Total-Energy-Cycle Emissions and Energy Use

Under the sponsorship of the U.S. Department of Energy's Vehicle Technologies Program, Argonne is conducting "total-energy-cycle assessments" to help decision-makers compare different vehicle strategies. Because of radical differences among the candidate technologies (e.g., hydrogen-powered fuel cells, low-sulfur-diesel compression-ignition engines), the evaluation procedure must consider all the activities and processes that go into vehicle and fuel production, not just the energy consumed and emissions generated during vehicle operation. Total-energy-cycle assessments consider all the energy used and emissions resulting from each stage in the use of a particular technology.

Argonne has developed analytical tools to assess the benefits of alternative fuels and engines for light-duty vehicles. The GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model estimates the energy and emissions benefits of alternative engines and fuels for light-duty vehicles. GREET estimates per-mile emissions and energy use rates for each stage in the energy cycle applicable to a particular engine/fuel combination. GREET also categorizes emissions of criteria pollutants into urban and all-location emissions.

GREET is being expanded to evaluate heavy-duty vehicles. The issue of deteriorating emission controls, especially on heavy vehicles, is being explored.

Recent Argonne analyses include the following:

• Hybrid Electric Vehicle Total Energy Cycle Assessment (HEVTECA)
• Well-to-Wheel Energy Use and Greenhouse Gas Emissions of Advanced Fuel/Vehicle Systems - North American Analysis

September 20, 2004