Exergoeconomic optimization of an adiabatic cryogenics-based energy storage system

Cryogenics-based energy storage (CES) is a low-carbon bulk energy storage technology without geographical constraints. CES additionally has a significantly higher exergy density, longer cycle life, low storage losses, and negligible environmental impact compared to competing technologies. This paper aims to identify the trade-offs between thermodynamic effectiveness and investment cost using the exergy-based methods. The base case system has a power of 100 MW/400 MWh, and integrated cold and heat recovery. The base case has a relatively high specific cost of installed capacity (2087 (sic)/kW). The cost of the discharged electricity is reduced from 267 to 195 (sic)/MWh. The cost of electricity charged to the system is revealed to have a small effect on the final product cost. Parametric and structureal measures to decrease the cost of the final product are identified and applied. The increase in compression pressure is found to improve the cost-effectiveness of the system most significantly. The iteration results of the exergoeconomic optimization are presented and compared to the base case. Cost savings amount to 40% and the optimized case enabled the system to approach the aimed range of product cost <200 (sic)/MWh with a reduction in efficiency from 47% to 40%. (C) 2019 Elsevier Ltd. All rights reserved.