A comprehensive review of compressed air energy storage technologies: Current status and future trends

As the world transitions to decarbonized energy systems, emerging long-duration energy storage technologies are crucial for supporting the large-scale deployment of renewable energy sources. Compressed air energy storage (CAES) is a promising solution for large-scale, long-duration energy storage with competitive economics. This paper provides a comprehensive overview of CAES technologies, examining their fundamental principles, technological variants, application scenarios, and gas storage facilities. An economic analysis using the levelized cost of storage (LCOS) indicates that the LCOS for large-scale CAES is only marginally higher than that of pumped hydro storage, positioning CAES for large-scale commercialization. The current status of major CAES projects worldwide is presented, comparing their technological routes, key technical specifications, operational status, and air storage methods. It reveals that CAES projects are evolving toward larger scales, higher efficiency, and more environmentally friendly practices. The future trends in CAES are analyzed, focusing on potential efficiency improvements, commercialization prospects, and coupling with renewable energy sources.