China is leading the world in pumped hydro energy storage. Its National Energy Administration says there are already 19.23 gigawatts of pumped hydro capacity in China and another 31.15 gigawatts (GW) under construction for a total of 40 GW. The first phase of the 3.6 GW, $2.78 billion Fengning storage project in Hebei province is scheduled to come online prior to the start of the 2022 Winter Olympics. Once the second phase is completed in 2023, it will be the largest pumped hydro facility in the world.
The 1.8 GW first stage will include six 300 kW variable speed reversible generators that will pump water uphill and make electricity when it flows back downhill. Chinese authorities say it will take about 5 minutes to reverse the generators when there is a need to supply electricity to the grid. The Fengning project will use two 500 kV transmission lines to connect to China’s national grid. Construction of the facility began in 2013.
CleanTechnica readers are more interested in gigawatt-hours than gigawatts. According to the State Grid Corporation of China, the designed annual power generation is 3.424 terawatt-hours (TWh) with 4.565 TWh of corresponding pumped water. SGCC goes on to wax eloquent about the benefits of the Fengning facility.
“Upon its completion, the station will be connected to Beijing-Tianjin-North Hebei grid with two 500 kV lines for peak shaving, frequency modulation, phase modulation and emergency backup. It will also be used as large capacity power storage for the system, which will play an important role to accelerate scaled development of wind power, solar power and other REs in northern Hebei, meet the need for grid peak shaving, maintain the safe and stable operation of the grid, enhance power supply quality and the economy of grid operation, and utilize resources more efficiently. At the same time, the power station will boost local employment, facilitate tourism and farming industries, promote energy saving and emission reduction, help with climate change and have significant social, ecological and economic benefits.”
Whew. That’s a lot of benefits!
General Electric’s Power Conversion division will collaborate with ANDRITZ and Dongfang Electric Machinery to make the variable speed generating technology work. That division “will provide the variable speed technology — constituting two variable speed MV7000 converters for two 300-megawatt generators provided by ANDRITZ as well as one static frequency converter for the rest of the four generators provided by Dongfang Electric Machinery Co., Ltd.
“The Fengning hydro project is the first order in China to incorporate variable speed technology. Variable speed drive technology provides a full range of speed that is the best performing and most economical to pump water to the upper reservoir — when in the saving mode — or to release water to a lower reservoir to generate power. The more flexible system provides not only more efficiency, but also can help stabilize the grid during the Winter Olympics when the demand for electricity will be significantly higher than usual,” reads a company press release.