Opportunities and Challenges of Grid-Scale Green Hydrogen Energy Storage

Hydrogen (H2) has emerged as a promising sustainable energy vector due to its scalability, high energy density, and its ability to enable sector coupling across electricity, heating, transportation, and industry. There remains a huge technical challenge to overcome. The economic implications of low round-trip efficiency, high capital costs, the limited lifespan of fuel cells and electrolyzers, and infrastructure constraints on H2’s relative competitiveness have not been comprehensively studied. In a comparative assessment against other storage options such as batteries, pumped hydro, and compressed air energy storage (CAES), we highlight the potential of H2 as a grid-scale storage solution. The novelty of this paper is that it compares H2 as a competing option with other storage technologies and highlights its unique suitability for seasonal and grid-scale applications where others fall short. The paper also discusses the technological opportunities for AI and other digital technologies in the H2 grid. Unlike general reviews, this work emphasizes the engineering performance of H2’s production cost and economic viability, electrolyzer technology maturity, infrastructure readiness, safety and lifecycle considerations, and provides critical synthesis and implications. With this, the paper extends beyond the theoretical capacity for H2 and gives an engineering-focused analysis that informs the drive toward sustainable and resilient power grids.