Life cycle assessment of a Proton Exchange Membrane Unitized Regenerative Fuel Cell for residential buildings

A Life Cycle Assessment (LCA) of unitized regenerative fuel cell (URFC) system with polymeric electrolyte membrane (PEM) applicable in residential buildings is carried out to evaluate the energy and environmental performances of this emerging energy storage technology. The individual components of the URFC system (catalyst, stack, balance of plate, storage tank, electric and electronic auxiliary devices) were modelled using Simapro software. The scope of analysis is cradle-to-grave, with a functional unit of 1 kWh of electricity produced by the URFC system in 10 years. The life cycle inventory of the study includes both primary and secondary data. In particular, primary data was collected from laboratory experiments conducted within the “ELETTRORIGENERA” project (PO FESR SICILIA 2014-2020 AVVISO 1.1.5 - PROGETTO ELETTRORIGENERA N. 08ME2899200216). Instead, secondary data, such as peer-reviewed studies and commercial databases, are used when primary data are unavailable. The potential impacts are evaluated using Cumulative Energy Demand (CED) and CML-IA baseline assessment methods. The results showed that 1 kWh of electricity produced by the URFC system could emit about 0.263 kg CO2 eq in global warming potential and 15 MJ of cumulative primary energy. The operation phase is responsible for more than 65% of all impact categories, except for photochemical oxidation and acidification potentials, in which the highest impacts are linked to the manufacturing phase. In addition, the analysis identified that catalysts generate the most significant impacts in URFC system manufacturing. On the contrary, although end-of-life treatments generate negligible impacts, recycling part of metals and catalysts to avoid the production of virgin materials could reduce the impacts by at least 38%. Further, these results could be used in future studies to evaluate the impacts generated by different end-of-life and control strategies of the URFC system and their effects on the hydrogen technology’s performance and compare alternative energy storage technologies.