Compressed air energy storage (CAES) is an effective solution for balancing this mismatch and therefore is suitable for use in future electrical systems to achieve a high penetration of renewable energy generation.
Most compressed air energy storage systems addressed in literature are large-scale systems of above 100 MW which most of the time use depleted mines as the cavity to store the high pressure fluid. Three main concepts are researched; diabatic, adiabatic and isothermal.
The air, which is pressurized, is kept in volumes, and when demand of electricity is high, the pressurized air is used to run turbines to produce electricity . There are three main types used to deal with heat in compressed air energy storage system .
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 .
In a Compressed Air Energy Storage system, the compressed air is stored in an underground aquifer. Wind energy is used to compress the air, along with available off-peak power. The plant configuration is for 200MW of CAES generating capacity, with 100MW of wind energy.
Research has shown that isentropic efficiency for compressors as well as expanders are key determinants of the overall characteristics and efficiency of compressed air energy storage systems . Compressed air energy storage systems are sub divided into three categories: diabatic CAES systems, adiabatic CAES systems and isothermal CAES systems.
OverviewTypesCompressors and expandersStorageEnvironmental ImpactHistoryProjectsStorage thermodynamics
Compressed-air-energy storage (CAES) is a way to store energy for later use using compressed air. At a utility scale, energy generated during periods of low demand can be released during peak load periods. The first utility-scale CAES project was in the Huntorf power plant in Elsfleth, Germany, and is still operational as of 2024 . The Huntorf plant was initially developed as a load balancer for fossil-fuel-generated electricity