A team from Argonne National Laboratory recently produced a program record for the DOE Offices of Vehicle Technologies, Hydrogen and Fuel Cell Technologies, and Bioenergy Technologies in which the Argonne researchers documented cradle-to-grave (C2G) and well-to-wheels (WTW) greenhouse gas (GHG) emissions of light-duty vehicles, assuming key parameters for a variety of current (2020) and future (2050) vehicle-fuel technology pathways.
C2G emissions are a sum of WTW emissions and emissions associated with vehicle manufacturing. The vehicle manufacturing cycle includes impacts of raw material extraction, vehicle parts production, assembly, as well as its disposal and related materials recycling processes.
Using current technologies, all evaluated biofuel, battery electric, and hydrogen fuel cell vehicle pathways offer significant C2G GHG emissions reduction compared to the current gasoline internal combustion engine vehicle.
The C2G GHG emissions results were generated using Argonne’s Greenhouse gas, Regulated Emissions, and Energy use in Technologies (GREET) model, with inputs of fuel economy and vehicle component sizing provided by Argonne’s Autonomie model.
Emissions associated with electricity used for battery charging are based on three generation scenarios: the average United States (US) grid mix, a California (CA) average grid mix, and renewable electricity.
Among the findings of the report, which was reviewed by representatives from Phillips 66, GM, Shell, Toyota Motor North America and others, was that a 2020 battery-electric vehicle with 300 miles of real-world range (BEV300) using the average US grid mix emitted an average of 206 g CO2e/mi—about half that of a 2020 conventional gasoline small sport utility vehicle (SUV) (420 g CO2e/mi).
A 2020 fuel cell vehicle fueled by hydrogen from natural gas (gray hydrogen) clocked in at 237 g CO2e/mi; however, when fueled by a 40% blend of renewable hydrogen, the FCEV emissions dropped to 167 g CO2e/mi. When fueled by hydrogen produced from landfill gas, the total dropped to 117 g CO2e/mi.
Life cycle GHG emissions (g CO2e/mi) for current (2020) and future (2050) fuels and vehicle technologies for small SUVs. Source: DOE program record Nº 21003
The 2050 scenario represents vehicle technologies that are assumed to have met DOE performance targets by 2050. Key assumptions for these two scenarios (e.g., powertrain efficiency, component weights, etc.) were provided by the three DOE Transportation Offices (Vehicle Technologies Office, Hydrogen and Fuel Cell Technologies Office, and Bioenergy Technologies Office), within the Office of Energy Efficiency and Renewable Energy, and were incorporated into Autonomie to determine the fuel economy for each vehicle technology. The fuel economy and vehicle component weights were then incorporated into GREET to determine the WTW and C2G GHG emissions.