CAES works by compressing air using excess energy and storing it in underground caverns or above-ground tanks. When electricity demand increases, the compressed air is released, driving a turbine and generating electricity. CAES has several advantages, including high efficiency, long-duration storage capabilities, and the ability to utilise existing infrastructure such as natural gas pipelines or abandoned mines.

The needed CAES capacity in the least-expensive case, with no extra wind and solar power generation, is 3.71 TWh. A stringent net-zero curtailment requirement would increase the amount of storage needed by 3.2% (3.83TWh), and the cost of power would rise by 9.8%. However, as more solar and wind energy is produced than is needed, the necessary CAES capacity lowers.