Optimizing the sizes of wind and photovoltaic power plants integrated into a hydropower station based on power output complementarity

Fluctuations in the output of wind and photovoltaic (PV) power limit the capacity of the grid to accommodate these energy sources. However, these inherent shortcomings can be overcome by integrating them into hydropower stations with a dispatching capacity. In this study, the optimal size and operation of complementary hydro-wind-PV power systems are explored to provide adequate and reliable power for the grid. First, a coefficient is defined to measure power output complementarity. A size optimization model is then established for the integration of wind and PV power plants into hydropower stations; this model is based on the power output complementary coefficient. The above method is applied to determine the optimal sites and sizes for wind and PV power plants to be integrated into the Jinping-I hydropower station in the Yalong River Basin, China. The power output complementarity benefits of the hybrid hydro-wind-PV power system are analyzed based on the optimization results. The results indicate that the plant site plays a critical role in the optimization of the sizes of wind and PV power plants; the joint operation of wind, PV power plants and hydropower stations increases the power output complementarity benefits of the power system. In particular, joint operation guarantees the quantity of electricity throughout the year and the quality of power throughout the day.