Batteries vs Fuel Cells for Decarbonizing Medium- and Heavy-Duty Vehicles Across Applications

We conduct a life cycle greenhouse gas (GHG) assessment of class 3–8 internal combustion engine vehicles (ICEVs), hybrid electric vehicles (HEVs), fuel cell electric vehicles (FCEVs), and battery electric vehicles (BEVs) in the United States. Compared to conventional diesel fueled alternatives, HEVs reduce emissions by 1-26% across vehicle types, FCEVs using hydrogen produced from steam methane reforming reduce emissions by 1-45%, and BEVs powered by the grid result in a 55-75% reduction. FCEVs using hydrogen produced from electrolysis powered by renewable electricity reduce emissions by 81-87% across vehicle types, while BEVs powered by renewable electricity result in an 89-94% reduction. These ordering of these powertrains holds across cargo weights, drive cycles, regional electricity grids, and grid projections. We also assess renewable electricity consumption and hydrogen leakage, two factors not included in most comparative life cycle assessments, which must be considered when evaluating the suitability of different powertrains for decarbonization.