Volume 65

Comparative Exergy Analysis of Salt-Cavern Compressed Air and Hydrogen Energy Storage Power Generation Systems Liangchao Huang, Zhengmeng Hou, Jianhua Liu, Qichen Wang, Yilin Guo, Tianle Shi

Abstract

With the large-scale integration of renewable energy into power grids, energy storage technologies play a crucial role in mitigating fluctuations and ensuring supply security. This study establishes five salt-cavern-based energy storage and power generation models using EBSILON: conventional compressed air energy storage (CAES), adiabatic compressed air energy storage (A-CAES), hydrogen-heated compressed air energy storage (HH-CAES), hydrogen gas turbine storage (HES-GT), and hydrogen fuel cell storage (HES-FC). Under consistent boundary conditions, the systems are evaluated and compared in terms of thermal efficiency and exergy efficiency. Results show that A-CAES achieves the highest exergy efficiency among compressed air systems, while HES-FC delivers the best thermal efficiency and nearly zero emissions. The analysis highlights the key roles of compression heat recovery, fuel selection, and conversion pathways in determining system performance. Finally, future research directions are proposed, including component-level exergy analysis, exergoenvironmental analysis, and exergoeconomic analysis, aiming to support the design of multi-energy complementary and low-carbon high-efficiency storage plants.

Keywords CAES, Hydrogen Energy Storage, Fuel Cell, Exergy Analysis, Salt Cavern Storage