(659g) Cryogenic Energy Storage: Design, Techno-Economic Analysis, and Integration with Power Plants and Renewables

Cryogenic energy storage (CES) is a promising storage alternative with a high technology readiness level and maturity.[1] However, the moderate round-trip efficiency (RTE) and high Levelized Cost of Storage (LCOS) pose implementation concerns.[2], [3] To improve the RTE, rigorous model-based design and optimization of CES systems can be done, but intricate thermodynamics at cryogenic temperatures and loops in the flowsheet pose considerable challenges. These models need to be simplified for grid-level frameworks to maintain computational tractability. At the process level, we present a simulation-based optimization strategy for CES processes. We achieve this with flowsheet decomposition and identification of hidden coupling constraints and demonstrate its use for optimizing the standalone CES design. At the systems level, we develop a generalized framework for energy storage integration in the grid. The framework consists of different energy sources such as power plants and renewables. We demonstrate the benefits of CES in the near term and future for integration with power plants and renewable farms.

Our results indicate that it is possible to achieve more than 52% round-trip efficiency under ambient conditions and an LCOS of $267/MWh for a 100 MW/400 MWh CES system.[4] The developed framework analyzes each demand scenario and renewable availability from the CAISO database.[5] Our results indicate that the short-term benefits of energy storage include the capability of meeting rising energy demands. A daily CES charge-discharge cycle can help meet a 15% rise in demand, whereas long-duration storage is needed for 30 or 45% increase. The increased demands can be met with no addition to the current power plant fleet. We also compare power generation scenarios from conventional sources and renewable sources. Our findings indicate that energy costs would range between $13/MWh-$108/MWh for renewable sources. However, these solutions are limited by significantly large land requirements. A baseload generator lowers energy costs and makes land requirements feasible. Even though complete dependence on green energy is possible, energy costs in the near term are unfavorable. Baseload generation combined with large-scale storage designed for a long duration (spanning over months) is essential to reach total green energy dependence.

[1] A. Harby and Y. Ding, “European Energy Research Alliance.” 2016, [Online]. Available: https://eera-es.eu/wp-content/uploads/2016/03/EERA_Factsheet_Liquid-Air-....

[2] A. Castillo and D. F. Gayme, “Grid-scale energy storage applications in renewable energy integration: A survey,” Energy Convers. Manag., vol. 87, pp. 885–894, 2014.

[3] K. Mongird, V. Viswanathan, J. Alam, C. Vartanian, V. Sprenkle, and R. Baxter, “2020 grid energy storage technology cost and performance assessment,” Energy, vol. 2020, 2020.

[4] A. Gandhi, M. S. Zantye, and M. M. F. Hasan, “Cryogenic Energy Storage: Standalone Design, Rigorous Optimization and Techno-economic Analysis,” (Under Review).

[5] “California Independent System Operator (CAISO).” 2022, [Online]. Available: https://www.caiso.com/.