The intermittency and volatility of renewable energy sources critically constrain their large-scale grid integration, positioning underground energy storage as an indispensable solution for the energy transition. This editorial provides a comprehensive overview of major underground energy storage technologies-including salt cavern compressed air energy storage, depleted gas reservoir storage, underground hydrogen storage, geological CO₂ sequestration, and underground thermal energy storage. For each modality, we identify key challenges such as multi-physics coupling, caprock integrity, geochemical reactivity, and long-term reservoir stability. We further highlight cross-cutting frontiers including digital rock physics, artificial intelligence-driven characterization, and digital twin technologies. Finally, we issue a formal call for contributions that bridge fundamental mechanisms with field-scale engineering practice, reaffirming the commitment of Advances in Geo-Energy Research to advancing geo-energy science for a sustainable future.

With the demand for peak-shaving of renewable energy and the approach of carbon peaking and carbon neutrality goals, salt caverns are expected to play a more effective role in oil and gas storage, compressed air energy storage, large-scale hydrogen storage, and temporary carbon dioxide storage. In order to effectively utilize the underground space of salt mines on a sound scientific basis, the construction of salt caverns for energy storage should implement the maximum utilization of salt layers, improve the cavern construction efficiency, shorten the construction period, and ensure cavern safety. In this work, built upon design experience and on-site practice in salt cavern gas storage, the four pivotal construction stages – conceptual design, solution mining simulation, tightness assessment, and stability evaluation – have been thoroughly enhanced, strengthening the technical framework for salt cavern energy storage.