Improvement perspectives of cryogenics-based energy storage

Abstract Advantages such as high energy density, minimal environmental impact, use of established system components and the absence of geographical limitations drive further research and development in cryogenics-based energy storage technology. This paper evaluates an adiabatic cryogenics-based energy storage system (large capacity of 100 MW/400 MWh) using advanced exergy-based methods in order to identify the potential for improvement (avoidable/unavoidable parts of thermodynamic inefficiencies, investment costs and environmental impacts) of the system components and the interdependencies among these components (endogenous and exogenous parts of thermodynamic inefficiencies). The simulation of the system was conducted in Aspen Plus®. The results show that the interactions among the components are strong. From the cost viewpoint, the two main heat exchangers are the most important components. The cost minimization of these components indicates that the minimum temperature difference in both heat exchangers should be increased. From the thermodynamic viewpoint, the expander and the main heat exchanger 2 dominate the avoidable inefficiencies. After application of the recommendations made here, cryogenics-based energy storage technology is expected to become thermodynamically and economically viable.