On May 25, the National New Energy Storage Pilot Demonstration Project - Southern Power Grid Baochi Energy Storage Station was put into operation in Wenshan Prefecture, Yunnan. This is the first large-scale lithium-sodium hybrid energy storage station in China, which realizes the "one-station application" of various new grid-building energy storage technologies, while ensuring the stable access of new energy to the power grid, and promoting the diversified development of new energy storage technologies in my country.
The Baochi Energy Storage Station, which covers an area of about 50 acres, has a scale of 200 MW/400 MWh. According to the calculation of two charges and two discharges per day, the power station can adjust 580 million kWh of electricity per year, which is equivalent to the annual electricity demand of nearly 270,000 households, of which 98% is green electricity. At the same time, the commissioning of the power station has created many world "firsts" such as the development and application of "the world's first grid-building sodium ion energy storage system" and "the world's largest single-unit high-voltage direct-mounted grid-building energy storage system".
Baochi Energy Storage Station was officially listed as a national new energy storage pilot demonstration project in January 2024. The preliminary work of the project was completed and construction started in October 2024. It was connected to the grid and transmitted electricity in December 2024. It was connected to the grid at full capacity in March 2025. It was officially put into operation in May 2025 after completing the inspection and testing as required.
According to relevant personnel, the sodium-ion energy storage system installed in Baochi Energy Storage Station not only uses the world's first large-capacity power sodium-ion battery, but also specially configured with a grid-type converter suitable for sodium batteries. It is the world's first multi-power composite sodium-ion battery energy storage system. "This new sodium-electric system can respond quickly to changes in the load of new power systems, random intermittent fluctuations in new energy sources, and power market trading needs, and can operate in multiple modes such as slow charging and slow discharging, fast charging and slow discharging, and fast charging and fast discharging. The maximum power and response speed are 3 times and 6 times that of existing sodium-ion batteries, respectively.
At present, among the new energy storage projects that have been built and put into operation in my country, lithium-ion battery energy storage accounts for as high as 97%, and sodium-ion battery energy storage accounts for less than 1%. Compared with lithium-ion batteries, sodium-ion batteries not only have many performance advantages such as a cycle life of more than 20,000 times and stable operation with an ambient temperature difference of 45 degrees Celsius, but also have a bright promotion prospect with a wide range of sources, abundant reserves, and low prices. At present, my country's sodium-ion battery energy storage is in a critical stage of starting development and moving towards mature application. The unit watt-hour cost before large-scale application is still significantly higher than that of lithium-ion batteries.
The construction of lithium-sodium hybrid energy storage stations can improve the adjustment ability of power stations to adapt to load fluctuations without significantly increasing the construction cost of energy storage power stations. Compared with pure lithium energy storage stations, the adjustment function is stronger; compared with pure sodium energy storage stations, the economic benefits are better.
