Tiantai Pumped Storage Power Station

The Tiantai hydropower project is a 1.7GW pumped storage power station under construction in the Zhejiang province of China.

China Three Gorges Construction Engineering Corporation, a subsidiary of China Three Gorges Corporation (CTG), is developing the project with an estimated investment of £1.09bn ($1.53bn).

Construction works officially started in December 2021, with the first unit expected to come online by July 2026, followed by the remaining three units by May 2027.

At full capacity, the Tiantai pumped storage power station is estimated to produce up to 1.7 billion kilowatt-hours (kWh) of electricity and offset one million tonnes (Mt) of carbon dioxide (CO^­­₂) emissions a year.

Location and site details

The Tiantai pumped storage power station is located near Tantou in Tiantai county, Zhejiang province, China.

The project site lies 240km and 150km away from Shanghai and Hangzhou, respectively.

Reservoir details

The upper reservoir of the pumped storage power project will have a storage capacity of 6.86 million cubic metres (Mcm) at a normal water level of 953m.

The lower reservoir will have an active storage capacity of 10.34Mcm at a normal water level of 204m.

Tiantai pumped storage power station make-up

The Tiantai pumped storage power station will be equipped with four 425MW power units, each of which will comprise a reversible Francis pump turbine unit placed in an underground powerhouse. The power plant will be designed to operate at a net water head of 725m.

The upper and lower reservoirs will be connected through a 483.4m-long inclined shaft for water diversion.

Other components of the project will include access and ventilation tunnels, and a 500kV switch station near the powerhouse.

Infrastructure facilities

The project also involves the construction of a 5.4km-long road to access the lower reservoir. The access road will comprise three bridges.

Power evacuation

The electricity generated by the Tiantai pumped storage power station will be evacuated into the Zhejiang power grid through a 500kV transmission line.

Contractors involved

China Power Construction Group (Power China) East China Survey and Design Research Institute (East China Institute) secured a £32m ($44m) contract to perform survey and design works for the project in February 2022.

East China Institute also prepared an environmental impact assessment (EIA) report for the 500kV switch station of the pumped-storage power project.

Sinohydro Bureau 5 has been engaged to perform geological exploration as well as construct the access and ventilation tunnels.

Tiantai pumped storage power station background

The People’s Government of Tiantai County signed an investment and construction agreement with CTGC to construct the Tiantai pumped storage power station in February 2021.

The feasibility study and the preliminary design of the project were completed in October 2021, whereas the Provincial Development and Reform Commission (DRC) of Zhejiang approved the construction of the power plant in December 2021.