Water scarcity challenges global power plant operation

Water scarcity intensified by climate change increasingly constrains thermoelectric power generation and threatens electricity system reliability. These risks are amplified when power plants are concentrated in regions that already face water scarcity. Yet how water scarcity driven by climate change affects the operational efficiency of thermoelectric power plants under different climate scenarios remains poorly understood. Here we assess operational efficiency losses and the potential for technical adjustment for 13,038 thermoelectric power plants, including coal, oil and gas, nuclear, and biomass, under climate driven water scarcity across SSP119, SSP126, and SSP245. We find that power plants located in water scarce regions accounted for 26.1% of global thermoelectric installed capacity in 2015, and this share increases to 31.9% under SSP245 by 2050. Operational efficiency losses vary across cooling technologies, with once through and other water intensive cooling systems experiencing larger reductions in usable capacity. Efficiency gains from technical adjustment differ across climate scenarios, remaining limited at 1.6% under SSP119 but increasing to 6.6% under SSP245, particularly in developing regions. These findings indicate that water scarcity will remain a persistent constraint on thermoelectric power generation under future climate scenarios.