Fundamentals of hydrogen production and use in a decarbonising power system

Stand-alone hydrogen production from cheap renewable power, notably solar, has received considerable attention as a way to produce fuel and feedstock for a future climate-neutral energy system. Here we assess the integration of green hydrogen production and electrolyser deployment with a power system that is progressively decarbonised by the deployment of wind and solar. For the Netherlands, we find that full power system decarbonisation with hydrogen-fired back-up generation is cost-optimal when ∼80 ± 3% of variable renewable power comes from wind. For EU countries with a mainly wind-based supply, electrolyser deployment becomes economically attractive only at ∼65 ± 10% grid decarbonisation. Afterward, electrolyser build-out scales linearly with further renewables deployment. The electrolyser-to-renewables deployment ratio depends strongly on the renewables mix but mildly on the cost ratio of electrolysers to renewables within the expected range. Finally, we find a substantial cost advantage for the coproduction of green power and hydrogen compared to stand-alone hydrogen production.