwh] 967 982 6 5 1034 1098 -- 1113 1212 1230 1249 1269 -------- 1209 1309 1329 1349 1370 1391 1413 ----1434 I457 1479 1502 L o r Rnu'ty HiDh Rnrity G".ml h l l Pow., lorg. P o r r r . SUCOMA .B l o n l p Wabr k P d n d Cmmnt .b k l W h i i h d .V&o hr Mill .olhr Lb-4ml bd  Table 2.2 ( S h ~ 2 r of 2) :ESCOM Load E on cast in^ Model a l .R n s * nii an* G~..ol k l Pmru b- - P .SUCOIU - U q n Wo*. b d - PoADd C., .a v i d whi*hd - Vphp hr MI -0llW S v L d b-l ............-.-. -. -. -- - .. . .. --- I N l E I C O N N F C I t D SVSTfM  - Table 2.3 (She& 1 of 2) :ESCOM Load Forecasting Model (Author: Kennedy & Donkin Power, August 1990) Southern Region k0-b rbC- Geld Smd ?m ?dz . ~ W * ~ -)abndu .lhn4dwi -V* -0k hr L(d +k*d k-' HT~ICONNM~O mrw lod Lk h u FirvY  - - 1 o$ooorbu Y=am ;r8882e% E t a ; I5 N S O ~ O O ~ UUN ~ ~ 7 Y 7 g288gNNU ON& LIUUS 13 9-oouu=p ?cub 3 6 8 8 ba~b m. uro- u.00 I 10 - oroo-vve *uuz A N - iE883ti~ ern. 11 Tabla 2.4 (Sheet 2 of 2) :ESCOM Load Forecasting Model Central Region - la) 13.91 15.Q 1 5 1697 17.84 18.69 20.19 2 2 4 . 26.18 28.34 30.35 32.87 35.59 38.54 41.73 9 4 51.05 M.W 6O.m Auk- 0.01 0.W 0.W 0.10 0.10 0.11 0.12 0 2 0.3 0.14 0 bll 0~11 619 0~21 h23 0 2 bid 0.2 0.30 0.33 Table 2.5 (Sheet 1 o - f 2) :ESCOM Load Forecasting Model (Author: Kennedy & Donkin Power Systems, August 1990) Northem Region f % g fI[ - E$ 58 -. 0. \ a, * I y; Z j g z i ! g = ; a ! I , ,r h)  MI MV LV sala Gmwlh cab in sd.r in sda [MW (Mw (K million) (M (MW (K r nw 1989 87.56 66.77 30.08 1990 94.68 7.12 1.60 69.10 2.33 1.57 43.34 ' 13.26 15.21 lWl 108.80 14.12 3.18 81.29 12.19 8.24 37.16 -6.18 0.00 lW2 115.02 6.22 1.40 84.83 3.54 2.39 37.99 0.83 0.95 1993 122.03 7.01 3.17 89.9 1 5.08 3.43 39.83 1.84 2.1 1 lW4 129.95 7.92 8.27 96.39 6.48 4.38 42.66 2.83 3.25 1995 138.52 8.57 14.82 103.66 7.27 4.9 1 46.04 3.38 3.88 1996 149.52 11.00 28.78 11 1.70 8.04 5.43 49.85 3.81 4.37 1997 159.31 9.79 20.69 120.47 8.77 5.93 54.02 4.17 4.78 1998 169.90 10.59 2.39 130.00 9.53 6.44 58.58 4.56 5.23 l9W 181.31 11.41 2.57 140.34 10.34 6.99 63.56 4.98 5.71 2000 1 93.53 12.22 7.71 151.53 11.19 7.56 68.97 5.4 1 6.20 2001 206.53 13.00 2.93 163.62 12.09 8.1 7 74.82 5.85 6.71 2002 220.56 14.03 3.16 176.71 13.09 8.85 81.20 6.38 7.32 2003 235.56 15.00 3.38 190.73 14.02 9.48 88.00 6.80 7.80 2004 251.98 16.42 3.70 206.15 15.42 10.42 95.64 . 7.64 8.76 2005 269.56 17.58 3.96 222.68 16.53 11.17 103.80 8.16 9.36 LFmmlVdue (h) 59.70 58.25 69.44 46.93 21.12 30.66 Including o+M AumpCwnnmdMIh 975.83 Annu9 107.50 1 10.73 AwqehKnnwnrdMVCmb 786.08 Annuity 86.60 89.20 Avwog.~LVCosts 513.59 AMU* 56.58 58.28 Table 4.1 : MALAWl TRANSMISSION SYSTE - M P U K LOAD FLOW 04.07.90 BUSBARS :- BUSNAME GEN. VOL TS ANG. GENERATION LOAD lYPE (PIJ) (DEGI (MW) (MVW (MWJ (MVARI NKULAAl 1 NKLllAB11 NKULAB66 NKULB211 NKULAA66 NKULAl32 'TEDZAN11 TEDZAN66 FUNDK66 FUNDK33 UWOND66 UWOND33 DEDZA 66 BALAKA66 NTCHEU66 LlLONA66 ULONAl1 ULONB66 ULONB33 ULONBl1 ULONC66 LlLONCl 1 ULOB132 SAUMA66 SUM132 MAPANG66 MAPANG33 CHICHI66 CHICHI33 CHICHI11 SUCOM132 NKHOTA66 NKHOTA33 DWANGW66 CHINTH66 TEHlU66 TEHlU33 CHIKAN66 KAPlC132 PAGE 1 Table 4.1 (contd) :MALAW1 TRANSMISSION SYSTEM PEAK LOAD FLOW - 06.07.90 GEN. VOLTS ANG. GENERATION LOAD TYPE lWl (DEGI IMW W A R ) (MW) IMVARJ ZOMBA 33 MANGOC33 MTUNTH33 KASUNG33 THYOlA33 M A S 3 3 THYOlB33 THYOlBl 1 CUSTOM33 CUSTOM1 1 MICHIR33 MICHlRl1 CHILEK33 CHlLEKl 1 DAVWHS33 D A M S 11 UMBEA33 UMBEAl1 KASUNGl1 MTUNTH1 1 CHIKAN1 1 MAKWAS11 MANGOC11 SUCOMAl 1 ZOMBA 11 SAUMA11 NKHOTAl 1 MZUZU 33 MZUZU 11 SUCOMA33 THYOLAl 1 BAlAKAl 1 NTCHEUl 1 CHINTH33 CHINTH11 DWANGWl1 DEDZA 33 TOTALS LOSSES PAGE 2  - Tobb 4.1 (contd) :M A W TRANSMISSION !WSl€M PEAK LOAD FLOW 04.07.90 BRANCHES :- BUSNAMES NO. SEND RECEMNG TAP FROM TO (Mwl IMw) (MVARI (%I NKULAAl 1 NKULAA66 24.00 NKUlABl 1 NKUlAB66 40.00 NKUlAB66 NKUlA132 17.58 NKUlAB66 MAPANG66 13.62 NKUlAB66 MAPANG66 14.76 NKULB211 NKUlA132 25.36 NKULAA66 NKULAB66 4.62 NKULAA66 BALAKA66 10.08 NKULAA66 CHICHI66 15.30 NKUlAl32 W 1 3 2 34.32 NKULA132 KAPlC132 8.54 TEDZANl 1 TEDZAN66 30.00 TEDZAN66 NKULAB66 7.10 TEDZAN66 NKULAA66 6.18 TEDZAN66 CHICHI66 16.49 FUNDM66 FUNDlX33 1.52 UWOND66 UWOND33 2.10 UWOND33 MANGOC33 1.67 DEDZA 66 ULONA66 6.1 1 DEDZA 66 DEDZA 33 0.42 BALAKA66 UWOND66 2.1 1 BALAKA66 MCHEU66 7.13 BAIAKA66 BAlAKAl 1 0.44 MCHEU66 DEDZA 66 6.73 MCHEU66 NrcHEUl1 0.20 ULONA66 ULONAl 1 5.93 ULONB66 ULONB33 3.01 ULONB66 ULONBl 1 15.59 ULONB66 ULONC66 3.22 ULONC66 ULONCl1 3.22 ULOB132 ULONB66 21.93 SAUMA66 NKHOTA66 8.23 SWM132 ULOB132 22.35 W l 3 2 SAUMA66 8.25 SAUM132 SAUMAl 1 1.49 MAPANG66 FUNDU(66 1.53 MAPANG66 MAPANG33 9.89 MAPANG66 CHICHI66 16.10 MAPANG33 ZOMsA 33 5.68 MAPANG33 CHllEK33 3.53 CHICHI66 CHICHI33 46.26 PAGE 3 Tabh 4.1 IcontdJ :MALAWI TRANSMISSION SRXEM PEAK LOAD ROW 0607.90 BRANCHES :- BUSNAMES NO. SENDING RECEIVING TAP FROM TO ww WAR) [Mw) (MVW WVA) I%) CHICHI33 CHICHI1 1 CHICHI33 THY01833 CHICHI33 UMBEA33 SUCOM132 SUCOMAll NKHOTA66 NKHOTA33 NKHOTA66 DWANGW66 NKHOTA33 MTUMH33 NKHOTA33 NKHOTAl1 DWANGW66 CHINTH66 DWANGW66 DWANGW11 CHINTH66 TEHlU66 CHINTH66 CHlKAN66 CHlNlH66 CHINTH33 TEHlU66 TEHlll.33 TEHlU33 MZUZU 33 CHIKAN66 CHlKAN11 KAPIC132 SUCOMl32 ZOMBA 33 ZOMBA 11 MANGOC33 MANGOCll MTUNTH33 KASUNG33 MTUNTH33 MTUNTHl1 KASUNG33 KASUNGl1 THYOM33 W A S 3 3 THYOM33 THYOM11 W A S 3 3 W A S 1 1 THY01833 THYOLA33 THVOLB33 THY01811 CUSTOM33 CHICHI33 CUSTOM33 CUSTOM11 MICHIR33 CUSTOM33 MICHlR33 MICHlRl1 CHllEK33 CHlLEKl1 DAVWHS33 CHICHI33 DAVWHS33 DAVWHS11 wEA33 WEAl1 SUCOMAl 1 SUCOMA33 MZUZU 33 MZUZU 11 CHINTH33 CHINTH11 PAGE 4 Table 4.2 :Summary of 132/66/33kV System Load Flow Results YEAR Power Loss Energy Loss O h Yo Table 4.3 : Summary of 132/66 kV System Load Flow Results YEAR Power Loss Energy Loss % % lab* 4.4 :Summary of 33 kV System Lood Flow Results YEAR Powrr Lou Energy Lou % %  Table 4.5 :Summary of 66kV konduetoring Analysis Nkula A Chichiti Demand Power Loss Energy Lou (MW) (%I 1%) 1990 Pre-Loss Redudion 199 1 Post-loss Reduction 2005 Pro-Lou Reduction 2005 Post-loss Reduction Loss Reduction Measures: Reconductor 46km with 175 rq.rnm. conductor Capitol Cost (MK): 46km @ MK 48,000 = MK 2.2m Internal Rate of Return: - 1.27% Nkula B - Mapanga Demand Power Loss Energy Lou (MWI 1%) (%I 1990 Pre-Lou Reduction 199 1 Post-Loss Reduction 2005 Pre-Loss Reduction 2005 Post-Lou Reduction Loss Reduction Measures: Reconductor 44krn with 175 sq.mm. conductor Capital Cost (MK): 44km @ MK 48,000 = MK 2.1 m internal Rate of Return: -1.25% 1990 h l a p Rcdudbn 199 l Pod-Lou Red& 2005 h L o u Redudion 2005 Polt-Lor Reduction (a) b a d on EXXW Urw brt Edimdu Table 4.7 :Transmission Line Parameten Line Type Conductor Size Resistance New Line Cost Estimates ESCOM KDP International (sq.mm) (Ohms/km) (MK/km) (MK/km) 66kV W d Pole 75 A CSR 0.3623 70000 100 A CSR 0.2733 78000 1 25 ACSR 0.21 85 85000 1 75 ACSR 0.1576 96000 66kV Steel 75 A CSR 0.3623 95000 100 A CSR 0.2733 105000 1 25 ACSR 0.2 185 1 15000 175 A CSR 0.1 576 130000 33kV W d Pob 50 AAAC 1 -phase 1.0996 17657 50 AAAC 0.5498 22970 100 AAAC 0.2769 32747 150 AAAC 0.1 830 39538 57300 Table 4.8 :Summary of 33kV-66kV Voltage Upgrading Analysis Demand Power Loss Energy Iws (kw) 1%) 1%) 1990 Pre-Loss Redudion 1991 Post-Lou Reduction 2005 Pre-Loss Reduction 2005 Post-Loss Reduction Lou Reduction Measures: Convert 74 km of 33 kV OHL t o 66 kV operation Capital Cost (MK): MK - Substation costs only; 1,050,000 as line constructed for 66 kV operation Internal Rate of Return: 16.83% For the case of h e line originolly built for 33 kV operation, Capital Cost (MK): 74 km @ MK 70,000+ 1,050,000= MK 6,230,000 Internal Rate of Return: - 2.28 %  - Table 4.9 :Summary of Transformer Loading Results Blantyre Main Feeder 515 Transformer ESCOM Sire Time Total Average Corrected Demand at 1890 Ref. Measured Demand P.F. kW kVAr kVA (kVA) IkVA) ALC Workshop New B T Market To Mandala F/Stn. P Ku a Road Mbelwa Road State House Browns Road Old Hospifal St. Andrew's Prim. Sch. Mount Pleasant Police Camp Sunnyside Smythe Road Bank Road Central Avenue Ring Road Arnold Road Wilson Avenue Gatreis Consulate Road Namiwawa South Sanjika Stadium Sanjika House Saniika House TOTALS Table 4.10 : Summary of 1 1kV Feeder Analysis Feeder Peak Demand P.F. Load Loss Percentage Losses (kW) Factor Factor Power Energy BL ANTY RE MAIN 5L5 G RO UP 202 CHlCHlRl 9L5 CHlCHlRl 6L5 LM l B E 1L5 LILONGWE B 3L5 LILONGWE B 6L5 LILONGWE B 1L5/5L5 Averages: 2.24% 1.58%  Table 4.1 1 : Sensitivity Analysis of 1 1 kV Reconductoring Load Levels (a) Variation of Load Factor Annual Load Load Thresholds Recondu~torin~ Growth Rate Factor 50 sq mm - 150 sq mm - 100 sq mm 150 sq mm Y o % kVA kVA 8.5 48.4 850 1680 8.5 54.2 820 1620 8.5 62.3 800 1580 8.5 90.1 720 1420 (b) Variation of Load Growth Rate Annual Load Load thresholds Recondu~torin~ Growth Rate Factor 5 0 s q m m - 150sqmm 100 sq mm - 150 sq mm o Y o Y kVA kVA 10.0 62.3 700 1380 8.5 62.3 800 1580 7.6 62.3 850 1 700 5.0 62.3 1050 2100 2.0 62.3 1300 2600 0.0 62.3 1500 2950 1 Tabb 4.12 :Summary of 11kV Fwder Recondudoring Analysis hand Power loss Energy Lw (kW 1%) 1%) hu o n d u d o d Fdwh g ~~ (bm) Capital 6r,(MI0 Internal Rate of Return ULONGWE B 3LS Demand Power Lou Energy Lou &W (%I (46) - ladl kccmdudond fbd Capid Car, Internol Rate of Return GROUP 202 hand Power Lou Energy Lou IkW WI (461 F d r Longl Rccaducrorod (Lm) Capitd 6rl (MJ Intam01 Rate of Roturn Table 4.1 3 : 1 1 kV Line and Cable Parameters Line Type Condudor Size Resistana New Line Cost Edmates ESCOM K DP lnternafional lsq.mm) (Ohms/W lMJ(/km) lMJ(/kml 1 I kV Wood Pole 50 AAAC 1 -phase 1.0996 14619 50 AAAC 0.5498 18924 1 00 AAAC 0.2769 28561 150 AAAC 0.1 830 32280 47600 I 1kV Cable 16 sqmmCu 1.334 42800 70 sq mm Cu 0.3 1 1 63000 1 20 sq mm Cu 0.177 150400 185 sq mm Cu 0.1 15 208000 240 sq mm Cu 0.0875 236200 354000 Table 4.14 :ESCOM Loss Reduction Study : Summary of I 1kV Recond~ctorin~ Proposals Feeder Peak Demand Length Sections to Reconductor Total Cost to Reconductor IkVA) (kml (MK) B W R E Blantyre Main 5L5 2028 1.9 BTMoin - SL5, SL5 - FUS14 90400 Chichiri 2L5 5019 1.1 Chich 1 1 - Group Hosp. 1 1 389700 Chichiri 5L5 3445 2.5 ABS 1682 - ABS488 119000 0.4 Chichl 1 - ABS1 682 141700 Chichiri 6L5 2704 13.3 ABS 1 5 - ABS 17, SL254 - ABS 15, 633100 - FUS9 1 4 - 51254, ABS 1742 FUS2408, SL282 - ABS1742 Chichiri 9L5 2358 4.7 Chichl 1 - ABS23, ABS23 - ABS1585, 223700 ABS2396 - ABS23 Chileka 3L0 1075 6.7 Chi111 - ABS 1 140, ABS 1 140 SL493, - 3 18900 51493 - RM1105 Group 202 4002 5.4 ABS420 - ABS190, SL1587 - ABS420, 257000 SL1586 - 511587, SL1586 - ABS1585, SL1 385 - FUS1328 0.5 Group 1 1 - ABS 190 177100 LILONGWE Lilongwe A 2L5 1780 3.7 - LilAl 1 - ABS8, ABS8 ABS32, 176100 - ABS32 - ABS 17, ABS 17 ABS33, - ABS17 ABS40, ABS40 ABS680 - Lilongwe A 3L5 Lilongwe B 3L5 3353 2.9 ABS363 - ABS 338, ABS338 ABS488, - 138000 ABS488 - FUS408, FUS408 FUS409, - FUS409 - FUS432 0.2 LilB11 - ABS363 70900 Lbngwe B 4L5 Lilongwe B 6L5 TOTAL 3850900  Table 4.1 5 :Summory of Lilongwe B d15 Lou Radudion A n o w Dunand Paww Lou Ef=QYk (kw) 1%) I%) 1990 Befwe Lorr Red- 1 99 1 Aher LOU Rdudion 2005 Before Lou Redudion 2005 Aher Lou Redudion LOU Redudion Abanwos : Capital Cod (w Internal Rate of Rotum ULONGWE B 6l5 Dmwrnd Powac Lou (kwl 1%) 1990 Before Los Redudion 1991 A h r Lou ~ e d u d i i 2005 Before Lou Redudion 2005 Aher LOU Reduction [kmad Pomr Lou Enew (kw) (%I (%I 1990 ffon Lou Reduction 1991 Au Lou R & i h 2005 &lam Loa Roductii r 2005 A h r Lou Reddon Fmkr hgfh R d d(h) 6 F a l Cat (MI0 Intomol Rate of Rotum Table 4.1 6 :Transformer Loss Evaluation Data Base Rating Core Loss Winding Loss Capital Cost Comments kVA kW % kW % MK 15 0.07 0.48 0.34 2.28 ASSUMED LOSSES 25 0.12 0.48 0.57 2.28 4871 50 0.18 0.36 1.O 2.00 6660 100 0.3 0.30 1.7 1.70 9228 200 0.52 0.26 2.7 1.35 14380 3 15 0.72 0.23 3.8 1.21 15212 400 0.88 0.22 4.3 1.08 ASSUMED LOSSES 500 1.1 0.22 5.4 1.08 21 110 800 1.6 0.20 8.0 1.00 Marginal Cost of Power 527.98 MK/kW Mar inal Cost of Energy 0.045 MK/kWh Loacf' Factor : 62.30% Loss Factor: 45.80% Peak Load: 250 Table 4.1 7 : Summary of 1 1/0.4 kV Transformer Loss Evaluation 1 1kV Feeder Peak Demand Transformer Utilisation PERCENTAGE TRANSFORMER LOSSES Capacity Factor Core Winding Total (kvA) (kVA) (%) Power Energy Power Energy Energy Loss CHlCHlRl 615 2704 5325 50.8 0.57 1.22 1.28 0.74 1.96 CHlCHlRl 915 2358 5725 41.2 0.60 0.76 0.83 0.67 1.43 GROUP 202 4002 8530 46.9 0.55 0.98 0.97 0.66 1.64 L I M E 115 1954 4275 45.7 0.57 0.55 0.82 0.40 0.95 BLANMRE MAIN 5l5 2028 3815 53.2 0.50 0.89 1.02 0.65 1.54 LILONGWE B 215 3 169 9180 ' 34.5 0.77 1.1 8 0.67 0.54 1.72 LILONGWE B 315 3353 6825 49.1 0.40 0.44 0.58 0.52 0.96 LILONGWE B 6l5 2322 6390 36.4 0.70 0.8 1 0.68 0.59 1.40 LILONGWE A 215 1733 2645 . 65.5 0.48 0.60 3.35 2.89 3.49 LILONGWE A 315 3261 6255 52.1 0.50 0.84 1.19 0.82 1.66 LILONGWE A 115 1930 6345 30.4 1.27 2.04 1.20 0.80 2.84 Average Utilisation Factor : 46.0 % Average Total Energy Loss: 1.78 %  hhmdF..d.rRotDmad(MW) ridh.kcRotDmad M.ound Fadu P.F. d Pd 24 hour bnrgy b m n a h (kwh) 24 hour 6R Enrgy la QWh) 24hwrW* LoukWh) E'Rw lord T l o r J a ~ParnlnMkW) k~ndhgpowrlakw) Tod TrmrlamrPo*rlouW r ESCOM Rd. 10 CHlNYONGA 11 QTYGARAGE 12 KANUKAROU) 13 SUSERWRNITURE 1 4 ~ N E W k l O l 6 W G 15 KMMRCnATS 16 KANlEDUWTH 17KANRDUNOlITHI 18 cwracuAmosPAREs 19 RAB R m LlD 20 KASUNGU aEsm 21 MJLTK~OU'JlRY 22 CMCCENTRE 23 DIGITAL EXOWJCE 24 UlM 25 F a y RESIDENCE 26 KAMUZU S T- 27 iw a cu o s 28 iwacuosI 29 iwamI 30 31 SOOEECSf 32 KUWA HOTR 33 U J G W N S W A 34 ZNGWANCWA 35 ST FW S 36 NKOlOKOW I - 37 O1MwAwHwDi 38 NEW QIMWANWWM AREA 39 NEW OIMWANWWDA AREA 40 OIOIIRIPPISON 41 PUYMUGE 42BWBSOOEKWS 43 K K W R S UPOUQSMMSK)N 4sKANEOUMUSsm Tobb 4.19 :Sumnmry of Transformer -R - Group Substation, Feeder 202 Transformer Sue OPTMISATION PROGRAMME No. into No. t o be Unit Cod Total Transformer (kV4 No. Re d No. Introduced Skire Purchated (In,. Budgetary) G ~ I MK M K TOTAL 45400 lnrkllation : 12 Tmndormer Rspbcsmenh @ MK270 3240 TOTAL COST 48640 TRANSFORMER LOSSES Capital Cost [MK) Internal R a b of Return Table 4.20 :Summary d Overall 1 1/0.4 kV Transformer Replacement Programme Feeder 1990 Installed Capacity Transformers io be Purchased % of Installed Capaaty (kvA) 50 kVA 100 kVA 200 kVA 500 kVA Chichiri 615 Chichiri 915 Group 202 Limbe 11 5 L i b A 215 Lilongwe A 315 Likngwe B 115 Lilongwe B 215 Likngwe B 3L5 Libngwe B 615 Totals 57105 30 23 3 6 % of Total Purchased Transformer Capacity 20% 31% 8% . 41% Total 1990 Intermneckd System 11/0.4 kV Transformer Capacity: 203125 kVA % Addifiial Capacity t o be Purchased (from sample) : 13 % Additional Capacity io be Purchased : 26322 kVA Size % of Total kVA No. of Units Unit Cost Instal~ation (MIQ (per unit) TOTAL COST 2799800 Tobk 4.21 : Present LV Syrttm Loss l e v e l s Feeder LoadFactor Loss Factor Power Loss Energy Loss Minimum V o h g e (%I 1%) (%I 1%) M BANGWE 2 177.3 48.56 28.14 12.5 7.2 162 CHILOBWE BEER HAL 1 43.1 52.43 32.1 2 5.8 3.6 204 CHllOBWE BEER HAU 2 169.6 52.43 32.12 12.7 7.8 193 BROWNS ROAD 1 145.8 54.37 ' 37.10 6.9 4.7 195 Table 4.22 :LV Line Parameters Line Type , Conductor Size Resistance New Line Cost Estimates ESCOM KDP International [sq.mml (Ohms/kml W/H W / h ) 400 V 4-wire 50 AAC 1 -phase 1.0838 12570 Wood Pole 50 AAC 0.54 1 9 17930 100 AAC 1 -phase 0.5404 15330 100 AAC 0.2702 23380 150 AAC 0.1825 30737 46 1 05  Table 4.23 :Summary of Browns Road LV Feeder Reconductoring Analysis BROWNS ROAD 1 Demand Power Loss Energy Loss Minimum Vohage (kW1 (%I (O/O) M 1990 Pre-Reconductoring 1 99 1 Post-Reconductwing 2005 Pre-Reconductoring 2005 Post-Recondudwing i Feeder Length Reconductored (km) Capital Cost (MK) T a k 4.24 :LV System Reconduetoring Analysis Transformer Total Circuit Circuit Length Unit Cost Total Cost Length Reconductored (m) (4 (%I (MK/km) (MIQ Chileka 210 S/S 1 928 852 Chileka 2L0 Lunzu Trading 2749 Limbe 1 15 1 956 Blantyre Main SLS Browns Road 151 8 Lilongwe 0 4L5 S/S 678 764 Totals 9167 Total LV System Len& (1 990 - Interconnected System) Total Reconductoring Total Cost Table 5.1 :Power Stations Meter Accuracy Results as at 14/12/90 power Station Unit Tested Accuracy Units Units (%I Metered Over-read (MWh) (MW) 1989-90 1989-90 NKUU A Generator Transformer 1 Generator Transformer 2 2.0 Generator Transformer 3 1.8 NKUlA B Generator Transformer 4 0.6 Generator Transformer 5 0.5 Generator Transformer 6 0.1 Generator Transformer 7 3.6 TEDZANI Generator Transformer 1 0.8 Generator Transformer 2 1.1 Generator Transformer 3 -3.7 Generator Transformer 4 -3.0 Sfation Transformer -0.2 NKUlA A Generator 1 2.7 49254 -1304 Generator 2 -2.0 Generator 3 3.8 52725 - 1944 NKUlA B Generator 4 2.7 112275 -2998 Generator 5 3.4 113622 -3 748 Generator 6 2.1 44210 -926 Generator 7 2.8 782 10 -21 15 TEDZANI Generator 1 2.5 41 850 - 1004 Generator 2 1.1 4343 1 -479 Generator 3 3.9 46915 -1754 Generator 4 1.2 45097 -533 TOTALS 627589 - 16805 Error 2.68% CukmwNan, mUsTRt4lcWSWERS SUCW DaridWhO&&Sar a w -w w iKVAJ 1 989-90 15000 5750 -1.23 1.26 Unb 1989-90 51670 31739 -M - lal I 1989-90 645 (396~ Yz" MDCAS 1969 -90 1989 -90 0 0 b 0 0 Rowwb La, 0 0 Told Rovolwo La, 1989 -90 0 0 hboLdTabocco6 1490 0.63 5305 031 0 0 0 0 z5Eiz- L.VwB& 1300 760 710 0.80 2.00 0.4 4241 2903 3165 (33 157 (141 0 0 0 0 0 0 0 0 0 0 0 0 Gmin&MlIhgG 690 0.63 1878 (124 0 0 0 0 Md~dlJd 440 1.06 2692 08 0 0 0 0 kduhiw 465 1.05 1658 (17 0 0 0 0 ENCOR Rodvcb 375 0.06 990 11 0 0 0 0 Wwpriwbn)ainr 330 0.10 1510 (1 0 0 0 0 MIBchJ.toPumphONo2 3650 -0.69 22016 154 0 0 0 0 BWBdrj.tolJwl@qNol 3650 1.95 0 0 . 0 0 BWWdkd~Fwy-NWa 5800 0.72 0 0 0 0 #odic Produd, LID 325 0.09 0 0 0 0 llbynwm) 370 -49.05 1625 1,564 303 54,741 6,080 60,821 Movn)s#h.Ho).l 310 -50.48 1091 1.1 12 256 38,931 5,135 44,067 Nomin'gombo 1 . Fad~ry-ThydG 0 615 -0.78 7 0 UONCWE MR=-hOf.m 114 -25.23 236 80 44 2.784 880 3,663 &khRu&auhCif.mm~r 1 14 -2.08 0 L i m b . L . d T h ~ 4 1490 1.13 0 Unrb.LdTaboccoOvrdl 1490 -24.45 - 6507 2,106 401 73,713 97,279 170.991 SkncaTabo&oPodurLID 1240 1.13 '-525 1 4 0 0 0 0 *wokrBaani h w MindlmrponKUNol nwu 1200 363 1200 ?%\ -47.05 2332 02 (15 2,072 0 0 0 72,535 0 0 0 4.480 0 0 79,015 M~~~TWU~OI~KMN~~WU -85.70 105 629 0 22,003 6,480 28,483 (L.~~BantdhAohi 620 1.97 1885 (36 0 0 0 0 Cap)ol Hdd 188 0.46 2716 (9 0 0 0 0 FipobdrudwrLTD 209 -65.75 ' 265 508 303 17,793 6,077 23,870 SMSKamuzutntml~l 209 1.81 895 [I& 0 0 0 0 SourkmlbrllrrLTD 202 0.81 633 (5 0 0 0 0 195 0.88 580 (5 0 0 0 0 Shorn R& LTD 180 1.46 405 46 0 0 0 0 LiI0npmWdwBaaniNo2 0.18 484 (1, .O 0 0 K o m u n r ~ 360 1.20 120s 0 0 0 S)aprCo~dl 37 -19.3 176 42 14 1,476 286 1,762 TOTALS 1dOpS2 8,180 0 2 120,697 412,673 Table 5.3 : Summary of Meter Accuracy Results as at 14/12/1990 Total metered generation at Nkula A & B and Tedzani 627589 MWh Meters over-rebd at above power stations by 16805 MWh True generation 610784 MWh Total generator metering error 2.68 % Energy lost due to consumer meter undereading 8189 MWh Percentage of lost energy 1.34 % Energy Lost + Power station meter over read 24994 MWh Total loss figure as a percentage of true generation 3.98 % Table 5.4 (a) :Resuht of Mehr Test B.nch Checks FOSTER BENCH Test 1 : 20A, Unity P.F. Test Bench Readings Dronetz Readings Percentage Error VA-N 230 23 1.8 4.78 VB-N 230 23 1 4.43 VC-N 230 231.1 4.48 1A 20 19.82 -0.90 IB 20 19.79 -1.05 IC 20 19.68 -1.60 WA 4600 4596 4.09 WB 4600 4573 4.59 WC 4600 4546 +1.19 Total 13800 13715 +0.62 PF 0.99 0.99 0 Test 2 : 20A, 0.5 P.F. ~~~~~ Total W 6950 7146 -2.74 PF 0.5 0.52 -4.00 Test 3 : 1 OOA, 1.O P.F. Toral W 69000 68230 +I .12 Test 4 : 1 OOA, 0.5 P.F. Tot01W 34500 34750 -0.72 Test 5 : 4400A, 1.O P.F. Totol W 276000 275500 +O. 18 Table 5.4 (b) :R D S ~ ) of~ M.hr Tort Chocks LANDIS & GYR SUBSTANDARD METER Test Period Lwd Substandard Reading Draneh Reading Percentage Error Ihl 4 1 fkWJ IkWH) 1%) 1 .W 100 78.00 75.98 +2.66 2.00 50 79.57 78.64 +1.19 1.00 5 3.60 3.55 +I .49 TABLE 5.5: NUMBERS OF METER READERS SOUTHERN Region 01 antyre Special meter readers Ordinary meter readers Total 25 -rhyo10 Mu1anj e Nchalo Bangu 1a Zomba Mangoch 1 L i wonde Total Southern r e g i o n CENTRAL Region L i longwe Speclal meter readers Ordlnary meter readers Total 15 Kasungu Mchinji Sal lma Dedza Nkhota-Kota Dowa Total Central region NORTHERN Region Mzuzu Rumph i Karonga Chi t i pa Total Northern region GRAND TOTAL  - Table 5.6 : Financial And Economic Analysis Of Non-Technical losses Meter Box Option COSTS FINANCIAL BENEFITS ECONOMK: BENEFITS Meter Billing Meter Meter Meter Solid Total Small Domestic Total Net Resource Net Year Boxes System Test Pliers Test State Cost Power 8 General Benefit Financial Cost Economk Benches Room Meters Benefit Benefit BeneRt Savings Benefit I990 0 0 0 0 0 0 1991 751960 1082005 332850 8650 80000 75000 2330465 195474 142017 337490 - 1992975 142430 -1 430631 1992 431960 166740 598700 354931 284033 638964 40264 269854 -212128 1993 431960 166740 598700 541 106 426050 967156 368456 408410 -73572 1994 431960 166740 598700 731499 568067 1299566 700866 548723 66741 1995 431960 166740 598700 949199 710083 1659282 1060582 700414 218432 1996 431960 166740 598700 1060172 793969 1854141 1255441 783538 301556 1997 431960 166740 598700 1150869 877855 2028724 1430024 858214 376232 1998 431960 166740 598700 1 250865 961741 221 2605 1613905 936764 454782 1999 431960 166740 598700 1362586 1045626 2408213 180951 3 1020199 538217 2000 431960 166740 598700 1487280 1 12951 2 261 6793 201 8093 1 109040 627058 2001 431960 166740 598700 1622181 1213398 2835579 2236879 1202134 720152 2002 431960 166740 598700 1771052 1 297284 3068336 2469636 1301049 819067 2003 431960 166740 598700 1932783 1381 170 33 13952 2715252 1405322 923340 2004 431960 166740 598700 2110616 1465055 3575672 2976972 1516304 1034322 I 2005 ( 431960 166740 598700 2305777 1548941 3854719 3256019 1634507 1152525 IFRR 37.57% IERR 16.44% Tobh 5.7 :Financial And Economic Analysis Of Non-Technical Lorsets - W e t Type Meters COSTS FINANCIAL BENEFITS ECONOMK BENEFITS Socket Billing Meter Meter Mekr Solid Total Small Domestic Total Net Resource Net Yeor Meters System Test fliers Test Slate Cost Power & Generol Benefit Financial Cost Eoonomic Software Benches Room Meters Benefit Benefit Benefit Savings &ndt 1990 0 0 0 0 0 0 1991 913945 1082005 332850 8650 80000 75000 2492450 195474 142017 337490 -2154960 142430 -1592616 1992 593945 166740 760685 354931 284033 638964 - 121721 269854 -374113 1993 593945 166740 1 760685 541 106 426050 967156 206471 408410 -235557 1994 593945 166740 760685 73 1499 568067 1299566 538881 548723 -95244 1995 593945 166740 760685 949199 710083 1659282 898597 700414 56447 ,1996 593945 166740 760685 1060172 793969 1854141 1093456 783538 139571 1997 593945 166740 760685 1150869 877855 2028724 1268039 8582 14 2 14247 1998 593945 166740 760685 1250865 961741 2212605 1451920 936764 292797 1999 593945 166740 760685 1362586 1045626 2408213 1647528 1020199 376232 2000 593945 166740 760685 1487280 11 295 12 26 1 6793 1856108 1 109040 465073 2001 593945 166740 760685 1622181 1213398 2835579 2074894 1202134 558167 2002 593945 166740 760685 1771052 1297284 3068336 230765 1 1301049 657082 2003 593945 166740 760685 1932783 1381170 33 13952 2553267 1.405322 761355 2004 593945 166740 760685 2110616 1465055 3575672 2814987 1516304 872337 2005 593945 166740 760685 2305777 1548941 3854719 3094034 1634507 990540 IFRR 31.31% lERR 8.78% Tabk 5.8 :FinaKial And Economic Analysii Of Nm-Tcchri~al - Losses -Socket Type Meters Increased lnrto!~& Corh - COSTS FINANCIAL BENEFITS ECONOMK BENEFITS Socket Billing Meter Meter Meter Solid Total Small Domestic Tala1 Net Resourcs Net Year Meters System Test Pliers Test State Cost Power 8 General Bendit Financial Cost Eamomic Software Benches Room Meters Benefit Benefit Benefit Savings Benefit 1990 0 0 0 0 0 0 1991 1 1 1 5235 1082005 332850 8650 80000 75000 2693740. 195474 142017 337490 -2356250 142430 -1793906 1992 795235 166740 96 1975.1 35493 1 284033 638964 -323011 269854 -575403 1993 795235 166740 961975.1 541 106 426050 967156 5181 408410 -436848 1994 795235 166740 961975.1 73 1499 568067 1299566 337590 548723 -296534 1995 795235 166740 96 1975.1 949 199 7 10083 1659282 697307 7004 14 - 144843 1996 795235 166740 961975.1 1060172 793969 1854141 892166 783538 -61719 1997 795235 166740 961975.1 1 150869 877855 2028724 1066749 858214 12956 1998 795235 166740 961975.1 1250865 961 74 1 221 2605 1250630 936764 91506 1999 795235 166740 961975.1 1362586 1045626 2408213 1446237 1020199 174942 2000 795235 166740 961975.1 1487280 1129512 2616793 1654817 1109040 263783 2001 795235 166740 961975.1 1622181 1213398 2835579 1873604 1202134 356877 2002 795235 166740 961975.1 1771052 1297284 3068336 2106361 1301049 455792 2003 795235 166740 961975.1 1932783 1381 170 33 13952 2351977 1405322 560065 2004 795235 166740 961975.1 21 10616 1465055 3575672 2613697 1516304 671047 2005 795235 166740 96 1975.1 2305777 1 54894 1 38547 19 2892743 1634507 789249 KRR 24.76% IERR 0.19clq Table 6.1 :Summary of loss Roddon Budgot Roquimmonh Project Local Cost Fodgn Cost MKm US$ m 33 kV-66kV Line Upgrading 0.1 57 0.357 Mtunthama 105 1 1kV Reconduetoring and 0.58 1 1.316 Capacitor Placement 1 1kV/O.4kV Transformer Replacement 0.420 0.952 LV System Reconducforing 3.741 8.48 1 1 1kV/LV System Optimisation Study 0.000 0.045 Billing System 0.000 0.433 Meter Test Room 0.080 0.000 2 x Meter Test Benches 0.000 0.133 Meter Test &n& In~tallationflrainin~ 0.000 0.01 2 15 Solid State Meters 0.000 0.075 Installation of Meter Boxes 6.479 0.128 50 Pairs of Meter Pliers 0.000 0.003 2 x Demand Analysers (ind. PC's) 0.000 0.020 Sub-Total 11.46 1 1.95 Physical Contingencies (I 0 46) 1.15 1.20 Engineering Contingencies (5 %) 0.57 0.60 TOTAL 13.1 8 13.75 Exchange Rate : MK 2.5 = US$ 1.O MW Demand MWh Sales mousands)  0 L I 1 I I 1 I I I 1 I I I r l s l 5 l 7 1 9 111 1 1 3 ~ 1 S ~ 1 1 7 1 1 9 I 2112 3 1 2 4 6 8 10 12 14 16 18 20 22 24 Hourm July 100 I  Fig. 4.2 :1990 Peak Load Flow High Loss 132/66/33kV Lines NKULA-SALIMA (23.3%) OTHERS (26. SALJMA-NKHOTAKOTA (3.5%) NKULA-LILONGWE A CHICHIRI-THYOLO (3.9%) MAPANGA-ZOMBA (4.0%) NKUIA-MAPANGA (8.9%) SALIMA-LILONGWE B (4.4%) TEDZANI-CHICHIRI (7.4% KUIA A-CHICHIRI (7.7%)  Fig 4.3 :1994 Peak Load Flow Breakdown of 132/66/33kV Losses TRANSFORMER  Fig. 4.4 :66kV New Line Loading Ranges ACSR Conductors, Wood Pole Lines 0 I b6 I 12b0(24b0~36b0~4800(60b0(7~00~84~0~96b 0 1800 3000 4200 5400 6600 7800 9000 1 INITIAL MAX DEMAND (KVA)  f TOTAL NPV OPE ATlNG CO T (Kwacha/KM) Rhousand8 TOTAL N W OPE TlNG COST (KwachafKM) flousands)  Fig. 4.7 :66kV Reconductoring Loading Ranges ACSR Conductors, Steel Tower Lines T I I44d00 16600 I& 110600~$g&~&,t~~~&odoo 1000 3000 5000'7000 9000 11 INITIAL MAX DEMAND (KVA)  f TOTAL NPV OPE ATING CO T (Kwacha/KM) hhousands Fig. 4.9 :33kV Reconductoring Loading Ranges AAAC Conductors INITIAL MAX DE  Demand (kW) (Thousands) PPPPPPPPP +++++++++ A O ~ N w P m a 4 m m ~ ~ N O P w m ~ a m N  - Fig. 4.1 1 :Blantyre Main Feeder 5L5 - Power Factor Profile :9/8/90 10/8/90 Time (hh:mm:ss) 11 kV Voltage (p.u.) Fig. Variation of 11kV ReconduetoringThresholds with Load Growth Rate 2 4 6 Annual Load Growth Rate (%I TOTAL NPV OPERATING COST (KwachaIKM) (Millions)  Fig. 4.15 :11kV New Line Design Loading Ranges AAAC Conductors 190 1 / 10 ' b INITIAL MAX DEMAND (KVA)  Fig 4.16 :I I kV New Cable Deslgn Loading Ranges 3-core Copper XLPE Cables 900 1 1 01 idoo l I5'0012000125'00Iad00 I ado0 140'00145'0015000 f 0 1250 1750 2250 2750 32 0 3750 4250 4750 INITIAL MAX DEMAND (KVA  ! Annual Op rathg Cot (Kwacha) f~houunds  \ Annual Op rating Cos (Kwacha) f~housands Fig 4.1 9 :11 kV10.4 kV Transformer Optimisatlon - ESCOM Cost Data 40% Load Factor Demand (kW)  - Fig 4.21 :Browns Road Transformer Power Factor Profile 14/8/90 15/8/90 Time (hh:mm:ss) Voltage OI)  - Fig. 4.23 : Browns Road Transformer Instantaneous Demand 14/8/90 15/8/90 R Phase 4 Time hh:mm:ss) + Phase 0 B Phase TOTAL NPV OPE ATlNG COST (Kwacha/KM) hhousands) Fig 4.25 :LV Reconductoring Loading Ranges Power MVAr & Volt Drop % Fig 4.27 :LV Power Circle Diagram Ikm 400V 100 sq.mm. Overhead Line Power MW  Fig 4-28 :LV Power Circle Diagram Ikm 40W 150 sq-mm. Overhead Line 0.07 -0.01 0 0.02 0.04 0.06 0.08 Power MW  Fig. 4.30 :LV System Operating Costs 15 year Analysis- Costs of Additional Transformers and Reconductoring v 20' I 50 1 150 1 250 1 350 I I I I I 100 200 300 50 950 900 1 1000 Original LV Feed 1 + 2 0 3 A 4 x 5 v Reconductor No. of Transformers  - Fig. 4.31 :LV System Operating Costs 7 year Analysis Alternative Reconductoring Ratios 130 1  PV Cost (Thousands) A A A A A s s ~ s a e a a s ~ s o o o o h ) o m Fbure 6.1 :Ruourco Coat Srvlngs Flg. 6.1 :Summary of Exi8tlng Lo88 kvol8 Load Bmkdown - Coruumptlon % of 1989 Net Generated Energy, voltage Level corrected for meterlng erron found Large Power 25.0 % Small Power 32.5 % DomesUc Generel Breakdown d L o u E8Unutoa ~evel Energy Lorn Mlmate 132/66/33 kV TranwnlWon 11 kV Diribution Percentage of energy 11B.4 W Tnnsformation 1.8 % enterlng each level LV Dlstrlbution 4 2% Non-Technical Losses Found 4.0% j Percentage of net Non-Technld Losses Remslnlng 2.9 % generated energy Energy Flow Dlagmm LV System 25.O 16.3 16.3 32.4 t Technical Lo88 Edlmnte (96 of Net Generated Energy) TOTAL LOSS ESTIMATE AT START OF STUDY : 17.0 % ESTIMATE OF REMAINING LOSSES : 13.0 % Fig. 6 9 :Summary of Target Loss Levels Load Breakdown Class Consumption corrected for NorrTechnical Voltage Level Loss Reduction Large Power Smell Power Domestic General Breakdown of Lola Edlmater Level Energy Loss Estimate 132/66/33 kV Transmission 6.7 % 11 kV Distribution Percentage of energy 1 110.4 kV Transformation 1.5 % enterlng each level LV Distribution 3.0 % NorrTechnlcal Losses 0.5 % Percentage of net generated energy Energy Flow Dlagmm O0 132/66/33 kV System -+$ f 68-0 System Transformers 32,: System 25.3 17.1 17.1 31.4 t Technical Loss Estlrnate (% of Net Generated Energy) t (% of Net Generated Energy) TARGET LOSS ESllMATE W I E R LOSS REDUCION : 9.6 % Fig. 6.3 :Progmmmo for Impkmontation of Lou Reduction Mwsurea ACmmY Ywr 1 Ywr 2 Ywr 4 Year5 12 3 6 9 I2 3 6 . . . . . .9 12 3 6 9 I I kV Recdudoring Billing Splcrn Imlolklion ~ - . . . . . ........ .......... ..,.............. ................. ; .:.... ............. ; ......... ........................... : .. . ..................... .............. ;- .;.., .. .. ".;.?...'"."....i....n ................................... ; .................... ...... ,:.,.:* .... ...... ; : 7%" ... . ...-."" .... %'..'....'.'...-'.'.'.'.,.'(..(....(... ............. ;...r ................. :. ... < ? . > .. ......... ....:,............. ; :..... :: ...................................... Ahtar T8sl Room ConJruction k t e r Tes~Bench Procurement LV Sflem Oplimimlion Sludy ~ r o v ud l Revid LV Measures m LV SyJern ~econdudain~flrodonner Replacement 33kV - 66kV Upgrade (Mlun~homo105) M d e r Box Inslollolions ( 1 5 year programme) ~ ......;... ..;. .... . .....:........:..:... : ; ..... :.. ..:.::.: ..... ......................................................... ...:...;............. ....:.:............,......." ............................................................ ;i... .. :.:. .:...:: >.. ;. .:. :'....;..... :. :.:. :<..:.:.::: ........ ......,.... : <.+:; ; .,......... <.. ........................................ ...... ........................ .............. :... ...... ...;:.. ::?..:: ...:.. .... . . . . . .. ..:.::.:.i::..::+.: .j:..i:::?:,.:.)i::j:::::. .. : : : : ; ...:~~.:j~.:.,:.,:~-::,.;.,:.Ij:Ij:'lif.:.i:;.':';.;;~;$~ :-.::::i:.:.:r:;:-:::y.i2:+ ' ;:j:i:i::.;:$j~~:$":: ESCOfl TRANSMISSION SYS?EH  IBRD 23398 MALAWI POWER V PROJECT ,o a District Cnpitals * Notional Capital Major substations Hydro Power Stations Future (Investigated) --- Region Boundaries Possible Future Hydro Power Stations - lnternationol Boundories - 132 kV O.H.L. Existing ,,, 132 kV O.H.L. Under construction Reinforcement of 132 kV O.H.L. Operating at 66 kV - 66 kV O.H.L. Existing . . . . 66 kV O.H.L. Planned 33 kV O.H.L. Existing . - - 33 kV O.H.L. Plonned . . .. . . 1 1 kV O.H.L. Thtr mop hor been prepored by The World Bonk's rtaff exclusrvely for the convenience of reoders ond ir far the rnterool use of The World Book GroupThe denominations used ond the bouodornes shown on this mop do not imp1 on the pan 01 The World ~ o n l ~ r o u ~ , any jud ment an the leg01 51otm 0$ any territory or ooy endoiremeof or occeptonce of such boundones. Moy 1992