China’s Liquid-Air Battery Stores Power by Chilling Air to −194°C

October 31 — According to CCTV News today, the world’s largest 60-megawatt liquid air energy storage national demonstration project has successfully connected to the grid — a major breakthrough in the engineering and commercial deployment of the technology.

The project is in Golmud, Qinghai province, with a total capacity of 60,000 kilowatts. It can help absorb 600,000 kilowatt-hours of clean energy a day and deliver about 180 million kWh a year, enough to meet the electricity needs of 30,000 households for a year.

The project uses a core ultra-low-temperature cryogenic liquefaction process at −194°C, with air as the working medium, to store and release electrical and cooling energy at ambient pressure and ultra-low temperature — combining large scale, long duration and long service life.

“Equipment localisation reached 100%,” said Ji Wei, chief engineer of China Green Development’s energy storage company. “Both storage power and capacity rank first in the world, and several core indicators are world-leading.”

During construction the project developed a series of first-of-their-kind core machines, including the world’s largest horizontally split centrifugal compressor and the liquid expander with the largest single-unit flow. That linked the whole chain from core components and system integration to engineering deployment, achieving precise control of the “compress — liquefy — store — generate” process and real-time coordinated dispatch of “cold — heat — power — gas” energy flows.

Liquid air energy storage is a new long-duration storage technology. It relies neither on special mine caverns nor on chemical batteries; it moves energy by liquefying and vaporising air, which suits China’s vast renewable energy bases.

The project uses a −194°C cryogenic liquefaction process. In plain terms: when wind and solar output is in surplus and grid load is low, the spare electricity cools air to −194°C until it liquefies, storing it as a liquid at ambient pressure; at peak demand the liquid air is vaporised and expanded to drive turbine generators. Energy is thus “stored in the trough and used at the peak”, shifting electricity across time.

With air as its circulating medium, liquid air storage emits no pollutants and does not depend on special terrain, offering flexible siting, long cycle life and high safety. It suits renewable energy absorption, deep peak-shaving for coal plants and integrated use of LNG cold energy, adding to China’s options for long-duration storage.