alfred piggott 2012.05.31 compressed air vehicle comparison diesel electric gasoline thermal
DESCRIPTION
Compares Compressed Air Vehicles with Battery Electric, Gasoline and Diesel energy conversion using key metrics. Metrics are serial efficiency, volumetric energy density of the fuel (MJ/M3), cost per Kilowatt output ($/kW), and mass of CO2 per energy output (kg/kWh)TRANSCRIPT
Research ObjectivesMEEM4200
Group 1
Are compressed air
powered vehicles a
viable automotive propulsion alternative?
How far can you go and how
hard is it to refuel a
compressed air vehicle?
What is the fossil fuel-to-motor output
serial efficiency for a
compressed air vehicle?
Are compressed air vehicles a
“green” propulsion
technology?
How do compressed air
vehicles compare in cost
to other vehicles?
Car photo: http://www.popularmechanics.com/cars/news/preview-concept/4251491
1
Seth BrezeeStephen BuckleyAlfred PiggottAndrew Schorfhaar
12/10/2010
Compressed Air Vehicle - Basics
Image Source: http://www.mdi.lu/english http://zeropollutionmotors.us/, http://www.google.com/patents
,
Vehicle
Energy Storage
Pneumatic Motor
Compressed Air Tanks
2
Compressed Air Vehicle – Analysis
V
P
n=1Isothermal
1<n<k
n=k
IsentropicP2
P1
V
P
n=1Isothermal
1<n<k
n=k
IsentropicP2
P1
V
P
n=1Isothermal
1<n<k
n=k
IsentropicP2
P1
V
P
n=1Isothermal
1<n<k
n=k
IsentropicP2
P1
1
22
1
21 ln
p
pV
p
ppWisothermal
Time
p
pV
p
pp
Powerisothermal
1
22
1
21 ln
48.0InputPowerElectric
OutputPowerAircompressor
PVU2
3
Isothermal Compression and Expansion
Compressed Air Internal Energy
Serial Efficiency
Isothermal Power
31.0InputPowerAirCompressed
OutputPowerShaftMotorPneumatic
35.0AveragePlantPower
935.0GridElectric
0487.0)31.0)(48.0)(935.0)(35.0( serial
2211 VpVp
Image Source: <http://www.me.mtu.edu/~jstallen/courses/MEEM4200>
UWQ
First Law Air Compression
3
Battery Electric Vehicle - Basics
Propelled by:
Nissan Leaf
Charging Station(source www.GE.com)
Lithium Ion BatteryCapacity = 24 kWh
Motor Controller 80 kW Motor
(source www.nissanusa.com)
4Fuel Economy Label
(source www.nytimes.com)
Range = 73 miles
Battery Electric Vehicle - Analysis
Electric Power Plant (0.35)
Transmission Grid (0.935)
Charging Station (0.86)
AC/DC Converter (0.90)
Battery Charge Efficiency (0.99)
Battery Storage Efficiency (1.0)
Battery Discharge
Efficiency (0.99)
Motor Controller (0.96)
Electric Motor (0.804)
Fossil Fuel
Power Out
Serial (0.35)(0.935)(0.86)(1.0)(0.99)(0.90)(0.99)(0.96)(0.804) Efficiency = 0.192
Carbon 0.608 kg/kWh (CO2 for 1 kWh at plant) Footprint 0.192 (serial efficiency)
= 3.17 kg/kWh5
Gasoline Powered Vehicle - Analysis
Serial Efficiency of Gasoline Power:
Fossil Fuel Engine out = 18%
A gasoline powered vehicle that was rated for around 30MPG was used for comparison.
Gasoline Engine Cost in Dollars 4000Technology Cost 28.25
Vehicle Power Output in kW 141.55
dollars dollars
kW kW
Technology Cost for Gasoline Power:
Vehicle Cost for Gasoline Power:o An average sedan in the market, for example, a Chevrolet Malibu
has a base price of $22,000.o The Malibu is rated at 23 MPG in town and 34MPG on the
Highway while powered by a stock 193 HP 2.4 liter 4-Cylinder engine.
1. "Advanced Technologies & Energy Efficiency." Fuel Economy. Web. 05 Dec. 2010. <http://www.fueleconomy.gov/feg/atv.shtml>.2. "2011 Chevy Malibu Sedan Specs and Features | Chevrolet." 2011 Cars, SUVs, Trucks, Crossovers & Vans | Chevrolet. Web. 09 Dec. 2010.
<http://www.chevrolet.com/malibu/features-specs/>. 6
Gasoline Powered Vehicle Cont…
44Carbon Content 2,241 0.99 8.8
12
grams amu kg
gallon amu gallon
8.8 8.8
Carbon Footprint 1.74
. 33.7 0.15
kg kggallon gallon kg
kWhkWh kWhEFF
gallon gallon
Carbon Footprint for Gasoline Power:
Energy Density of Gasoline:
66 3 3 3
1 1Energy Density 122 10 32, 230
10 3.7854 10
Joules MJ gallon MJx
gallon J x m m
Vehicle Range :
Vehicle Range 30 16 480miles gallons miles
gallon tank tank
7
Diesel Powered Vehicle - Analysis
Diesel Serial Efficiency Fossil Fuel-to-motor output:
Motor Efficiency = 40% = 0.40
Diesel Conversion Technology Cost
Cost = (Diesel Engine Cost)/(Engine Output)Calculation: $5000 / 126.8 kW (2010 Jetta TDI) = $39.42/ kW
Diesel Vehicle Cost Comparison
• The average diesel vehicle costs about $1000 more than a comparable petrol model.
- 2010 VW Jetta TDI (Diesel) starts at $22,000, 2010 VW Jetta (petrol) starts at $20,000-2010 VW Jetta TDI gets 40/22 mpg (hwy/city), gas model gets 30/20 mpg (hwy/city)
1. Way, By The. "2010 Volkswagen Jetta TDI - Top Speed." Web. 10 Dec. 2010. <http://www.topspeed.com/cars/volkswagen/2010-volkswagen-jetta-tdi-ar75332.html>2. "2010 VW Jetta TDI Buyers Guide Myturbodiesel.com - VW TDI Forum, Web. 10 Dec. 2010. <http://www.myturbodiesel.com/1000q/a5/2009-2010-VW-Jetta-TDI-checklist.htm>3. "Gas Mileage of 2010 Volkswagen Jetta." Fuel Economy. Web. 10 Dec. 2010. <http://www.fueleconomy.gov/feg/bymodel/2010_Volkswagen_Jetta.shtml>
8
Diesel Powered Vehicle - Analysis
Carbon Footprint for Diesel Energy (Using Serial Efficiency for between Refinement and Motor Output.)
Diesel Carbon Content = 2.7 kg/liter, Diesel Energy Content = 10.1 kW-h /literSerial Efficiency = 40.0 %
Carbon Footprint (kg/ kW-h) = (Carbon Content) / (Energy Content * Serial Efficiency)Calculation: 2.7/ (10.1*0.40) = 1.7 kg/ kW-h
Diesel Energy Density (Calculated for diesel with a density of 0.84 g/ ml)
Diesel Energy Content = 36.4 MJ/ liter; 1 liter = 1000 cm^3; 1 m^3 = 1,000,000 cm^3Calculation: 36.4 * 100^3 / 1000 = 36.4 * 10^3 MJ/ m^3
Diesel Vehicle Range
As stated previously, the gas mileage of the 2010 VW Jetta TDI is 40 mpg highway. A standard tank size for a mid to small size car is between 12 and 15 gallons. This would put the range of the Jetta between 480 and 600 miles (504 used for comparison).
1. Lucy, By. "The Pros and Cons of Going Diesel." Mortgage Rates Credit Cards Refinance Home CD Rates by Bankrate.com.2. US Environmental Protection Agency. Web. 09 Dec. 2010. http://www.epa.gov/otaq/models/ngm/may04/crc0304c.pdf3. Lucy, By. "The Pros and Cons of Going Diesel." Mortgage Rates Credit Cards Refinance Home CD Rates by Bankrate.com. Web. 6. 09 Dec. 2010. http://www.bankrate.com/brm/news/auto/20030804a1.asp4. Web. 09 Dec. 2010. http://www.evworld.com/library/energy_numbers.pdf 9
Summary – Energy Efficiency
Diesel
Gasoline
Battery Electric
Compressed Air
0.000.050.100.150.200.250.300.350.40
0.40
0.15
0.19
0.05
Efficiency (Fossil Fuel to Motor Out)
Conclusion: Compressed air vehicles are on the low end of efficiency, diesel is unmatched for converting fossil fuel to
usable motor power 10
Summary – Carbon Emissions
For Battery and Air: C.F. = (0.608 kg / kW-hr) (1/serial efficiency)For Gasoline: C.F. = (0.261 kg / kW-hr) (1/serial efficiency)For Diesel: C.F. = (0.667 kg / kW-hr) (1/serial efficiency)
Diesel
Gasoline
Battery Electric
Compressed Air
0 2 4 6 8 10 12 14
1.7
1.7
3.2
12.5
Carbon Footprint (kg / KWh)
Conclusion: Compressed air vehicles produce lots of CO2 when powered by fossil fueled power plants 11
Summary – Energy Volumetric Density
Diesel
Gasoline
Battery Electric
Compressed Air
0 10,000 20,000 30,000 40,000
36,400
32,230
1,080
47
Energy Density (MJ/meter cubed)
Conclusion: Compressed air energy storage systems are not able to store a great deal of energy, limiting their range.
12
Summary – Technology Cost Analysis
Diesel
Gasoline
Battery Electric
Compressed Air
$0 $20
$40
$60
$80
$100
$120
$140
$160
$180
$39
$28
$62
$167
Technology Cost (Dollars/kW)
Conclusion: Compressed air vehicles are on the high end in terms of cost to produce power due to low power output.
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Summary – Cost and Range
Conclusion: Compressed air and electric vehicles will create “range anxiety” condition with customers, they will be worried about returning home before their energy reserve is depleted.
Compressed Air
Battery Electric
Gasoline Diesel
Vehicle Cost $4600-$17,800 $32,780 $22,000 $20,000
Overall Vehicle Cost Summary:
Compressed Air
Battery Electric
Gasoline Diesel
Vehicle Range 29 miles 73 miles 480 miles 504 miles
Vehicle Range Summary:
14
Technology Comparison – Customer Focus
Customer Metric
Compressed Air
Battery Electric Gasoline Diesel
Co2 Emissions? Relocates CO2 emissions, but creates more
Relocates CO2 emissions, but creates more
Emits CO2 at place of operation
Emits CO2 at place of operation
Easy to Refuel? No, need air compressor, large power draw
No, takes too long, expensive charger required
Refuel quickly with large refueling infrastructure
Refuel quickly with large refueling infrastructure
Costly to Own? Not likely, but exact figures unknown
Expensive to buy, lower cost to operate
Inexpensive to buy, costly to operate
Slightly more costly to buy, same as gas to operate
Future Promise? May be charged at home, reduce dependence on oil
May be charged at home, reduce dependence on oil
Most convenient to own, limited future for low cost oil
Most efficient to own, limited future for low cost oil
Future Hurdles? Must improve efficiency, on board energy storage, and infrastructure
Efficiency improving but must still increase on board storage and charging infrastructure
Fuel will continue to increase in cost, raising operating costs
Fuel will continue to increase in cost, but can be modified to use bio fuels
Green Factor High, clean power if charged by renewable sources
High, clean power if charged by renewable sources
Low, bad reputation for increasing air pollution
Low, bad reputation for increasing air pollution, fine particles
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Conclusions
Compressed air vehicles are on the low end of efficiency, cannot store enough energy, and have serious infrastructure
issues.
Diesel powered vehicles have the best efficiency overall
Battery electric vehicle green energy claims should be challenged when they are powered by fossil fuel power plants
Both air and electric powered vehicles require a refueling infrastructure to be viable
Gasoline and Diesel vehicles will continue to be popular for their ability to refuel quickly and carry a massive amount of
chemical energy
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