Multiple Tiered Methodology for Micro- to Macro-Scale Assessment of Plug-In Hybrid Electric Vehicles (M4-PHEVs)

0853766

Frey

The PI plans to develop M4-PHEV, a new Multiple-tiered Methodology for Micro- to Macro-scale assessment of Plug-In Hybrid Electric Vehicles (PHEV) direct and indirect energy use and emissions (EU&E). This framework will enable accurate assessment of the energy use and emissions of plug-in hybrid electric vehicles (PHEVs) at high spatial and temporal resolution, as well as at regional and national scales, using consistent data and coordinated approaches. The EU&E impacts will account for consumption of fossil fuels (gasoline, diesel), biofuels (ethanol, biodiesel), and electricity. The main objectives are to: (1) develop and demonstrate a new methodological framework for multi-scale modeling that links sensor data to micro-scale models, and micro-scale outputs to energy system model inputs; (2) create micro-scale models of PHEV energy use and emissions at high spatial and temporal resolution with explicit consideration of four vehicle fuels: gasoline, diesel, ethanol, and biodiesel; and (3) use the MARKAL energy systems model to provide a robust, quantitative characterization of PHEV energy use and emissions under U.S. market penetration scenarios. They will develop a new methodology for real-world field data collection and analysis of second-by-second activity, energy use, and emissions of PHEVs using portable emission measurement systems (PEMS). They will quantify how vehicle energy consumption fluctuates between the engine and battery systems as a function of externally-observable factors such as roadway type, speed, acceleration, road grade, and ambient conditions. Detailed models of PHEV fuel and electricity use will be derived. The models will allocate energy use and tailpipe emissions in time and space. We will account for charge depleting and charge sustaining modes. We will build upon our recent work, using PEMS to quantify the effect of biodiesel versus petroleum diesel, as well as ethanol versus gasoline, to assess biofueled-PHEVs. The microscale models will enable comparison of PHEVs with previously developed microscale models for conventional vehicles in order to quantify the marginal impact of PHEVs under specific real-world conditions.

The macro-scale approach will feature the use of a MARKet ALlocation (MARKAL) energy systems model with a 9-region representation of the U.S. in order to assess how the demand for electricity and fuels by PHEVs affects choices among vehicle and power generation technologies, end-use electricity demand across the economy, resource utilization, and regional emissions. They will share results of this work, via a 5-point dissemination plan, with students, the public, practitioners, decision-makers, international collaborators, and researchers to enable realization of the broader impacts of this work. The key hypotheses of this work are: (a) quantitatively accounting for vehicle-specific micro-scale impacts of PHEVs enables development of energy use and emissions models with improved accuracy and precision; (b) such models can be aggregated to develop accurate and precise estimates of EU&E for vehicle fleets and longer time scales; and (c) a modeling framework at multiple scales enables quantification of not only the marginal effects of one PHEV in place of one conventional vehicle, but the system-wide implications for resource utilization and secondary shifts in energy mix, including the impacts of PHEV use of biofuels versus fossil fuels. PHEVs will use energy differently and emit tailpipe emissions intermittently compared to conventional vehicles. Their wide-scale deployment will lead to the complex coupling of the transportation and power generation energy sectors. In addition, the timing and location of direct and indirect emissions from PHEVs is critical to the accurate quantification of localized air quality impacts. This project will provide new methods and data for: (a) more precise estimates of micro-scale vehicle-specific EU&E to support improved emission inventory development; (b) development of a consistent framework for estimating EU&E at different temporal and spatial scales; (c) enabling an improved basis for evaluation of transportation improvement programs (TIPs) and (d) an improved basis for real-time estimation and management of EU&E. This work will impact undergraduate and graduate students who participate in the research, and will be shared with the public, practitioners, and others via a detailed dissemination plan.