CEEN 596 Project Presentation - Rene Lipp

The Costs and Benefits of a Fuel Cell Enhanced Battery Electric Vehicle

CEEN-596 Final Project

By René Lipp

December 12, 2011

Outline

• Introduction

• Simulation Model

• Simulation Results

• Conclusion

2

Nissan Leaf

Source: www.nissan.ca/LEAF

3

http://www.nissan.ca/LEAF

Nissan Leaf

• Cost: $27,700 (After Incentives)

• Vehicle Mass: 1,520kg

• Top Speed: 150 km/h

• Traction Motor: 80kW (280Nm Torque)

• Battery Capacity: 24kWh

• Energy Consumption: 21.1 kWh/100km (2.2 L / 105 mpg equiv.)

• Range: 100-150 km’s

Source: www.nissan.ca/LEAF

4

http://www.nissan.ca/LEAF

Honda Clarity

Source: http://automobiles.honda.com/fcx-clarity/

Large load following 100kW FC sized to meet peak power requirements

Small Battery pack for regenerative braking & acceleration

5

http://automobiles.honda.com/fcx-clarity/




Fuel Cell (FC) ‘Enhanced’ Battery Electric Vehicle (BEV)

• FC & BEV’s both have the potential to significantly reduce vehicular CO2 emissions but FCEV’s are extremely costly and BEV’s have a limited range.

• Taking a different approach; a small FC is added to ‘enhance’ the performance of BEV.

6

Battery Electric Energy Storage

• Typically 80% Efficient

• Electricity Cost: $0.12/kWh1 (≈1/3rd of Gasoline2)

• 0.14 kWh/kg (≈1/25th of Gasoline)

1 $0.10/kWh and a 85% charger efficiency 2 $1/L untaxed at conversion efficiency of 25%

BATTERY

e- e-

7

Hydrogen FC Energy Storage System

• Typically 25% Efficient • Fuel Cost: $0.26/kWh1 electricity equiv. • 14.8 kWh/kg H2 fuel (≈x105 Battery) • 110-3,300 g/kWh CO2 equiv. (Compared to 950 g/kWh2 CO2 equiv. for Gasoline)

1 $4.50/kg Hydrogen and a cell efficiency of 50% 2 http://www.ec.gc.ca/ges-ghg/default.asp?lang=En&n=AC2B7641-1#section2

co2

(From CH4 Reforming Only)

STORAGE or

CH4 e-

H2 STORAGE

ELECTROLYIS

or

REFORMING

e- H2

F.C. e-

Storage

Storage

8

http://www.ec.gc.ca/ges-ghg/default.asp?lang=En&n=AC2B7641-1







Simulation Model

Governing Equations

• 𝐹𝑔 = 𝑀𝑔 sin 𝛼

• 𝐹𝑟 = 𝑀𝑔0.01 1 +𝑉

160cos 𝛼

• 𝐹𝑎 = 1

2𝜌𝐴𝑓𝐶𝐷

𝑉−𝑉𝑤

3.6

2

•𝑑𝑉

𝑑𝑡=

𝐹𝑡− 𝐹𝑟+ 𝐹𝑎+ 𝐹𝑔

𝛿𝑀 𝑚

𝑠2

Fg + Fr + Fa

Mg

α Mg sin(α) Mg cos(α)

10

Idealized Motor Efficiency Curve

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Mo

tor

Effi

cie

ncy

Motor Speed [rpm]

Lower Efficiencies at Lower Speeds

11

Typical Lithium-Ion Battery Efficiency Curve

60%

65%

70%

75%

80%

85%

90%

1 3 5 7 9 11 13 15 17 19

'C' Rate

Efficiency Decreases with Load

12

Powertrain Model Schematic M

oto

r e- H2

FC

Tan

k

e- Battery

e- e-

13

Vehicle Model Parameters • Vehicle Base Mass: 1,125kg (1,500kg w/Batteries) • Top Design Speed: approx. 150 km/h • Rolling Resistance Coefficient: 0.01 • Aerodynamic Drag Coefficient: 0.3 • Frontal Area: 2.5m2 • Transmission Efficiency: 90% • Traction Motor: 100kW (285Nm Torque) • Max. Motor Speed: 10,000rpm • Motor Efficiency: 90% Max. • Tire Radius: 0.305m [12”] • Wheel Base: 2.7m (approx. 60% Front Brake Distribution) • Rated Battery Capacity: 30kWh (Baseline) • Useable Battery Capacity: 80-20% Rated Capacity

• Fuel Cell Power Density: 0.8 kW/kg • Hydrogen Fuel Tank: 15 kg/kg H2 fuel (40L/kg H2) at 70MPa • Hydrogen Fuel Storage: 5 kg max.

14

EPA Urban Drive Cycle

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000 1200 1400

Ve

hic

le S

pe

ed

[km

/h]

Time [s]

1,369 second (22min : 49sec), 12.0 kilometres, 31.5 km/h avg. speed

‘Stop-and-Go’ Traffic

15

Vehicle Power Demand Curve

0

10

20

30

40

50

60

0 200 400 600 800 1000 1200 1400

Ve

hic

le P

ow

er

De

man

d /

Su

pp

ly [

kWe

]

Time [s]

Motor Demand ReGenerative Braking Average

Includes transmission and motor efficiencies but not energy storage efficiency

Peak Power Demand

Average Power Demand

16

Battery Power Demand Curve

-70

-60

-50

-40

-30

-20

-10

0

10

20

0 200 400 600 800 1000 1200 1400

Ene

rgy

Sto

rage

Po

we

r [k

W]

Time [s]

Regenerative Braking

Supplied to Vehicle Drive Motor

17

EPA Highway Drive Cycle

765 second (12min : 45sec), 16.5 kilometres, 77.7 km/h avg. speed

0

10

20

30

40

50

60

70

80

90

100

0 100 200 300 400 500 600 700 800

Ve

hic

le S

pe

ed

[km

/h]

Time [s]

18


0

5

10

15

20

25

30

35

40

45

0 100 200 300 400 500 600 700 800

Ve

hic

le P

ow

er

De

man

d /

Su

pp

ly [

kWe

]

Time [s]

Motor Demand ReGenerative Braking Average


19


0

5

10

15

20

25

30

35

40

45

0 100 200 300 400 500 600 700 800

Ve

hic

le P

ow

er

De

man

d /

Su

pp

ly [

kWe

]

Time [s]

Motor Demand ReGenerative Braking Average FC


15kW FC sustains the Battery’s energy level

20

Effect of Grade on a BEV

Road Angle

(Grade)

Urban Drive Cycle Highway Drive Cycle

Avg.

Power

[kW]

Energy

Consumption

[Wh/km]

Regenerative

Braking

Avg.

Power

[kW]

Energy

Consumption

[Wh/km]

Regenerative

Braking

-20°

(-36.4%)

-14.5 -461 100% -16.5 -302 100%

-15°

(-26.8%)

-11.7 -372 100% -23.1 -298 100%

-10°

(-17.6%)

-7.8 -248 100% -18.1 -234 100%

-5° (-8.7%) -2.7 -84 100% -7.1 -92 100%

Flat 6.3 200 9.3% 15.7 203 2.3%

5° (8.7%) 22.5 713 0.7% 59.3 764 0.1%

10° (17.6%) 40.2 1,275 0%

Exceeds Motor Power Rating 15° (26.8%) 58.6 1,858 0%

20° (36.4%) 76.8 2,437 0%

21

Key Points

• The average power demand of a vehicle is significantly less than its peak demand;

– Thus a FC could be downsized to meet this average power demand whilst,

– The battery provides peak load-following power.

22


Simulation Results

BEV Energy Consumption

0

100

200

300

400

500

600

700

800

100 150 200 250 300

Ene

rgy

Co

nsu

mp

tPe

nal

tykm

]

Range [km]

BEV

24

BEV Range Limitations

-

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

0

50

100

150

200

250

300

350

400

0 250 500 750 1000

Ve

hic

le M

ass

[kg]

Ve

hic

le R

ange

[km

]

Battery Capacity [kWh]

Range Mass

25

Trade-off Btw. Battery Efficiency and Weight

0

100

200

300

400

500

600

700

800

100 150 200 250 300

Ene

rgy

Co

nsu

mp

tPe

nal

tykm

]

Range [km]

BEV 1 to 5kW FC-BEV

Higher Battery Efficiency Dominates

Battery Weight Penalty Dominates

26

Vehicle Incremental Costs: 250km Range

$129,750

$60,000

$18,750 $11,250

$2,500

$5,000 $7,500

$500

$1,000 $1,000

$7,325

$3,375

$1,050 $625

$6,025

$10,100 $11,150

$45

$170

$260

$285

$-

$20,000

$40,000

$60,000

$80,000

$100,000

$120,000

$140,000

$160,000

0/173 BEV 2.5/80 FCBEV 5/25 FCBEV 7.5/15 FCBEV

Incr

em

en

tal V

eh

icle

Co

st

Fuel Cell [kW] / Battery [kWh]

CO2 Tax

Fuel

Electricity

Tank

FC

Battery

Battery: $750/kWh FC: $1,000/kW Tank: $500/kg H2 Electricity: $0.10/kWh (150,000km's) Fuel: $10/kg H2 (150,000km's) CO2 Tax: $25/Tonne O&M: Not Included

27

Key Points

• A long-range BEV isn’t practical;

– The low energy density of the battery limits the vehicles range.

– It can be more cost effective to add a small FC, than it is to increase the size of the battery.

• Next Step; A ‘side-by-side’ comparison.

28

FC-BEV Energy Consumption

200

130

120

0

50

100

150

200

250

300

0/30-BEV 25/15-FCBEV

Ene

rgy

[Wh

/km

]


Fuel Cell (Hydrogen)

Battery (Electricity)

90km Range

555km Range

(Baseline) 29

De

pe

nd

ant

on

%

Dai

ly T

rip

Dis

trib

uti

on

FC-BEV CO2 equiv. Emissions

6 4

31

-

5

10

15

20

25

30

35

40


CO

2 E

mis

sio

ns

[g/k

m]


Hydrogen (SMR)

Electricity

25 gCO2/kWh 10kgCO2/kg H2

Note: 2011 Toyota Prius @ 3.7 L/100km equates to 85 g/km (Tank-Wheel) 30

“How Much Range is Enough Range?”

1995 NTPS Daily Driving Distances Distribution

≈90km

(≈250km)

31

Accepting the Range Limitations of BEV’s;

Public Charging Stations Depends On:

Source: http://www.ecomagination.com/technologies/wattstation

• Willingness to change driving behaviour

• The development of supporting infrastructure

32

http://www.ecomagination.com/technologies/wattstation

Accepting the Range Limitations of BEV’s;

Battery Swapping Stations Depends On:

Source: : http://www.betterplace.com

• Willingness to change driving behaviour

• The development of supporting infrastructure

• The availability of alternative transportation options (if need be)

33

http://www.betterplace.com/

$7,500

$3,750

$2,500

$375

$3,525

$2,300

$2,050

$90 $515

$-

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

$14,000


Incr

em

en

tal V

eh

icle

Co

st


CO2 Tax

Fuel

Electricity

Tank

FC

Battery

90km Range

Total Additional Cost $375 (or 3%)

Future Target Cost Considerations

Based Upon: Battery: $250/kWh, FC: $100/kW, Tank: $75/kg H2, Electricity: $0.10/kWh (150,000km's) Fuel: $4.5/kg H2 (150,000km's), CO2 Tax: $100/Tonne, O&M: Not Included

34

Future Target Cost Considerations

$7,500

$3,750 $3,000

$7,000

$11,750

$750

$2,500

$7,500

$7,500

$7,500

$7,500

$3,525

$2,300

$2,150

$3,175

$4,000

$2,050

$2,175

$1,075

$575

$5,525

$-

$5,000

$10,000

$15,000

$20,000

$25,000

$30,000

0/30-BEV 25/15-FCBEV 75/12.5-32kmPFCEV 75/28-64kmPFCEV 75/47-96kmPFCEV 75/2.5-HFCEV

Incr

em

en

tal V

eh

icle

Co

st


CO2 Tax

Fuel

Electricity

Tank

FC

Battery

90km Range

Based Upon: Battery: $250/kWh, FC: $100/kW, Tank: $75/kg H2, Electricity: $0.10/kWh (150,000km's) Fuel: $4.5/kg H2 (150,000km's), CO2 Tax: $100/Tonne, O&M: Not Included

Typical Economy Class ICE & 150,000km Fuel Costs (untaxed @ $1/L )

35

Conclusion

• A long-range BEV isn’t practical.

• Enhancing a BEV with the addition of a FC can significantly increase the vehicles range; – However this comes at the cost of increased CO2

emissions.

• If future target cost reductions of 1/3rd for batteries and 1/10th for fuel cells are meet; – A downsized FC-BEV would be highly cost competitive.

• In the near term, acceptance of low-emissions vehicles depends on the consumers willingness to pay more and/or change their driving behaviour.

36

Future Outlook: • Battery Electric and Fuel Cell vehicle technologies will

converge.

• The optimum combination of Battery+Fuel Cell will depend on driving behavior;

Battery FC

Higher Efficiency

Higher Energy

Density

Mostly Shorter Trips Mostly Longer Trips

Thank you; Eric Mazzi, P.Eng., Ph.D. (Project Sponsor) 37

Documents

CEEN 596 Project Presentation - Rene Lipp