Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record
ECONOMIC ASSESSMENT OF ELECTRIC- DRIVE VEHICLE OPERATION
IN CALIFORNIA AND THE UNITED STATES
Jeffrey R. Lidicker, M. A., M. S. ( corresponding author)
Transportation Sustainability Research Center
University of California, Berkeley
1301 S. 46th Street, Richmond Field Station ( RFS), Bldg. 190, Richmond, CA 94804
( 510) 295- 4411; 510- 665- 2183 ( F)
jlidicker@ tsrc. berkeley. edu
Timothy E. Lipman, Ph. D.
Transportation Sustainability Research Center
University of California, Berkeley
2614 Dwight Way, MC 1782, Berkeley, CA 94720- 1782
510- 642- 4501 ( O); 510- 642- 5483 ( F)
Email: telipman@ tsrc. berkeley. edu
Susan A. Shaheen, Ph. D.
Honda Distinguished Scholar in Transportation, University of California, Davis &
Transportation Sustainability Research Center
University of California, Berkeley
1301 S. 46th Street, Richmond Field Station ( RFS), Bldg. 190, Richmond, CA 94804
( 510) 665- 3483; 510- 665- 2183 ( F)
sashaheen@ tsrc. berkeley. edu
March 15, 2010
Words: 5,300, Tables: 2, and Figures: 5
# TRB10- 3667
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
1
ECONOMIC ASSESSMENT OF ELECTRIC- DRIVE VEHICLE OPERATION
IN CALIFORNIA AND THE UNITED STATES
ABSTRACT
This study examines the relative economics of electric vehicle operation in the context of current
electricity rates in specific utility service territories. The authors examined 14 utility territories
offering electric vehicle ( EV) rates, focusing on California but also including other regions of the
United States. The consumer costs of EV charging were examined in comparison with gasoline
price data, geographic location, and during three highly variable gasoline price periods of July
2008, January 2009, and July 2009. In a switch from a conventional 23 mile per gallon ( 10.2
liters/ 100 kilometers) vehicle to a 300 watt- hours/ mile electric vehicle driven 10,000 miles
( 16,100 km) per year, the study finds that savings in fuel costs ranged from approximately
$ 100US to $ 1,800US annually, with considerable geographic variation and with higher- end
values mostly in Summer 2008 when gasoline prices were relatively high. Charging off- peak
instead of during peak periods saves an average of only a few hundred dollars US per year,
rendering the incentive to charge off- peak a relatively small one except perhaps during some
summer months when the on- peak prices are especially high. Gasoline price variances have a
larger effect and switching from a low fuel economy conventional vehicle to the reference EV
( compared with a switch from an already efficient vehicle) presents the highest savings level.
The West and Midwest are generally the most favorable regions for EV economics, when EV
charging rates and gasoline prices are considered together.
Key Words: electric vehicle, electricity utility, time- of- day rate, plug- in hybrid, operational cost
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
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INTRODUCTION
This study examines the extent to which specific utility EV electricity rates, in combination with
fluctuating local gasoline prices, can be shown to provide vehicle operational economic benefits
of switching from conventional to electric vehicles ( EVs). The context for the study is the
resurging interest in EVs, including plug- in hybrid electric vehicles ( PHEVs) and pure battery
electric vehicles ( BEVs). Several established and new- entry automakers have now announced
their intent to commercialize these vehicles in the 2010 to 2012 timeframe and in a few cases
have already done so.
The main goal of this study is to gain consumer market and policy insights related to the
latest electricity rates in California and across the United States ( U. S.) that have been developed
for EV recharging. At present, there are significant other purchase incentives for consumers to
switch to electric- drive vehicles, including a major federal program that would save consumers
up to $ 7,500US per “ new qualified plug- in electric drive vehicle” through a tax credit that runs
through the end of 2014 ( 1). There also are various state- level programs such as the California
Fueling Alternatives Rebate Program whose first phase just ended, which offered up to
$ 5,000US for qualified electric and other alternative fuel vehicles for a few years ( 2). These
programs were put in place to help to encourage the early commercialization of EVs for their
environmental and energy- use benefits, but they are not expected to last in the longer term when
relative EV costs to consumers are expected to have declined.
Previous studies of the overall economics of PHEVs have found that reducing the cost of
PHEV batteries is critical to their ability to achieve cost- effective greenhouse gas ( GHG)
reductions compared with other strategies. There also are important trade- offs related to vehicle
design, where larger capacity battery PHEVs will have more expensive battery packs in an
absolute sense but lower costs per kilowatt- hour ( kWh) when expressed in those terms ( 3). With
regard to cost effectiveness in reducing GHGs, one study found that with current battery prices,
PHEVs require very low- carbon electricity to be cost effective or significant government
subsidies to lower consumer costs ( 4). The study found that battery costs below about $ 500US
per kWh can lead to reasonably cost- effective PHEVs for GHG abatement, depending on the
carbon intensity of the electricity generation and the value of the carbon reduction per ton. The
study further found that if PHEV battery costs could reach $ 200US per kWh, then PHEVs could
be cost effective for consumers and society even absent the consideration of GHG benefits and
the generation method ( 4).
Another key issue is the EV design, particularly for PHEVs where vehicles can be
designed as either “ series drive/ charge depleting” or “ power split/ blended mode” hybrids and
with varying amounts of battery capacity in each case. The distinction between series drive and
blended mode relates to the extent to which the vehicle can purely rely on the electric drive
system for propulsion. Series drive hybrids only use the electric motor for direct propulsion,
where the gasoline engine runs a generator to recharge the battery, while blended mode hybrids
use the electric drive to supplement what is typically a larger gasoline engine propulsion system
and where both are connected to the vehicle transmission in a more conventional hybrid vehicle
configuration. Charge- depleting hybrids offer the ability to completely shut the gasoline engine
off for significant time periods, especially at high states of battery charge, thus running in “ pure
EV mode.” The amount of battery capacity included in a PHEV is often referred to in terms of
how many miles of all- electric range ( AER) is available, which is a theoretical concept for
blended- mode hybrids ( e. g., “ PHEV- 20” for a PHEV with 20 miles/ 32 kilometers ( km) of AER
and “ PHEV- 40” for 40 miles/ 64 km of AER).
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
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With regard to EV fuel costs, many electric utilities offer attractive electricity rates or
off- peak charging at nighttime hours, with what are called “ time- of- use” ( TOU) rates. EV
owners who install a separate meter for their vehicle can qualify for better rates, offering
considerable savings over the rates that often would apply if the EV charging was billed through
the regular household meter and the regular residential rate tariff. This is because many utilities
have reverse- tiered billing, where the power cost to residential consumers goes up in steps with
higher monthly usage rates. Other incentives for EVs and alternative- fuel vehicles are based on
other aspects of vehicle ownership, such as in California where very clean fuel vehicle drivers
can get carpool lane stickers.
Thus, some major utility companies offer special EV rates, which may or may not include
TOU rates. This paper investigates the annual savings gained or lost by drivers who make use of
special EV rates or the time- of- day rates where available, the variation in the rates around the
country, and the extent to which these variable rates help or hurt the private economics of EV
ownership. As much of the electricity supply is unused during off- peak hours ( 5, 6), providing
incentives for EV charging during these times could help the economics of utility companies by
making better and more efficient use of the utility grid through higher realized capacity factors,
reducing the overall costs of delivering power to consumers.
This paper examines in detail variations in EV operating costs around California and the
U. S., focusing on differences in electricity and gasoline fuel expenses and especially analyzing
the latest utility electricity rate schedules in detail. As some of the utility TOU rate schedules are
rather complex, involving TOU, weekly, and seasonal characteristics as well as a tiered structure
( where rates go up in tiers by the amount used per month), the authors developed a detailed
spreadsheet analysis tool to calculate annual fuel costs for electricity and savings compared with
gasoline costs. Following the methodological discussion and study results, the authors examine
notable policy implications in the results section and provide a summary conclusion.
METHODOLOGY
This section describes the data collected, the assumptions used, and the analysis approach. The
dataset of utility EV charging rates does not represent a random sample but more a
representation of large population regions where residential EV electricity rates may be
available. Thus, the results are illustrative of what EV drivers in California and different parts of
the country may expect, but they are only comprehensive in California.
Electric Utility Rate and Gasoline Price Data
Rates from utility companies found to offer special EV charging rates or TOU pricing options
were collected for May 2009. Some companies represented a whole state or many states, while
others only covered a metropolitan area within a state. Further, some companies had multiple
sub- companies where each may have their own rates or sub- regions within their jurisdiction with
varying rates. Parent utility company service territories numbered 14, with sub- companies, sub-regions,
and service differences providing 42 final rate structures ( see Table 1). Peak and off-peak
rates were offered by 20 ( 49%) of the utilities. An additional medium- peak rate was offered
by 11 ( 27%) additional utilities. Only four ( 10%) of the utilities had a flat rate scheme, while six
( 15%) offered a tiered rate scheme ( based on use, not time- of- day). One utility has peak and off-peak
rates and a tiered scheme with increasing usage ( Pacific Gas & Electric Company in
Northern California).
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
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Statewide and metropolitan area average prices for regular octane gasoline were obtained
from the American Automobile Association ( AAA) ( 7). An examination of additional regional
gasoline price using federal Energy Information Administration data confirms that both low and
high national prices are reflected in this study by virtue of the inclusion of Texas and Colorado
for some of the lowest prices in the country and California and Hawaii for the highest prices ( 8).
Additional Assumptions and Underlying Analysis
Most utility companies have electric rates that varied by season of the year. Driving patterns can
also vary somewhat seasonally, but for purposes of this analysis the authors did not assume
seasonal variations in driving distances.
Also, while outdoor temperatures often require heating or cooling within a vehicle, the
base case analyzed here assumes that EV energy use is constant, with an overall average of 300
watt- hours ( Wh) per mile/ km from the wall plug ( whether a battery EV or a PHEV for either
actual or theoretical “ AER miles”). This value typically ranges from about 200 Wh/ mi
( 124Wh/ km) for small electric vehicles up to 400 Wh/ mile ( 249Wh/ km) for larger vehicles and
also depends on vehicle design. For example, for the extensively tested Toyota RAV4 “ small
SUV” type of EV, using its test mileage for U. S. Environmental Protection Agency ( EPA)
certification purposes and the “ 55/ 45” city/ highway mileage split yields 301 Wh/ mi ( 187
Wh/ km), based on the reported 270 Wh/ mi ( 168 Wh/ km) city and 340 Wh/ mi ( 211 Wh/ km)
highway ( 9).
More modern EVs coming on the market in 2010 from Nissan and Mitsubishi, as well as
PHEVs from Toyota, GM, Ford, and other manufacturers in the 2010 to 2012 timeframe are
likely to exhibit higher energy efficiency than the now several years old RAV4 EV from Toyota
due to battery and other recent improvements. Hence, an assumption of 300 Wh/ mi or 190
Wh/ km⎯ either actual in a charge- depleting hybrid or “ virtual” for a blended mode hybrid⎯ for
a near- term EV sedan or small SUV is reasonably conservative for this analysis, but it is also
intended to account for charging losses to be a value of electricity used from the wall plug. More
efficient EVs will exhibit more savings than this paper presents.
With regard to a comparison of conventional vehicle fuel economy, an analysis of the
federal Bureau of Transportation Statistics national averages for U. S. passenger vehicles ( cars
and light trucks) currently in use produced an estimate of 23 miles per gallon ( mpg) ( or 10.2
liters/ 100 km) ( 10). The authors note that over time this number will increase due to recent
regulations requiring fleet averages of 35 mpg ( 6.7 liters/ 100km) by 2020. Hence, further
looking studies of EVs relative to conventional vehicles will have to consider this changing
landscape of vehicle fuel economy in their consideration of EV operational economics relative to
conventional vehicles. Of course, as with EV energy use, this assumption can be easily varied to
examine more specific cases.
The estimated savings per year is further based on traveling an assumed 10,000 electric
miles ( 16,100 km) per year. This number implies either a pure BEV or a PHEV with significant
AER of at least 40 miles ( 64 km) and somewhat higher overall miles ( km) driven than 10,000
( 16,100) for PHEV drivers. One recent study of the interaction between PHEV design and
driving patterns suggests that about 50% of drivers drive less than 40 miles ( 64 km) per day on
average, and 70 to 80% of drivers drive less than 50 miles ( 80 km) ( 11). This means that the
10,000 miles ( 16,100 km per year) of “ electric mile” driving assumed in this study could be
captured either by a BEV driver driving 10,000 miles ( 16,100 km) per year, a PHEV- 40 driver
driving approximately 20,000 miles ( 32,200 km) per year, or supplementing off- peak charging
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
5
with some peak charging ( 12). Many PHEV- 40 or PHEV- 50 drivers who did some morning
recharging at their work location could easily capture 80 to 90% of their total driving with
electric fuel. This may or may not be the most economical overall vehicle solution due to higher
battery costs for PHEV- 40 and PHEV- 50 vehicles compared with PHEV- 10 or PHEV- 20
vehicles, but it does allow for higher operational cost savings in terms of electricity versus
gasoline.
For comparison purposes, annual fuel- cost savings are estimated for 100% off- peak
charging, 100% peak charging, and each increment of 10% in between. A linear combination of
the off- peak and peak rates was used for the incremental estimates. Some electric utilities had
off- peak, medium- peak, and peak rates. For those companies, the medium- peak rate was ignored.
Future analysis based on more detailed assessment of driving and charging patterns would allow
for these rate periods to be considered more carefully in scenarios of vehicle use for specific
drivers; again, the current study is meant to be illustrative of the variation in electricity charging
costs by the amount of charging done off- peak.
Costs of traveling 10,000 miles ( 16,100 km) were calculated for both an EV and a
replaced gasoline vehicle that averaged 23 mpg ( 10.2 liters/ 100km). For purposes of this
comparison, an average gasoline price was used to represent an example year. The savings is the
difference between the two costs and is based only on energy consumption. Additional savings
from lack of smog tests, oil changes, higher maintenance costs associated with combustion
engines and environmental or GHG emission savings were not included. To gain further policy
insights, sensitivity analyses were conducted for the gasoline price and the average fuel economy
of the comparison vehicle.
Data processing and analysis was done in Microsoft Excel 2004 and 2008 ( Seattle, WA),
with the three- dimensional plots rendered in MatLab version r2006b by The MathWorks, Inc.
( Natick, MA).
RESULTS
The annual operational savings figures for the three gasoline price periods analyzed in six- month
intervals cover a considerable range of values ( see Table 1). For the highest gasoline priced
period ( July, 2008), the annual savings for a driver who drives 10,000 electric drive miles
( 16,100 km) per year instead of a vehicle with the national average of 23 mpg ( 10.2
liters/ 100km) is an average of $ 1,447US. The highest annual savings around the U. S. for this
gasoline price period is approximately $ 1,800US and the lowest is $ 1,000US. Lower gasoline
prices imply considerably lower savings; for example, in one case when gasoline prices were at
their lowest ( January 2009) the annual savings dropped as far as $ 100US.
The effect of 100% peak versus 100% off- peak charging is shown in Figure 1 where the
difference in annual savings is estimated ( for gasoline prices at their historic high of July 2008).
Notice that the difference between peak and off- peak charging savings has a maximum of just
over $ 400 per year or an average of less than $ 1 per day, offering little incentive for drivers to
charge off- peak. The authors note that this may have serious policy and GHG emission
implications to EV use with current pricing schemes. The relatively weak price signal for
consumers to charge off- peak may add to demands on the utility grid during peak periods instead
of maximizing the use of surplus electricity supply during off- peak periods. Since additional
peak period electricity supplies are often generated by less desirable fuels, particularly in some
parts of the country, this could have significant implications for the overall GHG emission
reductions and other environmental benefits that EVs can offer ( 13).
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To see how other factors drive more dramatic changes in the savings, refer to the three-dimensional
Figures 2( a) and ( b). Figure 2( a) shows how changes in gasoline prices have a much
more dramatic effect on savings amounts than does off- peak or peak charging. We note that a
gasoline tax in increments of $ 0.50US per gallon would each increase annual savings by more
than $ 200US.
Figure 2( b) demonstrates that EV operational savings are exponential with respect to the
fuel economy of the substituted vehicle as expressed in mpg. This is partly due to the assumption
that any gasoline vehicle, regardless of fuel economy, is being replaced with an EV that uses 300
Wh/ mi ( 190 Wh/ km) for “ electric miles” driven. However as the variation in results to
conventional vehicle fuel economy shows, these findings are consistent with other studies that
note that replacing an already high fuel economy vehicle with a PHEV is less beneficial ( with
respect to energy and GHG emissions) than replacing an SUV with a PHEV- SUV or even better,
replacing an SUV with a smaller EV ( 4). Also of interest is the fact that when a high mileage
conventional vehicle is compared with an electric vehicle that is charged on- peak, there is
virtually no annual savings. Similarly, switching from a high fuel economy HEV to a PHEV or
EV may offer limited benefit.
Geographic Analysis
The authors gathered gasoline prices and subsequent annual operational cost savings amounts
were then located on a map of the U. S. This was done for three different dates, each six months
apart. The period examined in 2008 to 2009 provided an interesting range of variation with
moderate gasoline prices in July 2009, low prices in January 2009, and very high prices in July
2008. It is historically unusual that these extremes are all represented in a one- year period; this
incidentally underscores the volatility in the global oil market and the relative stability of
electricity prices in comparison. The estimated average gasoline prices used in the study appear
in Table 2. Note that several utility company sub- regions had the same estimated gasoline price
( such as Hawaii) and are therefore listed only by the parent company.
To get a sense of regional differences in operating costs, the utility and gasoline price
regions studied were located on maps of the U. S. and results were plotted on the maps. The maps
for each of the three time periods appear in Figures 3, 4( a), and 4( b). Colored circles ( textured to
be discernable in black and white) represent approximate locations of utility companies but do
not represent the magnitude of the jurisdictions. Some circles represent entire states, while others
only a city. However, the goal is to show the relative economic climate for EV adoption in
various parts of the country. Note that the utility companies that the authors surveyed in the
Northeast and Texas present an economic climate less suited for savings from switching to EVs
than the West Coast or the Midwest. It must be cautioned that these observations do not
represent a comprehensive or random sample of utilities and therefore do not necessarily provide
inference for other utility companies not included in this study or for the U. S. in general.
The first map in Figure 3 shows the situation last year when gasoline prices were at their
peak ( July 2009). EV operational economics during that period are found to be most favorable in
the West and Upper Midwest, where annual fuel cost savings of over $ 1,500US per year are
possible. Values in the Northeast typically range from $ 1,000 to $ 1,500US per year and from
$ 1,250 to $ 1,500US in other parts of the country.
Six months later, in January 2009, gasoline prices were much lower. The relative annual
savings are shown in Figure 4( a). Note the scale for what constitutes red, yellow, or green ( and
the textured patterns) are different for all three maps and thus the color or texture codes are not
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
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comparable across maps. Note the same basic trends are apparent in Figure 4( a) as in Figure 3.
The most recent gasoline prices and their associated EV savings appear in Figure 4( b),
representing another six months later ( July 2009). Given current prices, only the West Coast and
Hawaii remain particularly hospitable to EV operational economics, with annual fuel cost
savings of around $ 1,000US per year.
Study Limitations
This study is relatively narrow in scope, focusing on the difference between fuel costs between
EVs and comparison vehicles in different utility service territories. It does not take a broader
lifecycle approach as in previous studies that include vehicle capital costs, battery capital costs,
and the full range of operating costs⎯ as in Delucchi and Lipman, for example ( 14). Rather this
study is meant to contribute to better utility rate understanding and inputs to those study types
and to expand over time to become a broader vehicle operating cost assessment model that
includes additional aspects of operating cost differences of new vehicle types.
The authors also note that the utility companies used in this study do not constitute a
random sample and thus the inference to other utilities is limited. Also, electricity rates were
assumed to be the same for the time period examined in the study ( mid- 2008 through mid- 2009).
Additionally, no sensitivity analysis was conducted on the energy use ( in watt- hours per mile or
kilometer) of the EVs and the effect on annual fuel cost savings. Additionally, some “ series”
PHEV designs have all electric drive and use the gasoline engine only to recharge the battery
with a generator after the initial battery charge is exhausted. As these vehicles are expected to be
relatively efficient even in this “ charge sustaining” mode, they can be expected to offer
additional gasoline cost savings compared with conventional vehicles that the authors do not
analyze and include here.
Areas for Future Study
This study spurs a host of possible new directions for future research. First, it could be
extended with a more comprehensive analysis of national utility rates and their structures in both
depth and geographic detail. A look into proposed rate structures for companies not currently
offering time- of- day rates also could be included. In addition the study could be expanded to
formally accommodate commercial vehicles and utility rates and/ or heavier vehicles ( e. g.,
delivery vans, airport shuttles, taxis, etc.) with high annual mileage where the potential for
savings is greater. Also, as noted above, the authors would like to integrate a more careful
assessment of driving patterns and how these would impact both BEV and PHEV miles ( km)
driven as “ electric miles ( km),” integrating some of the research being done at Argonne National
Laboratory and the National Renewable Energy Laboratory. Battery costs, performance, and
subsequent implications on EV economics can be additionally folded into the analysis for better
accuracy and more meaningful application. For example, issues raised in the past suggest
estimating annual fuel saved per kWh of battery capacity instead of using a 10,000 mile ( 16,100
km) assumption ( 12). Also, annual savings per dollar cost by type of EV may shed more
information on the advantages and disadvantages of each type of EV. The extent that lithium is
available may also have implications on the types of EVs and their associated savings.
CONCLUSIONS
The authors find that the variation in EV ownership costs versus conventional vehicles across the
U. S. is considerable, ranging typically from several hundred to up to a few thousand U. S. dollars
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
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per year. This base case is for a driver who drives 10,000 electric- drive miles ( 16,100 km) a year
instead of a 23- mpg ( 10.2 liters/ 100km) conventional vehicle. The higher end of that range ( over
$ 1,500US per year) is found only during relatively high gasoline prices, such as those seen
during mid- 2008. The highest savings around the U. S. for this gasoline price period is
approximately $ 1,800US, and the lowest is $ 1,000US. Lower gasoline prices imply considerably
lower savings; for example, when gasoline prices were at their lowest ( January 2009), the least
savings observed was only about $ 100US.
The average savings during the peak gasoline prices of July 2008 is around $ 1,500US per
year suggesting that under a regime where price levels were maintained a PHEV or BEV driven
10,000 miles ( 16,100 km) on electric fuel could “ pay back” ( in “ simple payback” terms) a
$ 6,000US price premium in four years and a $ 9,000US price premium in six years. This is
absent consideration of other economic differences in vehicle operations associated with battery
replacement costs, potential maintenance cost differences, and the higher fuel economy of
PHEVs, than conventional vehicles, when operating on gasoline.
For a simple example, the reader could consider a vehicle with a 16 kWh battery pack
and with a cost of $ 15,000US more than a comparable conventional vehicle but that would
presently qualify for a federal tax credit of $ 7,500US. With a fuel cost savings of $ 1,500US per
year ( again in a relatively high gasoline price regime), this vehicle would then have a simple
payback of about five years. Of course lower gasoline prices⎯ especially the much lower levels
observed in early- 2009⎯ would extend the potential payback times considerably. The authors
note that these payback estimates are consistent with those of other studies, such as ( 11), which
examined various driving cycles and patterns in interaction with PHEV designs, but with a
simpler set of electricity cost and gasoline price assumptions, and that also found PHEV simple
payback times in the four- to six- year range.
A key finding of this study is that gasoline prices have a more dramatic effect on EV
savings than peak or off- peak charging. This is due to the relatively small difference in rates
between the peak and off- peak hours. This suggests that the economic incentive may not be there
at present, even with TOU rates, for consumers to pay much attention to time- of- day charging ( to
the extent some flexibility is possible, for example, in the evening). Increasing the difference
between off- peak and on- peak rates could help to provide stronger incentives for consumers to
charge at off- peak times, thereby reducing potential grid impacts. The sensitivity of annual EV
savings to gasoline prices underscores how policy designed to insure a minimum price for
gasoline would stabilize EV economics.
Another major finding is that if drivers who currently are driving larger and lower fuel
economy vehicles switch to smaller EVs, this would have a particularly strong effect on their
operational cost savings as well as on energy consumption and GHG emissions. This is
consistent with other studies. Certainly, raising the gasoline price as a policy would help further
this agenda. A gas tax in increments of $ 0.50US per gallon ($ 0.13US liter) would increase
annual savings for EV drivers by approximately $ 200US for each increment. More importantly,
higher gas taxes may motivate drivers to purchase and use smaller vehicles than they are
currently, which will have a more dramatic effect on savings, energy consumption, and GHG
emissions.
The authors also find that location- specific gasoline prices have some effect on the
economic viability of switching to an EV. A combination of electricity rates and gasoline prices
give rise to favorable economic climates for EVs in the West and Midwest but not in Texas or
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
9
especially the Northeast. It is also the case that, owing to their efficiency advantages, EV
economics improve with higher usage rates.
Finally, also of note is the fact that a high mileage comparison vehicle when combined
with mostly peak- time charging offers virtually no annual savings. Similarly, switching from a
high fuel economy HEV to a PHEV or EV may offer limited benefits compared with shifts from
lower fuel economy vehicles. This speaks to the need for policy measures designed to provide
consumers with market incentives to shift from purchasing conventional vehicles to PHEVs and
EVs to focus on the relative improvement in fuel efficiency.
ACKNOWLEDGEMENTS
The authors would like to thank and acknowledge the anonymous reviewers who graciously
donated their time, energy, and expertise to significantly improving the paper in both clarity and
content. Thanks also to Dana Goin, Brett Williams, and Samuel Lam of the Transportation
Sustainability Research Center of the University of California, Berkeley for their contributions to
this project. We also thank the California Air Resources Board, and Craig Childers and Elise
Keddie in particular, for providing support under Assembly Bill 1811 for the larger research
project upon which this paper is based. The contents of this paper reflect the views of the authors
and do not necessarily indicate acceptance by the sponsors.
REFERENCES
1. Public Law 111- 5, Sections 1141- 1144, and 26 U. S. Code 30D
2. California Center for Sustainable Energy. Fueling Alternatives: California’s Alternative
Fuel Rebate Program. http:// energycenter. org/ index. php/ incentive- programs/ fueling-alternatives.
Accessed July 2009.
3. Santini, D. Battery Pack Requirements and Targets Validation FY 2009 DOE Vehicle
Technologies Program. U. S. DOE Annual Merit Review, Argonne National Lab, May
21, 2009.
4. Kammen, D. M., S. M. Arons, D. M. Lemoine, and H. Hummel. Cost- Effectiveness of
Greenhouse Gas Emission Reductions from Plug- in Hybrid Electric Vehicles, Chapter
Nine in Sandalow, D. B. ( editor) Plug- In Electric Vehicles: What Role For Washington?,
Brookings Institution Press, Washington, D. C., 2009.
5. Lemoine, D. M., D. M. Kammen, and A. E. Farrell. An innovation and policy agenda for
commercially competitive plug- in hybrid electric vehicles. Eviron. Res. Lett. 2008, Vol.
3, No. 014003, pp. 10.
6. EPRI / NRDC. Environmental Assessment of Plug- In Hybrid Electric Vehicles, Volume
1: Nationwide Greenhouse Gas Emissions, Report No. 1015325, July, 2007.
7. AAA. AAA’s Daily Fuel Gauge Report, July 14th, 2009.
http:// www. fuelgaugereport. com/ sbsavg. html. Accessed July 14th, 2009.
8. Energy Information Administration ( 2009), " Weekly Retail Gasoline
and Diesel Prices," U. S. Department of Energy, Worldwide Web,
http:// tonto. eia. doe. gov/ dnav/ pet/ pet_ pri_ gnd_ dcus_ nus_ w. htm. Accessed November
11th, 2009.
9. Alternative Fuels Data Center. Model Year 2002: Alternative Fuel Vehicles. National
Renewable Energy Laboratory, 2001.
10. Bureau of Transportation Statistics. National Transportation Statistics: Table 4- 23:
Average Fuel Efficiency of U. S. Passenger Cars and Light Trucks. Research and
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
10
Innovative Technology Administration. 2006.
http:// www. bts. gov/ publications/ national_ transportation_ statistics/ html/ table_ 04_ 23. html
. Accessed July 16th, 2009.
11. Moawad, A., G. Singh, S. Hagspiel, M. Fellah, and A. Rousseau, Impact of Real World
Drive Cycles on PHEV Fuel Efficiency and Cost for Different Powertrain and Battery
Characteristics. EVS24 Stavanger, Norway, Argonne National Laboratory, May 13- 16,
2009.
12. Vyas A. D., Santini D. J., and L. R. Johnson. Plug- in Hybrid Electric Vehicles’ Potential
for Petroleum Use Reduction: Issues Involved in Developing Reliable Estimates ( TRB
09- 3009). Transportation Review Board 2009 Annual Meeting CD- ROM, Washington
DC.
13. Argonne National Laboratory. Well- to- Wheels Energy Use and Greenhouse Gas
Emissions Analysis of Plug- in Hybrid Electric Vehicles. ANL/ ESD/ 09- 2, Energy Systems
Division, February 2009.
14. Delucchi, M. A. and T. E. Lipman. An Analysis of the Retail and Lifecycle Cost of
Battery- Powered Electric Vehicles, Transportation Research – Vol. D, No. 6, 2001, pp.
371- 404.
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
11
LIST OF TABLES AND FIGURES
TABLE 1 Electric Utility Company and Savings per Year From EV Use⎯ 10,000 Electric Miles
( 16,000 Km) per Year, 23 MPG ( 10.2 L/ 100km) Comparison Vehicle, 100% Off- Peak Charging
TABLE 2 Electric Utility Regions and Estimated Average Price per Gallon for Gasoline by
Time Period ( AAA Data⎯ U. S. Dollars)
FIGURE 1 Histogram of difference in annual savings ($ US) per year from EV charging peak
versus off- peak for 10,000 electric miles ( 16,000 km) per year, 23 mpg ( 10.2 liters/ 100km)
comparison vehicle, and July 2008 gasoline prices.
FIGURES 2 ( a) and ( b) annual operating cost savings ( US$/ yr) for example utility PG& E for
10,000 electric miles ( 16,100 electric kilometers) per year.
FIGURE 3 Relative annual fuel cost savings from switching to EVs based on estimated gasoline
prices in July 2008 ( 10,000 electric miles/ 16,100 electric kilometers per year and comparison
vehicle with 23 mpg/ 10.2 liters/ 100km).
FIGURES 4 ( a) and ( b) Relative annual fuel cost savings from switching to EV based on
estimated prices of gasoline for 10,000 electric miles ( 16,100 km) per year and comparison
vehicle with 23 mpg.
Note to editor: Although some figures are in color, each has been designed to print well in black
and white.
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
12
TABLE 1 Electric Utility Company and Savings per Year From EV Use⎯ 10,000 Electric
Miles ( 16,000 Km) per Year, 23 MPG ( 10.2 L/ 100km) Comparison Vehicle, 100% Off- Peak
Charging
Region
Additional
Info
Gasoline
Price
Date
Power
Co.
( If
Applicable)
( If
Applicable)
7/ 14/ 08
1/ 14/ 09
7/ 14/ 09
Pacific
Gas
&
Electric
$ 1,793
$ 723
$ 1,101
Southern
California
Edison
$ 1,482
$ 395
$ 773
San
Diego
Gas
and
Electric
$ 1,656
$ 569
$ 948
Sacramento
Muni.
Util
District
$ 1,584
$ 515
$ 893
LA
Dept.
of
Water
&
Power
$ 1,697
$ 610
$ 967
Detroit
Edison
Energy
$ 1,615
$ 563
$ 858
Florida
Power
and
Light
Co.
$ 1,390
$ 451
$ 742
National
Grid
USA
Massachusetts
$ 1,091
$ 99
$ 421
Nantucket
$ 1,126
$ 135
$ 456
New
Hampshire
$ 1,208
$ 229
$ 551
Rhode
Island
$ 1,310
$ 310
$ 675
New
York
Adirondack
$ 1,163
$ 150
$ 494
Capital
$ 1,143
$ 130
$ 474
Central
$ 1,164
$ 151
$ 494
Frontier
$ 1,173
$ 160
$ 504
Genesee
$ 1,172
$ 158
$ 502
Utica
$ 1,162
$ 149
$ 492
Hawaii
Electric
Company
HEC
Single
phase
$ 1,419
$ 510
$ 897
HELC
$ 1,612
$ 704
$ 1,091
MEC
Maui
$ 1,634
$ 725
$ 1,112
Lanai
$ 1,634
$ 725
$ 1,112
Molokai
$ 1,634
$ 725
$ 1,112
New
York
State
Elect& Gas
$ 1,334
$ 321
$ 665
NSTAR
Boston
Edison
$ 1,161
$ 140
$ 501
Austin
Energy
$ 1,354
$ 345
$ 671
Seattle
City
Light
Shoreline
$ 1,697
$ 623
$ 1,010
Seattle
$ 1,707
$ 634
$ 1,021
Tukwila
$ 1,691
$ 617
$ 1,004
Suburban
$ 1,699
$ 625
$ 1,012
XCEL
Energy
Colorado
$ 1,454
$ 445
$ 771
Michigan
$ 1,563
$ 580
$ 828
Minnesota
Overhead
$ 1,504
$ 587
$ 804
Underground
$ 1,480
$ 563
$ 780
New
Mexico
$ 1,413
$ 478
$ 748
North
Dakota
Overhead
$ 1,477
$ 530
$ 821
Underground
$ 1,453
$ 506
$ 797
South
Dakota
Overhead
$ 1,553
$ 597
$ 888
Underground
$ 1,529
$ 573
$ 864
Texas
$ 1,461
$ 501
$ 766
Wisconsin
Single
phase
$ 1,532
$ 601
$ 832
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
13
TABLE 2 Electric Utility Regions and Estimated Average Price per Gallon for Gasoline by
Time Period ( AAA Data⎯ U. S. Dollars)
Region-­‐ Utility
Company
7/ 15/ 08
1/ 15/ 09
7/ 15/ 09
Regions
Used
for
Gas
Price
Estimates
SF-­‐ Bay
Area
( PG& E)
$ 4.54
$ 2.08
$ 2.95
SF,
Oakland
Los
Angeles
( SoCal
Edison)
$ 4.51
$ 2.01
$ 2.88
LA,
Orange,
Riverside,
San
Bernardino
San
Diego
( SDG& E)
$ 4.50
$ 2.00
$ 2.87
San
Diego
Sacramento
( SMUD)
$ 4.42
$ 1.96
$ 2.83
Sacramento
Los
Angeles
( LADW& P)
$ 4.51
$ 2.01
$ 2.88
LA,
Orange,
Riverside,
San
Bernardino
Detroit
( Detroit
Edison
Energy)
$ 4.18
$ 1.76
$ 2.44
Detroit
( MI)
Florida
( FPLC)
$ 4.06
$ 1.90
$ 2.57
Florida
Massachusetts
( Nat'l
Grid
USA)
$ 4.09
$ 1.81
$ 2.55
Massachusetts
Nantucket
( Nat'l
Grid
USA)
$ 4.09
$ 1.81
$ 2.55
Massachusetts
New
Hampshire
( Nat'l
Grid
USA)
$ 4.04
$ 1.79
$ 2.53
New
Hampshire
Rhode
Island
( Nat'l
Grid
USA)
$ 4.10
$ 1.80
$ 2.64
Rhode
Island
New
York
( Nat'l
Grid
USA)
$ 4.31
$ 1.98
$ 2.77
New
York
Hawaii
( Hawaii
Electric
Co.)
$ 4.47
$ 2.38
$ 3.27
Hawaii
New
York
( NY
State
Elect
&
Gas)
$ 4.31
$ 1.98
$ 2.77
New
York
Boston
( NSTAR
Boston
Edison)
$ 4.08
$ 1.73
$ 2.56
Boston
( MA)
Austin
( Austin
Energy)
$ 3.97
$ 1.65
$ 2.40
Austin
( TX)
Seattle
( Seattle
City
Light)
$ 4.35
$ 1.88
$ 2.77
Seattle
( WA)
Colorado
( XCEL
CO)
$ 4.07
$ 1.75
$ 2.50
Colorado
Michigan
( XCEL
MI)
$ 4.18
$ 1.92
$ 2.49
Michigan
Minnesota
( XCEL
MN)
$ 3.97
$ 1.86
$ 2.36
Minnesota
New
Mexico
( XCEL
NM)
$ 4.05
$ 1.90
$ 2.52
New
Mexico
North
Dakota
( XCEL
ND)
$ 4.06
$ 1.88
$ 2.55
North
Dakota
South
Dakota
( XCEL
SD)
$ 4.05
$ 1.85
$ 2.52
South
Dakota
Texas
( XCEL
TX)
$ 3.97
$ 1.76
$ 2.37
Texas
Wisconsin
( XCEL
WI)
$ 4.09
$ 1.95
$ 2.48
Wisconsin
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
14
FIGURE 1 Histogram of difference in annual savings ($ US) per year from EV charging
peak versus off- peak for 10,000 electric miles ( 16,000 km) per year, 23 mpg ( 10.2
liters/ 100km) comparison vehicle, and July 2008 gasoline prices.
0 200 400
5
10
15
Difference in AnnDuifaf l inS Paevaikngs ($ US) Peak v ersus Off- peak
Number of Utilities
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
15
FIGURES 2 ( a) and ( b) annual operating cost savings ( US$/ yr) for example utility PG& E
for 10,000 electric miles ( 16,100 electric kilometers) per year.
% Off- Peak Charging
Cost of Gasoline ($/ gal)
Mileage of Vehicle ( mi/ gal) % Off- Peak Charging
Savings by Switching to EV ($/ yr) Savings by Switching to EV ($/ yr)
( b) By Comparison Vehicle Fuel Economy and Charging Pattern
( a) By Gasoline Price and Charging Pattern for 23 mpg ( 10.2 L/ 100km)
Comparison Vehicle
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
16
FIGURE 3 Relative annual fuel cost savings from switching to EVs based on estimated
gasoline prices in July 2008 ( 10,000 electric miles/ 16,100 electric kilometers per year and
comparison vehicle with 23 mpg/ 10.2 liters/ 100km).
Lidicker, Lipman, and Shaheen. 2010 Transportation Research Record.
17
FIGURES 4 ( a) and ( b) Relative annual fuel cost savings from switching to EV based on
estimated prices of gasoline for 10,000 electric miles ( 16,100 km) per year and comparison
vehicle with 23 mpg.
( a) January 2009 Low Prices
( b) July 2009 Most Current Prices