Levelised Cost of Storage (LCOS) analysis of liquid air energy storage system integrated with Organic Rankine Cycle

Liquid Air Energy Storage (LAES) is a unique decoupled grid-scale energy storage system that stores energy through air liquefaction process. In order to further increase the utilization ratio of the available waste heat discharged by the air compression and not effectively recovered during the discharge phase, the authors have previously investigated the thermodynamic feasibility of different integrated LAES systems and promising results have been shown for the LAES coupled with Organic Rankine Cycle (integrated system LAORC). In order to assess the economic feasibility of the integrated system, this paper presents a techno-economic comparative analysis of the stand-alone LAES and the integrated system LAORC. The LAES systems have been designed by means of the quasi non-dimensional maps developed by the authors and the Levelised Cost of Storage (LCOS) has been employed to evaluate the economic viability of the investment by also comparing the LAES with Li-ion batteries. The results show that the stand-alone LAES system is generally cost-competitive with Li-ion batteries and even more in LAORC integrated system with the advantage of additional power output from the ORC. When LAES is operated in cogenerative configuration, the LAORC integrated system produces the most significant results decreasing the LCOS by 10%. (C) 2020 Elsevier Ltd. All rights reserved.