China has commenced operations on the world’s largest compressed-air power storage plant in Jiangsu Province. The move marks a major step in the country’s effort to expand energy storage to support its green transition. The plant can generate 600 megawatts of power, facilitating in China’s endeavor to renewable energy transition. Furthermore, it will facilitate to meet the annual demand of 600,000 households.

The statement on the plant was issued by Harbin Electric which participated in construction of the project. Such facilities represent the most cost-effective, long-duration solution to storing energy. The unveiled project works by pumping compressed air into underground caverns at night. Later on, it is released during the day to spin turbines and produce electricity. The nation’s energy sector has seen explosive growth. One of the reasons is the country’s rapid deployment of renewable energy. Another world largest renewable energy project located in China is the world’s largest offshore solar farm covering 1,200 hectares of ocean surface.

Scope of Implementation on the World’s Largest Compressed-Air Power Storage Plant in China

The world’s largest compressed-air power storage plant in China commenced construction in December, 2024. It has also taken approximately 13 months for the project to move from implementation to being commissioned, a monumental feat. The full name is the Huaneng Jintan Salt Cave Compressed Air Energy Storage Power Generation Phase II Project. Two sets of 350MW compressed air energy storage (CAES) units will be built.

This means the facility will have a total power of 700MW On the other hand, energy storage capacity will be 2.8GWh, via compressed air stored in a cavern with a capacity of 1.2 million cubic meters. That implies a discharge duration of four hours.

The plant has been claimed as the largest CAES system in the world by single unit power, capacity and efficiency. Furthermore, it has been jointly developed by utility China Huaneng and state-owned firm China Salt Group. The government has set a target of over 180 gigawatts of new capacity by 2027, fostering a boom in battery storage and alternative technologies such as compressed air.

Project Factsheet

Project Name

• Huaneng Jintan Salt Cave Compressed Air Energy Storage (Phase II)

Location

• Jiangsu Province, China

Project Type

• Compressed Air Energy Storage (CAES)

Total Capacity

• 700 MW power output

• 2.8 GWh energy storage

Plant Configuration

• Two CAES units at 350 MW each

• Underground salt cavern volume: 1.2 million cubic meters

• Discharge duration: 4 hours

Operational Status

• Construction started: December 2024

• Also commissioned in 13 months

• Furthermore, it is now operational

Technology

• Compressed air stored underground at night

• Released during peak demand to drive turbines

Energy Impact

• Supplies electricity for 600,000 households annually

• Also supports grid stability for renewable energy

Developers

• China Huaneng

• China Salt Group

Strategic Significance

• Largest CAES plant globally by unit size and capacity

• Also part of China’s push to expand long-duration energy storage

• Supports national target of 180 GW new storage capacity by 2027