The number of sites available for compressed air energy storage is higher compared to those of pumped hydro [, ]. Porous rocks and cavern reservoirs are also ideal storage sites for CAES. Gas storage locations are capable of being used as sites for storage of compressed air .
Overview of compressed air energy storage Compressed air energy storage (CAES) is the use of compressed air to store energy for use at a later time when required , , , , . Excess energy generated from renewable energy sources when demand is low can be stored with the application of this technology.
Compressed air energy storage systems may be efficient in storing unused energy, but large-scale applications have greater heat losses because the compression of air creates heat, meaning expansion is used to ensure the heat is removed [, ]. Expansion entails a change in the shape of the material due to a change in temperature.
In thermo-mechanical energy storage systems like compressed air energy storage (CAES), energy is stored as compressed air in a reservoir during off-peak periods, while it is used on demand during peak periods to generate power with a turbo-generator system.
Additionally, they require large-scale heat accumulators. Compressed Air Energy Storage (CAES) and Liquid Air Energy Storage (LAES) are innovative technologies that utilize air for efficient energy storage. CAES stores energy by compressing air, whereas LAES technology stores energy in the form of liquid air.
(1) explains how electrical energy can be stored as exergy of compressed air in an idealized reversed process. The Adiabatic method achieves a much higher efficiency level of up to 70%. In the adiabatic storage method, the heat, which is produced by compression, is kept and returned into the air, as it is expanded to generate power.