Objective Underground Hydrogen Storage (UHS) represents a critical pathway for large-scale hydrogen energy storage due to its extended storage cycles, cost-efficiency, and interseasonal peak-shaving capabilities. While four primary geological hydrogen storage carriers—salt caverns, depleted hydrocarbon reservoirs, saline aquifers, and lined rock caverns—have been explored globally, current research remains insufficient to guide site selection and scheme optimization for underground hydrogen storage projects.

Methods Four representative UHS repositories are taken as research objects. Based on global technical advances, the repositories are classified into cavity-type and porous-type categories according to storage-space morphology, and their distinct hydrogen containment mechanisms are comparatively evaluated. Key operational parameters are quantitatively analyzed across each geological type, including burial depth, storage capacity, cushion gas volume, produced gas purity, annual injection-production frequency, operating pressure, and unit storage cost. Three core application scenarios are established: high-frequency peak shaving, seasonal energy storage, and economic efficiency. To evaluate multi-dimensional engineering applicability, subjective weights are determined using the Analytic Hierarchy Process (AHP), objective weights are calculated via the Entropy Weight Method (EWM), and Grey Relational Analysis (GRA) is applied to assess the correlation between each repository type and optimal operating conditions.

Results Cavity-type repositories rely on surrounding rock self-healing or lining integrity for hydrogen containment, whereas porous-type repositories trap hydrogen via structural traps and caprocks. Key operational constraints include inter-layer creep, microbial biochemical reactions, and fluid mixing. Salt caverns operate at pressures of 3.5–20.0 MPa, require a cushion gas volume of only 30％ of total capacity, yield produced hydrogen purity above 99％, and support up to 10 annual injection-production cycles. Depleted hydrocarbon reservoirs and saline aquifers offer the largest storage volumes; however, their required cushion gas volumes reach 40％–50％ and 50％–80％ of total capacity, respectively, with produced hydrogen purity limited to 80％–95％. Lined rock caverns operate at 2.0–20.0 MPa and enable high-frequency injection-production cycling, but incur high unit storage costs of CNY 6.61–19.89/kg. Multi-scenario quantitative evaluation demonstrates that salt caverns deliver the highest overall suitability. Depleted hydrocarbon reservoirs are optimal for large-capacity seasonal storage, saline aquifers exhibit the lowest overall performance, and lined rock caverns are suitable primarily for small-scale applications in regions lacking salt rocks and hydrocarbon resources.

Conclusion The newly established capacity calculation methods and multi-scenario evaluation framework provide a theoretical foundation and technical reference for the construction, operational optimization, and risk management of demonstration hydrogen storage projects in salt caverns, abandoned mines, and depleted hydrocarbon reservoirs.