Hydrogen is viewed by many as the most promising fuel for light-duty vehicles (LDVs) for the future. Hydrogen can be produced through a large number of pathways and from many feedstocks (both fossil and renewable). A key issue in evaluating the sustainability of a hydrogen fuel cell vehicle (FCV) is an analysis of the processes employed to produce the hydrogen and the efficiency of its use in the vehicle, the ‘well-to-wheel’ (WTW) activities.
Several recent WTW studies, which include conventional as well as alternative fuel/propulsion system LDVs, are examined and compared. One potentially attractive renewable feedstock for hydrogen is biomass. A biomass to hydrogen pathway and its use in a FCV has only recently been included in WTW studies. The analysis is based on those studies which include biomass-derived hydrogen, comparing it to gasoline/diesel internal combustion engine vehicles (ICEVs) and FCV which utilize hydrogen from other feedstocks (natural gas and wind-generated electricity).
Since hydrogen is not commercially produced from biomass, all of these studies utilize process and emissions data based on research results and extrapolations to commercial scale. We find that direct comparison of results between studies is challenging due to the differences in study methodologies and assumptions concerning feedstocks, production processes, and vehicles. Overall however, WTW results indicate that hydrogen produced via the gasification of biomass and its use in a FCV has the potential to reduce greenhouse gas (GHG) emissions by between 75% and 100% and utilize little fossil energy compared to conventional gasoline ICEVs and hydrogen from natural gas FCVs.