Identifying conditions for hydrogen sector coupling amid policy shifts and rising electricity demand

Hydrogen has emerged as an alternative energy carrier used to decarbonize hard-to-electrify sectors and serve as a long-duration storage asset, but deployment pathways remain uncertain. Using a hydrogen-coupled capacity expansion model, we explore the policy, economic, and demand conditions necessary to support power-to-gas-to-power infrastructure in 2050. We find that steam methane reformation constitutes up to 78% of hydrogen production capacity even under optimistic cost and demand scenarios and that significant policy support is necessary for electrolyzer deployment. Fuel cell deployment is only viable under net-zero conditions and is limited by the need to meet end-use hydrogen demand, with only 33% of scenarios dispatching fuel cells for more than 24 h per year. Additionally, while storage from power-to-gas-to-power infrastructure can reduce power capacity requirements by up to 11%, projected large load growth could offset sector coupling benefits. Our results elucidate the conditions necessary for large-scale hydrogen deployment and its potential competitiveness.