Time For Electric Vehicles
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ELECTRIC vs. ICE
Debunking the Myth
of EVs and Smokestacks
by Chip Gribben
Electric Vehicle Association of Greater Washington, D.C (EVA/DC)
Introduction
As ozone levels in the U.S. remain at unhealthy levels, researches and
government officials continue to study alternatives to reduce air
pollution from gasoline-powered cars.
Among the alternatives are ultra-low emission vehicles (ULEVs) and
zero-emission vehicles (ZEVs). ULEVs are equipped with emission
controls that release only 45 pounds of carbon monoxide per 12,000
miles. ZEVs produce no tailpipe emissions at all. ZEVs include
vehicles powered by electricity, flywheels, hydrogen fuel cells, and
other zero emission energy sources. Although some ZEVs are still in
the experimental stage, electric vehicles (EVs) are available today.
In fact, more EVs roamed the nation's roads in the early 1900's than
did gas-powered cars.
Unlike a gasoline car that is powered by an internal combustion engine
(ICE), an EV uses electricity stored in batteries to power one or more
electric motors. When the batteries need recharging, you simply plug
in from the convenience of your home. EVs have no tailpipe or
evaporative emissions, because they have no fuel, combustion, of
exhaust systems. In fact, EVs are virtually maintenance-free because
they never need oil changes, air filters, tune-ups, mufflers, timing
belts, or emission tests.
Are EVs true ZEVs?
One of the most common issues surrounding EVs today is their status as
ZEVs. Critics proclaim that EVs are simply "elsewhere emission
vehicles" because they transfer emissions from the tailpipe to the
smokestack. Although there are emissions associated with coal- and
oil-fired power plants, smokestack emissions associated with charging
EVs are extremely low (3). In fact, EVs can charge from zero emission
sources such as nuclear, hydroelectric, solar, and wind power.
The purpose of this paper is to prove that EVs recharging from today's
power plants are substantially cleaner than even the most efficient
ICE vehicles. The myth that EVs are "elsewhere emission vehicles" will
be put to the test with facts that clearly show EVs and power plants
are cleaner, more efficient and more reliable than the infrastructure
that supports ICE vehicles.
The Effects of the ICE Age
The golden age of the automobile has lasted more than 50 years.
However, the golden haze cause by our love affair with the ICE car
will have long-lasting effects. Despite stringent standards to improve
tailpipe emissions, the number of vehicles and miles traveled are
increasing every year. Scientists predict that our increased reliance
on the automobile could increase pollution levels 40 percent by the
year 2010 (4). In California, where the automobile is considered a
necessity, ICE vehicles account for 90 percent of the carbon monoxide,
77 percent of nitrous oxides, and 55 percent of reactive organic gases
(5). In addition, greenhouse gases such as carbon dioxide are expected
to increase approximately 33 percent by the year 2010.
Continual exposure to these pollutants can cause a variety of symptoms
and aggravate existing medical conditions. The elderly and the young
are more susceptible to the risks imposed by air pollution. Children
in the Los Angeles area have 10 to 15 percent less lung capacity than
children in cleaner cities such as Houston, Texas.
The following list describes the potential health risks associated
with these emissions.
Carbon Monoxide (CO): An odorless and colorless gas which is highly
poisonous. CO can reduce the blood's ability to carry oxygen and can
aggravate lung and heart disease. Exposure to high concentrations can
cause headaches, fatigue and dizziness.
Sulfur Oxides (SOx) and Sulfur Dioxide (SO2): When combined with water
vapor in the air, SO2 is the main contributor to acid rain. Gasoline
typically contains .03 percent sulfur.
Nitrogen Oxides (NOx) and Nitrogen Dioxide (NO2): These chemicals form
the yellowish-brown haze seen over dirty cities. When combined with
oxygen from the atmosphere, NO becomes NO2, a poisonous gas that can
damage lung tissue.
Hydrocarbons (HC): This is a group of pollutants containing hydrogen
and carbon. Hydrocarbons can react to form ozone. Some (HCs) are
carcinogenic and other can irritate mucous membranes. Hydrocarbons
include:
Volatile organic compounds (VOC)
Volatile organic gases (VOG)
Reactive organic gases (ROG)
Reactive organic compounds (ROC)
Non-methane hydrocarbons (NMHC)
Non-methane organic gases (NMOG)
Ozone (O3): This is the white haze or smog seen over many cities.
Ozone is formed in the lower atmosphere when NMOG and NOx react with
heat and sunlight. Ozone can irritate the respiratory system, decrease
lung function and aggravate chronic lung disease such as asthma.
Ozone gases have contributed to smog levels as high as 80 parts per
billion, an average of 84.3 days per year since 1982 in Baltimore,
Maryland. Federal safety standards state the risk level is 120 parts
per billion when exposed to smog for an hour. However, recent studies
suggest that exposure to 80 parts per billion is enough to cause lung
inflammation which can lead to permanent scarring.
Carbon Dioxide (CO2): CO2 is a naturally occurring gas in the
atmosphere and is a necessary ingredient of the ecosystem. However, in
large quantities, it can allow more solar radiation to enter the
atmosphere than can escape. The excess heat from the trapped solar
radiation can lead to the "greenhouse effect" and global warming.
Clearing the Air About Power Plant Emissions
EVs have the unique advantage of using electricity generated from a
variety of fuels and renewable resources. The overall mix of power
plants in the U.S. is 55 percent coal, 9 percent natural gas, and 4
percent oil (9). The other 32 percent include nuclear power and
renewable energy sources such as hydroelectric, solar, wind, and
geothermal.
Many EVs critics point out that charging thousands of EVs from aging
coal plants will increase greenhouse gases such as CO2 significantly.
Although half the country uses coal-fired plants, EVs recharging from
these facilities are predicted to produce less CO2 than ICE vehicles.
According to the World Resources Institute, EVs recharging from
coal-fired plants will reduce CO2 emissions in the country from 17 to
22 percent.
Reductions in pollutants such as HCs, CO, NOx, SO2, and particulates
vary according to a region's power plant mix. If EVs were introduced
on a global scale, urban pollution would improve significantly. (See
Table 1) In France, where most of the power comes from nuclear energy,
emissions produced to charge EVs would be cut across the board.
Countries such as the U.S. and the U.K. use a mix of coal- and
oil-fired facilities that produce an elevated level of SO2 and
particulates. However, levels of HC, CO and NOx would decrease
significantly.
HCs CO NOx SO2 Particulates
France -99 -99 -91 -58 -59
Germany -98 -99 -66 +98 -96
Japan -99 -99 -66 -40 +10
U.K. -98 -99 -34 +407 +165
U.S. -96 -99 -67 +203 +122
California -96 -97 -75 -24 +15
Table 1. Electric Vehicles Reduce Pollution
(percentage change in emissions)
Cleaner Sources
Although half the electricity generated in the U.S. comes from
coal-fired plats, larger regions of the country such as California and
the Northeast are turning toward cleaner fuels such as natural gas.
In California, where over half of the state's pollution comes from ICE
vehicles, the overall mix of power plants is one of the cleanest in
the country. (See Table 2) Power plants burning cleaner fuels, such as
natural gas, account for a major share of the state's electricity. In
fact, natural gas facilities in California emit 40 times less NOx than
existing coal plants in the Northeast (2). Renewable sources such as
hydro, solar, wind, and geothermal produce a respectable share of the
electricity generated in California.
Power Plant Percent
Natural Gas 33
Hydroelectric 20
Coal 16
Nuclear 15
Solar and Wind 6
Geothermal 6
Table 2. Power Plant Mix in California
Taking advantage of California's abundance of sunlight, several
utilities are using Solar Charge Ports to charge EVs. Charge Ports are
facilities that have an array of solar panels placed strategically on
the roof of the structure. The solar panels convert sunlight into
electricity where it is distributed to the vehicles or the adjacent
building's power supply. On cloudy days, the building supplies the
electricity to charge the EVs. Charge Ports are in operation in
several cities in California including Diamond Bar, Azusa, and Santa
Monica.
Because California has a mix of cleaner fuels and renewable sources,
several studies have concluded that improvements in air quality can be
achieved easily by plugging in to EVs.
The California Air Resources Board (CARB) estimates that EVs operating
in the Los Angeles Basin would produce 98 percent fewer hydrocarbons,
89 percent fewer oxides of nitrogen, and 99 percent less carbon
monoxide than ICE vehicles.
In a study conducted by the Los Angeles Department of Water and Power,
EVs were significantly cleaner over the course of 100,000 miles than
ICE cars. The electricity generation process produces less than 100
pounds of pollutants for EVs compared to 3000 pounds for ICE vehicles.
(See Table 3)
Engine Type CO ROG NOx Total
Gasoline 2574 262 172 3008 lb.
Diesel 216 73 246 835 lb.
Electric 9 5 61 75 lb.
Table 3. Pounds of Emissions Produced per 100,000 miles
CO2 emissions are also significantly lower. Over the course of 100,000
miles, CO2 emissions from EVs are projected to be 10 tons versus 35
tons for ICE vehicles (5).
Many EV critics remain skeptical of such findings because California's
mix of power plants is relatively clean compared to that in the rest
of the country. However, in Arizona where 67 percent of power plants
are coal-fired, a study concluded that EVs would reduce greenhouse
gases such as CO2 by 71 percent (6).
Similar comparisons to those in California and Arizona can be found in
the northeastern part of the country where the majority of power
plants are coal-fired.
A study conducted by the Union of Concerned Scientists found that EVs
in the Northeast would reduce CO emissions by 99.8 percent, volatile
organic compounds (VOC) by 90 percent, NOx by 80 percent, and CO2 by
as much as 60 percent (7).
According to the Northeast States for Coordinated Air Use Management
(NESCAUM) study, use of EVs results in significant reductions of
carbon monoxide, greenhouse gases, and ground level ozone in the
region, with magnitudes cleaner than even the cleanest ULEV.
In the future, EVs in the Northeast will reap the benefits of
switching to cleaner fuels such as natural gas. In the next 15 years,
aging coal plants will be replaced by modern natural gas fired plants.
This improvement alone will reduce power plant emissions
significantly.
Several northeastern states are also exploring renewable sources such
as solar energy to generate electricity for EVs. The EVermont Project
is using a successful solar-powered system to charge a mail delivery
truck used at the General Services Center in Middlesex, Vermont. A
solar array was installed and wired into the system's power grid. The
solar array generates electricity during the day and the truck charges
at night. Overall, the solar panels put out more power than the truck
uses on its daily rounds.
The Efficiency Advantage of EVs and Power Plants
EVs recharging from fossil-fueled power plants such as coal and oil
have unique efficiency advantages over ICE vehicles. As a system, EVs
and power plants are twice as efficient as ICE vehicles and the system
that refines gasoline (See Table 4). Although there are losses
associated with generating electricity from fossil-based fuels, EVs
are significantly more efficient in converting their energy into
mechanical power.
EVs & Power Plants ICE & Fuel Refining
Processing 39% (Electricity Generation) 92% (Fuel Refining)
Transmission Lines 95% -
Charging 88% -
Vehicle Efficiency 88% 15%
Overall Efficiency 28% 14%
Table 4. Operating Efficiency Comparison Between EVs and ICE Vehicles
Since EVs operate more efficiently than their ICE-powered
counterparts, overall fuel economy is higher. However, making a direct
comparison between the fuel efficiencies of both vehicles is
difficult. By applying a common unit of energy, such as British
Thermal Units (BTUs), we can get a fair comparison between the two.
For the following example we will compare the fuel efficiencies of a
1995 Acura 3.2 TL and GM's new electric vehicle: the EV1. See Table 5.
Both cost about $34,000 and can accelerate from 0 to 60 mph in 8.5
seconds.
Electric-Powered GM EV1 Gasoline-Powered Acura .2TL
Start with 1 million BTUs Start with >1 million BTUs
Energy left after generation (39% efficiency) 390,000 BTUs Energy left
after refining (92% efficiency) 920,000 BTUs
Energy left after charging losses (88% efficiency) >343,000 BTUs
Energy left after transport (95% efficiency) 874,000 BTUs
BTUs per kilowatt-hour 3412 BTUs BTUs per gallon of gasoline 115,400
BTUs
Electricity available 100.6 kWhr Gallons available 7.6 gallons
Energy efficiency 0.19 kWhr/mile Fuel economy> 24 mpg
Miles per million BTUs 529.5 miles Miles per million BTUs 182.5 miles
Equivalent mpg 69 mpg Equivalent mpg 24 mpg
Table 5. Fuel Efficiency Comparison Between EVs and ICE Vehicles
Even though the GM EV1 has 43 percent fewer BTUs after electricity
generation, it can be driven almost 350 miles farther because the
vehicle is more efficient than the Acura. In fact, the GM EV1 has the
gasoline equivalency of 69 mpg (23) even after factoring in losses
from electricity generation and charging!
Scrubbing Out Power Plant Emissions
We've discussed how the system of power plants and EVs can improve air
quality, improve operating efficiencies, and save fuel, but just how
efficient are power plant emissions controls?
Controlling emissions from several hundred power plants is much easier
than controlling the emissions from 187 million ICE vehicles. In fact,
electric utilities go through considerable efforts to monitor and
remove emissions from their facilities. Teams of engineers carefully
maintain the plants at peak operating efficiency. State-of-the-art
equipment such as scrubbers are installed to remove emissions.
Electrostatic precipitators (ESPs) between the boilers and smokestacks
remove up to 9g - 75 percent of the ash emitted by power plants.
Coal-fired plants in Texas using ESPs remove up to 13.4 million tons
of ash each year, releasing only 3000 tons into the atmosphere (24).
The amount released falls below U.S. EPA regulations for ash
emissions.
Over the next seven years, electric utilities in the Northeast are
committed to reducing NOx emissions by 55 to 70 percent (25). When one
power plant upgrades its emission controls, thousands of EVs
immediately reap the benefits from this improvement.
Catalytic Clunkers
Upgrading and maintaining emissions for ICE vehicles is a different
story. According to Drew Kodjak, a lawyer from NESCAUM, ICE vehicles
pollute more over time while power plants tend to pollute less over
time. Over the course of its lifetime, a gasoline car will spew out 60
times more CO, 30 times more VOC, and twice as much CO2 as an electric
power plant.
The U.S. Environmental Protection Agency estimates that tailpipe
emissions increase 25 percent for every 10,000 miles traveled (26). As
gasoline cars age, their engines, catalytic converters, and other
emission control devices become less efficient. The cleanest a
gasoline car ever will be is the day it rolls off the assembly line.
The deterioration of emission control systems on ICE vehicles can
increase emissions up to 90 percent. To deal with increased emissions,
state governments have adopted emission inspection programs with
varied degrees of success. Many of these programs have been delayed
due to public concern for the cost of repairing emission components.
In Maryland, drivers can receive a waiver if they document attempts to
repair their ICE cars even though the cars continue to fail emission
tests.
Newer cars entering the market are not necessarily the cleanest
either. The hottest vehicles on the market today are sport utility
vehicles (SUVs) which now account for 40 percent of all new car sales.
These gas guzzlers are driving up this country's demand for imported
oil, decreasing overall fuel efficiency, and increasing emissions.
Today's Power Plants Meeting Tomorrow's Recharging Needs
Many critics ask how this country could possibly support millions of
EVs on today's existing power grid. The Electric Power Resource
Institute (EPRI) estimates that this country has the ability to
support 50 million EVs without building any more power plants. Another
study puts this number closer to 20 million (27). Even so, 20 million
EVs is only 10 percent of today's fleet of 187 million cars. Thousands
more could be added if they are charged at night during off-peak
hours. Twenty million EVs, each with 100,000 miles on the odometer,
would reduce CO2 emissions in this country by 500 million tons without
building more power plants.
Southern California Edison (SCE) estimates that it has enough off-peak
capacity to refuel up to 2 million cars, 25 percent of the area's
automobiles. SCE estimates it will only need to add 200 megawatts of
capacity by 2008 to accommodate EVs.
Summary
In conclusion, EVs will have a considerable impact on reducing air
pollution, improving fuel efficiency, and reducing our overall
dependence on foreign oil. As power plants improve efficiency and turn
to cleaner fuels such as natural gas and zero-emission renewable
sources, EVs will continue to be the best solution towards attaining
clean air.
Notes
Bob Brandt, Build Your Own Electric Car, (Tab Books, Blue Ridge
Summit, PA, 1994), Table 2-2, p. 35.
Evaporative emissions include fumes and gases that evaporate during
refueling, and fumes and gases from components of the engine, such as
the carburetor.
Bob Brandt goes one step further stating, "There is no emission from
an electric vehicle and, until there exists an appreciable number of
them they do not impact in any way the emissions from the power plant
used to generate the electricity." Bob Brandt, Build Your Own Electric
Car, (Tab Books, Blue Ridge Summit, PA, 1994), p. 32.
Electric Power Research Institute, "Electric Vehicle Infrastructure,"
Will Electric Vehicles Contribute to a Cleaner Environment, (1992).
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), Table 1, p. 3.
Bob Brandt, Build Your Own Electric Car, (Tab Books, Blue Ridge
Summit, PA, 1994), p. 33.7.
Ibid, p. 31.
Timothy B. Wheeler, "Smog risk greater than believed," The Baltimore
Sun, (March 5, 1995), Section C 1.
James J. MacKenzie, The Keys to the Car, (World Resources Institute,
Baltimore, Maryland, May 1994), p. 91.
James J. MacKenzie, The Keys to the Car, (World Resources Institute,
Baltimore, Maryland, May 1994), p. 92.
Daniel Sperling, "The Case for Electric Vehicles," Scientific American
, (November 1996), article available from the Scientific American
website, http://www.sciam.com/1196issue/1196sperling.html
Drew Kodjak, "EVs: Clean Today, Cleaner Tomorrow," Technology Review,
(August/September 1996), p. 66-67.
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), Table C-6, p. 61.
Steve McCrea, Why Wait for Detroit, (South Florida Electric Vehicle
Auto Association, 1992), p. 39.
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), Table C-6, p. 68.
"Emissions, Quantifying the Air Quality Impact of EV Recharging,"
Green Car Journal, (October 1993), p. 116.
Center for Technology Assessment Transportation Technology Review,
"CTA Findings Reveal Carnegie-Mellon Study Misrepresents Environmental
Impacts of Electric Vehicles," (1995), p. 5.
Hilton Dier III, VT Electric Car Co.
Ovonic fact sheet, "Fuel Efficiency Comparison."
Table derived from "Why Wait for Detroit," Steve McCrea, (1992), p.
42. In the comparison, each vehicle is given 1 million BTUs to start
with. After losses are factored in, the results are divided by the BTU
equivalents of kilowatt-hours (3,412 BTUs/kWh) for the EV and gallons
(114,500 BTUs/gallon) for the ICE car. These results are divided by
the given efficiency for each vehicle. The final results are miles
each vehicle can travel.
Equivalent for 3,412 BTUs per kilowatt-hour obtained from CARB.
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), p.72.
Equivalent for 114,500 BTUs per gallon obtained from CARB. California
Air Resources Board, Draft Technical Document for the Low-Emission
Vehicle and Zero-Emission Vehicle Workshop on March 25, 1994,
Zero-Emission Vehicle Update, (1994), p.72.
The formula for figuring equivalent mpg for the electric car is:
1)Vehicle Efficiency x BTUs per kWh ÷ power plant efficiency = BTUs
per mile
2)BTUs per mile ÷ charging efficiency = BTUs per mile
3)BTUs per gallon ÷ BTUs per mile = mpg
To obtain 59 mpg for EV substitute the numbers from Table 5.
1)190 Wh/mi x 3.412 BTUs /Wh ÷ 0.39 (power plant effic.) = 1662.25
BTUs /mi
2)1662.25 BTUs /mi ÷ 0.88 (charging effic.) = 1955.58 BTUs /mi
3)114,500 BTUs /gal ÷ 1955.58 BTUs /mi = 58.55 mpg
Central Southwest System Homepage, "Air Quality,"
http://www.csw.com/er/airqual.html
Drew Kodjak, "EVs: Clean Today, Cleaner Tomorrow," Technology Review,
(August/September 1996), p. 66-67.
Ibid, p. 66-67.
Fortune Magazine, "Electric Vehicles, Technology Recreates the
Automobile." (Reprint from June 26, 1995)
Acknowledgements
Kevin Conners, Advocacy Institute; Kyle Davis, Southern California
Edison; Hilton Dier III, VT Electric Car Co.; Dave Goldstein President
EVA/DC; Monica Gribben, EVA/DC; Jane Hathaway, NRDC; Jason Marks,
Union of Concerned Scientists; and David Rezachek, Ph.D., P.E.
of EVs and Smokestacks
by Chip Gribben
Electric Vehicle Association of Greater Washington, D.C (EVA/DC)
Introduction
As ozone levels in the U.S. remain at unhealthy levels, researches and
government officials continue to study alternatives to reduce air
pollution from gasoline-powered cars.
Among the alternatives are ultra-low emission vehicles (ULEVs) and
zero-emission vehicles (ZEVs). ULEVs are equipped with emission
controls that release only 45 pounds of carbon monoxide per 12,000
miles. ZEVs produce no tailpipe emissions at all. ZEVs include
vehicles powered by electricity, flywheels, hydrogen fuel cells, and
other zero emission energy sources. Although some ZEVs are still in
the experimental stage, electric vehicles (EVs) are available today.
In fact, more EVs roamed the nation's roads in the early 1900's than
did gas-powered cars.
Unlike a gasoline car that is powered by an internal combustion engine
(ICE), an EV uses electricity stored in batteries to power one or more
electric motors. When the batteries need recharging, you simply plug
in from the convenience of your home. EVs have no tailpipe or
evaporative emissions, because they have no fuel, combustion, of
exhaust systems. In fact, EVs are virtually maintenance-free because
they never need oil changes, air filters, tune-ups, mufflers, timing
belts, or emission tests.
Are EVs true ZEVs?
One of the most common issues surrounding EVs today is their status as
ZEVs. Critics proclaim that EVs are simply "elsewhere emission
vehicles" because they transfer emissions from the tailpipe to the
smokestack. Although there are emissions associated with coal- and
oil-fired power plants, smokestack emissions associated with charging
EVs are extremely low (3). In fact, EVs can charge from zero emission
sources such as nuclear, hydroelectric, solar, and wind power.
The purpose of this paper is to prove that EVs recharging from today's
power plants are substantially cleaner than even the most efficient
ICE vehicles. The myth that EVs are "elsewhere emission vehicles" will
be put to the test with facts that clearly show EVs and power plants
are cleaner, more efficient and more reliable than the infrastructure
that supports ICE vehicles.
The Effects of the ICE Age
The golden age of the automobile has lasted more than 50 years.
However, the golden haze cause by our love affair with the ICE car
will have long-lasting effects. Despite stringent standards to improve
tailpipe emissions, the number of vehicles and miles traveled are
increasing every year. Scientists predict that our increased reliance
on the automobile could increase pollution levels 40 percent by the
year 2010 (4). In California, where the automobile is considered a
necessity, ICE vehicles account for 90 percent of the carbon monoxide,
77 percent of nitrous oxides, and 55 percent of reactive organic gases
(5). In addition, greenhouse gases such as carbon dioxide are expected
to increase approximately 33 percent by the year 2010.
Continual exposure to these pollutants can cause a variety of symptoms
and aggravate existing medical conditions. The elderly and the young
are more susceptible to the risks imposed by air pollution. Children
in the Los Angeles area have 10 to 15 percent less lung capacity than
children in cleaner cities such as Houston, Texas.
The following list describes the potential health risks associated
with these emissions.
Carbon Monoxide (CO): An odorless and colorless gas which is highly
poisonous. CO can reduce the blood's ability to carry oxygen and can
aggravate lung and heart disease. Exposure to high concentrations can
cause headaches, fatigue and dizziness.
Sulfur Oxides (SOx) and Sulfur Dioxide (SO2): When combined with water
vapor in the air, SO2 is the main contributor to acid rain. Gasoline
typically contains .03 percent sulfur.
Nitrogen Oxides (NOx) and Nitrogen Dioxide (NO2): These chemicals form
the yellowish-brown haze seen over dirty cities. When combined with
oxygen from the atmosphere, NO becomes NO2, a poisonous gas that can
damage lung tissue.
Hydrocarbons (HC): This is a group of pollutants containing hydrogen
and carbon. Hydrocarbons can react to form ozone. Some (HCs) are
carcinogenic and other can irritate mucous membranes. Hydrocarbons
include:
Volatile organic compounds (VOC)
Volatile organic gases (VOG)
Reactive organic gases (ROG)
Reactive organic compounds (ROC)
Non-methane hydrocarbons (NMHC)
Non-methane organic gases (NMOG)
Ozone (O3): This is the white haze or smog seen over many cities.
Ozone is formed in the lower atmosphere when NMOG and NOx react with
heat and sunlight. Ozone can irritate the respiratory system, decrease
lung function and aggravate chronic lung disease such as asthma.
Ozone gases have contributed to smog levels as high as 80 parts per
billion, an average of 84.3 days per year since 1982 in Baltimore,
Maryland. Federal safety standards state the risk level is 120 parts
per billion when exposed to smog for an hour. However, recent studies
suggest that exposure to 80 parts per billion is enough to cause lung
inflammation which can lead to permanent scarring.
Carbon Dioxide (CO2): CO2 is a naturally occurring gas in the
atmosphere and is a necessary ingredient of the ecosystem. However, in
large quantities, it can allow more solar radiation to enter the
atmosphere than can escape. The excess heat from the trapped solar
radiation can lead to the "greenhouse effect" and global warming.
Clearing the Air About Power Plant Emissions
EVs have the unique advantage of using electricity generated from a
variety of fuels and renewable resources. The overall mix of power
plants in the U.S. is 55 percent coal, 9 percent natural gas, and 4
percent oil (9). The other 32 percent include nuclear power and
renewable energy sources such as hydroelectric, solar, wind, and
geothermal.
Many EVs critics point out that charging thousands of EVs from aging
coal plants will increase greenhouse gases such as CO2 significantly.
Although half the country uses coal-fired plants, EVs recharging from
these facilities are predicted to produce less CO2 than ICE vehicles.
According to the World Resources Institute, EVs recharging from
coal-fired plants will reduce CO2 emissions in the country from 17 to
22 percent.
Reductions in pollutants such as HCs, CO, NOx, SO2, and particulates
vary according to a region's power plant mix. If EVs were introduced
on a global scale, urban pollution would improve significantly. (See
Table 1) In France, where most of the power comes from nuclear energy,
emissions produced to charge EVs would be cut across the board.
Countries such as the U.S. and the U.K. use a mix of coal- and
oil-fired facilities that produce an elevated level of SO2 and
particulates. However, levels of HC, CO and NOx would decrease
significantly.
HCs CO NOx SO2 Particulates
France -99 -99 -91 -58 -59
Germany -98 -99 -66 +98 -96
Japan -99 -99 -66 -40 +10
U.K. -98 -99 -34 +407 +165
U.S. -96 -99 -67 +203 +122
California -96 -97 -75 -24 +15
Table 1. Electric Vehicles Reduce Pollution
(percentage change in emissions)
Cleaner Sources
Although half the electricity generated in the U.S. comes from
coal-fired plats, larger regions of the country such as California and
the Northeast are turning toward cleaner fuels such as natural gas.
In California, where over half of the state's pollution comes from ICE
vehicles, the overall mix of power plants is one of the cleanest in
the country. (See Table 2) Power plants burning cleaner fuels, such as
natural gas, account for a major share of the state's electricity. In
fact, natural gas facilities in California emit 40 times less NOx than
existing coal plants in the Northeast (2). Renewable sources such as
hydro, solar, wind, and geothermal produce a respectable share of the
electricity generated in California.
Power Plant Percent
Natural Gas 33
Hydroelectric 20
Coal 16
Nuclear 15
Solar and Wind 6
Geothermal 6
Table 2. Power Plant Mix in California
Taking advantage of California's abundance of sunlight, several
utilities are using Solar Charge Ports to charge EVs. Charge Ports are
facilities that have an array of solar panels placed strategically on
the roof of the structure. The solar panels convert sunlight into
electricity where it is distributed to the vehicles or the adjacent
building's power supply. On cloudy days, the building supplies the
electricity to charge the EVs. Charge Ports are in operation in
several cities in California including Diamond Bar, Azusa, and Santa
Monica.
Because California has a mix of cleaner fuels and renewable sources,
several studies have concluded that improvements in air quality can be
achieved easily by plugging in to EVs.
The California Air Resources Board (CARB) estimates that EVs operating
in the Los Angeles Basin would produce 98 percent fewer hydrocarbons,
89 percent fewer oxides of nitrogen, and 99 percent less carbon
monoxide than ICE vehicles.
In a study conducted by the Los Angeles Department of Water and Power,
EVs were significantly cleaner over the course of 100,000 miles than
ICE cars. The electricity generation process produces less than 100
pounds of pollutants for EVs compared to 3000 pounds for ICE vehicles.
(See Table 3)
Engine Type CO ROG NOx Total
Gasoline 2574 262 172 3008 lb.
Diesel 216 73 246 835 lb.
Electric 9 5 61 75 lb.
Table 3. Pounds of Emissions Produced per 100,000 miles
CO2 emissions are also significantly lower. Over the course of 100,000
miles, CO2 emissions from EVs are projected to be 10 tons versus 35
tons for ICE vehicles (5).
Many EV critics remain skeptical of such findings because California's
mix of power plants is relatively clean compared to that in the rest
of the country. However, in Arizona where 67 percent of power plants
are coal-fired, a study concluded that EVs would reduce greenhouse
gases such as CO2 by 71 percent (6).
Similar comparisons to those in California and Arizona can be found in
the northeastern part of the country where the majority of power
plants are coal-fired.
A study conducted by the Union of Concerned Scientists found that EVs
in the Northeast would reduce CO emissions by 99.8 percent, volatile
organic compounds (VOC) by 90 percent, NOx by 80 percent, and CO2 by
as much as 60 percent (7).
According to the Northeast States for Coordinated Air Use Management
(NESCAUM) study, use of EVs results in significant reductions of
carbon monoxide, greenhouse gases, and ground level ozone in the
region, with magnitudes cleaner than even the cleanest ULEV.
In the future, EVs in the Northeast will reap the benefits of
switching to cleaner fuels such as natural gas. In the next 15 years,
aging coal plants will be replaced by modern natural gas fired plants.
This improvement alone will reduce power plant emissions
significantly.
Several northeastern states are also exploring renewable sources such
as solar energy to generate electricity for EVs. The EVermont Project
is using a successful solar-powered system to charge a mail delivery
truck used at the General Services Center in Middlesex, Vermont. A
solar array was installed and wired into the system's power grid. The
solar array generates electricity during the day and the truck charges
at night. Overall, the solar panels put out more power than the truck
uses on its daily rounds.
The Efficiency Advantage of EVs and Power Plants
EVs recharging from fossil-fueled power plants such as coal and oil
have unique efficiency advantages over ICE vehicles. As a system, EVs
and power plants are twice as efficient as ICE vehicles and the system
that refines gasoline (See Table 4). Although there are losses
associated with generating electricity from fossil-based fuels, EVs
are significantly more efficient in converting their energy into
mechanical power.
EVs & Power Plants ICE & Fuel Refining
Processing 39% (Electricity Generation) 92% (Fuel Refining)
Transmission Lines 95% -
Charging 88% -
Vehicle Efficiency 88% 15%
Overall Efficiency 28% 14%
Table 4. Operating Efficiency Comparison Between EVs and ICE Vehicles
Since EVs operate more efficiently than their ICE-powered
counterparts, overall fuel economy is higher. However, making a direct
comparison between the fuel efficiencies of both vehicles is
difficult. By applying a common unit of energy, such as British
Thermal Units (BTUs), we can get a fair comparison between the two.
For the following example we will compare the fuel efficiencies of a
1995 Acura 3.2 TL and GM's new electric vehicle: the EV1. See Table 5.
Both cost about $34,000 and can accelerate from 0 to 60 mph in 8.5
seconds.
Electric-Powered GM EV1 Gasoline-Powered Acura .2TL
Start with 1 million BTUs Start with >1 million BTUs
Energy left after generation (39% efficiency) 390,000 BTUs Energy left
after refining (92% efficiency) 920,000 BTUs
Energy left after charging losses (88% efficiency) >343,000 BTUs
Energy left after transport (95% efficiency) 874,000 BTUs
BTUs per kilowatt-hour 3412 BTUs BTUs per gallon of gasoline 115,400
BTUs
Electricity available 100.6 kWhr Gallons available 7.6 gallons
Energy efficiency 0.19 kWhr/mile Fuel economy> 24 mpg
Miles per million BTUs 529.5 miles Miles per million BTUs 182.5 miles
Equivalent mpg 69 mpg Equivalent mpg 24 mpg
Table 5. Fuel Efficiency Comparison Between EVs and ICE Vehicles
Even though the GM EV1 has 43 percent fewer BTUs after electricity
generation, it can be driven almost 350 miles farther because the
vehicle is more efficient than the Acura. In fact, the GM EV1 has the
gasoline equivalency of 69 mpg (23) even after factoring in losses
from electricity generation and charging!
Scrubbing Out Power Plant Emissions
We've discussed how the system of power plants and EVs can improve air
quality, improve operating efficiencies, and save fuel, but just how
efficient are power plant emissions controls?
Controlling emissions from several hundred power plants is much easier
than controlling the emissions from 187 million ICE vehicles. In fact,
electric utilities go through considerable efforts to monitor and
remove emissions from their facilities. Teams of engineers carefully
maintain the plants at peak operating efficiency. State-of-the-art
equipment such as scrubbers are installed to remove emissions.
Electrostatic precipitators (ESPs) between the boilers and smokestacks
remove up to 9g - 75 percent of the ash emitted by power plants.
Coal-fired plants in Texas using ESPs remove up to 13.4 million tons
of ash each year, releasing only 3000 tons into the atmosphere (24).
The amount released falls below U.S. EPA regulations for ash
emissions.
Over the next seven years, electric utilities in the Northeast are
committed to reducing NOx emissions by 55 to 70 percent (25). When one
power plant upgrades its emission controls, thousands of EVs
immediately reap the benefits from this improvement.
Catalytic Clunkers
Upgrading and maintaining emissions for ICE vehicles is a different
story. According to Drew Kodjak, a lawyer from NESCAUM, ICE vehicles
pollute more over time while power plants tend to pollute less over
time. Over the course of its lifetime, a gasoline car will spew out 60
times more CO, 30 times more VOC, and twice as much CO2 as an electric
power plant.
The U.S. Environmental Protection Agency estimates that tailpipe
emissions increase 25 percent for every 10,000 miles traveled (26). As
gasoline cars age, their engines, catalytic converters, and other
emission control devices become less efficient. The cleanest a
gasoline car ever will be is the day it rolls off the assembly line.
The deterioration of emission control systems on ICE vehicles can
increase emissions up to 90 percent. To deal with increased emissions,
state governments have adopted emission inspection programs with
varied degrees of success. Many of these programs have been delayed
due to public concern for the cost of repairing emission components.
In Maryland, drivers can receive a waiver if they document attempts to
repair their ICE cars even though the cars continue to fail emission
tests.
Newer cars entering the market are not necessarily the cleanest
either. The hottest vehicles on the market today are sport utility
vehicles (SUVs) which now account for 40 percent of all new car sales.
These gas guzzlers are driving up this country's demand for imported
oil, decreasing overall fuel efficiency, and increasing emissions.
Today's Power Plants Meeting Tomorrow's Recharging Needs
Many critics ask how this country could possibly support millions of
EVs on today's existing power grid. The Electric Power Resource
Institute (EPRI) estimates that this country has the ability to
support 50 million EVs without building any more power plants. Another
study puts this number closer to 20 million (27). Even so, 20 million
EVs is only 10 percent of today's fleet of 187 million cars. Thousands
more could be added if they are charged at night during off-peak
hours. Twenty million EVs, each with 100,000 miles on the odometer,
would reduce CO2 emissions in this country by 500 million tons without
building more power plants.
Southern California Edison (SCE) estimates that it has enough off-peak
capacity to refuel up to 2 million cars, 25 percent of the area's
automobiles. SCE estimates it will only need to add 200 megawatts of
capacity by 2008 to accommodate EVs.
Summary
In conclusion, EVs will have a considerable impact on reducing air
pollution, improving fuel efficiency, and reducing our overall
dependence on foreign oil. As power plants improve efficiency and turn
to cleaner fuels such as natural gas and zero-emission renewable
sources, EVs will continue to be the best solution towards attaining
clean air.
Notes
Bob Brandt, Build Your Own Electric Car, (Tab Books, Blue Ridge
Summit, PA, 1994), Table 2-2, p. 35.
Evaporative emissions include fumes and gases that evaporate during
refueling, and fumes and gases from components of the engine, such as
the carburetor.
Bob Brandt goes one step further stating, "There is no emission from
an electric vehicle and, until there exists an appreciable number of
them they do not impact in any way the emissions from the power plant
used to generate the electricity." Bob Brandt, Build Your Own Electric
Car, (Tab Books, Blue Ridge Summit, PA, 1994), p. 32.
Electric Power Research Institute, "Electric Vehicle Infrastructure,"
Will Electric Vehicles Contribute to a Cleaner Environment, (1992).
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), Table 1, p. 3.
Bob Brandt, Build Your Own Electric Car, (Tab Books, Blue Ridge
Summit, PA, 1994), p. 33.7.
Ibid, p. 31.
Timothy B. Wheeler, "Smog risk greater than believed," The Baltimore
Sun, (March 5, 1995), Section C 1.
James J. MacKenzie, The Keys to the Car, (World Resources Institute,
Baltimore, Maryland, May 1994), p. 91.
James J. MacKenzie, The Keys to the Car, (World Resources Institute,
Baltimore, Maryland, May 1994), p. 92.
Daniel Sperling, "The Case for Electric Vehicles," Scientific American
, (November 1996), article available from the Scientific American
website, http://www.sciam.com/1196issue/1196sperling.html
Drew Kodjak, "EVs: Clean Today, Cleaner Tomorrow," Technology Review,
(August/September 1996), p. 66-67.
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), Table C-6, p. 61.
Steve McCrea, Why Wait for Detroit, (South Florida Electric Vehicle
Auto Association, 1992), p. 39.
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), Table C-6, p. 68.
"Emissions, Quantifying the Air Quality Impact of EV Recharging,"
Green Car Journal, (October 1993), p. 116.
Center for Technology Assessment Transportation Technology Review,
"CTA Findings Reveal Carnegie-Mellon Study Misrepresents Environmental
Impacts of Electric Vehicles," (1995), p. 5.
Hilton Dier III, VT Electric Car Co.
Ovonic fact sheet, "Fuel Efficiency Comparison."
Table derived from "Why Wait for Detroit," Steve McCrea, (1992), p.
42. In the comparison, each vehicle is given 1 million BTUs to start
with. After losses are factored in, the results are divided by the BTU
equivalents of kilowatt-hours (3,412 BTUs/kWh) for the EV and gallons
(114,500 BTUs/gallon) for the ICE car. These results are divided by
the given efficiency for each vehicle. The final results are miles
each vehicle can travel.
Equivalent for 3,412 BTUs per kilowatt-hour obtained from CARB.
California Air Resources Board, Draft Technical Document for the
Low-Emission Vehicle and Zero-Emission Vehicle Workshop on March 25,
1994, Zero-Emission Vehicle Update, (1994), p.72.
Equivalent for 114,500 BTUs per gallon obtained from CARB. California
Air Resources Board, Draft Technical Document for the Low-Emission
Vehicle and Zero-Emission Vehicle Workshop on March 25, 1994,
Zero-Emission Vehicle Update, (1994), p.72.
The formula for figuring equivalent mpg for the electric car is:
1)Vehicle Efficiency x BTUs per kWh ÷ power plant efficiency = BTUs
per mile
2)BTUs per mile ÷ charging efficiency = BTUs per mile
3)BTUs per gallon ÷ BTUs per mile = mpg
To obtain 59 mpg for EV substitute the numbers from Table 5.
1)190 Wh/mi x 3.412 BTUs /Wh ÷ 0.39 (power plant effic.) = 1662.25
BTUs /mi
2)1662.25 BTUs /mi ÷ 0.88 (charging effic.) = 1955.58 BTUs /mi
3)114,500 BTUs /gal ÷ 1955.58 BTUs /mi = 58.55 mpg
Central Southwest System Homepage, "Air Quality,"
http://www.csw.com/er/airqual.html
Drew Kodjak, "EVs: Clean Today, Cleaner Tomorrow," Technology Review,
(August/September 1996), p. 66-67.
Ibid, p. 66-67.
Fortune Magazine, "Electric Vehicles, Technology Recreates the
Automobile." (Reprint from June 26, 1995)
Acknowledgements
Kevin Conners, Advocacy Institute; Kyle Davis, Southern California
Edison; Hilton Dier III, VT Electric Car Co.; Dave Goldstein President
EVA/DC; Monica Gribben, EVA/DC; Jane Hathaway, NRDC; Jason Marks,
Union of Concerned Scientists; and David Rezachek, Ph.D., P.E.
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