Construction has begun on a major hydrogen storage project using salt caverns in Changzhou city, eastern Jiangsu province, marking a significant step forward in China's development of large-scale hydrogen storage technology.

Touted as one of the most promising clean energy sources, hydrogen is seen as a key component to China's energy transition strategy. However, storing the gas remains a technical challenge because hydrogen is the smallest molecule in nature and has a high penetration capability.

Salt caverns — large underground spaces created within natural salt deposits — are increasingly favored for hydrogen storage due to their excellent sealing performance, large capacity, low cost and high safety standards. Their natural impermeability and structural stability make them well suited for storing gases such as hydrogen.

The project is being developed by China National Salt Industry Group in collaboration with Tsinghua University. It involves the construction of two salt caverns, two wells for hydrogen injection and extraction, and two additional wells for injecting high-pressure air and expelling brine, according to a statement on the company's website.

Qian Qihu, an academician with the Chinese Academy of Engineering, has welcomed the project's launch, describing salt cavern hydrogen storage as a "golden key" to solving technological bottlenecks in the hydrogen energy industry. He said the facility is expected to turn underground salt caverns into an "energy treasure trove", creating a new development model for hydrogen storage and helping to amplify China's voice in the global clean energy space.

Li Yaoqiang, chairman of China National Salt Industry Group, said the project will serve the country's dual carbon goals — peaking carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060 — while contributing to national energy security. He said the company will harness its rich salt cavern resources and technical expertise to support the expansion of hydrogen energy infrastructure and promote innovation in salt cavern use.

"Salt will evolve from seasoning and industrial material to a foundation for future energy storage," Li said.

limenghan@chinadaily.com.cn