The Changlongshan pumped storage power station, being developed in the Zhejiang province of China, will have a total installed capacity of 2.1GW.

Although the project was officially launched by the owner and developer China Three Gorges Corporation in 2006, the main construction works were started in November 2015.

Estimated to cost approximately £1.03bn ($1.56bn), the power station will comprise a total of six pumped storage units.

The installation of unit-1 entered the final assembly stage with the hoisting of its generator rotor in October 2020.

While the first unit is expected to be completed by October 2021, the remaining units are scheduled for commissioning by the end of 2023.

The Changlongshan hydroelectric power plant will be one of the biggest pumped-storage hydropower facilities in China in terms of installed capacity. It will also operate at one of the highest operating water heads in the country.

Location and site details

The Changlongshan pumped storage power station is located in the Yu village of Shanchuan township, near Tianhuangping town, approximately 25km away from Anji County, in the Zhejiang province of China.

Located adjacent to the commissioned Tianhuangping pumped-storage power station, the Changlongshan project site lies on the top of Changlong Mountain, approximately 1km above the sea level.

Changlongshan pumped storage facility make-up 

The Changlongshan pumped storage hydroelectric facility comprises an underground powerhouse, upper and lower reservoirs, a water delivery system, and a ground switch station.

The powerhouse will be equipped with six 350MW Francis vertical-axis, mixed-flow, reversible pump-turbine units operating at a water head of 710m.

The upper and lower reservoirs are created using reinforced concrete face rockfill dams with a maximum dam height of 103m and 100m respectively.

While the normal storage level of the upper reservoir will be 976m, its dead water level will be approximately 940m. The total storage capacity of the upper reservoir will be 10.99 million cubic metres (mcm) and the normal storage level will be 10.44mcm.

The lower reservoir will have a normal storage level of 243m and a dead water level of 220m. The normal storage capacity of the lower reservoir will be approximately 14mcm while the total storage capacity will be 16.11mcm.

The water delivery system comprises three 850m-long diversion inclined wells with straight sections of 435m, 434m, and 432m, respectively.

Power evacuation 

The electricity generated by the Changlongshan pumped storage power station will be evacuated through two 500kV power transmission lines.

The facility will be connected to the East China Power Grid from the transformer tunnel.

Infrastructure facilities 

The infrastructure facilities at the pumped storage power station will include two sets of diesel generators along with auxiliary equipment support communication system, diversion tunnel among others.

Contractors involved

Voith signed an agreement with Three Gorges for the supply of two 350MW reversible pump-turbine generator units for the Changlongshan pumped storage power station in July 2017.

Dongfang Electric signed a contract with Three Gorges for the supply of the remaining four pumped storage units in June 2017.

East China Survey and Design Institute was engaged for the engineering and design works of the Changlongshan pumped storage hydropower project while the 12th Bureau of Hydropower was contracted for the construction of the Changlongshan pumped storage power station.

The 14th Hydropower Bureau was awarded a contract worth £32.72m ($43.46m) by Three Gorges for the installation of electrical and mechanical equipment at the hydropower station in June 2018.

The Eighth Hydropower Bureau was awarded a contract for the supply of construction steel for the Changlongshan hydropower plant in November 2019.