https://j.people.com.cn/n3/2026/0629/c95952-20472204.html

Unit 4 of the Tiantai Pumped-Storage Power Station in Zhejiang Province officially began operations on June 25. This marks the start of operations for all four units of the pumped-storage power plant, which boasts the largest single-unit capacity in China.

With a total installed capacity of 1.7 million kilowatts (kW), the Tiantai Pumped-Storage Power Station comprises an upper reservoir, a lower reservoir, a water conveyance system, and an underground powerhouse. The station is equipped with four reversible pump-turbine generator units, each with a capacity of 425,000 kW. Not only is this the largest single-unit capacity among similar projects currently under construction worldwide, but the effective head—the vertical distance between the upper and lower reservoirs—reaches 724 meters, making it the highest in the world for a pumped-storage plant under construction.

Serving as a “voltage stabilizer” for the Zhejiang power grid, the station will significantly enhance the grid’s peak-shaving, load-leveling, and emergency response capabilities. It is capable of supplying approximately 1.7 billion kilowatt-hours (kWh) of clean electricity annually—enough to meet the yearly household power needs of a city with a population of 1.6 million.