The article highlights the importance of hydrogen as a clean energy carrier in decarbonizing various sectors to reduce greenhouse gas emissions. It discusses the challenges posed by the intermittent nature of renewable energy sources like solar and wind, emphasizing the need for effective energy storage solutions. Surface-based storage methods are noted for their convenience but face limitations in capacity and safety risks. The focus shifts to underground hydrogen storage in geological formations, particularly salt caverns and porous media like depleted gas reservoirs and saline aquifers, as promising alternatives. These options offer large-scale, cost-effective, and safe storage, addressing key factors such as storage capacity, environmental impact, and safety. The article delves into the technical and operational similarities of UHS with natural gas storage and carbon capture and storage, drawing insights from existing practices. Specific geological assessments, numerical simulations, and optimized storage strategies are essential for the successful implementation of UHS. Depleted gas reservoirs are highlighted for their data availability, seal integrity, and existing infrastructure advantages, making them suitable for near-term deployment. On the other hand, saline aquifers offer design flexibility and scalability for long-term storage needs. Seal quality and containment efficiency are crucial factors, with depleted reservoirs demonstrating proven containment capabilities compared to aquifers, which require thorough verification. The article concludes by emphasizing the need for careful evaluation of geological storage options based on project requirements, infrastructure, seal integrity, and storage capacity, to maximize the benefits of underground hydrogen storage for large-scale renewable energy solutions.