A 1,000 MWh coal-plus-molten-salt energy storage project at CHN Energy's Suzhou power plant in Anhui province marked its first anniversary of commercial operation on Aug 30.

The project, the first gigawatt-hour-class coal-fired molten salt heat storage and exchange system in China, was officially commissioned on Aug 30, 2025 and was selected as one of the first national green low-carbon advanced technology demonstration projects.

After a year of operation and optimization, the system's comprehensive performance has improved significantly. Heat storage and release efficiency rose from 83% at initial commissioning to 90%, while peak heat supply capacity expanded from 150 tonnes per hour to 410 tonnes per hour. Cumulative annual heat supply increased by 630,000 gigajoules year on year, up 20.4%.

The project absorbs curtailed wind and solar power from around the plant, boosting regional renewable energy consumption by approximately 68 GWh annually and cutting carbon emissions by 45,000 tonnes. Its stable high-quality heat supply meets the needs of more than 50 industrial and commercial enterprises, with customer satisfaction rising from 83% to 100%.

Molten salt heat storage is an emerging energy storage technology offering high conversion efficiency, large energy density and low operating costs.

The system uses molten salt as the storage medium, paired with high- and low-temperature dual tanks and heat exchangers, capturing idle heat during off-peak grid periods, solar thermal energy and industrial waste heat from coal-fired plants, then releasing stored heat during peak electricity and heating demand.

This enables both additional power generation from steam turbines and direct supply for district heating, ensuring stable 24-hour electricity and heat supply.