During the wet season, hydropower takes the lead, while photovoltaic generation steps in during dry periods. The energy storage system intervenes in real-time to precisely stabilize fluctuations from renewable sources like solar power. Excess electricity drives pumped storage to accumulate energy, which is then released for power generation during peak demand hours. Working in coordination with flexible, adjustable cascaded hydropower, it swiftly fills electricity supply gaps.
On March 18, it was announced that China’s first cascaded hydro-solar-storage hybrid power generation project—the integrated hydro-solar-storage project in the Xiaojinchuan River Basin of Sichuan's Aba Prefecture—has been fully commissioned. This provides a core technical demonstration for integrated river basin development.
The photovoltaic base project in the Xiaojinchuan River Basin is situated on a plateau with an average altitude of 3,700 meters, covering an area of 3,227 acres. It has a total installed capacity of 160 MW and is equipped with a 16 MW/32 MWh grid-forming energy storage system. This integrated project is China’s first demonstration project achieving real-time coordinated control of hydro, solar, and storage resources. Through multi-energy complementary joint dispatch, the project generates an average of 280 GWh of electricity annually, sufficient to meet the yearly electricity needs of 140,000 households. It saves 87,000 tons of standard coal and reduces carbon dioxide emissions by 262,500 tons each year.
The hydropower component consists of the already operational Mupo, Chunchangba, Zanla, and Mengguqiao hydropower stations in the Xiaojinchuan River Basin, with a combined installed capacity of 195 MW. The energy storage aspect relies on the 5 MW pumped storage unit of the Chunchangba Pumped Storage Power Station. Together, they form a hybrid power generation system comprising "195 MW hydropower + 160 MW photovoltaic + 5 MW pumped storage + 16 MW energy storage."
"The core lies in the multi-energy complementary model," explained an industry expert. Simply put, hydropower dominates during the wet season, solar power compensates during the dry season, and the energy storage system intervenes in real-time to accurately smooth out fluctuations from renewable sources like photovoltaics. Surplus electricity drives pumped storage for energy accumulation, which is discharged during peak demand periods. This works in synergy with flexible, adjustable cascaded hydropower to quickly cover electricity shortfalls. The energy storage system can also be used for black start restoration, ensuring grid stability.
The project also innovatively introduces an "agrivoltaic" ecological model. "By using elevated photovoltaic components mounted 2 meters high, herders can graze livestock in the open spaces between panels, while vegetation restoration is carried out underneath the panels," stated a project manager. This achieves a three-dimensional composite utilization model of "power generation above, grazing between, and restoration below," providing a replicable and scalable demonstration model for building a new power system in western China.