Water-scarcity footprints of industrial hydrogen production under Vietnam’s power-sector transition plan

Hydrogen can support industrial decarbonization, but its expansion may transfer environmental pressure to freshwater systems, where production in developing countries coincides with regional water scarcity. This study quantified the volumetric and scarcity-weighted blue-water implications of industrial hydrogen production under Vietnam's 2030 and 2050 power-sector transition scenarios. A cradle-to-gate water-footprint inventory was combined with region-specific Available Water Remaining (AWARE) characterization factors to compare wind-powered hydrogen (WPH), photovoltaic hydrogen (PVH), and coal-based hydrogen (CTH) under mutually exclusive deployment scenarios using the upper bounds of the production ranges as scenario-scale assumptions. Under the scenarios, WPH had the lowest national water consumption (WC) and hydrogen water-scarcity footprint (HWSF) in both years: 18.20 million m 3 and 39.60 million m 3 eq in 2030, and 728.00 million m 3 and 1648.13 million m 3 eq in 2050. In 2030, CTH had a lower HWSF than PVH (65.92 versus 68.51 million m 3 eq) despite having the highest WC (34.02 million m 3 ). In 2050, CTH had the highest HWSF (2340.31 million m 3 eq), whereas PVH had the highest WC (1333.00 million m 3 ). Rankings depended on the indicator used: in 2050, CTH had the unweighted grid-referenced system-scale comparative potential (1476.02 million m 3 ), whereas WPH had the highest scarcity-adjusted grid-referenced potential (3579.90 million m 3 eq). Water-aware reallocation reduced national HWSF by 17.7-42.5% but increased regional HWSF in the Southern region. These results indicate that technology choice, deployment scale, power-system structure, and spatial allocation shape hydrogen-related water outcomes. Hydrogen siting and power-sector planning should incorporate spatial water-scarcity screening and explicitly evaluate regional burden shifting. • WPH minimized national water consumption and HWSF in both scenarios. • CTH HWSF was below PVH in 2030 but highest by 2050. • CTH led the unweighted grid-referenced system-scale potential; WPH led the scarcity-adjusted grid-referenced potential. • Water-aware allocation cut national HWSF by 17.7-42.5%. • Spatial scarcity screening improves industrial hydrogen location.