Techno-economic analysis of solar aided liquid air energy storage system with a new air compression heat utilization method

Abstract

Solar aided liquid air energy storage (SA-LAES) system is a clean and efficient large-scale energy storage system. Traditional SA-LAES system requires the storage equipment for air compression heat, which results in a high economic cost and low energy storage density. And the air compression heat cannot be completely utilized. To solve these problems, this study proposes a novel solar aided liquid air storage system (SA-LAES) with a new cascade air compression heat utilization method in the charging process. The results show that the round trip efficiency (RTE) of the new system (Case 2) is 110.29%, 2.97% higher than that of the reference system (Case 1). The energy storage density of the Case 2 is 35.38 kWh/m3, 75.67% higher than that of the Case 1. The payback period of Case 2 is 5.25 years, 41.79% lower than that of Case 1. The levelized cost of energy (LCOE) is 0.07 $/kWh, 20.73% lower than that of Case 1. At the same time, Case 2 can effectively avoid the heat accumulation phenomenon of Case 1. These results show that the proposed SA-LAES system (Case 2) is efficient and economical and can be a promising candidate for advanced energy storage technology in engineering applications.