The world's first 10 megawatt salt cave compressed air energy storage national demonstration power station in Feicheng [Photo/Dazhong News]

In Feicheng Economic Development Zone, there is a unique energy storage power station, which is an abandoned salt cave thousands of kilometers underground that compresses air to store energy without burning coal and natural gas.

Dubbed an "urban power bank", it is world's first 10 megawatt salt cave compressed air energy storage national demonstration power station. It began to generate energy in September 2021 and was approved as China's first compressed air energy storage independent power station involving spot electricity transaction.

It only takes 12 minutes from receiving instruction to the 100 percent efficient operation of generating equipment. The power station takes six hours to complete a single charge and can continuously generate electricity for four hours, with each hour able to provide 10,000 kilowatt hours of electricity, which can meet the daily needs of 4,500 households.

A salt cave is an abandoned mine left after salt mining that is situated between 800 to 1,000 meters underground, which can be used for storing pressure-air, natural gas, petroleum, and hydrogen.

Feicheng treats these abandoned salt caves as "green fortune". The city is mapping out the construction of a salt cave energy storage industrial park and an energy storage power station project.

"The utilization and exploration of these abandoned salt caves offers another path for sustainable, green, and high-quality development,"said Sun Dong, director of the administrative committee of Feicheng Economic Development Zone.

The construction of the 300MW salt cave compressed air energy storage power station is also under way. After its completion, the power station will be able to generate 310,000 kilowatts of electricity per hour.

Shandong's wind electricity and photovoltaic industry are also in rapid development, but cannot meet energy storage demand.

"Tai'an is rich in salt mineral resources, which not only offers opportunities to explore underground salt caves for compressed air energy storage but also for natural gas storage. Tai'an has the potential to be the energy storage center of Shandong province, which will play an important role for its energy transition," said Yang Chunhe, an academician of the Chinese Academy of Engineering.

In the future, Feicheng will build a gigawatt-level salt cave energy storage base and a corresponding energy storage industry.