Seawater Electrolysis for Hydrogen Production: Objectives and Pathways

• • Global clean hydrogen demand is projected to reach 436 Mt annually by 2050, requiring daily water consumption of 15 Mt; this demand cannot be met by freshwater electrolysis alone given that major renewable installations are in arid regions with limited water resources. • • China's renewable capacity expansion is geographically decoupled from freshwater availability: Xinjiang added 42.11 GW in 2024 versus Fujian's 7.93 GW, yet Xinjiang has only 80 billion m3 of freshwater compared to Fujian's 130 billion m3, necessitating salt-affected groundwater or seawater as feedstock. • • Direct seawater electrolysis using corrosion-resistant electrodes eliminates the need for desalination infrastructure, reducing system complexity and land footprint while tolerating Cl− and other impurities; this enables deployment at offshore wind sites where freshwater supply is absent. • • Electrolyte engineering strategies and anti-fluctuation electrode designs now permit stable operation with intermittent renewable power from off-grid sources, addressing the mismatch between variable renewable generation and continuous electrolyzer operation.