China's first underground salt cavern gas storage facility was made operational on Sunday after a major expansion, significantly boosting the country's ability to manage peak demand and ensure energy security, said experts.

The Jintan facility, located in Changzhou, Jiangsu province, was built within a salt mine and utilizes natural salt formations to create stable underground caverns for storing natural gas, said its operator China Oil and Gas Pipeline Network Corp.

The expansion has dramatically increased the facility's operational efficiency, playing a critical role in balancing seasonal fluctuations in gas consumption, said the company, also known as PipeChina, China's largest energy infrastructure enterprise.

Daily gas injection capacity has risen by 60 percent to 13.2 million cubic meters, while daily peak shaving withdrawal capacity has tripled to 18 million cubic meters. Emergency withdrawal capacity has also increased by 80 percent to 27 million cubic meters per day.

Salt cavern compressed air energy storage (CAES) technology stores energy by using surplus electricity to compress air into underground salt caverns. This compressed air is then released to power turbines and generate electricity when demand is high.

Unlike aboveground LNG tanks, which require extensive safety perimeters and significant surface area, salt caverns located deep underground offer a more secure and compact storage solution.

The natural geological properties of salt formations provide a robust barrier against leaks and external threats, while minimizing the environmental footprint compared to sprawling LNG terminal complexes. This makes salt cavern storage particularly attractive in densely populated regions like the Yangtze River Delta, where land resources are at a premium.

The expanded Jintan gas storage facility represents a leap forward in China's ability to manage natural gas supply and demand, PipeChina said.

Industry experts said that the Jintan facility not only ensures stable gas supply for urban areas during peak seasons, but also plays a vital role in maintaining the overall gas balance of PipeChina's national network.

The expansion project showcases China's commitment to innovation in energy infrastructure, fostering the development of domestically produced, cutting-edge technologies, said Lin Boqiang, head of the China Institute for Studies in Energy Policy at Xiamen University.

As salt cavern CAES technology continues to mature, anticipated improvements in efficiency are expected to drive wider adoption and further growth within the energy storage sector, he said.

Chinese companies have been stepping up efforts in salt cavern technology and compressed air energy storage in recent years, signaling a growing commitment to these innovative energy solutions.

In 2022, China Petroleum and Chemical Corp, the world's largest refiner, put into use the country's deepest underground natural gas salt cavern storage well, running more than 2,000 meters deep. In the same year, the country's first 300 megawatt compressed air energy storage demonstration project was launched in Yingcheng, Hubei province, and was connected to the grid in 2024.

This expansion of the Jintan facility comes amid a backdrop of steadily increasing natural gas consumption across China in recent years.

Driven by urbanization, industrial growth and a push for cleaner energy sources to replace coal, demand for natural gas has surged in recent years. China's natural gas consumption rose 8 percent to 426.1 billion cubic meters last year, according to data released by the National Development and Reform Commission.

This growing reliance on natural gas necessitates a robust and reliable storage infrastructure to ensure stable supply, particularly during peak demand periods and unforeseen disruptions, said Lin.

Looking ahead, the Jintan salt cavern gas storage facility is expected to serve as a cornerstone of energy security, providing reliable energy supply for the integrated development of the Yangtze River Delta region, said PipeChina.

zhengxin@chinadaily.com.cn