Techno-economic analysis of a Liquid Air Energy Storage (LAES) for cooling application in hot climates

This work investigates the technical and economic feasibility of a Liquid Air Energy Storage (LAES) for building demand management applications. The thermodynamics and processes of the LAES configuration, as well as the description of the daily cooling energy demand profile, are described in details and the assumptions and constrains are pointed out. The quantitative analysis has been carried out for a daily cooling energy demand of an existing office building, located in Singapore, locality characterized by a typical hot climate. A thermodynamic analysis has been carried out for LAES configuration by means of the Aspen HYSYS® process simulation code. Under the technical assumptions formulated, LAES achieves an overall round trip efficiency of 45% with a specific consumption of 0.20 kWh/kgLA. The exergy analysis shows that LAES is characterized by an exergy efficiency of 84% and 67% for the liquefaction and the discharge processes, respectively; the compressor and the power turbines account for the highest exergy losses. Finally, the economic results show that under the actual condition of peak tariff and off-peak tariff in Singapore, the investment proposed is not convenient but in case of high values of LAES round trip efficiency and lower OPT the investment may be attractive. However, future works have to deal with the limitations introduced in the analysis, such as neglecting LAES operation costs, and the uncertainty related to capital costs figures.