Overview of current compressed air energy storage projects and analysis of the potential underground storage capacity in India and the UK

Abstract Compressed air energy storage (CAES) is an established and evolving technology for providing large-scale, long-term electricity storage that can aid electrical power systems achieve the goal of decarbonisation. CAES facilities often utilise large underground storage caverns to ensure high capacity systems. This results in the need of locations with suitable geological features to develop a CAES plant. This paper examines recent and ongoing large-scale CAES projects and presents candidate methods of storing high pressure air using underground features. An assessment of the overall potential for CAES in India is presented by examining its geological features and locations with the greatest potential for CAES plants are determined. This is combined with an analysis of the renewable electricity generation potential in India to identify candidate areas for renewable generation and CAES integrated systems. Up to 1.05% of Indian land area is deemed suitable for CAES plant development and if fully utilised would be sufficient to meet the energy storage needs of India, however, practically a very small fraction of the total suitable land that could be developed so other competing energy storage technologies should be considered. Conversely, the UK possesses a very good potential for CAES, enough to greatly exceed necessary energy storage, owing to the abundance of salt beds not present in India. For CAES to garner serious consideration in India, aquifer storage based CAES needs to be demonstrated.