On January 9, the "Energy Storage No. 1", the world’s first 300 MW compressed air energy storage (CAES) demonstration project, was fully connected to the grid in Yingcheng, Hubei Province.
Source: People’s Daily Online
On January 9, the "Energy Storage No. 1", the world’s first 300 MW compressed air energy storage (CAES) demonstration project, was fully connected to the grid in Yingcheng, Hubei Province. The facility is expected to generate nearly 500 million kilowatt-hours of electricity annually, saving 159,000 tons of standard coal and reducing carbon dioxide emissions by 411,000 tons each year. It effectively mitigates the intermittency and variability of renewable energy, supporting grid stability and boosting renewable energy integration. The project has set three world records: largest single-unit capacity, largest energy storage scale, and highest energy conversion efficiency. Additionally, it features 100% domestically produced core equipment and subsurface technology.
Experts describe CAES plants as “green super batteries” for their innovative use of compressed air to generate electricity. During off-peak periods, surplus electricity powers compressors to store air in sealed underground facilities, such as salt caverns or artificial chambers. Heat generated during compression is stored in above-ground thermal tanks using materials like hot water or molten salt. During peak demand, the stored high-pressure air is released from the underground reservoirs, while the thermal tanks release heat. The heated air expands rapidly, driving turbines to generate electricity for the grid.
Wan Mingzhong, Chief Expert of China Energy Engineering Group and Chairman of its Digital Technology Group, noted that the project features a 300 MW single-unit capacity, 1,500 MWh of energy storage, and a 700,000-cubic-meter underground air reservoir. Each pressurized tank holds up to 3,500 cubic meters. The system operates on an 8-hour storage and 5-hour discharge cycle, aligning perfectly with daily fluctuations in China’s power grid. With a lifespan of over 30 years, the project represents a groundbreaking innovation in CAES technology, developed entirely in China with proprietary intellectual property.