An initial evaluation of humidified discharge cycle for liquid air energy storage

Abstract

The research community is becoming more interested in liquid air energy storage among the leading innovative technologies for long duration and grid-scale energy storage. Practical Uses of liquid air energy storage are currently somewhat limited, though, mostly due to the intricate design of LAES plants and the poor “roundtrip efficiency” that is the ratio of the energy recovered from the LAES system during the discharge cycle to the total energy input. With so many components already present in the LAES plant, nearly every research project underway adds even more complexity to the mix. The objective of the work that is being presented aims to increase the use of the heat of compression that has been stored during the charging without adding additional complexity. A mixture of water vapour and air, or humidified air, serves as the working fluid in the presented concept. Thermodynamic performance of the proposed discharge configuration is evaluated and compared on a consistent basis with the stand alone LAES system. The results demonstrate significant increase in the roundtrip efficiency.