In the Gobi Desert in Golmud City, Haixi Mongolian and Tibetan Autonomous Prefecture in northwest China's Qinghai Province, giant white tanks stand out against the gravel plain. Inside the tanks, in an ultra-cold environment of minus 194 degrees Celsius, energy is stored as liquid air.

This is the Qinghai 60,000-kilowatt / 600,000-kilowatt-hour (kWh) liquid air energy storage demonstration project, the largest such project under construction worldwide, built by China Green Development Investment Group (CGDG). The project has entered its final commissioning stage.

Qian Yadong, a technical specialist on the project team, said the core of the project is to transform air into an energy storage carrier under extreme cold. To achieve this, CGDG formed a joint team with the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences, and a campaign to overcome key bottlenecks began. After countless tests, the team overcame a bottleneck in ultra-low-temperature cascade technology for cold storage, developed an atmospheric-pressure low-temperature storage system, and solved the core challenges of air storage and constant-pressure release.

The system has a total power output of 60,000 kilowatts and an energy storage capacity of 600,000 kilowatt-hours. During off-peak hours, surplus power drives compressors. Purified air is compressed into a high-pressure, high-temperature gas, cooled, and sent to a cold box for liquefaction, then stored in atmospheric-pressure cryogenic tanks. Heat generated during compression is recovered and stored in high-pressure spherical tanks. During peak demand, the liquid air is pressurized and gasified. With dual heating from cold storage media and recovered heat, it becomes a high-pressure, high-temperature gas that drives an expander to generate electricity, forming a closed loop that "stores off-peak power for peak use."

Liquid air has a density about 750 times that of ambient air and can be stored safely at atmospheric pressure. The technology not only addresses pain points of some traditional storage options, such as relatively low energy density and weaker safety performance, but also offers notable clean, low-carbon advantages. The working medium is air, with no carbon dioxide or pollutant emissions throughout operation. The equipment has a long service life and no geographical constraints, enabling stable operation even in extreme environments such as the Gobi Desert and high plateaus.

Upon completion, the project is expected to set two world-leading benchmarks in both power output and storage capacity. Each charge can support 10 hours of continuous discharge, delivering 600,000 kilowatt-hours of clean electricity. Annual power delivery is expected to reach about 180 million kilowatt-hours, enough to meet the yearly electricity demand of 30,000 households. A supporting 250,000-kilowatt photovoltaic project will also give the 'Air Battery' green, self-supplied charging capability.

According to the project team, the technology can help address renewable energy curtailment and grid supply-demand imbalances, offering a new solution for building renewable energy bases in the Gobi Desert and other arid regions, and providing a Chinese approach to the development of the global new-type energy storage industry.