Efficiency analysis of ocean compressed air energy storage system under constant volume air storage conditions

The proposed technical solution, which integrates compressed air energy storage systems with marine renewable energy sources, promises to provide stable power to offshore users. In this paper, a method of direct compression of air using wave mechanical energy under constant capacity storage conditions is presented. Based on the analysis of the damping characteristics of the compressor, a control strategy that adapts to the wave conditions and pressure variations by varying the number of compressors working is simultaneously proposed to maintain a reasonable difference between the driving force and the damping force of the compressor group and to obtain more active output. The proposed scheme achieves a maximum Capture Width Ratio (CWR) of 27 % and a maximum wave-to-compressed air energy conversion efficiency of 15.6 %. To further enhance expansion efficiency, the system's overall energy efficiency is analyzed under various potential marine reheating conditions. The results indicate that by primarily utilizing wave energy, supplemented with a small amount of power from other marine renewable sources and surface seawater thermal energy, the system can attain a generation efficiency of 10.6 %. Moreover, the analysis of damping characteristics and system energy efficiency highlights potential pathways for further improving the system's performance.