Overview
In 2026, compressed-air energy storage (CAES) using abandoned salt caverns has moved from pilot to pipeline across China, becoming a distinctive pillar of the new-storage landscape. In Huaian, Jiangsu, two 300 MW-class non-fueled units have entered full operation, delivering a combined 2,400 MWh of storage and about 792 GWh of annual generation—enough peak-shaving for roughly 600,000 households, with single-site scale among the world’s largest.
The first to prove commercial operation was the 60 MW Jintan salt-cavern CAES station (China Salt), which by July 24, 2026 had run continuously for over 1,500 days—the world’s first non-fueled and China’s first long-run commercial salt-cavern storage. The 300 MW Yingcheng station in Hubei is also operational; Jintan, Huaian, and Yingcheng together validate a complete domestic equipment route.
Background & Interpretation
1. Industry Background and Policy Context
The “more in summer, less in winter” variability of wind and solar has long been seen as a curtailment weakness. CAES uses mined-out salt cavities as containers: surplus power compresses and stores air at low load, releases it to generate at peak—without coal or supplemental gas—offering large-scale, long-duration, safe storage that fits the “capacity-type” storage needs of a new power system.
2. Core Drivers and Underlying Mechanism
The principle is straightforward: at off-peak hours a compressor sends air into a ~1 km-deep cavern under high pressure; at peak, released air drives a turbine. Non-fueled routes rely on waste-heat or thermal storage rather than fossil combustion, avoiding emissions and fuel dependence. The 1,500-day run—through multiple seasonal charge-discharge cycles with no seal failure—proves long-term reliability.
3. Market Structure and Industry Impact
Linking Jintan, Huaian, and Yingcheng means exploration, cavern retrofitting, and core equipment (compressors, turbines, heat exchangers) no longer require imported assemblies. Coordination among salt resources, heavy-equipment makers, and grid dispatch turns “a giant battery breathing with the seasons” from concept to arrayed deployment, supporting long-duration peak-shaving in wind/solar-rich regions.
Implications & Outlook
Near term, as demos mature, salt-cavern CAES may shift from single-point pilots to regional clusters, complementing lithium and flow batteries in a “short + long duration” matrix. Watch the capex and levelized-cost decline, cavern-resource surveys, and how spot and capacity markets price its value.
Takeaways for Industry Participants
Utilities and grid firms should fold salt-cavern storage into source-grid-load-storage planning, assessing salt-mine location and cavity endowment. Equipment makers should iterate domestic turbines, compressors, and thermal storage. Investors should watch valuation resets as long-duration storage business models couple with power-market rules.
This column compiles industry information and shares technical perspectives; it does not constitute investment advice.