Low-temperature adiabatic Compressed Air Energy Storage for island applications

Compressed air energy storage is a promising storage technology to face the challenges of high shares of renewable energies in an energy system by storing electric energy for periods of several hours up to weeks. The particularly advantageous adiabatic CAES concepts, which are not dependent on fossil fuels, are technical feasible, but still not widespread. Low-temperature adiabatic CAES concepts address some of the existing barriers by limiting process temperatures for higher flexibility and use of market available components to lower CAPEX. On the other hand, these advantages are achieved at the expense of roundtrip efficiency losses. Therefore, a suitable plant layout is highly dependent on the specific application. The new KompEx LTA-CAES® design presented in this paper reduces CAPEX even further by using a combination of reversibly operable turbo- and piston machinery. Doing so, these modules can be combined with any compressed air storage volume and thus not only salt caverns, but also decentralized storage units such as pipe storage or LRC can be used. As a case study for decentralized application, the use of a KompEx LTA-CAES® module to support the integration of renewable generation from PV on an island without interconnection to the mainland electricity grid is evaluated.