Comparative thermodynamic analysis of compressed air and liquid air energy storage systems

The paper presents a thermodynamic analysis of selected CAES and LAES systems. The LAES cycle is a combination of an air liquefaction cycle and a gas turbine power generation cycle. CAES and LAES systems are simulated using Aspen HYSYS software. CAES is modeled in a dynamic mode. A comprehensive thermodynamic analysis was conducted along with the comparison of storage volumes. The results indicate that both systems are characterized by high energy storage efficiency, equal to approximately 40% for the CAES and 55% for the LAES systems. One clear advantage of the LAES over the CAES is the significantly lower volume demanded for energy storage. For the considered LAES system,the liquid air tank volume is around 5000 m3, while for the CAES the cavern volume is approximately 310000 m3. Heat exchangers and combustion chambers are the main contributors to the total exergy destruction in the analyzed systems.