ceen 596 project presentation - rene lipp
TRANSCRIPT
The Costs and Benefits of a Fuel Cell Enhanced Battery Electric Vehicle
CEEN-596 Final Project
By René Lipp
December 12, 2011
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
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
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
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
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
Vehicle Power Demand Curve
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
Includes transmission and motor efficiencies but not energy storage efficiency
19
Vehicle Power Demand Curve
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
Includes transmission and motor efficiencies but not energy storage efficiency
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
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 [kW] / Battery [kWh]
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
0/30-BEV 25/15-FCBEV
CO
2 E
mis
sio
ns
[g/k
m]
Fuel Cell [kW] / Battery [kWh]
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
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
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
$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
0/30-BEV 25/15-FCBEV
Incr
em
en
tal V
eh
icle
Co
st
Fuel Cell [kW] / Battery [kWh]
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
Fuel Cell [kW] / Battery [kWh]
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