Fuel cell electric vehicles: An option to decarbonize heavy-duty transport? Results from a Swiss case-study

CO2 emissions of road freight transport may seem secondary to passenger cars, but electrification could eliminate direct emissions of cars. For heavy-duty trucks, it is unclear if substituting Diesel is even an option. We developed a data-driven approach to explore this issue: it estimates feasibility considering the daily operation patterns of every vehicle in the fleet. This paper presents results for fuel cell propulsion systems. If every Swiss truck drove on hydrogen produced exclusively by electrolysis, full decarbonisation would draw over 8 TWh of renewable electricity (13% of the national consumption). That corresponds to roughly 60 km(2) of photovoltaic panels with 1.5 GW peak power. We found that current fuel-cell technology almost completely realized that potential, provided vehicles could refuel during the day. The autonomy range was generally better than with battery electric systems without significant weight increase (relative to the original vehicle). Refuelling could take over half an hour, requiring a dense energy infrastructure, able to refuel hundreds of vehicles in parallel to avoid congestion (i.e. vehicles waiting). The reduction of direct emissions was easily overcompensated by indirect emissions of generation: the Swiss consumer mix lead to virtually no overall reduction, while natural gas powerplants lead to a significant CO2 increase. We concluded that hydrogen is technically a very attractive decarbonisation agent for heavy-duty vehicles, but significant investments may be required to ensure that (a) hydrogen production is truly renewable and (b) vehicles have adequate access to additional energy during the day.