Realistic roles for hydrogen in the future energy transition

Hydrogen has been promoted as a revolutionary fuel for 50 years, yet usage is confined to oil refining and fertilizer production. For hydrogen to advance global decarbonization, many barriers must be overcome. In this Perspective, we examine the challenges hydrogen faces from production to usage, assessing its environmental and economic credentials, controversies and uncertainties. We provide the evidence base for companies and governments to assess clean hydrogen’s current and potential future competitiveness. Fuel cell cars and space heating are among the least promising applications owing to rapid advances in direct electric alternatives. Hydrogen holds potential in industry, long-duration energy storage and long-haul transport, but its competitiveness depends on large-scale deployment yielding substantial cost reductions. Current production cost estimates range by a factor of five and suggest that targets for 2030 will be difficult to achieve, especially once costs for transport and storage are included. The climate impacts of hydrogen production are also uncertain, with production from electrolysis or methane gas with carbon capture potentially increasing system-wide or upstream emissions, alongside water scarcity and persistent organic pollution. Future research must resolve these uncertainties, with strategic focus on deploying hydrogen in priority areas where it is most competitive.