UC Davis Institute of Transportation Studies

General. This report provide an overview of basic assumptions and general results for all of the fuel, feedstock, and light-duty vehicle combinations treated in the LEM, and somewhat more detailed results and discussions for the longer-term advanced options, including compressed or liquefied hydrogen from natural gas, compressed or liquefied hydrogen from water via electrolysis, and liquid biofuels developed from wood, grass, or corn. It considers fuel-cell electric vehicles (FCVs) as well as internal-combustion engine vehicles (ICEVs).

Target years. The LEM has the capability of modeling lifecycle environmental impacts in any target year from 1970 to 2050. For this analysis we have estimated results for the near term (2010) and the long term (2050). (We originally proposed to run the LEM for three dates, 2005, 2020, and 2050, but for three reasons have modeled 2010 and 2050 instead: there is not enough difference between 2005 and 2020 to warrant separate runs; having three target years instead of two increases the already large number of results tables by 50%; and Nissan has the LEM and hence the capability to run any year it is interested in.)

Countries. The LEM also has the capability of modeling lifecycle environmental impacts in up to 30 countries simultaneously. For this project, we have performed lifecycle analysis for Japan, China, the U. S., and Germany, using existing data in the LEM. (We originally proposed to run the LEM for Poland, Italy, and the U. K. as well, but for several reasons we omitted them: the data for these countries are not as good as the data for China, Japan, and the U. S.; presenting results for three more countries would greatly multiply the already-large number of results tables; and Nissan has the LEM and hence the capability to run any country it is interested in.)

Results reported. The LEM produces a wide range of quantitative outputs related to lifecycle emissions from the use of alternative transportation fuels and modes. For this report we provide estimates of lifecycle CO2-equivalent GHG emissions in grams per mile, by stage of lifecycle and fuel/feedstock/vehicle combination; emissions of pollutants from the "upstream" fuel cycle (i.e., all stages of the fuel lifecycle excluding end use) in grams per million BTU of fuel, by individual pollutant including CO2-equivalent and fuel/feedstock combination; and emissions of pollutants from the vehicle and materials lifecycle, in grams per pound of material, by individual pollutant (including CO2-equivalent) and vehicle type.

We discuss the key assumptions of the analysis and their impacts on the results. We pay particular attention to inputs and outputs that determine or reveal differences among countries, including kinds and sources of feedstocks for various fuel production pathways, differences in technologies, and differences in emissions regulations and fuel properties.