Opinion of Advocate General Saugmandsgaard Øe delivered on 29 October 2020.#Federazione nazionale delle imprese elettrotecniche ed elettroniche (Anie) and Others and Athesia Energy Srl and Others v Ministero dello Sviluppo Economico and Gestore dei servizi energetici (GSE) SpA.#Requests for a preliminary ruling from the Tribunale Amministrativo Regionale per il Lazio.#References for a preliminary ruling – Environment – Articles 16 and 17 of the Charter of Fundamental Rights of the European Union – Principles of legal certainty and of the protection of legitimate expectations – Energy Charter Treaty – Article 10 – Applicability – Directive 2009/28/EC – Article 3(3)(a) – Promotion of the use of energy from renewable sources – Production of electricity from solar photovoltaic installations – Alteration of a support scheme.#Joined Cases C-798/18 and C-799/18.