The Value of Compressed‐Air Energy Storage for Enhancing Variable‐Renewable‐Energy Integration: The Case of Ireland

Mixed integer programming (MIP) was used to formulate a unit commitment and economic dispatch (UCED) algorithm that included two models for simulating the dynamic performance of compressed-air energy storage (CAES) units. The first model assumes CAES operating with fixed efficiencies (FEs) on both the compression and expansion side, similar to models commonly used in industry and academia. The second model is a detailed thermoeconomic (TE) model, which uses power curves obtained by CAES manufacturers to model the effect of cavern pressure on operation limits of both the compressor and expander. The UCED and CAES models were combined to identify the contribution of CAES on minimizing the impacts of wind integration into the Irish power sector in 2020. The results of the UCED-TE model show that the addition of a CAES unit in the North Ireland grid can reduce wind curtailment, CO2 emissions, and system costs. The cost reductions result mainly from reductions in wind curtailment and coal-fired generation. The FE model shows much higher reductions of wind curtailment, CO2 emissions, and total system costs. However, both models show that the benefit of CAES on the system increases with variable renewable energy and CAES installed capacity. The difference in the results of the two models is reduced in scenarios of high CAES capacity. The main conclusions of the study are that existing fixed-efficiencies CAES models overestimate reductions on wind curtailment whereas both models show the system-wide economic benefits of CAES grow considerably as wind production grows.