Quantification of fresh water consumption and scarcity footprints of hydrogen from water electrolysis: A methodology framework

Towards decarbonizing the global economy, hydrogen produced through water electrolysis is expected to be one of the key solutions for variable renewable energy storage and sector coupling, in particular, via the transport sector in the next few decades. Even though water is an important aspect of the environmental impact, the impact assessment of hydrogen production on water is lacking. This paper proposes a comprehensive methodology for assessing the water footprints of hydrogen production from electrolysis. A major innovative aspect is to demonstrate the geographical distribution of the footprints along the supply chain. The water footprints for hydrogen produced from grid electricity, wind and solar power in Australia was analysed as a case study. Sensitivity analysis was used to evaluate the influence of key parameters including Solar Radiation Level, Silicon Efficiency, and Lifetime of PV Modules. The study finds that the water consumption footprint is much less than that reported in the literature and large part of the water could be consumed indirectly outside of hydrogen producing countries. The quantity of water footprint varies significantly among different assumptions. The findings provide insights into both domestic and cross-boundary water impacts of hydrogen electrolysis and can thus inform policy debates in each nation and beyond.