Water Footprint and Scarcity Risks of Low-Carbon Fuels

Abstract Production of ammonia, methanol, and hydrogen is key to decarbonizing hard-to-electrify sectors but is also water-intensive. However, the water implications of scaling these energy carriers under low-carbon pathways remain poorly understood. Here, we integrate direct water consumption with facility-level geospatial analysis and hydrological modeling to quantify water-scarcity exposure across each production facility in North America. Low-carbon production routes require more direct and indirect water consumption than conventional pathways, with electrolytic hydrogen and e-methanol increasing water-intensity by up to 5-fold in regions with limited renewable availability─a trade-off further amplified by supply chain effects, particularly for solar PV-based electricity and direct air capture-based CO2 feedstocks. Water scarcity already affects about 58% of methanol production in Mexico, 2% of ammonia production in the U.S., and 5% and 27% of refinery production in the U.S. and Mexico, respectively. Under midcentury climate scenarios, exposure increases in both magnitude and spatial extent. Although irrigation accounts for over 80% of local water consumption in various fuel production facilities, municipalities and manufacturing often exert the greatest pressure on low-carbon fuel production, depending on the product and country.. These results demonstrate that technology choice, system design, and facility siting are as important as hydrology considerations in determining water risks. Incorporating water availability in low-carbon fuel projects is therefore essential to ensure that decarbonization pathways are scalable, operationally resilient, and truly sustainable.