Cost-Benefit Analysis of Plug

Electric Vehicle T

22nd International Electr

Ah

Andrew Simpson an

T

National Renewable 

U.

Office of Energy Efficienc

FreedomCAR and Vehic

NREL/PR-540-40847
3

Presentat

• Plug-in hybrid-electric vehicle (PHEV) as a • 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
4

A Plug-In Hybrid-Electric Veh

ADVANCED ENGINE

ENGI

ENGINE DOWNSIZING

BATTERY RECHARGE

ELECTRICITY

PETROLEUM

AND/OR

Fuel Flexibility

6

KEY CH• Recharg• Battery • Compon• 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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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 (%) Cha

HEV 

Prius (Corolla)Civic Accord Highlander Escape Vue HEV PHEV20 PHEV40 PHEV60 Battery power Battery energy
8

Vehicle Configurations conventional automatic pre-transmission parallel hybrid: 

HEV or PHEV

 2 technology scenarios

– near term and long term

PHEV Study Scope 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 

Di

Power (kW)
9

Key Study As

• Usable State of Charge window 

varies from 40% for HEV0 to 70% for PHEV60

— Based on battery life of 15 years 

and daily travel distance probability

• Mid-size car platform (Malibu/Camry)

— High volume vehicle

— Performance equivalent to existing 

vehicles

— No platform engineering and no 

engine technology improvements

» Isolate the PHEV technology impacts

• Battery attributes scale with 

Power/Energy ratio
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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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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 

P

Module Specific Cost ($/kWh)

NiMH (near-term)Li-Ion (long-term)
12

Results: Battery Spe

Midsize Sedans 

Battery Power vs Energy for PHEVs

0

20406080

100120

0 5 10 15 20 25 

Total Battery Energy (kWh)

Battery Power (kW)

10 6 

20

P/E= P/E= 

US06 all-electric

P/E = Energy/Total Energy
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Reduction in Fuel Consumption vs Powertrain Cost Increment - 

$-

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

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

0 100 200 300 400 500 

Reduction in Annual Petroleum Consumption (gals

Retail Cost Increment

Results: Increm

Reduced C

Long-term scenarioLI-ION BATTERIES

~50% reduction

~$8K

Varying 

Higher baLower bat
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PHEV Onboard Energy Use: Long-Term Sce

0

100200300400500600

Conventional HEV0 PHEV10 PHEV20 

Annual Petroleum Consumption (gals)

Long-TerLong-Ter

PHEV 

UDDS AER PHE

23 mpg Long-term scenario

LI-ION BATTERIES
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Powertrain Costs Comparison 

UDDS AER 

Powertrain Costs (incl. retail markups)

$4,004 $2,876 $2,930 $2,9

$1,998

$1,994 $2,006 $2,0

$1,680 $1,845 $1,8$2,523

$4,864

$6,9

$-

$663

$66

$14,4

$12,307

$9,073

$6,002

$-

$5,000

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

Conventional HEV0 PHEV10 PHEV

Charging PlugBatteryMotor/InverterTransmissionEngine

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

$-

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

0 5 10 

Years after purchase

Cumulative Cost 

Near-term scenarioNIMH BATTERIES

Near-term HEV Fuel Savings Offset In

Maintenance costs not included, no discount ra

$3.00/gal. 

$0.09¢/kWh (2005 average, not off

$3.00/gal. 

$0.09¢/kWh (2005 average, not off-p
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Cumulative Vehicle plus Energy (Fuel/Elec.) C

$-

$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. $0.09¢/kWh (2005 average, not off-p

Long-term Battery Cost Reductions A

For PHEV to Payback 

Maintenance costs not included, no discount ra
18

Cumulative Vehicle plus Energy (Fuel/Elec.) C

$-

$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

Both Higher Gas Prices and Low

Required for PHEV to Payback 

Maintenance costs not included, no discount ra

$5.00/gal. (future?)

$0.09¢/kWh (2005 average, not off-peak)
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Why Consumers Might Pay More 

1. Green image, “feel-good factor”2. Of-peak charging3. Tax incentives4. Reduced petroleum use, air polluti

5. National energy security6. Less maintenance

7. Reduced fill-ups8. Convenience of home recharging (9. Improved acceleration (high torque 

motors)

10.Alternative business models
20

C

1. Systems simulation extremely important and valuab

exploring the broad HEV/PHEV design spectrum.

2. 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 petroleum use by appro

• Per-vehicle petroleum use reduced by up to 50% for P

PHEV40s.

• Long-term powertrain cost increments are predicted to 

$7K-$11k for PHEV20s and $11K-$15k for PHEV40s

4. Based on overall costs (powertrain plus energy):

• HEVs become the most cost-competitive EITHER if ga

OR projected battery costs are achieved.

• PHEVs become cost-competitive ONLY if projected ba

AND fuel prices increase.

• Tax incentives and/or alternative business models (e.g

required for successful marketing of PHEVs