Abstract: In response to the challenge of capacity mismatch in the multi-energy complementary systems located in the complicated terrain areas of the plateau, this paper focuses on the optimization of capacity allocation for hydroelectric-wind-photovoltaic-pumped storage system in the study area of the middle Yarlung Zangbo River basin. We use the Ward's hierarchical clustering algorithm to the field of spatial layout optimization for wind and solar resources development, and construct a refined 8760-hour simulation framework for four-dimensional hydroelectric-wind-photovoltaic-pumped storage. This method breaks through the time resolution limitation of traditional monthly-scale planning. And to verify its applicability, we examine a study cases of the under-construction Jiexu hydropower station, and the planned Yongmu pumped storage power station within the basin. Based on high-precision meteorological data sets, fine evaluation of the wind and solar energy resources in the study area indicates the middle reaches have a development potential of 23.5 million kW for wind power and 238 million kW for solar energy. Our predictions show new energy consumption can be regulated significantly by a hydroelectric-wind-photovoltaic-pumped storage multi-energy complementary system that is based on the two power stations of Jiexu and Yongmu. Wind-solar complementarity enhances the consumption rate; the pumped-storage power stations can mitigate the volatility of wind-solar outputs and increase power grid stability. Furthermore, if considering the flexibility of the demand side, the installed capacity ratio of new energy to pumped-storage power stations would increase significantly.

Key words: new energy, evaluation of wind and solar resources, multi-energy complementary, capacity allocation