Well-to-Wheels Results of Energy Use, Greenhouse Gas Emissions and Criteria Air Pollutant Emissions of Selected Vehicle/Fuel Systems

A fuel-cycle model—called the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model—has been developed at Argonne National Laboratory to evaluate well-to-wheels (WTW) energy and emission impacts of motor vehicle technologies fueled with various transportation fuels. The new GREET version has up-to-date information regarding energy use and emissions for fuel production activities and vehicle operations. In this study, a complete WTW evaluation targeting energy use, greenhouse gases (CO2, CH4, and N2O), and typical criteria air pollutants (VOC, NOX and PM10) includes the following fuel options – gasoline, diesel and hydrogen; and the following vehicle technologies – spark-ignition engines with or without hybrid configurations, compression-ignition engines with hybrid configurations, and hydrogen fuel cells with hybrid configurations. Based on the detailed up-to-date data, probability-based distribution functions for key input parameters regarding WTP activities and vehicle operations were built into GREET to address the uncertainties of energy use and emissions. The WTW analysis shows that advanced vehicle/fuel systems achieve reductions in energy use, GHG emissions and criteria pollutant emissions compared to baseline gasoline vehicles by 1) improved vehicle fuel economy, 2) declined tailpipe/evaporative vehicle emissions, and/or 3) differences in fuel production pathways.