A Life Cycle Assessment Framework for Evaluating the Climate Impact of Hydrogen-Based Passenger Vehicle Technologies Toward Sustainable Mobility

Hydrogen-based mobility solutions could offer viable technology for sustainable transportation. Current research often examines single pathways, leaving broader comparisons unexplored. This comparative life cycle assessment (LCA) evaluates which vehicle type achieves the best environmental performance when using hydrogen from grey, blue, and green production pathways, the three dominant carbon-intensity variants currently deployed. This study examines seven distinct vehicle configurations that rely on hydrogen-derived energy sources across various propulsion systems: a hydrogen fuel cell electric vehicle (H2FCEV), hydrogen internal combustion engine vehicle (H2ICEV), methanol flexible fuel vehicle (MeOH FFV), ethanol flexible vehicle (EtOH FFV), Fischer-Tropsch (FT) diesel internal combustion vehicle (FTD ICEV) and renewable compressed natural gas vehicle (RNGV). Via both grey and blue hydrogen production, H2 FCEVs are the best options from the viewpoint of GWP, but surprisingly, in the green category, FT-fueled vehicles take over both first and second place, as they produce nearly half the lifetime carbon emissions of purely hydrogen-fueled vehicles. RNGV also emerges as a promising alternative, offering optimal engine properties in a system similar to H2ICEVs, enabling parallel development and technological upgrades. These findings not only highlight viable low-carbon pathways but also provide clear guidance for future targeted, detailed, applied research.