Compressed Air Energy Storage Power Station in North America

Compressed air energy storage (CAES) is one of the many energy storage options that can store electric energy in the form of potential energy (compressed air) and can be deployed near central power plants or distribution centers. In response to demand, the stored energy can be discharged by expanding the stored air with a turboexpander generator.

The basic idea of CAES is to capture and store compressed air in suitable geologic structures underground when off-peak power is available or additional load is needed on the grid for balancing. The stored high-pressure air is returned to the surface and used to produce power when additional generation is needed, such as during peak demand periods.

2. Storage: The compressed air is stored, typically in large underground caverns such as salt domes, abandoned mines, or depleted natural gas reservoirs. Above-ground alternatives include high-pressure tanks or specially designed vessels, though these are generally more expensive and limited in capacity.

For example, the state of Kansas has facilitated these processes with their Compressed Air Energy Storage Act, effective since 2009. A study that reports on promising locations, permitting processes and challenges, and mitigating solutions would help developers navigate these issues during the planning phase.

The largest component in such systems is the storage medium for the compressed air. This means that higher pressure storage enables reduced volume and higher energy density.

CAES systems are categorized into large-scale compressed air ES systems and small-scale CAES. Large-scale systems are capable of producing >100 MW, while the small-scale systems only produce 10 MW or less . Moreover, the reservoirs for large-scale CAES are underground geological formations such as salt formations, host rocks and porous media.