15-10-2025 | Posted by Principia
It is not the first time that we write about pumped storage. The reason for revisiting the subject now is the recent completion of the Fengning Pumped Storage Power Station. Located in Hebei province, the plant has a total installed capacity of 3.6 GW and is operated by the State Grid Corporation of China (SGCC). The project reached its completion on 11 August 2024 with the operation of the twelfth and final reversible turbine unit.
Designed initially to support the 2022 Beijing Winter Olympics, the Fengning plant is the largest pumped hydro station worldwide in terms of capacity. It was constructed in two 1.8 GW phases, with the first generator commissioned in 2019 and full commercial operations started in 2024. The project cost was approximately US$1.87 billion.
The facility features an elevation difference of 425 metres between its upper and lower reservoirs. This height difference enables it to generate electricity efficiently by releasing water from the upper to the lower reservoir, driving turbines in the process. The lower reservoir holds up to 66.2 million cubic metres of water, of which 41.5 million can be used for power generation. The capacity of the upper reservoir is 48.8 million cubic metres, with 40.6 million available for power generation.
Pumped hydropower plants like Fengning are essential for stabilising energy grids, especially with increasing participation of renewable sources, since they are inherently discontinuous. The Fengning Pumped Storage Power Station is a key part of China’s renewable energy infrastructure, supporting a 10 GW wind and solar base in nearby Zhangjiakou.
The plant is designed to generate 6.61 TWh annually while consuming 8.71 TWh of electricity for pumping, and it connects to the North China power grid via four 500 kV transmission lines.
According to the World Hydropower Outlook 2024, China continues to lead the world in new hydropower development, with 2023 alone seeing the country bring 6.7 GW of new capacity into service, including more than 6.2 GW of pumped storage hydropower. With the Fengning station now online, China is on track to expand its pumped storage capacity to 80 GW by 2027, with a broader goal of reaching a total hydropower capacity of 120 GW by 2030.
Pumped Storage Hydropower is the main form of renewable energy storage, with nearly 200 GW installed capacity providing more than 90% of all long duration energy storage across the world with over 400 projects in operation. To recognise the importance of pumped storage hydropower development, the International Hydropower Association (IHA) is highlighting it with a year-long campaign that will culminate at the International Forum for Pumped Storage Hydropower 2.0 in Paris in 2025.
Principia did not participate in the Fengning Power Station but has gathered considerable experience in solving many of the problems encountered at those facilities. And it is likely to gather much more in the future, as the trends in electricity generation imply a growing demand for long duration storage and there are very few alternatives to pumped storage.
