Long-term Power Purchase Agreement for photovoltaic energy as a solution for enhancing the profitability of the Tashmarunishta pumped-storage hydro power plant

This paper analyzes the potential of a long-term Power Purchase Agreement (PPA) as a mechanism to enhance
the profitability of the Tashmarunishta pumped-storage hydro power plant (PSHPP). The study focuses on a 20 year agreement for the procurement of electricity from a 300 MW photovoltaic (PV) power plant, with purchase price of 32 €/MWh. The electricity generation of the PV power plant is modeled and simulated in PV*SOL premium on an hourly basis. Furthermore, based on data from the pre-investment study for PSHPP Tashmarunishta, the required electricity for water pumping and the expected electricity production from the PSHPP are analyzed. The proposed operational regime includes ten hours of water pumping during PV electricity production for six consecutive weeks, followed by one week with nine hours of pumping and seven hours of electricity generation from the PSHPP in the evening, when market prices are at their peak. The hourly-level analysis enables an assessment of the technical and economic benefits of this mechanism, examining the potential improvement in the economic sustainability of the Tashmarunishta PSHPP through the optimal utilization of renewable energy sources.