With a rough estimate of 80% of U.S territory being geologically suitable for CAES, it has the potential to be a leading system within the storing of compressed air energy . One of the main disadvantages associated with this type of storage system is the need for the heating process to cause expansion.
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.
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.
Analysis of compressed air energy storage systems is usually conducted by taking both compression and expansion stages into consideration using ideal gas laws. Expanders’ mechanical work is first transformed.
The compressed air storages built above the ground are designed from steel. These types of storage systems can be installed everywhere, and they also tend to produce a higher energy density. The initial capital cost for above- the-ground storage systems are very high.
There are several compression and expansion stages: from the charging, to the discharging phases of the storage system. 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 .