Life cycle assessment of green hydrogen production through electrolysis: A literature review

This study reviews the electrolysis techniques for green-hydrogen (GH2) production, with primary focus on their environmental sustainability implications. Different stages of the GH2 value chain are characterized regarding the life cycle analysis (LCA), presenting the methods, materials, energy sources, and efficiency. Qualified LCA results would lead to proper decision-making, which depends on the input choices and data quality used. Therefore, the life cycle inventory and useful technical data for GH2 electrolysis production in LCA studies are reviewed. Also, the recent developments regarding electrolysis techniques toward potentially enhancing their life cycle are discussed. The results showed that solar and wind energies as the most promising sources for GH2 production, with lower Global Warming Potential (GWP) for wind turbine cases. The reported results of environmental impacts (EIs) are lower for proton-exchange membrane (PEM) technology. There is still limited data regarding comparing the various EIs (e.g. freshwater eutrophication) and accompanying costs. However, it is recommended to consider the recent developments in H2 electrolysis production, mainly the efficiency, energy consumption and lifetime along with the miniaturization. Also, future LCA studies may consider the final use of produced GH2 (e.g. fuel cells), heat recovery and materials recycling stages for complete visibility towards optimizing the efficiency and EIs.