Reliable-economical equilibrium based short-term scheduling towards hybrid hydro-photovoltaic generation systems: Case study from China

The inherent uncertainty associated with hydro and solar energy sources means that there have been significant challenges in ensuring reliable and stable power supplies. Therefore, constructing hybrid generation systems to take advantage of multiple compensatory resources has attracted increased research attention. This paper proposes a short-term optimization strategy for the hybrid hydro-solar power supplier to allow for reasonable scheduling decisions based on natural limitations and policy impacts. To handle the seasonal and daily uncertainties involved in hydro and solar power, nine typical generation scheduling scenarios are proposed and the fuzzy theory is applied separately. In each scheduling scenario, short-term operation decisions considering reliable power supply and beneficial power generation equilibrium is achieved using multi-objective optimization. By applying the epsilon-constraint method and introducing the suppliers' attitude parameter, the model is transformed into its equivalent single form and solved by LINGO software. A case study from the Longyang Gorge hybrid hydro-photovoltaic generation system in China is conducted to demonstrate the practicality and efficiency of the optimization method. The calculation results found that this multi-objective method was effective in solving the conflicts between reliable and economical power supplies. The solar power output proportion can reach 10.95-24.5% of total output in the nine typical scenarios. Furthermore, we found that renewable electricity subsidy policies can efficiently help to adjust energy supply structure, especially in hybrid energy supply system. Management recommendations for power supplier, the electricity industry, and administration department are proposed to better explore equilibrium scheduling for hybrid power generation systems.