Besides its use as a chemical feedstock, hydrogen can also be combusted to produce process heat. Due to efficiency losses for hydrogen produced by electrolysis for process heat compared to other competing technologies, e.g., heat pumps and direct resistive heating (Section 3), the adoption of powerto-hydrogen for low-heat applications may not be cost-effective on a dollar-per-calorie basis. However, hydrogen combustion could provide high-temperature heat in decarbonizing industrial applications currently powered by natural gas combustion that cannot be electrified directly. Like direct heating, hydrogen-based heat can be deployed for existing chemical production facilities, though some material changes and retrofits are likely required to enable hydrogen combustion . One impediment to using hydrogen for high-temperature heat applications has been the low average costs of fossil-derived heat.