Performance analysis and optimization design of a 300 MW adiabatic compressed air energy storage system

With the increasing penetration of renewable energy into power grids, large-capacity, high-parameter, and non-reheat adiabatic compressed air energy storage (A-CAES) systems are required to help maintain grid stability. In this study, a simulation model of a 300 MW A-CAES system was proposed, and the effects of cavern air pressure and the allocation of stage-wise compression ratios on system thermodynamic performance and heat exchanger area were investigated. Furthermore, multi-objective optimization of system efficiency and total heat exchanger area was conducted. The results indicate that increasing the cavern air pressure from 15 MPa to 20 MPa significantly improves system efficiency, although the accompanying increase in heat exchanger area leads to higher investment costs. When the cavern air pressure is fixed at 15 MPa, increasing the first-stage compression ratio from 8 to 15 causes the heat exchanger area after the first-stage compression to increase, while the second-stage heat exchanger area decreases; the total heat exchanger area initially decreases and then increases, and the system round-trip efficiency first rises and then falls. The extreme points occur when the first-stage compression ratio accounts for 7.33%–8% of the total compression ratio. Through multi-objective optimization, an optimal solution was reached with a cavern pressure of 17.8 MPa and a first-stage compression ratio of 12, yielding a system round-trip efficiency of 71.88% and a total heat exchanger area of 1.13 × 105 m2.