LTA-CAES - a low-temperature approach to adiabatic compressed air energy storage

Most of the recent approaches on Adiabatic Compressed Air Energy Storage (A-CAES) aim at high temperatures in the Thermal Energy Storage (TES). High TES temperatures together with high pressures are not easy to handle. In order to avoid this technical challenge, we introduce a Low-temperature Adiabatic Compressed Air Energy Storage (LTA-CAES) plant. We select and design multistage radial compressors and expanders with single stages rotating with different speeds allowing for intermediate cooling and reheating of the air flow. The proposed LTA-CAES design shows cycle efficiencies in the range of 54 to 67%, slightly lower compared to those envisioned for high temperature A-CAES. However, it can be shown that its fast start-up characteristics and wide-ranging part load ability overcompensate the lower cycle efficiencies with regard to plant profitability.