Hydrogen and fuel cell technologies for low-carbon energy systems: production, storage, integration, and sustainability

Hydrogen is increasingly recognized as a key energy carrier for low-carbon energy systems because it can support renewable energy storage, industrial decarbonization, clean transport, and distributed power generation. However, large-scale deployment remains constrained by high production costs, storage and distribution losses, infrastructure gaps, fuel-cell durability limitations, and inconsistent sustainability assessment. This review provides an integrated evaluation of hydrogen and fuel cell technologies across the full value chain, including production, storage, distribution, utilization, techno-economic performance, life-cycle impacts, and policy readiness. Fossil-based hydrogen with and without carbon capture, renewable electrolysis, and waste-to-hydrogen pathways are compared using common indicators, including efficiency, carbon intensity, maturity, scalability, and infrastructure dependence. The review shows that no hydrogen pathway is universally optimal; deployment suitability depends on regional electricity mix, feedstock availability, storage route, transport distance, end-use sector, and regulatory support. The study highlights system integration, digital optimization, circular-economy strategies, standard certification, and coordinated infrastructure planning as essential requirements for commercially viable low-carbon hydrogen systems.