Social life cycle assessment of green hydrogen integration with geothermal power plants: production and use as a spinning reserve

This study performs an ex-ante Social Life Cycle Performance Assessment to a hydrogen-based supplementary section of a geothermal power plant, operating as a spinning reserve, i.e. storing surplus energy and dispatching it when required. The system operates in two modes: accumulation phase, for hydrogen production via geothermal-powered electrolysis and storage, and electricity generation phase through oxy-combustion of stored gases. The assessment, aligned with ISO 14075:2024, identifies social hotspots within this hybrid configuration. Results indicate that the storage subsystem and operational stage account for over 70% of social risks. Upstream processes associated with the accumulation subsystem, particularly the extraction of critical materials like nickel and platinum for the electrolyser stack, are primary risk drivers. The findings demonstrate the usefulness of ex-ante Social Life Cycle Performance Assessment in early-stage technology design, supporting decisions as prioritising low-impact material supply chains, improving supplier selection criteria, and guiding policy frameworks for socially responsible hydrogen deployment.