600 MW compressed air storage plant fully operational

The presumably world's largest Compressed Air Energy Storage (CAES) plant has commenced full operation, as indicated in a statement from Shanghai Electric, a supplier. The CAES demonstration project is located in the Huai'an salt cavern in China's Jiangsu Province.

The plant essentially consists of two CAES units, each with a capacity of 300 MW. With a total installed capacity of 600 MW and a storage capacity of 2400 MWh, the plant is expected to achieve an efficiency of 71 percent.

In the Huai'an salt caverns, approximately 980,000 m³ of which are utilized by the power plant, surplus energy generated during off-peak hours is used to compress air at depths of 1150 m to 1500 m. The technology employed is adiabatic high-temperature compression, which operates with molten salt and pressurized thermal water. No fossil fuels are combusted in this process. The compression heat is stored and used throughout the entire process. When needed, the expanding compressed air is converted back into electricity via turbines to cover peak demand periods. This allows for significant CO₂ savings, the company explains.

CAES power plant fully connected to the grid

Block 2 of the CAES power plant, with a capacity of 300 MW, already went into full operation in December 2025. Now, the first block follows, meaning the entire plant is now connected to the grid and fully operational.

The CAES power plant is expected to generate 792 million kWh of electricity annually. This is intended to supply approximately 600,000 households. According to Shanghai Electric, it is possible to save the energy equivalent of 250,000 tons of coal annually, which corresponds to a reduction in CO₂ emissions of about 600,000 tons.

The costs for the CAES power plant demonstration project are reported to be a total of 520 million US dollars.

(olb)