HUAI’AN, China — China activated the world’s largest compressed-air energy storage facility on January 26, 2026, in Jiangsu province, with capacity to supply electricity to approximately 600,000 households annually, according to Harbin Electric Corporation, which participated in the project’s construction. The Guoxin Suyan Huai’an Salt Cavern Compressed Air Energy Storage Demonstration Project began full commercial operations with 600 megawatts of generation capacity and 2,400 megawatt-hours of storage capacity.
From Storage Caverns to Residential Power
The facility translates industrial-scale infrastructure into tangible residential energy security, with officials projecting annual electricity generation of 792 gigawatt-hours. This output directly addresses grid stability challenges as China expands intermittent renewable energy sources like wind and solar, which fluctuate based on weather conditions.
The plant consists of two 300-megawatt non-combustion units that compress air into underground salt caverns during off-peak hours, typically at night when electricity demand drops. During peak demand hours in daylight, the facility releases pressurized air to spin turbines and generate electricity without burning fossil fuels.
Advanced Heat Management Technology
The system employs advanced molten salt and pressurized thermal water storage for heat management during the compression and expansion cycles, achieving 71 percent conversion efficiency, according to equipment supplier Harbin Electric. This adiabatic approach stores energy through air compression while capturing heat generated during the process, eliminating the need for fuel combustion.
“The facility represents a significant leap in long-duration storage technology,” Harbin Electric stated in its announcement.
BloombergNEF identified compressed air energy storage as the most cost-effective solution for long-duration electricity storage compared to lithium-ion batteries. The technology requires specific geological conditions—underground salt caverns or similar formations—which limits potential deployment locations.
Environmental and Economic Impact
The plant is projected to reduce standard coal consumption by 250,000 metric tons and mitigate 600,000 tons of carbon dioxide emissions annually. The project took approximately 13 months from construction start to commercial operation, representing rapid deployment for industrial-scale energy infrastructure.
Officials positioned the facility as critical infrastructure for balancing China’s expanding but intermittent renewable generation capacity with stable electricity supply for residential and commercial users. The storage system addresses a core challenge in renewable energy integration: maintaining consistent power delivery when solar panels produce no electricity at night and wind turbines stop during calm periods.
China’s Energy Storage Expansion
Beijing set a target to reach over 180 gigawatts of new energy storage capacity by the end of 2027, with expected investment of approximately $35 billion through that timeline. China exceeded its original 2025 target of 30 gigawatts of storage capacity in 2023, two years ahead of schedule.
The Jiangsu facility marks a shift toward alternative long-duration storage technologies beyond conventional lithium-ion battery installations. The National Development and Reform Commission released a strategy in September 2025 emphasizing both battery energy storage systems and supporting technologies like compressed air for the 2024–2027 period.
Jiangsu province, located in central China, hosts the demonstration project as part of the country’s broader effort to transform its energy grid infrastructure while maintaining reliable electricity access for residential consumers.
The facility began generating power for commercial use following completion of full-load testing on its second 300-megawatt unit, according to Harbin Electric’s recent announcement.
