Plug-In Hybrid Modeling and A

Cost / Bene

Presented at the 3rd AVL Summer Conference on Automotive S

Modeling of Advanc

A

National Renewable 

Thur

U

Office of Energy Efficien

FreedomCAR and Vehi

NREL/PR-540-40504
2

Presentat

• What is a plug-in hybrid-electric vehicle (P• Potential petroleum reduction from PHEVs• Simulation of PHEV efficiency and cost

— Baseline vehicle assumptions— Powertrain technology scenarios— Components models (cost, mass, efficiency)

• Results

— Component sizing— Fuel Economy— Incremental cost— Payback scenarios

• Conclusions & Next Steps
3

A Plug-In Hybrid-Electric Veh

ADVANCED ENGINE

ENG

ENGINE DOWNSIZING

REGENERATIVE BRAKING

ELECTRICITY

PETROLEUM

AND/OR

Fuel Flexibility
4

Some PHEV 

All-Electric Range (AER): After a full recharge, the 

electrically (engine-off) before the engine turns on 

Blended Mode: A charge-depleting operating mode 

engine is used to supplement battery/motor power

PHEV20: A PHEV with useable energy storage equ

of driving energy on a reference driving cycle. 

NOTE: PHEV20 does not imply that the vehicle will a

AER on the reference cycle nor any other driving ccharacteristics depend on the power ratings of compowertrain control strategy and the nature of the d
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KEY CH• Rechar• Battery • Compo• Vehicle 

KEY BENEFITS

Consumer:

• Lower “fuel” costs• Fewer fill-ups• Home recharging convenience• Fuel flexibility

Nation:

• Less petroleum use• Less greenhouse and regulated 

emissions

• Energy diversity/security

PHEV Key Benefits and 

Cost-Be
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National Dr

1995 National Personal Transp

0 20 40 60 8

0

102030405060708090

100

Daily Mileage (mi)

Probability (%)

Daily Mileage Distribution and Utility Factor Curv

Daily mileage dUtility Factor cu
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Potential Petroleum Reduction 

WHAT ARRELATIVE 

0%

10%20%30%40%50%60%70%80%90%

100%

0% 20% 40% 60% 

Reduction in Charge-Sustaining Mode Petroleum 

Total Reduction in Petroleum Consumption (%) Ch

HEV 

Prius (Corolla)Civic Accord Highlander Escape Vue HEV PHEV20 PHEV40 PHEV60 Battery power Battery energy
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Vehicle Configurations conventional automatic pre-transmission parallel hybrid: 

HEV or PHEV

 2 technology scenarios

– near term and long term

PHEV Efficiency and 

Approach Dynamic, power-flow simulation Calculates component sizes and costs Iterative mass-compounding Measures fuel/electricity consumption using NREL

revisions to SAE J1711

 Battery definition is key input to the simulation

-30-20-10

0

10203040506070

0 5 10 15 

D

Power (kW)
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Baseline Vehicle Characteristics – 

MIDSIZE SEDAN (AUTOMATIC)Platform ParametersGlider Mass 905 kgCurb Mass 1429 kgTest Mass 1565 kg (136 kg load)Gross Vehicle Mass (GVM) 1899 (470 kg load)Drag coefficient 0.30Frontal area 2.27m2Rolling resistance coefficient 0.009Baseline accessory load 800 W elec. + 2900 W A/CPerformance ParametersStanding acceleration 0-60 mph in 8.0 sPassing acceleration 40-60 mph in 5.3 sTop speed 110 mphGradeability 6.5% at 55 mph at GVM with 2/3 fuel converter powerVehicle attributesEngine power 121 kWFuel economy 22.2 / 35.2 / 26.6 mpg (urban / highway / composite, unadjuste
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Powertrain Technology 

Engine Near-Term Scenario LEfficiency 35% peak efficiency curve Cost EPRI Mass Based on MY2003 production engines Battery Near-Term Scenario LChemistry NiMH 

Module cost Double EPRI projections, see slide 12 EPR

Packaging cost EPRI Module mass NiMH battery design function (Delucchi), see slide 12 Li-Ion battery dePackaging mass Delucchi 

Efficiency Scaleable model based on P/E ratio SOC window SOC design curve based on JCI data

for NiMH cycle-life, see slide 11

(assumes Li-Ion 

Motor Near-Term Scenario LMass DOE 2006 current status Based Efficiency 95% peak efficiency curve Cost EPRI (near term) 

* Engine technologies were not improved so as to isolate the benefits of impro
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Battery Definition as Key Input 

kWh/mi(from simulation)SOC windowPHEV rangeP/E ratioPerformance constraints

kWh usable

kWh total

kWmotorkWengine

DOH

Tot

mass compounding

Input parameters tha

DOH = degree of hybridization
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0%

10%20%30%40%50%60%70%80%90%

100%

0 10 20 30 40 

Daily Mileage / PHEVx

Design SOC window 

based on PHEVx

0%

10%20%30%40%50%60%70%80%90%

100%

0 10 20 30 40 

Daily Mileage / PHEVx

Averaswing milea

Daily mileage probability distribution

Battery SOC Desi

Battery SOC design curve for 15 year cycle 
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Battery Models 

Battery Design Functions

0

200400600800

100012001400160018002000

0 20 40 60 80 100 120 140 160 180 200

Specific Energy (Wh/kg)

Specific Power (W/kg)

NiMH (near-term scenario)LI-ION (long-term scenario)

2

50 20 10

5

Ba

0

200400600800

10001200

0 5 10 

Module Specific Cost ($/kWh)

NiMH (near-term)Li-Ion (long-term)
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Results: Battery Sp

Midsize Sedans 

Battery Power vs Energy for PHEVs

0

20406080

100120

0 5 10 15 20 2

Total Battery Energy (kWh)

Battery Power (kW)

10 6 

20
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Reduction in Fuel Consumption vs Powertrain Cost Increment - M

$-

$2,000$4,000$6,000$8,000

$10,000$12,000$14,000$16,000$18,000$20,000

0 100 200 300 400 

Reduction in Annual Fuel Consumption (gals.)

Powertrain Cost Increment

Long-term scenarioLI-ION BATTERIES

Results: Battery Sp
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PHEV 

UDDS AER PHE

27 mpg

PHEV Onboard Energy Use: Near and Long-Term Sc

0

100200300400500600

Conventional HEV0 PHEV10 PHEV20 

Annual Petroleum Consumption (gals)

Near-Long-Near-Long-
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Powertrain Costs Comparison 

UDDS AER 

Powertrain Costs (incl. retail markups)

$4,004 $2,902 $2,995 $3,0

$1,998

$2,000 $2,018 $2,0

$2,166 $2,414 $2,5

$3,907

$8,296

$12,8

$663

$66

$21,18

$16,386

$10,976

$6,002

$-

$5,000

$10,000$15,000$20,000$25,000$30,000

Conventional HEV0 PHEV10 PHEV

Charging PlugBatteryMotor/InverterTransmissionEngine
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Powertrain Costs Comparison 

UDDS AER 

Powertrain Costs (incl. retail markups)

$4,004 $2,876 $2,925 $2,9$1,998

$1,994 $2,005 $2,0$1,680 $1,842 $1,8$2,523

$4,677

$6,7

$663 

$66

$14,2

$12,111

$9,073

$6,002

$-

$5,000

$10,000$15,000$20,000$25,000$30,000

Conventional HEV0 PHEV10 PHEV

Charging PlugBatteryMotor/InverterTransmissionEngine
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Cumulative Vehicle plus Energy (Fuel/Elec.) 

$-

$10,000$20,000$30,000$40,000$50,000$60,000

0 5 10 

Years after purchase

Cumulative Cost 

$3.00 / gal. (today)

Near-term scenarioNIMH BATTERIES

$0.09¢/kWh (2005 average)

Overall Cost Comparison for HEV

Maintenance costs not included, no discount ra
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Cumulative Vehicle plus Energy (Fuel/Elec.) 

$-

$10,000$20,000$30,000$40,000$50,000$60,000

0 5 10 

Years after purchase

Cumulative Cost 

Long-term scenarioLI-ION BATTERIES

$3.00 / gal. (today)$0.09¢/kWh (2005 average)

Overall Cost Comparison for HEV

Maintenance costs not included, no discount ra
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Cumulative Vehicle plus Energy (Fuel/Elec.) 

$-

$10,000$20,000$30,000$40,000$50,000$60,000

0 5 10 

Years after purchase

Cumulative Cost 

$5.00 / gal. (day after tomorrow

Long-term scenarioLI-ION BATTERIES

$0.09¢/kWh (2005 average)

Overall Cost Comparison for HEV

Maintenance costs not included, no discount ra
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Vehicle 

Why might PHEV buyers pay more?1. Tax incentives2. Reduced petroleum use, air pollution an3. National energy security4. Less maintenance5. Reduced fill-ups6. Convenience of home recharging (off-pe7. Improved acceleration (high torque of e8. Green image, “feel-good factor”9. Backup power10. Vehicle-to-grid (V2G)
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C

1. There is a very broad spectrum of HEV-PHEV desig2. Key factors in the HEV/PHEV cost-benefit equation 

• Battery costs• Fuel costs• Control strategy (particularly battery SOC window)• Driving habits (annual VMT and trip-length distribution

3. Based on the assumptions of this study:

• HEVs can reduce per-vehicle fuel use by approx. 30%• PHEVs can reduce per-vehicle fuel use by up to 50% 

for PHEV40s.

• In the long term, powertrain cost increments are pred

HEVs, $7-11k for PHEV20s and $11-15k for PHEV40projected component (battery) costs can be achieved

• Note this study did not consider benefits from platform 

mass/drag reduction).
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Conclus

4. Based on overall costs (powertrain plu

• At today’s fuel and powertrain component c

vehicles are the most cost-competitive.

• HEVs become the most cost-competitive E

increase OR projected battery costs are ac

• PHEVs become cost-competitive ONLY if p

costs are achieved AND fuel prices increas

• Tax incentives and/or alternative business 

lease) may be required for successful mark
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• Present this work at EVS22• Expand the HEV-PHEV analysis space to 

— Platform engineering (mass/drag reduction)— Different performance constraints / compone

SA

• Detailed simulation of promising PHEV de

— Real world driving patterns (e.g. St Louis da— Control strategy optimization

TR

• Optimization of PHEV market competitiven

Technical Targets Tool

Ong