Current Adiabatic Compressed Air Energy Storage (A-CAES) aim at high temperatures in the Thermal Energy Storage (TES). Such high TES temperatures together with high pressures are not easy to handle. In order to avoiding this technical challenge, we developed a Low-temperature Adiabatic Compressed Air Energy Storage (LTA-CAES) plant based on a two-tank non-thermocline TES. We selected and designed multistage radial compressors and expanders with single stages arranged at the ends of several pinion shafts rotating with different- and for the assembled impellers optimal speeds. The proposed LTA- CAES design shows cycle efficiencies in the range of 58 to 67%, slightly lower compared to those envisioned for high temperature A-CAES. However, it can be shown that its fast start-up characte ristics and wide-ranging part load ability overcompensate the lower cycle efficiencies with regard to plant profitability.
