Hydrogen systems are gaining importance in view of a progressive decarbonisation of societies, and becoming more and more cost-competitive alternatives in many sectors (e.g., mobility). However, the sustainability of these technologies must be carefully assessed following a holistic approach which embraces not only environmental but also social aspects. Social Life Cycle Assessment (S-LCA) is an insightful methodology to evaluate potential social impacts of products along their life cycle. In the frame of the project eGHOST, social risks of a proton exchange membrane fuel cell (PEMFC) stack were assessed through an S-LCA. The functional unit was defined as one 48 kW stack (balance of plant excluded), targeted for mobility applications. The supply chain was defined assuming Spain as the manufacturing country and involving from the material/energy production plants to the stack manufacturing. Beyond conventional life cycle inventory data, trade information and additional inventory data were retrieved from the UN Comtrade and PSILCA databases, respectively. Besides, working hours for the manufacturing plants of the stack and its subcomponents were calculated based on literature data. Social life cycle inventories were modelled and evaluated using openLCA and the PSILCA method. Two stakeholder categories, workers and society, were considered through the following social indicators: child labour, contribution to economic development, fair salary, forced labour, gender wage gap, and health expenditure. The choice of these indicators is in line with the eGHOST project purpose. Despite the relatively small amount contained in the product, platinum clearly arose as the main social hotspot under each of the selected indicators. At the level of component plants, the manufacturing of bipolar and end plates was also found to be relevant under some indicators. On the other hand, electricity consumption generally accounted for a minor contribution. Overall, in order to avoid burden shifting from environmental to social issues, a careful design of technologies is needed.
Life cycle assessment of hydrogen from proton exchange membrane water electrolysis in future energy systems
