Carbon emissions and water consumption are inextricably linked through energy systems, yet the water implications of electricity defossilization remain under-investigated despite their importance for economic and energy security, particularly in water-scarce regions. A considered energy transition can foster reduction synergies in greenhouse gas (GHG) emissions and water consumption. This study quantifies life-cycle GHG and water intensities of national and subnational electricity mixes in the United States, China, and the European Union+ for current operations and systematically projected scenarios through 2050. A novel global-warming-potential-to-water-consumption ratio was introduced to elucidate their relationship and identify synergistic trends. Results show that ongoing electricity defossilization generally lowers both GHG and water intensities, but the magnitude and timing of benefits vary across regions: China’s coal-heavy profile sustains higher burdens, while the US sees most gains accrue by 2030 under its current trajectory; however, recent US policy shifts have weakened defossilization incentives, risking elevated regional water stress. Policy, economic, and technological uncertainties in US electricity mixes were further captured by a rigorous Monte Carlo simulation, generating plausible technology-share ranges across regional grids at three-year intervals. By decomposing the drivers of GHG and water intensities, this work offers actionable, region-specific insights to inform low-carbon, water-efficient electricity planning amid global climate and water-security challenges.
Du et al. (Thu,) studied this question.