Numerical assessments of the effects of injected air temperature and well configuration on the cycle performance in compressed air energy storage in aquifers


 Aquifers have advantages over salt caverns as the storage vessels for compressed air energy storage due to their wider availability for suitable sites and lower one-off capital investment for construction. We conducted numerical simulations for compressed air energy storage in aquifers (CAESA) to investigate the effects of injected air temperature, the number of injection/production wells and their configurations on cycle performance, based on the data from the Pittsfield CAESA test. The results show that injected air temperature has a negligible effect on the overall energy recovery efficiency, but a higher injected air temperature leads to a higher energy storage capacity. A multiple-injection/production-well arrangement can achieve a larger storage capacity than single-well systems. The distance between the injection/withdrawal wells will affect the storage capacity. This suggests that for a multiple-well CAESA system, a comprehensive modelling study should be used for the optimal system design to achieve the most desirable storage capacity.