The development, frontier and prospect of Large-Scale Underground Energy Storage: A bibliometric review

Large-Scale Underground Energy Storage (LUES) plays a critical role in ensuring the safety of large power grids, facilitating the integration of renewable energy sources, and enhancing overall system performance. To explore the research hotspots and development trends in the LUES field, this paper analyzes the development of LUES research by examining literature related to five technologies-Underground Gas Storage (UGS), Underground Hydrogen Storage (UHS), Underground Thermal Energy Storage (UTES), Underground Pumped Hydro Storage (UPHS), and Underground Compressed Air Energy Storage (UCAES)-indexed by Web of Science from 2000 to 2023. Utilizing VOSviewer and Citespace software for bibliometric analysis, visual knowledge maps were created to analyze publication trends, collaborative networks, research hotspots, and future research directions in the LUES field. The analysis reveals an exponential growth in LUES publications over recent years, with research intensity in UGS and UHS significantly higher than in other technologies. Leading contributors, including China, the United States, and Germany, maintain robust collaborative relationships. Future research trends in LUES include the integration of intelligent and renewable energy systems, the development of hybrid energy storage technologies, underground biomethanation, and new CAES technologies. Conclusions highlight the key areas for future research, offering scholars a deeper understanding of the current state of LUES research and guiding future research directions.