a fuel efficiency horizon for u.s. automobiles
DESCRIPTION
Presented at the SAE Government-Industry Meeting, Washington, DC, May 2011TRANSCRIPT
A Fuel Efficiency Horizon for Grid-Free Automobiles
John M. DeCiccoEnergy Institute / School of Natural Resources and
Environment, University of Michigan
Government-Industry MeetingWashington, DC • January 26, 2011
2
Study Goals Adopt a problem-embracing perspective
Address not only what can be done to improve vehicle efficiency, but also
What must be done to put the sector on a path that supports the attainment of challenging climate protection targets
Analyze new fleet levels attainable through 2035 Fundamentals-based analysis, 2005 baseline Use transparent assumptions building on previously
published engineering simulation results
Assume success in "revolution by evolution" Ambitious but non-disruptive technology change
(estimates restricted to "grid-free" options) What are the implications of the resulting efficiency
horizon for "revolutionary" alternatives?
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Family Haulers Then and Now
1975 Mercury Marquis
2005 Ford Freestyle
• 6.6L V8, 150 hp• Rudimentary pollution
control• Seat belts• 11 MPG
• 3.0L V6, 203 hp• Ultra-low
emissions• Sophisticated
safety features throughout
• 24 MPG
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Technologies Considered Evolutionary change, efficiency optimized Powertrains (examples):
Gasoline -- turbo DI, w & w/o lean operation; advanced valvetrains including camless
Diesel -- advanced turbo DI, within NOx limits Hybrid -- non-grid-connected Transmission -- dual clutch auto direct, CVT
Platforms: Modest net mass reduction (≈20% on average
over the full 30 year horizon, 2005-2035) Ongoing aero, tire improvements
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Fuel economy and related trends
0.75
1.00
1.25
1.50
1.75
1975 1980 1985 1990 1995 2000 2005 2010
Index 1975=1
New U.S. Light Duty Combined Fleet
Source: U.S. EPA Fuel Economy Trends report 2010
On-road MPG
Horsepower to Weight
Ratio
Test Weight
2.6%/yr 2004-104.4%/yr
1975-87
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Performance Size Fuel economy Index (PSFI)
Source: An & DeCicco, SAE Transactions, Journal of Engines 116: 859-873 (2007)
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Automobile efficiency is best viewed as a matter of design priority Technological progress has been steady
Most technologies have multiple benefits Whether fuel efficiency is gained depends on:
• Design objectives of a given vehicle• Overall mix of vehicles sold (e.g., car vs. truck)
Until recently, most of the prior two decade's technology improvements were applied to enhance power, capacity and other amenities
What path will auto efficiency follow going forward? Net energy/GHG impact is a market outcome It will depend on jointly expressed priorities of
consumers, automakers and policymakers
8
Engine specific power trends
Source: EPA Fuel Economy Trends report; selections from Ward's 10 Best Engines, 2006-10
53 kW/L
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Advanced engines
Now-breaking wave:
Turbocharged, direct- injection (DI) gasoline
GM 3.0L V-6270 hp, 67 kW/L
Audi 2.0L I-4211 hp, 79 kW/L
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MIT simulation results
Source: Kasseris & Heywood, SAE 2007-01-1605
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Technology adoption ratesHistorical data from EPA Fuel Economy Trends report:
Front-wheel drive in new cars Fuel injection in new light vehicles
0%
20%
40%
60%
80%
100%
1970 1980 1990 2000 2010
Sh
are
of
New
LD
Vs
Logistic model:
U(t) = Umax(1 + Ae-bt)-1
Parameter estimates: A = 40 b = 0.68 for Umax = 100%
0%
20%
40%
60%
80%
100%
1970 1980 1990 2000 2010
Sh
are
of
New
Car
s
Logistic model:
U(t) = Umax(1 + Ae-bt)-1
Parameter estimates: A = 55 b = 0.44 for Umax = 87%
These are examples of relatively rapid technology diffusion Other technologies, such as multivalve engines, saw
significantly slower rates of adoption historically
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How rapidly might hybrid electric vehicles (HEVs) see widespread adoption?
13
Quadratic fits to cost estimates
0
2,000
4,000
6,000
8,000
10,000
0 10 20 30 40 50Consumption Decrease (GJ/yr)
RP
E I
nc
rea
se
(2
01
0$
)
0
2,000
4,000
6,000
8,000
10,000
0 10 20 30 40 50 60 70Consumption decrease (GJ/yr)
RP
E In
crea
se (
2010
$)
Cars
Light Trucks
Near-term estimates as used to support the California proposal, similar to those used for the MY 2011-16 CAFE rule
Long-term estimates as used in the MIT "On the Road in 2035" study
Adjustments: assume lower costs of mass reduction based on Lotus (2010) study, but phased in gradually for 20% mass savings at zero net cost by 2035.
Declining costs over time are modeled as rightward shift of quadratic curves.
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Resulting cost curvesNew fleet average Retail Price Equivalent (RPE) estimates
15
Fleetwide costs and benefits
0
2,000
4,000
6,000
8,000
10,000 2
010$
2020 2025 2030 2035
Model Year
Costs
Benefits
Present value (per-vehicle average)for efficiency horizons trajectory
Lifetime benefits were calculated assuming: 7% discount rate 10% rebound effect $2.50 /gal fuel (pre-tax) $0.18 /gal oil externality $22 /tonne CO2 cost
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Efficiency horizon trajectory
1.83 kJ/m (52 MPG) implied by 2025
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0%10%20%30%40%50%60%70%80%90%
0% 20% 40% 60% 80%
Reduction in GHG Emissions
Incr
eas
e in C
ost
GASOLINE
HYBRID
Relative Technology Benefits and Costs
H2 FUEL CELL
PLUG-IN HYBRID
BATTERY
ELECTRIC
Projected cost impacts and GHG reductions for efficiency-
optimized midsize cars in 2035 relative to a 2005 baseline
DIESEL TDIGASOLI
NEGASOLINE TDI
An evolutionary path can carry the U.S. automobile fleet quite far with manageable costs for technology and minimal risks for customer acceptance.
Baseline Vehicle
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Caution on "revolutionary alternatives" Basic characteristics of liquid hydrocarbons
The properties that make them so valuable for transportation also make them easy themselves to transport, and therefore fungible, globally traded commodities
Consider Resource diversity need not entail fuel product diversity Low carbon need not mean no carbon The road less hyped: creative chemical engineering plus
carbon separation and sequestration
Is the quest to "get off fossil fuels" but a fool's errand that wastes resources without solving real problems? "The Stone Age didn't end for lack of stone …"
(Ahmed Zaki Yamani, Saudi oil minister 1962-86) The end of the Stone Age was not centrally planned! That is not to say that public policy doesn't have a critical
role, but rather that its goals must be carefully defined
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Vehicle standards in context Important to recall that vehicle efficiency is just one
leg of the "three legged stool": Travel demand (VMT) Vehicle consumption rate (inverse of MPG) Characteristics of the fuel system (petroleum & carbon
intensity)
Current energy & climate policies are incomplete, if not indeed imbalanced
Can we change the fuel by changing the vehicle? Key fuel concerns going forward are systems issues, not
reducible to fuel properties Automakers can address vehicle efficiency, but not emissions
from fuel supply system (whether for liquids, electricity or hydrogen)
Innovation is wonderful, but subsidization is questionable
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Conclusions A horizon of 3x efficiency relative to recent U.S. new
fleet levels can be reached, given: Sufficient lead time (~2035; implied rate 3.7% per year) Plus major and ongoing changes in market priorities Following such a trajectory implies a 52 mpg (157 g/mi)
new LDV fleet by 2025, without EVs or PHEVs
Efficiency improvement appears more cost effective than alternative fuel and vehicle (AFV*) options at present Nevertheless, improving vehicle efficiency is just one
part of a sound energy-climate strategy for transportation
A complete strategy will also require measures to• Motivate efficient transportation planning, land use and
infrastructure investments • Manage net GHG emissions in fuel supply
*AFV refers to fuels or energy carriers other than liquid hydrocarbons
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Thank you!
The report, A Fuel Efficiency Horizon for U.S. Automobiles, can be downloaded from the University of Michigan Deep Blue archive at: http://hdl.handle.net/2027.42/78178
For further information, contact:
John M. DeCicco, Ph.D. Faculty Fellow • Michigan Memorial Phoenix Energy Institute (MMPEI) Senior Lecturer • School of Natural Resources and Environment (SNRE) University of Michigan, Ann Arboremail: [email protected] http://www.snre.umich.edu/profile/decicco http://www.energy.umich.edu/res/fac_10/fac_DeCiccoJ10.html