Fuel Consumption Modeling ofConventional and AdvancedTechnology Vehicles in thePhysical Emission Rate Estimator (PERE) - Draft (EPA-420-P-05-001,February 2005)

NOTICE This Technical Report does not necessarily represent final EPA decisions or positions. It is intended to present technical analysis of issues using data that are currently available. The purpose in the release of such reports is to facilitate an exchange of technical information and to inform the public of technical developments. Executive Summary This study proposes a modeling methodology for conventional and advanced technology vehicles including: • Conventional motorcycles • Conventional gasoline and diesel (light and heavy duty) • Advanced gasoline internal combustion engine • Advanced diesel internal combustion engines • Hybrid electric and gasoline/diesel • Hydrogen fuel cell and hybrid • Hydrogen internal combustion engine The model called PERE (Physical Emission Rate Estimator) is designed to support the new EPA energy and emissions inventory model, MOVES (MOtor Vehicle Emissions Simulator). PERE is a series of stand-alone spreadsheets, which can be run and modified by an informed user. It outputs Pump-to-Wheel (PTW) fuel consumption rates. The purpose of PERE is to fill data gaps in MOVES and to provide a tool to extrapolate to future projections of energy and emissions. The current version of PERE will model the fuel consumption from many of the advanced technologies in MOVES in addition to conventional vehicles. Criteria pollutant emissions will be modeled in a later version. If the user is knowledgeable of the vehicle parameters required in PERE, other technologies can be modeled that are not described in this report (e.g. alternative fuels, minimum/mild hybrids, etc.). MOVES is currently being integrated with GREET (developed at Argonne Laboratory), which produces upstream Well-to-Pump (WTP) energy and emissions rates. The combination of PERE, MOVES, and GREET will provide a powerful comprehensive modeling suite for anyone requiring emissions inventory projections or life cycle (energy/emissions) studies for mobile sources into the future. As the name implies, PERE uses physical principles to model propulsion systems in the vehicle. It is therefore built on a relatively strong foundation. It is based on a sound, yet elegantly simple model for the internal combustion engine. Modeling of hybrids is achieved by inserting a secondary power source (usually a battery/motor combination). Fuel cell vehicles are simulated by replacing the engine with an aggregate fuel cell system. PERE takes vehicle input parameters, then runs the vehicle through driving cycles defined by the user and outputs second-by-second fuel consumption rates. All of the processes are transparent to the user, which allows for easy updates. …