A New Hydropower Milestone for China
China has once again solidified its position as a global leader in large-scale infrastructure with the full commissioning of the Fengning pumped-storage hydropower plant. After an investment of $2.6 billion and over 11 years of construction, the facility is now the world’s most powerful pumped-storage hydropower plant, boasting a total capacity of 3.6 GW.
The announcement came from the State Grid Xinyuan Group Co., a subsidiary of the State Grid Corporation of China, on December 31, 2024. The company confirmed that the plant’s final variable-speed unit had been activated, marking the completion of the project and its transition to full operational status.
This milestone coincides with China’s approval of another ambitious project: the world’s largest hydropower dam, expected to generate a staggering 300 TWh annually. While still in the planning phase, this colossal endeavor underscores China’s unparalleled ambitions in renewable energy infrastructure.
Setting Four Records in One
When it comes to breaking records, China spares no effort. The Fengning plant not only claims the title of the largest pumped-storage hydropower plant in the world but also achieves four distinct records: installed capacity, storage capability, underground facility size, and cavern network scale.
The World’s Largest Pumped-Storage Facility
Located in Fengning County, Hebei Province, the plant features 12 single-stage pump-turbine units, each with a capacity of 300 MW. Two of these units employ variable-speed technology, enabling flexible load adjustments and faster frequency response to meet grid demands.
The facility relies on two reservoirs: an upper reservoir with a capacity of 45.04 million cubic meters and a lower reservoir holding up to 71.56 million cubic meters. Together, they allow the plant to store enough energy to operate at full capacity for 10.8 hours.
The plant is expected to generate 6.61 TWh annually, requiring 8.71 TWh of energy to pump water back to the upper reservoir. These figures highlight the intricate balance of energy input and output inherent to pumped-storage systems.
An Underground Engineering Marvel
The downstream structure of the plant is an engineering feat in itself, extending 414 meters underground with a height of 54.5 meters and a width of 25 meters. This massive subterranean construction also includes a record-breaking network of caverns accessed via 190 tunnels.
The facility is connected to the Zhangbei Roux DC conversion station, playing a critical role in load regulation and regional grid stability. According to the State Grid Xinyuan Group, the plant served as a key infrastructure project during the Winter Olympics. Its operation ensured 100% green energy coverage for the event venues while significantly advancing the adoption of clean energy in Beijing and Hebei.
