Incorporating GREET into EPA’s Mobile Source Emission Model

The U.S. Environmental Protection Agency’s (EPA’s) Office of Transportation and Air Quality (OTAQ) is developing a new generation of its mobile source emission model for state and local air management agencies to use in simulating mobile source emissions. The new model, called the MOtor Vehicle Emission Simulator (MOVES), will replace the current mobile source emission model called Mobile.

To address advanced vehicle technologies and new transportation fuels, EPA decided to incorporate fuel-cycle emissions into MOVES. Because of Argonne’s expertise in the fuel-cycle analysis area and its widely used GREET model, EPA approached Argonne to incorporate GREET into MOVES for MOVES’ fuel-cycle analysis. The U.S. Department of Energy (DOE) and EPA together provided support for Argonne’s effort to develop a special version of GREET and develop programming to incorporate GREET into MOVES. Through this joint effort, MOVES benefits from using the well-developed fuel-cycle simulation methodologies in GREET, and GREET benefits from MOVES’ detailed simulations of vehicle operation-related emissions. The chart below presents MOVES simulation methodologies. The well-to-pump simulations will be performed with the GREET model.

EPA MOVES Emission Simulation Approach

Through the GREET-MOVES integration effort, Argonne has developed new GREET programming features. In particular, GREET users can simulate a particular year between 1990 and 2020 by specifying a target year in GREET. GREET incorporates time-series tables for key input parameters to take into account technology improvements over time.

To address newly emerging fuel production pathways, GREET has been expanded to include additional fuel production options such as oil sands to gasoline and diesel, coal gasification to hydrogen, biomass gasification to hydrogen, among many other options.

With support from EPA and DOE, Argonne will continue to work with EPA on GREET-MOVES integration. After integrating the fuel-cycle simulations of GREET, Argonne will update the vehicle-cycle simulation feature in the GREET model, which will be incorporated eventually into MOVES.

September 27, 2004