U.S. Environmental Protection Agency
Office of Transportation and Air Quality
Assessment and Standards Division

March 11, 2004
                                


Document released for public review and comment:

"Advanced Technology Vehicle Modeling in PERE"
                             
Report Number EPA420-D-04-002


Abstract

This study proposes a modeling methodology for light duty advanced technology
vehicles including those powered by:
- Advanced gasoline internal combustion engine
- Advanced diesel internal combustion engines
- Hybrid electric and gasoline/diesel powertrains
- Hydrogen fuel cell hybrid

The model called PERE (Physical Emission Rate Estimator) is designed to
support the new EPA energy and emissions inventory model, MOVES (MOtor Vehicle
Emission Simulator). PERE is a stand-alone spreadsheet, which can be run by an
informed user. The inputs are vehicle parameters and second-by-second driving
traces. It outputs Pump-to-Wheel (PTW) fuel consumption rates. The purpose of
PERE is to fill data gaps in MOVES and to help it extrapolate to future
projections of energy and emissions. The current version of PERE will model
many of the advanced technologies in MOVES and is capable of capturing others. 

PERE uses physical principles to model propulsion systems in the vehicle. The
model is based on a simple model for the internal combustion engine.
Simulation of hybridization is achieved by inserting a secondary power source
and energy storage device (usually a battery/motor combination). Fuel cell
vehicles are simulated by replacing the engine with a fuel cell system. 

The model is validated to four production conventional, four hybrid, and one
fuel cell vehicles by comparing the PERE output to the rated fuel economy
figures. The model performs well, in most cases the predictions are within
10%. The report also includes a sensitivity analysis, which will help guide
users to determine which parameters require more accuracy. Finally, the report
describes how PERE might be used to support MOVES. It provides guidance for
how parameters may be estimated in order to perform future projections. It
also describes a methodology by which the PERE output can be integrated into
MOVES.


REQUEST FOR PUBLIC COMMENTS

Please send comments by email to newgen@epa.gov

or by regular mail to 

Edward Nam, PhD
US Environmental Protection Agency
Office of Transportation and Air Quality
Assessment and Standards Division
2000 Traverwood Drive
Ann Arbor, MI 48105

Electronic submission of comments is preferred. In your comments, please note
clearly the document that you are commenting on, including the report title
and number. Please be sure to include your name, address, affiliation, and any
other pertinent information.