Stability Evaluation of Compressed CO2 Energy Storage in Abandoned Salt Caverns

With the global transition toward a low‐carbon energy structure, large‐scale, long‐duration energy storage solutions are increasingly critical for modern power grids. Compressed carbon dioxide energy storage (CCES) is a promising alternative to compressed air energy storage (CAES), offering higher energy efficiency and storage density. However, the higher density of carbon dioxide (CO 2 ) causes more severe pressure fluctuations during compression and expansion, increasing the risk of cavern instability—especially in abandoned salt caverns with irregular geometries and weak zones. This study investigates the structural stability of such caverns for CCES applications. Based on engineering data, typical cavern characteristics and risk factors are identified and categorized. Key characteristics and potential risk factors of abandoned caverns are identified and categorized. Representative operational scenarios are developed based on engineering needs, and numerical simulations are used to assess key factors affecting stability. Results show that geological interlayers constrain creep deformation, while greater cavern depth increases volume shrinkage and instability risk. The single‐well convection method offers better stability than horizontal well butt schemes. Increasing the operating pressure range effectively reduces surrounding rock deformation, enhancing overall cavern integrity.