The sun, amounting to 99.8 percent of the entire solar system’s mass, produces a relatively constant energy output of 386 billion trillion kilowatts. The Earth’s ape-like inhabitants use approximately 15 trillion kilowatt-hours per year. Therefore, if 1 second of energy created from the sun could be harnessed, it would be enough to power the earth’s cumulative energy demands for 7,148,148 years.
* * *
Gas-Powered Sedan: The 2006 Volkswagen Golf GLS TDI gets between 37 and 44 miles per gallon of gasoline depending upon whether it is in the city or on the highway. That means that it burns about .0247 gallons per mile. One gallon of gasoline weighs only about 6 pounds, but when burned produces 19.4 pounds of carbon dioxide. Therefore, the 2006 Volkswagen Golf emits approximately 4.8 pounds of carbon dioxide per ten miles traveled.
Gas-Powered SUV: The 2007 Jeep Grand Cherokee Laredo 4X4 gets a maximum of 21 miles per gallon of gasoline or .0476 gallons per mile. Therefore, the 2007 Jeep Grand Cherokee emits approximately 9.2 pounds of carbon dioxide per ten miles traveled.
Hybrid: The most fuel-efficient, gasoline-powered car in the US is the rather unsightly Honda Insight, a hybrid that gets between 60 and 66 miles per gallon depending on whether it is in the city or on the highway. However, it only seats 2 people. 62.5 miles per gallon is equal to .0157 gallons per mile. Therefore, the Honda Insight emits approximately 3.1 pounds of carbon dioxide per ten miles traveled.
Diesel: In 2010, many European and Japanese automobile companies will introduce their new clean-diesel vehicles to the US. The Diesel Honda Accord will get 62.8 miles per gallon whether in the city or on the highway. It seats 5 people and can run off of bio-diesel as well as regular diesel. Diesel has higher energy content than gasoline and gives automobiles the ability to travel 30% farther on one gallon. The downside is that it takes 25% more unrefined petroleum to make 1 gallon of diesel than it does to make gasoline. 62.8 miles per gallon is equal to .0159 gallons per mile. Every gallon of diesel burned produces 22.2 pounds of carbon dioxide. Therefore, the Diesel Honda Accord will emit approximately 3.5 pounds of carbon dioxide per ten miles traveled.
Bio-diesel: With the combustion of bio-diesel, there is a 50 percent reduction in particulate matter and a 60-90 percent decrease in air toxics such as carbon monoxide. In addition, there are 75 percent less carbon dioxide emissions. However, bio-diesel gets 11 percent less miles per gallon than regular diesel. So in theory, the Diesel Honda Accord run on B100 bio-diesel would get about 55.9 miles per gallon and emit 5.55 pounds of carbon dioxide per gallon. Therefore, the Diesel Honda Accord run on pure bio-diesel would emit approximately 1.0 pound of carbon dioxide per ten miles traveled.
Ethanol: It takes 1.5 gallons of ethanol to travel the same distance as 1 gallon of gasoline. In 2006, the cost of domestic ethanol came to $3.16 per gallon. This means that one would have to pay $4.74 to get the same mileage as 1 gallon of gasoline. In addition, according to the EPA, volatile organic materials such as formaldehyde and ascetic acid produced from ethanol factories are up to 10 times worse than the acceptable amount. Environmentally, emissions from ethanol are quite positive; but in the life cycle of growing corn or sugar cane, producing ethanol and consuming it, the petroleum that goes into the entire procedure only amounts to a total savings in fuel efficiency of 10 percent. So in theory, the Volkswagen Golf run on bio-diesel, would get about 44.6 mpg. Therefore, the vehicle would emit approximately 4.3 pounds of carbon dioxide per ten miles traveled.
Electric: The Tesla Roadster is an electric car that goes 0-60 in 4 seconds. Its top speed is 130 mph with a range of over 200 miles per charge. It has a battery life of about 100,000 miles and receives a full battery charge in 3.5 hours. Its cost is $92,950. The electricity that would power this car comes from over 70% hydrocarbon-producing energy sources in the US and over 80% in China. In addition, due to America’s failure to due away with its copper-based electric network, over 10 percent of all electricity generated is lost to resistance in the wires. To fully charge the vehicles battery takes 56 kilowatt-hours of electricity assuming no electricity is lost during plug-in. In 2006, 3.7 trillion kilowatt-hours of electricity was consumed in the USA. The production of that electricity emitted approximately 2.3 billion metric tons of carbon dioxide. Therefore, the electric grid that the Tesla Roadster would be plugged into produces about .00062 tons of carbon dioxide per kilowatt-hour consumed. That means that the 56 kilowatt-hour charge needed to power-up the Tesla Roadster would emit .035 metric tons or 77 pounds of carbon dioxide from the production of electricity. Being that the Tesla Roadster electric car has the ability to travel 200 miles on one charge, it therefore emits approximately 3.7 pounds of carbon dioxide per ten miles traveled.
Hydrogen Fuel Cells: The emissions produced from vehicles using hydrogen fuel is 100 percent water in the form of vapor. However, 95% of America’s hydrogen is produced from natural gas. Hydrogen fuel cell vehicles can now travel 300 miles on 17.6 pounds of hydrogen or .0588 pounds per mile. Making 1 pound of hydrogen produced from natural gas emits approximately 2 pounds of carbon dioxide. Therefore, a hydrogen fuel cell powered automobile would emit approximately 1.2 pounds of carbon dioxide per ten miles traveled.
Simple Mathematics CO2 Efficiency Ratings
1.0 – Bio-diesel
1.2 – Hydrogen Fuel Cells
3.1 – Hybrid
3.5 – Diesel
3.7 – Electric
4.3 – Ethanol
4.8 – Gas-Powered Sedan
9.2 – Gas-Powered SUV
** (Ratings in pounds of carbon dioxide produced per ten miles traveled.)
* * *
Hybrids can result in a 35 percent reduction in CO2 emissions, but fossil fuel consumption is set to rise by 34 percent by 2030. Therefore, it is fairly shortsighted to invest in a 35% solution. And with only a 27% decrease in CO2 emissions clean diesel suffers the same problem.
According to the Union of Concerned Scientists, the combustion of B100, or pure bio-diesel, results in about 10 percent more nitrogen oxide emissions (emissions responsible for smog) than do the emissions of regular diesel. However, bio-diesel can be produced from nearly any organic oil which promotes crop rotation and with close to an 80% reduction in carbon dioxide emissions, it is a difficult option to ridicule. Ethanol, on the other hand, would require the clear cutting of rainforests for monoculture corn and sugarcane plantations to supply America’s demands, and the benefits of ethanol only amount to only a 10% reduction in overall carbon dioxide emissions than do the most efficient gasoline-powered sedans.
Electric powered vehicles amount to a 23% decrease in CO2 emissions and takes the pollution away from the cities and puts it at the power plants; but being that carbon dioxide is a green house gas, it’s effects are just as severe no matter where on earth the emissions originate. Carbon dioxide emissions related to electric automobiles completely depends upon where the electricity originates, so an electric automobile charged from 100 percent wind or solar power emits no carbon dioxide at all. In China, it is possible to buy a 3 kilowatt wind turbine for home use that is about the same size as a street lamp and relatively silent for $2,500 which would be more than sufficient to power a Tesla Roadster and just about everything in an average household. In addition, restructuring America’s power grid with superconductors would conserve 10 percent more electricity.
Hydrogen fuel cells would lessen CO2 emissions by 75%, but would cost close to $1 trillion just to set up the infrastructure. With improved technology, hydrogen could be a 100% CO2-free solution if it was produced via renewable energy resources. However, with present technologies, it would cost up to $3 trillion. Nuclear power also produces no carbon dioxide emissions, and at present, China is constructing a $300 million nuclear plant that can generate 195 thousand kilowatts and, in theory, is completely protected from meltdowns.
* * *
Of EPA Green Power Partners, PepsiCo rates number 1 in use of Green Energy (biogas, biomass, geothermal, small-hydro, wind and solar) with 100 percent of its 1.1 billion kilowatt-hours of energy coming from green. Number 2 is wells Fargo (42%). Number 3 is Whole Foods (100%). Number 4 is the U.S. Air Force, although it only accounts for 4 percent of its over 11 billion kilowatt-hour total energy consumption. The rest of the top 25 green power users includes Johnson & Johnson (39%), U.S. Environmental Protection Agency (100%), Los Angeles County Sanitation Districts (57%), Starbucks (20%), DuPont Company (4%), U.S. Department of Energy (3%), Vail Resorts (100%), HSBC North America (35%), Cisco Systems, Inc.(21%), Staples (20%), New York University (100%), The World Bank Group (100%), University of Pennsylvania (29%), IBM Corporation (4%), U.S, Department of Veterans Affairs (3%), Nature Works LLC (89%), Sprint Nextel (47%), Safeway Inc. (2%), Pennsylvania State University (20%), Kohl’s Department Store (8%) and Nike, Inc. who uses 72 percent green energy. **
**These rankings are determined by purchase of renewable energy credits (RECs) from the EPA, not direct production-consumption. Fossil fuels cost around .07 cents per kilowatt-hour compared to clean energy costs of .08 cents per kilowatt-hour. RECs allow for clean energies to enter the market and the public electric grid without taking a profit loss.
Sources:
UMD Energy. What are RECs? May, 2007
http://www.umdenergy.org/?page_id=12.
Monohan, Patricia and David Friedman, UCS. Grinning Planet. Diesel or Gasoline? May, 2007.
http://www.grinningplanet.com/2005/04-12/diesel-vs-gasoline-article.htm.
McElroy, Michael B. Harvard Magazine. The Ethanol Illusion. Nov.-Dec., 2006.
http://harvardmagazine.com/on-line/110634.html.
Radich, Anthony. Energy Information Administration. Biodiesel Performance, Costs and Use. May, 2007.
http://www.eia.doe.gov/oiaf/analysispaper/biodiesel/index.html.
Carbon Sequestration Leadership Forum. An Energy Summary of the USA. May, 2007.
http://www.cslforum.org/usa.htm.
Carbon Sequestration Leadership Forum. An Energy Summary of China. May, 2007.
http://www.cslforum.org/china.htm.
U.S. Environmental Protection Agency. Emission Facts: Greenhouse Gas Emissions From a Typical Passenger Vehicle. February, 2005.
http://www.epa.gov/otaq/climate/420f05004.htm.
U.S. Environmental Protection Agency. Average Carbon Dioxide Emissions Resulting From Gasoline and Diesel Fuel. February, 2005.
http://www.epa.gov/otaq/climate/420f05001.htm.
CarJunky.com. Motorcycles: A Fuel-Efficient Alternative. March 4, 2007.
http://news.carjunky.com/motorcycles-a-fuel-efficient-alternative-cde041.shtml.
My Drive. A Diesel Honda? That Gets 62.8 Miles a Gallon. April 30, 2007.
http://mydrive.roadfly.com/blog/ExJxZ3/.
Business Week. The Diesel Armada. May 4, 2007.
http://www.businessweek.com/autos/autobeat/archives/2007/05/the_diesel_arma.html.
Tesla Motors. The Tesla Roadster. May, 2007.
http://www.teslamotors.com/index.php?js_enabled=1.
Berdichevsky, Gene. Tesla Motors, Inc. The Tesla Roadster Battery System. August 16, 2006.
http://www.teslamotors.com/display_data/TeslaRoadsterBatterySystem.pdf.
Science Daily. Superconducting Wire Achieves Major Milestone. May 10, 2004.
http://www.sciencedaily.com/releases/2004/05/040510014333.htm.
China Daily. Three Gorges Dam Competed. May 21, 2006.
http://www.chinadaily.com.cn/bizchina/2006-05/21/content_596086.htm.
Schafer, Sarah. Newsweek. China Leaps Forward: The People’s Republic is Embarking on the World’s Biggest Nuclear Building Spree. February 6, 2006.
http://www.msnbc.msn.com/id/11080908/site/newsweek/.
Wise, Jeff. Popular Mechanics. The Truth About Hydrogen. November, 2006. Pp. 83-129.
Suzuki. High Mileage Suzuki. May, 2007
http://www.suzukicycles.org/high_milage_suzuki.shtml.
CBS News. Ethanol Pollution Surprise: EPA Finds Worrisome Levels of Toxic Air Pollutants at Ethanol Plants. May 3, 2002.
http://www.cbsnews.com/stories/2002/05/03/tech/main508006.shtml.
U.S. Environmental Protection Agency. Green Power Partnership. May, 2007
http://www.epa.gov/greenpower/partners/top25.htm.
Union of Concerned Scientists. Clean Vehicles: Biodiesel. May, 2007
http://www.ucsusa.org/clean_vehicles/big_rig_cleanup/biodiesel.html.
Energy Information Administration. International Energy Outlook 2006. May, 2007.
http://www.eia.doe.gov/oiaf/ieo/highlights.html.
Nine Planets.Org. The Sun. May, 2007.
http://www.nineplanets.org/sol.html.
Business Week Online. Science and Technology: Another Dawn for Solar Power. September 6, 2004.
http://www.businessweek.com/magazine/content/04_36/b3898119_mz018.htm.
* * *
Gas-Powered Sedan: The 2006 Volkswagen Golf GLS TDI gets between 37 and 44 miles per gallon of gasoline depending upon whether it is in the city or on the highway. That means that it burns about .0247 gallons per mile. One gallon of gasoline weighs only about 6 pounds, but when burned produces 19.4 pounds of carbon dioxide. Therefore, the 2006 Volkswagen Golf emits approximately 4.8 pounds of carbon dioxide per ten miles traveled.
Gas-Powered SUV: The 2007 Jeep Grand Cherokee Laredo 4X4 gets a maximum of 21 miles per gallon of gasoline or .0476 gallons per mile. Therefore, the 2007 Jeep Grand Cherokee emits approximately 9.2 pounds of carbon dioxide per ten miles traveled.
Hybrid: The most fuel-efficient, gasoline-powered car in the US is the rather unsightly Honda Insight, a hybrid that gets between 60 and 66 miles per gallon depending on whether it is in the city or on the highway. However, it only seats 2 people. 62.5 miles per gallon is equal to .0157 gallons per mile. Therefore, the Honda Insight emits approximately 3.1 pounds of carbon dioxide per ten miles traveled.
Diesel: In 2010, many European and Japanese automobile companies will introduce their new clean-diesel vehicles to the US. The Diesel Honda Accord will get 62.8 miles per gallon whether in the city or on the highway. It seats 5 people and can run off of bio-diesel as well as regular diesel. Diesel has higher energy content than gasoline and gives automobiles the ability to travel 30% farther on one gallon. The downside is that it takes 25% more unrefined petroleum to make 1 gallon of diesel than it does to make gasoline. 62.8 miles per gallon is equal to .0159 gallons per mile. Every gallon of diesel burned produces 22.2 pounds of carbon dioxide. Therefore, the Diesel Honda Accord will emit approximately 3.5 pounds of carbon dioxide per ten miles traveled.
Bio-diesel: With the combustion of bio-diesel, there is a 50 percent reduction in particulate matter and a 60-90 percent decrease in air toxics such as carbon monoxide. In addition, there are 75 percent less carbon dioxide emissions. However, bio-diesel gets 11 percent less miles per gallon than regular diesel. So in theory, the Diesel Honda Accord run on B100 bio-diesel would get about 55.9 miles per gallon and emit 5.55 pounds of carbon dioxide per gallon. Therefore, the Diesel Honda Accord run on pure bio-diesel would emit approximately 1.0 pound of carbon dioxide per ten miles traveled.
Ethanol: It takes 1.5 gallons of ethanol to travel the same distance as 1 gallon of gasoline. In 2006, the cost of domestic ethanol came to $3.16 per gallon. This means that one would have to pay $4.74 to get the same mileage as 1 gallon of gasoline. In addition, according to the EPA, volatile organic materials such as formaldehyde and ascetic acid produced from ethanol factories are up to 10 times worse than the acceptable amount. Environmentally, emissions from ethanol are quite positive; but in the life cycle of growing corn or sugar cane, producing ethanol and consuming it, the petroleum that goes into the entire procedure only amounts to a total savings in fuel efficiency of 10 percent. So in theory, the Volkswagen Golf run on bio-diesel, would get about 44.6 mpg. Therefore, the vehicle would emit approximately 4.3 pounds of carbon dioxide per ten miles traveled.
Electric: The Tesla Roadster is an electric car that goes 0-60 in 4 seconds. Its top speed is 130 mph with a range of over 200 miles per charge. It has a battery life of about 100,000 miles and receives a full battery charge in 3.5 hours. Its cost is $92,950. The electricity that would power this car comes from over 70% hydrocarbon-producing energy sources in the US and over 80% in China. In addition, due to America’s failure to due away with its copper-based electric network, over 10 percent of all electricity generated is lost to resistance in the wires. To fully charge the vehicles battery takes 56 kilowatt-hours of electricity assuming no electricity is lost during plug-in. In 2006, 3.7 trillion kilowatt-hours of electricity was consumed in the USA. The production of that electricity emitted approximately 2.3 billion metric tons of carbon dioxide. Therefore, the electric grid that the Tesla Roadster would be plugged into produces about .00062 tons of carbon dioxide per kilowatt-hour consumed. That means that the 56 kilowatt-hour charge needed to power-up the Tesla Roadster would emit .035 metric tons or 77 pounds of carbon dioxide from the production of electricity. Being that the Tesla Roadster electric car has the ability to travel 200 miles on one charge, it therefore emits approximately 3.7 pounds of carbon dioxide per ten miles traveled.
Hydrogen Fuel Cells: The emissions produced from vehicles using hydrogen fuel is 100 percent water in the form of vapor. However, 95% of America’s hydrogen is produced from natural gas. Hydrogen fuel cell vehicles can now travel 300 miles on 17.6 pounds of hydrogen or .0588 pounds per mile. Making 1 pound of hydrogen produced from natural gas emits approximately 2 pounds of carbon dioxide. Therefore, a hydrogen fuel cell powered automobile would emit approximately 1.2 pounds of carbon dioxide per ten miles traveled.
Simple Mathematics CO2 Efficiency Ratings
1.0 – Bio-diesel
1.2 – Hydrogen Fuel Cells
3.1 – Hybrid
3.5 – Diesel
3.7 – Electric
4.3 – Ethanol
4.8 – Gas-Powered Sedan
9.2 – Gas-Powered SUV
** (Ratings in pounds of carbon dioxide produced per ten miles traveled.)
* * *
Hybrids can result in a 35 percent reduction in CO2 emissions, but fossil fuel consumption is set to rise by 34 percent by 2030. Therefore, it is fairly shortsighted to invest in a 35% solution. And with only a 27% decrease in CO2 emissions clean diesel suffers the same problem.
According to the Union of Concerned Scientists, the combustion of B100, or pure bio-diesel, results in about 10 percent more nitrogen oxide emissions (emissions responsible for smog) than do the emissions of regular diesel. However, bio-diesel can be produced from nearly any organic oil which promotes crop rotation and with close to an 80% reduction in carbon dioxide emissions, it is a difficult option to ridicule. Ethanol, on the other hand, would require the clear cutting of rainforests for monoculture corn and sugarcane plantations to supply America’s demands, and the benefits of ethanol only amount to only a 10% reduction in overall carbon dioxide emissions than do the most efficient gasoline-powered sedans.
Electric powered vehicles amount to a 23% decrease in CO2 emissions and takes the pollution away from the cities and puts it at the power plants; but being that carbon dioxide is a green house gas, it’s effects are just as severe no matter where on earth the emissions originate. Carbon dioxide emissions related to electric automobiles completely depends upon where the electricity originates, so an electric automobile charged from 100 percent wind or solar power emits no carbon dioxide at all. In China, it is possible to buy a 3 kilowatt wind turbine for home use that is about the same size as a street lamp and relatively silent for $2,500 which would be more than sufficient to power a Tesla Roadster and just about everything in an average household. In addition, restructuring America’s power grid with superconductors would conserve 10 percent more electricity.
Hydrogen fuel cells would lessen CO2 emissions by 75%, but would cost close to $1 trillion just to set up the infrastructure. With improved technology, hydrogen could be a 100% CO2-free solution if it was produced via renewable energy resources. However, with present technologies, it would cost up to $3 trillion. Nuclear power also produces no carbon dioxide emissions, and at present, China is constructing a $300 million nuclear plant that can generate 195 thousand kilowatts and, in theory, is completely protected from meltdowns.
* * *
Of EPA Green Power Partners, PepsiCo rates number 1 in use of Green Energy (biogas, biomass, geothermal, small-hydro, wind and solar) with 100 percent of its 1.1 billion kilowatt-hours of energy coming from green. Number 2 is wells Fargo (42%). Number 3 is Whole Foods (100%). Number 4 is the U.S. Air Force, although it only accounts for 4 percent of its over 11 billion kilowatt-hour total energy consumption. The rest of the top 25 green power users includes Johnson & Johnson (39%), U.S. Environmental Protection Agency (100%), Los Angeles County Sanitation Districts (57%), Starbucks (20%), DuPont Company (4%), U.S. Department of Energy (3%), Vail Resorts (100%), HSBC North America (35%), Cisco Systems, Inc.(21%), Staples (20%), New York University (100%), The World Bank Group (100%), University of Pennsylvania (29%), IBM Corporation (4%), U.S, Department of Veterans Affairs (3%), Nature Works LLC (89%), Sprint Nextel (47%), Safeway Inc. (2%), Pennsylvania State University (20%), Kohl’s Department Store (8%) and Nike, Inc. who uses 72 percent green energy. **
**These rankings are determined by purchase of renewable energy credits (RECs) from the EPA, not direct production-consumption. Fossil fuels cost around .07 cents per kilowatt-hour compared to clean energy costs of .08 cents per kilowatt-hour. RECs allow for clean energies to enter the market and the public electric grid without taking a profit loss.
Sources:
UMD Energy. What are RECs? May, 2007
http://www.umdenergy.org/?page_id=12.
Monohan, Patricia and David Friedman, UCS. Grinning Planet. Diesel or Gasoline? May, 2007.
http://www.grinningplanet.com/2005/04-12/diesel-vs-gasoline-article.htm.
McElroy, Michael B. Harvard Magazine. The Ethanol Illusion. Nov.-Dec., 2006.
http://harvardmagazine.com/on-line/110634.html.
Radich, Anthony. Energy Information Administration. Biodiesel Performance, Costs and Use. May, 2007.
http://www.eia.doe.gov/oiaf/analysispaper/biodiesel/index.html.
Carbon Sequestration Leadership Forum. An Energy Summary of the USA. May, 2007.
http://www.cslforum.org/usa.htm.
Carbon Sequestration Leadership Forum. An Energy Summary of China. May, 2007.
http://www.cslforum.org/china.htm.
U.S. Environmental Protection Agency. Emission Facts: Greenhouse Gas Emissions From a Typical Passenger Vehicle. February, 2005.
http://www.epa.gov/otaq/climate/420f05004.htm.
U.S. Environmental Protection Agency. Average Carbon Dioxide Emissions Resulting From Gasoline and Diesel Fuel. February, 2005.
http://www.epa.gov/otaq/climate/420f05001.htm.
CarJunky.com. Motorcycles: A Fuel-Efficient Alternative. March 4, 2007.
http://news.carjunky.com/motorcycles-a-fuel-efficient-alternative-cde041.shtml.
My Drive. A Diesel Honda? That Gets 62.8 Miles a Gallon. April 30, 2007.
http://mydrive.roadfly.com/blog/ExJxZ3/.
Business Week. The Diesel Armada. May 4, 2007.
http://www.businessweek.com/autos/autobeat/archives/2007/05/the_diesel_arma.html.
Tesla Motors. The Tesla Roadster. May, 2007.
http://www.teslamotors.com/index.php?js_enabled=1.
Berdichevsky, Gene. Tesla Motors, Inc. The Tesla Roadster Battery System. August 16, 2006.
http://www.teslamotors.com/display_data/TeslaRoadsterBatterySystem.pdf.
Science Daily. Superconducting Wire Achieves Major Milestone. May 10, 2004.
http://www.sciencedaily.com/releases/2004/05/040510014333.htm.
China Daily. Three Gorges Dam Competed. May 21, 2006.
http://www.chinadaily.com.cn/bizchina/2006-05/21/content_596086.htm.
Schafer, Sarah. Newsweek. China Leaps Forward: The People’s Republic is Embarking on the World’s Biggest Nuclear Building Spree. February 6, 2006.
http://www.msnbc.msn.com/id/11080908/site/newsweek/.
Wise, Jeff. Popular Mechanics. The Truth About Hydrogen. November, 2006. Pp. 83-129.
Suzuki. High Mileage Suzuki. May, 2007
http://www.suzukicycles.org/high_milage_suzuki.shtml.
CBS News. Ethanol Pollution Surprise: EPA Finds Worrisome Levels of Toxic Air Pollutants at Ethanol Plants. May 3, 2002.
http://www.cbsnews.com/stories/2002/05/03/tech/main508006.shtml.
U.S. Environmental Protection Agency. Green Power Partnership. May, 2007
http://www.epa.gov/greenpower/partners/top25.htm.
Union of Concerned Scientists. Clean Vehicles: Biodiesel. May, 2007
http://www.ucsusa.org/clean_vehicles/big_rig_cleanup/biodiesel.html.
Energy Information Administration. International Energy Outlook 2006. May, 2007.
http://www.eia.doe.gov/oiaf/ieo/highlights.html.
Nine Planets.Org. The Sun. May, 2007.
http://www.nineplanets.org/sol.html.
Business Week Online. Science and Technology: Another Dawn for Solar Power. September 6, 2004.
http://www.businessweek.com/magazine/content/04_36/b3898119_mz018.htm.
