Environmental assessment of plug-in hybrid electric vehicles using naturalistic drive cycles and vehicle travel patterns_ A Michigan case study

Plug-in hybrid electric vehicles (PHEVs) use grid electricity as well as on-board gasoline for motive force. These multiple energy sources make prediction of PHEV energy consumption challenging and also complicate evaluation of their environmental impacts. This paper introduces a novel PHEV energy consumption modeling approach and compares it to a second approach from the literature, each using actual trip patterns from the 2009 National Household Travel Survey (NHTS). The first approach applies distance-dependent fuel efficiency and on-road electricity consumption rates based on naturalistic or real world, driving information to determine gasoline and electricity consumption. The second uses consumption rates derived in accordance with government certification testing. Both approaches are applied in the context of a location-specific case study that focuses on the state of Michigan. The two PHEV models show agreement in electricity demand due to vehicle charging, gasoline consumption, and life cycle environmental impacts for this case study. The naturalistic drive cycle approach is explored as a means of extending location-specific driving data to supplement existing PHEV impact assessments methods. & 2013 Elsevier Ltd. All rights reserved. ll rights reserved. DJ, composite EPA-adjusted vehicle efficiency following method in Elgowainy et al. (2010) for power-split PHEV design e Average Fuel Economy; CO, carbon monoxide; CO2, carbon dioxide; CD, charge depleting mode of PHEV operation; onventional vehicle; CVAVG, CV energy consumption model based on average efficiency estimate method using NDC, CV energy consumption model based on synthetic naturalistic drive cycle method; eGRID, emissions and nmental Protection Agency; EPRI, Electric Power Research Institute; eSOC, energy state of charge; FOT, field operational use gases, regulated emissions, and energy use in transportation; HHV, high heating value (129.25 MJ/gallon for Intergovernmental Panel on Climate Change; MEFEM, Michigan Electricity, Fleet and Emissions Model; MJ, mega-Joule; en oxide, NO and NO2; NREL, National Renewable Energy Laboratory; PECM, PHEV Energy Consumption Model; energy consumption model based on average efficiency method using composite-adjusted (ADJ) values unless l based on synthetic naturalistic drive cycle method; PM10, particulate matter with diameter of 10 μm or less; ty of Automotive Engineers; TFC, total fuel cycle; UDDS, Urban Dynamometer Driving Schedule; UF, utility factor; ch Institute; USLCI, U.S. Life Cycle Inventory; US06, supplemental test cycle representing aggressive driving behavior; s, School of Natural Resources and Environment, University of Michigan, Ann Arbor, 440 Church Street, . Tel.: +1 734 763 8564. et al., Environmental assessment of plug-in hybrid electric vehicles using naturalistic drive igan case study. Energy Policy (2013), http://dx.doi.org/10.1016/j.enpol.2013.03.037i B.M. Marshall et al. / Energy Policy ∎ (∎∎∎∎) ∎∎∎–∎∎∎ 2