Evaluating Salt Performance for Compressed‑Air Energy Storage

Compressed‑air energy storage (CAES) systems store excess energy underground and release it during periods of high demand. In salt caverns, this process can require hundreds of injection and withdrawal cycles each year. These rapid cycles create questions about how salt behaves under repeated loading and unloading, particularly over the long term.

RESPEC designed a program in our Materials Testing Laboratory to understand how salt responds to this high‑frequency cycling. In the controlled setting, the testing replicates the effects of repeated pressure cycling.

Simulating Years of Performance

Using a specialized lab device that applies pressure from all directions, the team can simulate thousands of stress cycles in just a few days. This approach allows engineers to evaluate how salt responds to cyclic fatigue, including changes in strength, deformation, and long‑term performance.

The testing program expands on established methods to more accurately represent real‑world CAES operations. And by accelerating the number of cycles applied during testing, RESPEC can observe the salt’s behavior that would otherwise take years to see in the field.

Supporting Safer, More Flexible Energy Storage

RESPEC’s testing results provide important insight into how salt caverns perform under repeated cycling conditions, and help engineers refine material models, evaluate cavern stability, and better define operating limits for CAES systems.

For further information on other RESPEC CAES projects, please see the publicly available references below.

• Goodman, W. M., D. J. Gnage, and R. B. Cole, 2008. Investigation of Potential Underground Compressed Air Storage Locations in the State of New York, RSI-2012, prepared by RESPEC, Rapid City, SD, for EPRI Office of Innovation Strategic Planning, Palo Alto, CA.
• Gnirk, P. F., T. Brandshaug, G. D. Callahan, and J. L. Ratigan, 1979. “Numerical Studies of Compensated Compressed Air Energy Storage Caverns in Hard Rock,” Proceedings, 1979 Mechanical and Magnetic Energy Storage Contractors’ Review Meeting, Washington, DC, August 19–22, US Department of Energy, Division of Energy Storage Systems, Washington, DC, pp. 106–117.