World's largest compressed-air energy storage power station being built

The world's largest compressed-air energy storage power station, the second phase of the Jintan Salt Cavern Compressed-Air Energy Storage Project, officially broke ground on Wednesday in Changzhou, East China's Jiangsu Province, marking a key milestone in China's energy storage advancements, according to a report by China Group Media.

The second phase of Jintan Salt Cavern Compressed-Air Energy Storage Project plans to build two 350-megawatt non-supplementary fired compressed air energy storage units, with a total volume of 1.2 million cubic meters, making it the largest in unit capacity, storage volume, and efficiency.

The project has overcome key technological bottlenecks, achieving 100 percent localization of air turbines and compressors, bolstering China's energy security strategy, China Group Media reported on Wednesday.

Once completed, the project will store 2.8 million kilowatt-hours per charge, powering up to 100,000 electric vehicles. It will save 270,000 tons of standard coal annually and reduce carbon dioxide emissions by 520,000 tons.

"The compressed-air energy storage station offers large capacity, long storage time (over 4 hours), and efficient response, making it comparable to small and medium-sized pumped storage power plants," Liu Yong, Secretary General of Energy Storage Application Branch of China Industrial Association of Power Sources told the Global Times on Wednesday.

Liu noted that the system operates without combustion, producing zero carbon emissions, and has a lifespan of up to 50 years. "It offers longer storage duration, extended lifespan, lower lifecycle cost, and better safety, compared to other energy storage technologies," Liu said.

Salt cavern compressed-air energy storage, dubbed as the underground "green power bank," stores electricity by compressing air into underground salt caverns during off-peak times. The air is then released during peak demand to generate electricity, balancing supply and demand, as China Group Media reported.