Life cycle analysis of hydrogen production by different alkaline electrolyser technologies sourced with renewable energy

Green hydrogen has been considered a promising alternative to fossil fuels in chemical and energy applications. In this study, a life cycle analysis is conducted for green hydrogen production sourced with a mixture of renewable energy sources (50% solar and 50% wind energy). Two advanced technologies of alkaline electrolysis are selected and compared for hydrogen production: pressurised alkaline electrolyser and capillary-fed alkaline electrolyser. The different value chain stages were assessed in SimaPro, enabling the assessment of the environmental impacts of a green hydrogen production project with 60 MW capacity and 20 years lifetime. The results evaluate the environmental impacts depending on the components, construction and operation requirements. The results demonstrated that capillary-fed alkaline electrolyser technology has lower potential environmental impacts by around 17 % than pressurised alkaline electrolyser technology for all the process stages. The total global warming potential was found to be between 1.98 and 2.39 kg of carbon dioxide equivalent per kg of hydrogen. This study contributes to the electrolysers industry and the planning of green hydrogen projects for many applications towards decarbonization and sustainability.