China has begun construction of a 600-megawatt pumped-storage hydropower station in Qinghai Province to help balance the grid serving Delingha’s 10-gigawatt clean energy base. The station, in Delingha’s Xuji township, is expected to enter full operation in 2034.The 5.23 billion yuan ($783 million) project is the highest-altitude pumped-storage station in northwest China, according to the State-owned Assets Supervision and Administration Commission of the State Council. The upper reservoir’s normal water level will sit at an elevation of 4,008 meters.Storing surplus power for peak demandThe project will comprise upper and lower reservoirs, a water conveyance system and an underground powerhouse. During periods of low electricity demand, the station will use surplus power to pump water from the lower reservoir to the upper one. When demand rises, it can release the stored water to drive turbines and supply electricity to the grid.The plant is designed to generate 1.2 billion kilowatt-hours (kWh) of electricity annually and use 1.6 billion kWh a year for pumping. By shifting electricity use and generation to different times of day, the station can help the grid meet peaks in demand. It will also provide emergency reserve capacity and help regulate the grid’s frequency and phase.Supporting Delingha’s clean energy baseThe National Energy Administration listed the station as a key project under China’s 14th Five-Year Plan, which covered 2021 through 2025. It also appears in the agency’s medium- and long-term pumped-storage development plan for 2021 through 2035. The project is intended to fill a gap in large-capacity energy storage in the region.Sun Chuanwang, a professor at Xiamen University’s School of Economics, told the Global Times on Tuesday that the station’s proximity to the clean energy base would help Delingha store and use the electricity it produces. The city already hosts solar power installations, green hydrogen production facilities, heat-absorbing towers and energy storage facilities.By 2026, Delingha had installed 6.05 GW of clean energy capacity, with another 950 MW under construction, according to city authorities. The city aims to exceed 14 GW of installed clean energy capacity by 2030.Pumped storage at higher elevationsDelingha’s altitude record applies to northwest China. A separate project in Daofu County, in southwestern Sichuan Province, is set to become the world’s highest-altitude pumped-storage power station, according to Xinhua News Agency. The Daofu station sits at an elevation of 4,300 meters.In Qinghai, the upper reservoir’s elevation marks where the Delingha station will hold water between pumping and generation. The water conveyance system will link the reservoirs and the underground powerhouse, allowing the station to switch between drawing power from the grid and supplying it.The 2034 target for full operation comes four years after Delingha’s deadline for exceeding 14 GW of clean energy capacity. Once fully operational, the station will give the grid a way to use surplus electricity when demand is low and return part of that energy when homes and businesses need more power.