Tunisia - Power efficiency study

EB EE3 m 0 ZEE 0 m OMEEDD El 3 E3 M a El E3 El E X ~~~~~~~M a S X~~~~~~~~~~~~~~~~~~~~~~Q  JOINT UNDP / WORLD BANK ENERGY SECTOR MANAGEMENT ASSISTANCE PROGRAMME (ESMAP) , a f f PURPOSE The Joint UNDP/World Bank Energy Sector Management Assistance Programme (ESMAP) was launched in 1983 to complement the Energy Assessment Programme, establibhed three years earlier. ESMAP's original purpose was to implement key recommendations of the Energy Assessment reports and ensure that proposed investments in the energy sector represented the most efficient use of scarce domestic and external resources. In 1990, an intermational Commission addressed ESMAP's role for the 1990s and, noting the vital role of adequate and affordable energy in economic growth, concluded that the Programme should intensif, its efforts to assist developing countries to manage their energy sectors more effectieely. The Commission also recommended that ESMAP concentrate on making long-term efforts in a smaller number of countries. The Commission's report was endorsed at ESMAP's November 1990 Annual Meeting and prompted an extensive reorganization and reorientation of the Programme. Today, ESMAP is conducting Energy Assessments, performing preinvestment and prefeasibility work, and providing institutional and policy advice in selected developing countries. Through these efforts, ESMAP aims to assist governments, donors, and potential investors in identifying, funding, and implementing economically and environmentally sound energy strategies. GOVERNANCE AND OPERATIONS ESMAP is governed by a Consultative Group (ESMAP CG), composed of representatives of the UNDP and World Bank, the governments and institutions providing financial support, and representatives of the recipients of ESMAP's assistance. The ESMAP CG is chaired by the World Bank's Vice President, Operations and Sector Policy, and advised by a Technical Advisory Group (TAG) of independent energy experts that reviews the Programme's strategic agenda, its work program, and other issues. The Manager of ESMAP, who reports to the World Bank's Vice President, Operations and Sector Policy, administers tne Programme. The Manager is assisted by a Secretariat, headed by an Executive Secretary, which supports the ESMAP CG and the TAG and is responsible for relations with the donors and for securing funding for the Programme's activities. The Manager directs ESMAP's two Divisions: The Strategy and Programs Division advises on selection of countries for assistance, carries out Energy Assessments, prepares relevant programs of technical assistance, and supports the Secretariat on funding issues. The Operations Division is responsible for formulation of subsectoral strategies, preinvestment work, institutional studies, technical assistance, and training within the framework of ESMAP's country assistance programs. FUNDING ESMAP is a cooperative effort supported by the World Bank, UNDP and other United Nations agencies, the European Community, Organization of American States (OAS), Latin American Energy Organization (OLADE), and countries including Australia, Belgium, Canada, Denmark, Germany, Finland, France, Iceland, Ireland, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Sweden, Switzerland, the United Kingdom, and the United States. FURTHER INFORMATION For further information or copies of completed ESMAP reports, contact: The Manager or The Executive Secretary ESMAP ESMAP Consultative Group The World Bank The World Bank 1818 H Street N.W. 1818 H Street, N.W. Washington, D.C. 20433 Washington, D.C. 20433 U.S.A. U.S.A.  TUNISIA POWER EHFICIENCY STUDY FEBRUARY 1992 ESMAP Operations Division The World Bank Washington, D.C. 20433 I This document has restricted distribution. Its contents may not be I disclosed without Government, UNDP or World Bank authorization.  FOREWORD This study, which was carried out at the request of the Tunisian Electricity and Gas Utility (STEG) in agreement with the Inustry and Energy Division of the Bank's Maghreb Department, was seen as a challenge from the begimring. STEG has good performance compared to that of most utilities in developin countries, with transmission and distribution losses of about 13 to 14% compared to 30 to 40% for many utilities of the same size. In addition to reduction of network losses, the study identifies technical, organizational, and Institutional changes that would increase the overall efficiency of Tunisias power system, and recommends the measures and/or additional studies needed to implement the proposed changes. This study was financed according to a special grant procedure, the "Trust Funds Extended Agreement' with the assistance of Mrs. J. Ferry of the Multilateral Aid Division of the French Foreign Ministry. The study was carried out within the framework of a contract between ESMAP and Blectricitd de France (EdF, the Consultant), with the active pat-cipation of a task force composed of representatives of the relevant STEG departments, coordinated by the Planning and General Studies Department, on behalf of STEG Management. fhe preliminary report of the study was examined at a meeting of STEG's Board of Directors on November 6, 1990, and a number of the recommendations ma4e in the report were adopted. The EdF team members were: Messrs. Henri Boyd (project manager), Gerard Aubeat (generadon specialist), Jean-Pau Barret (transmission specialist), Jean-Frangois Bruel (computer distribution specialist), Raymond Sinus (distribution operation specialist), Marie-Line Marcin (technical distribution specialist), Olivier Gourlay (customer management specialist), and Alain Polvent (customer management specialist). The STEG task force members were: Messrs. HEdi Turki and Hassen Mamud (Planning and peneral Studies Directorate), Messrs. Mahmoud Lakhoua, Mekki Ayed, Chekib Ben Rayana, Lamjpd Fekih, Mohamed El Kamel (Operations Directorate), Messrs. Khaed Hammou, HEdi, Turki, Chedl Jeddi, Taoufik Barbouche, Belgacel:. Ghariani (Distribution Directorate). Noureddine Berrah (Senior Economist and task manager, ESMAP) supervised the project, and wrote thbis report, basing it on the reports submitted by the Consultant and on the comments of the STEG task foc. F. Jouve (Power Engineer, ESMAP) contributed extensively to the final preparation of the report  ACRONYMS AND ABBREVIATIONS AME Agence de Mattse de l'Energie BCC Bureau central de conduite (Distribution Control Center) BDM Bureau des methodes (Procedures Department) CAO Consumption ascertained during operation CL Core losses COMELEC Comite maghrdbin de I'electricit6 DD Distribution Directorate DPWT DEpartement des techniques gdn6rales (Technical Facilities Departmet) EdF ElectrlcitE de France GT Gas turbine GTD Gestion technique des ouvrages HHV High heating value of fuel HR Heat rate (actual) HV High voltage JL Joule losses LV Low voltage MSI Mise en service industrielle (Commercial Operation) MV Medium voltage NORDEL Nord Electricit6 OBC Optimum base consumption OD Operations Directorate (Direction de l'exploitation) SME Service des Mouvements d'Fnergie ST Steam turbine STEG Socit tunisienne d'dlectricitW et du gas (Tunisian Electricity and Gas Utility) tan phi Tangent of power factor angle UCPTE Union de coordination des producteurs et transporteurs d'electricitd VHV Very high voltage ELECTRICITY MEASURES GWh Gigawatt hour I Joule kcal kilocalory kV kilovolt kVA kdlovolt amperes kW kilowatt Mi mega joule MVA megavolt ampere MW megawatt Ti tera joule toe ton of oil equivalent V volt  CURRENCY BQUWIALNT 1 US$ z 0.9 Tuniian Dinar FISCAL YEAR January 1 - December 31  TABLE OF CONTENTS SUMMARY ......................... i ]INTRODUCTION . 1 Organizational Structure of the Tunisian Electricity and Gas Utlity. 1 Demand Growth .. ... . 2 Study Objective and Methodology ............................ 2 Local Participation and Skills Transfer ...... 3 Report Organization. 4 II. ELECTRIC POWER GENERATION .5 Steam Turbines.... 7 Heat rate monitoring .... 7 Analysis of deviaions.... 9 Setting up efficiency monitoring in the STEG plants .... 12 Unavaiability rates ....13 Maintenance . . ...................................... 14 Inventory management ................................. 16 Combustion Turbines .................................... 17 Heat rates ......................................... 17 1vfahiteiaiice .... 17 Unavailability . . ..................................... 19 Hydropower Generation ...... ............................ 19 Efficiency/availability . . ................................ 19 Maintenance . . ...................................... 20 Conclusions and Recommendations ............................ 20 Short-term recommendations .............................. 21 Medium-term recommendations ............................ 21 M]. TRANSA>ON . ........................................ 24 Simulation of Transmission Network Operations ... ................ 24 Actions Needed to Reduce Losses ............................ 26 STEG NetworkControl ................................... 26 Voltage levels .................... .......................... 26 Compesaion ... 27 Operation ........................................... 29 Additional Actions Needed to Improve Transmission Network Efficiency .... 30  14~~ ~ ~ ~ ~ . . .. 3 - T"ifins ...................................., ......... 32 Iierconviicton .. . .... ............. . 32 IV. DISMUBTION........... 34 Data Collection and Loss Assessment Method ......... 35 Status of available data .. ....... ...... 36 Recommeniations .... ...... ..... 36 Loss assessment method............ 37 Reduction of MV Nework Losses. 38 Assessment of MV network losses. 38 Reduction of MV network losses. 39 Reduction of LV Network Losses .... ...41 Assessment of LV network losses. 41 Reduction of LV network losses ....42 Assessment and Reduction of Losses from Transformers . .45 Losses in the HV/MV taunforners. 45 Reduction of losses in HV/MV transformers . 46 Improving the transrmer utilization factor ..47 Losses in the MVLV transformers ..48 Reactive energy compensation ......... 49 Reactive energy billing. 50 Additional Problems Associated with Operation of the MV/LV Networks .... 51 Maintenance .....52 Prevention of risks associated with the use of PCB ...... 52 V. CUS N MANA...ER ...GE. . 53 Metering ....53 Unmetered consumption. . . .. 53 CustomerBilling ... . ....57 Processing new customers... 57 Meter reading. . . ..... 57 Monitoring of special-tariff customers . . ..... .58 Billing procedures and correction of anomalies . . . 58 Distibution of bllls . ....S.... . 59 DebtRecovery. . . .. 59 Tadff Policy .... . ..... 62 'W. CONCLUSIONS .......63 Main Actions Proposed......... 63 bpact on theEnvironient.. 64 Power Conservation at the Level of Final Use ..... .................. 64  I S OG Organizational Structure ................................ 66 2 Calculation of Losses ...................................... 68 3 Equivalence Between the Inmediate Rate of Return and the Internal Rate of Return 87 4 Heat Rates of the Steam Thermal Plants .......................... 88 5 Efficiency Monitoring ...................... .......,.. 94 6 On-Line Monitoring of the Operating Efficiency of the Fuel-Buming Thermal Power Plants 99 7 Unavailability Rates and Availability Statistics for Conventional Thermal Power Units ...................... ................. 107 8 Standard Maintenance Cone pts .. .I ................. ........... 109 9 Load Flow Calculations - Hypotheses and Summary of Results ........... . 112 10 Impact of Compensation on Loss Levels ........... ............... 116 11 Reactive Power Compensaion Survey ............................ 119 12 Economic Analysis of Compensation ............. ................ 123 13 Selection of Network Sample ................................. 127 14 Cross-Section Change ...................................... 142 15 Transformer Operation in the HV/MV Substations ...... .. ........ ... 154 16 Guide for Preparing Maintenance Procedures ............ ........... 155 TABLES I Reduction of MV Network Losses ....... ....................... vi 2 Reinforcement of the LV Network .................. vii 1.1 ElectricityBalance ........................................ 2 2.1 STEG Generating Equipment in 1991 ................. 6 2.2 Steam Plant Heat Rates in 1988 ...... ... ...................... 8 2.3 STEG: Combustion Turbines (1988-1990) ......... .. .............. 18 4.1 Key Features of STEG Distribution Zones ......... .. .............. 34 4.2 Network Losses: MV Sample ............... .................. 39 4.3 Reduction of Losses from MV Networks .......................... 41 4.4 Peak Power Losses: LV Feeder SanIple .......... .. .............. 42 4.5 Estimated Costs of Upgrading the STEG LV Network to 220 V ..... ....... 43 4.6 Network Reinforcement: LV Feeder Sample ....................... 44 4.7 Reinforcement of the LV Network .............. ................ 44 4.8 Losses in the HV/MV Transformers ........... .. ................ 46 4.9 Losses in the MV/LV Transformers ............................. 48 4.10 Savings Achievable by Reducing the Inventory of MV/LV Transformers .... .. 49 5.1 Change in Debt Due to STEG ................................. 60 6.1 Main Actions Proposed ..................................... 63 A2.1 SummuyoflInvestmentsinMVSubstations .............. 77 A2.2 Summary of nvestments MVlLV Substations ..................... 78 A2.3 Summary of Investnents ia LV Substations .......... .............. 80 A2.4 Annual Cost of One kW of Peak Losses .......................... 84  A2.5 Total Annual Cost of one kW of Core Losses in the Transformers .......... 85 A2.6 Annual Cos: of one kW of Losses ............. . ....... . ., .... . 86 A3. 1 Conversion of Immediate Rate of Return into Internal Rate of Retrn ........ 87 A5.1 Sample Variations in Operating Parameters and their Effects on the Heat Rates of a 125 MW Unit .... .................... 95 A6.1 Measurements Needed for Efficiency Monitoring of the Thermal Power Plants 99 A6.2 Cost Estimate for Installation of an Efficiency Monitoring System for Two UJnits .......................................... 101 A7.1 Unavailability Rates and Availability Statistics for Conventional llermal Power Units ...................................... 108 A9.1 Nodes: Active and Reactive Power ...... ....................... 112 A9.2 GeneratingSftData ...... ..... , 113 A9.3 UNOM