Comparison of underwater and underground CAES systems for integrating floating offshore wind farms

Floating offshore wind farms (FOWF) with advanced adiabatic compressed air energy storage (AA-CAES) are thermodynamically scrutinized to evaluate if the compressed air is better stored underground or underwater. The corresponding energy efficiency is deduced based on an exergy analysis that details the exergy destruction of each system. The effects of key parameters such as storage and expansion pressures are examined parametrically. It is revealed the underwater compressed air energy storage has a higher efficiency and exergy density. These advantages tend to diminish beyond a critical storage pressure.