Power utility generation portfolio optimization as function of specific RES and decarbonisation targets – EPBiH case study

•Guidelines for power utilities to reach specific decarbonisation targets offered.•Optimization model of RES share to be introduced into power system is proposed.•Single criteria analysis and multicriteria sustainability assessment are applied.•The optimization method has been demonstrated on a real power system.•In the considered case, HIGH RES scenario showed to be the preferable one. This paper provides guidelines and principles for power utilities to reach specific energy and decarbonisation targets. Method of power generation portfolio optimization, as function of sustainability and decarbonisation, along with appropriate criteria, has been proposed. Application of this optimization method has been demonstrated on a real power system – power utility JP Elektroprivreda BiH d.d. – Sarajevo (EPBiH), a typical example of South East European power system. The software tool WASP IV has been employed in the analysis, in order to define the dynamics and an optimized expansion of generation portfolio of the power system under consideration for the next period. The mid-term generation portfolio development plan for the EPBiH power system until year 2030 has been made during this research, taking into account the shutdown dynamics of existing power units and commissioning new ones, in order to provide safe supply of electric and heat energy for local consumers. Three basic scenario of renewable energy sources (RES) expansion have been analysed to reach specific RES and decarbonisation targets set for 2030, including RES share increase from the current level of 18% up to 35% (LOW RES), 45% (MID RES) and 55% (HIGH RES). Effects to the sustainability are considered through environmental, economic and social indicators. Multicriteria sustainability assessment gave an advantage to the HIGH RES, under assumption of equal weighting factors of economic and environment groups of indicators. Also, single criteria analysis has been made to support sustainability assessment. Results show that, considering the EPBiH generation portfolio planned under HIGH RES, 49% CO2 emissions cut in 2030 compared to 1990 is possible along with further increase of overall energy efficiency of the system. The proposed model can be used in conventional power systems for generation portfolio development as function of specific RES and decarbonisation targets.