Well-To-Wheels Energy Use and Greenhouse Gas Emissions of Plug-in Hybrid Electric Vehicles

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Well-To-Wheels Energy Use and Greenhouse Gas
Emissions of Plug-in Hybrid Electric Vehicles

• Amgad Elgowainy, Andy Burnham, Michael Wang, John
  Molburg, and Aymeric Rousseau
• Center for Transportation Research
• Argonne National Laboratory
• Presentation at MIT/Ford/Shell Research Workshop
• June 8, 2009

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Scope of Argonnes PHEV WTW Analysis

• To examine relative energy and emission merits of
  PHEVs the vehicle types addressed were
• Conventional international combustion engine
  vehicles (ICEVs)
• Regular hybrid electric vehicles (HEVs)
• ICE plug-in hybrid electric vehicles (PHEVs)
• Fuel cell (FC) PHEVs
• Fuel options
• Petroleum
• Gasoline
• Diesel
• E85 with ethanol from
• Corn
• Switchgrass
• Hydrogen with several production pathways
• Electricity with different generation mixes

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Argonnes PHEV WTW Analysis Addresses The
Following Key Issues

• PHEV performance evaluation with Argonnes PSAT
  model
• Explored PHEV operating strategies
• Processed fuel economy results for various PHEV
  configurations
• Examined effects of all electric ranges (AER) of
  PHEVs
• Electricity generation mixes to charge PHEVs
• Reviewed studies completed in this area
• Generated five sets of generation mixes for PHEV
  recharge
• PHEV mileage shares by power source
• Relied on national average distribution of daily
  vehicle miles traveled (VMT)
• Determined VMT shares by charge depleting (CD)
  and charge sustaining (CS) operations
• GREET WTW simulations of PHEVs
• Expanded and configured GREET for PHEVs
• Conducted GREET PHEV WTW simulations

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Five Sets of Generation Mixes for PHEV Recharge
Were Used in This Study ()

• US Average the default GREET average mix for
  2020
• IL, NY, and CA Marginal from the 2020 mix with
  2kW charging capacity starting at 10 PM from a
  study by Hadley et al.
• Renewable a scenario reflecting upper limit on
  benefits of PHEVs

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A Set of Vehicle/Fuel Systems Was Included in
This Analysis

• Vehicle types included
• ICEV Gasoline SI, E85 SI, Diesel CI
• HEV Gasoline SI, E85 SI, Diesel CI Hydrogen FC
• PHEV Gasoline SI, E85 SI, Diesel CI Hydrogen FC
• Model year 2015 midsize car
• Fuel economy results were adjusted using EPA
  2007-adopted formula for on-road performance

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Fuel Consumption Calculated from PSAT Fuel
Economy Values (Btu/mi)

• Fuel consumption for each operation is the
  following
• CD electric electricity consumption in CD
  operation
• CD Engine fuel consumption by ICE/FC in CD
  (blended mode) operation
• CS operation fuel consumption in CS operation

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PHEVs with 20-Mile AER Can Potentially Drive 40
of Daily VMT , PHEVs with 40-Mile AER More than
60
NHTS
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WTW Total Energy Use for CD Mode (Electricity and
Fuel) vs. CS mode (Fuel) 20 AER US Mix
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WTW GHG Emissions for CD Mode (Electricity and
Fuel) vs. CS Mode (Fuel) 20 AER US Mix
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WTW GHG Emissions for CD Mode (Electricity and
Fuel) vs. CS Mode (Fuel) 20 AER CA Mix
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WTW GHG Emissions for CD Mode (Electricity and
Fuel) vs. CS Mode (Fuel) 20 AER IL Mix
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WTW GHG Emissions US Mix Comparison of
Technology and All Electric Range
Regular Hybrid
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Summary of Petroleum Energy and GHG Effects of
All Evaluated Options
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Thank you!GREET web
sitehttp//www.transportation.anl.gov/modeling_s
imulation/GREET/index.html PHEV WTW Analysis
Reporthttp//www.transportation.anl.gov/pdfs/TA/
559.pdf
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PSAT Fuel Economy Results (Miles Per Gasoline
Equivalent Gallon, Wh/Mile for CD Electric
Operation)
CD electric operation and CD on-board operation
complement each other for the same CD miles
(i.e., blended mode operation)

• CD Electric charge depleting operation with
  grid electricity
• CD Engine charging depleting operation with
  on-board power systems (ICE or Fuel Cell)
• CS charge sustaining operation with on-board
  power systems
• AER 0 zero-mile AER (i.e., regular HEV)
• AER 10 10-mile AER AER 20 20-mile AER AER
  30 30-mile AER AER 40 40-mile AER
• UDDS Urban Dynamometer Driving Schedule HWFET
  Highway Fuel Economy Test

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Processing of PSAT MPG Results for GREET Fuel
Consumption Inputs

• PSAT fuel economy results were first converted
  into fuel consumption
• The city (UDDS) and highway (HWFET) results of
  PSAT were combined with 55 UDDS and 45 HWFET
• The PSAT results for CD electric operation did
  not include charging losses we assumed a 85
  efficient charger
• PSAT fuel consumption for CD and CS operations
  were combined using the Utility Factor
• (FCCDGrid FCCDICE ) UF FCCS (1-UF)

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Concluding Remarks

• PSAT simulations of the blended mode operation of
  PHEVs show that grid electricity accounts for a
  small share of total vehicle energy use in
  combined CD and CS operations (6 for PHEV10 and
  24 for PHEV40)
• The effect of electric generation mix becomes
  smaller with the blended mode operation However,
  electric generation mix is still shown to have a
  significant effects on WTW results, especially
  for GHG emissions
• Petroleum use declines when electricity is
  generated from non-petroleum sources
• GHGs are highest with large coal shares, but
  decreased with NG, and decreased even further
  with renewables
• HEV vs. PHEV
• Petroleum use decreases as AER increases (except
  for generation mixes with high share of oil)
• GHGs in general decrease as AER increases (except
  for carbon intensive generation mixes and
  biomass-to-E85 and H2)
• Gasoline ICE PHEV vs. FC PHEV
• FC PHEVs have much lower petroleum energy use
• FC PHEVs using SMR-H2 slightly reduce GHGs
  Biomass-to-H2 FC PHEVs significantly reduce GHGs
• Outstanding issues
• Electric generation mix for recharging PHEVs is
  affected by many factors total electricity
  demand by PHEVs, location of PHEVs, time of day
  for recharging, PHEV buffer ability for the
  utility system
• Utility dispatch modeling may be necessary for
  further analysis

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