Energy and exergy analysis of a novel advanced adiabatic compressed air energy storage hybridized with reverse osmosis system

Abstract

Providing sustainable energy and ensuring a reliable supply of clean freshwater are two critical and interconnected challenges. This paper introduces an innovative approach that combines an advanced adiabatic compressed air energy storage system with a reverse osmosis system to enhance energy storage efficiency and freshwater production. During the charging phase, compressed air is injected into a tank filled with saltwater. Simultaneously, the high-pressure compressed air forces saltwater into the reverse osmosis modules. In the discharge phase, water is pumped into the compressed air storage tank to maintain a nearly constant tank pressure. The results demonstrate the advantages of this hybrid system over separate adiabatic compressed air energy storage and reverse osmosis systems producing the same amount of fresh water. Specifically, the proposed hybrid system achieves an 11.3 % increase in generated power during discharge and a 1.2 % improvement in round-trip efficiency. Reducing the compressed air tank capacity from 1200 to 800 m3 accentuates the hybrid system's superiority, increasing the round-trip efficiency difference between the hybrid and separated systems to 5.6 %. By selecting an appropriate compression ratio, a round-trip efficiency of 61.9 % can be achieved. Furthermore, an exergy analysis highlights the compressed air storage tank and turbines as the most exergy-destructive components of the system.