Powering megawatt electrolyzers for low-carbon hydrogen production

A major barrier to wide adoption of low-carbon electrolytic hydrogen is its high cost. The main contributors to the high cost include the high cost of electricity and the low capacity factor of solar and wind power. Energy storage further increases the cost of electricity, and grid-powered electrolysis emits more carbon than fossil-fuel derived hydrogen for most regions of the planet. This article outlines some of the challenges in powering megawatt electrolyzers with solar and wind. To approach a 100% capacity factor without grid support or energy storage, multiple low-carbon power sources, such as solar, wind, hydro, and nuclear, must be delivered directly to the electrolyzer, bypassing the grid. To minimize energy delivery losses for these power sources, the electrolyzer should be co-located with and directly connected to the solar farm, whenever possible, for an up to 50% lower cost of solar electricity. All solar power should be tapped for electrolysis, with no solar into the grid. Wind power supplements solar for electrolysis, with excess wind into the grid. Hydro and nuclear power is reserved for additional capacity in the solar-powered, wind-backed electrolyzer.