Impacts of green hydrogen for steel, ammonia, and long-distance transport on the cost of meeting electricity, heat, cold, and hydrogen demand in 145 countries running on 100% wind-water-solar

As the world moves to clean, renewable energy, questions arise as to how best to produce and use hydrogen. Here, we propose using hydrogen produced only by electrolysis with clean, renewable electricity (green hydrogen). We then test the impact of producing such hydrogen intermittently versus continuously for steel and ammonia manufacturing and long-distance transport via fuel cells on the cost of matching electricity, heat, cold, and hydrogen demand with supply and storage on grids worldwide. An estimated 79, 32, and 91 Tg-H₂/y of green hydrogen are needed in 2050 among 145 countries, for steel, ammonia, and long-distance transport, respectively. Producing and compressing such hydrogen for these processes may consume ∼12.1% of the energy needed for end-use sectors in these countries after they transition to 100% wind-water-solar (WWS) in all such sectors. This is less than the energy needed for fossil fuels to power the same processes. Due to the variability of WWS electricity, producing green hydrogen intermittently, rather than continuously, thus with electrolyzer use factors significantly below unity (0.2–0.65), may reduce overall energy costs with 100% WWS. This result is subject to model uncertainties but appears robust. In sum, grid operators should incorporate intermittent green hydrogen production and use in planning.