Electric Vehicles are not "Green"
Western Governors University
October 26, 2011
Electric Vehicles are not "Green"
Over the last several years there has been much advancement in the automotive industry around hybrid technology as well as electric vehicles (EVs). There is also a lot of hype in the media around being "Green" or environment friendly. However, research shows that the production and operation of a pure electric car is no better to the environment and produces roughly the same greenhouse gasses as a traditional petroleum powered passenger car; this is because the majority of electricity needed to power an electric car is produced by burning fossil fuels; transmission and storage of electricity for electric cars is inefficient; and the materials used to store electricity for these cars must be mined, refined and shipped before they can be turned into batteries.
For the purpose of this paper, two like models of standard production car will be used so that we can directly compare one model to the other of the same car. First we have chosen the 2012 Ford (2011a) Focus ELECTRIC for the first car. This car is a four door hatch back with an all electric system. The battery in the car is a 23 kilowatt hour (kWh) lithium-ion battery. The kilowatt hour becomes important in our calculations so to explain that now, a kilowatt hour is a measurement of energy over time. This is different than a "kilowatt" which is an amount of power at a given moment. These numbers are related but indirectly. One kilowatt is equal to 1,000 watts; and one watt over one second is equal to 1 joule of energy. So 1 kilowatt is equal to 1000 joules. Since there are 3600 seconds in one hour, 1 kilowatt hour is equivalent to 3,600,000 joules of energy. (Blanco, 2009)
The second vehicle used in this research is the Ford (2011b) Focus gasoline powered vehicle. This vehicle was chosen to match the physical attributes of the first vehicle. This vehicle has a 12.4 gallon fuel tank and has a combined Environmental Protection Agency fuel economy rating of 31 miles per gallon. (Ford, 2011b)
In order to understand why plug-in electric vehicles are not green we need to understand where electricity comes from. According to Enderton (2006), in 2005 the majority of electricity generation comes from burning fossil fuels. As much as 72.8% of electricity in the United States comes from burning coal, oil, or natural gas; in fact, 49.88% comes from burning coal alone. Narain and Watson (2009) confirm that coal fuels 50% of the world’s energy demands and 90% of coal used in the United States is used for the production of power. Coal is also a leading cause of acid rain caused from Nitrous Oxide and Sulfur Dioxide.
Eilperin (2007) states that the United States produces 2.8 billion tons of carbon dioxide (CO2) each year directly from power generation; this is 40% of all greenhouse gases produced by the United States and 25% of all greenhouse gasses produced in the world. China, the United States each produce more carbon dioxide than all other countries combined (International Energy Agency, 2011).
Using calculations provided by the United States Environmental Protection Agency (2011a, 2011b, 2011c) we find that Oil, Natural Gas, and Coal respectively produce:
1672lbs/MWh of carbon dioxide, 12lbs/MWh of sulfur dioxide, and 4lbs/MWh of nitrogen oxides
1135lbs/MWh of carbon dioxide, 0.1 lbs/MWh of sulfur dioxide, and 1.7lbs/MWh of nitrogen oxides
2,249 lbs/MWh of carbon dioxide, 13 lbs/MWh of sulfur dioxide, and 6 lbs/MWh of nitrogen oxides
And with 28.11% of power not creating CO2 emissions, we get an average of 1388 pounds of carbon dioxide per Megawatt hour generated. To charge the 23 kilowatt hour battery fully will require nearly 29 kilowatt hours of energy for reasons which will be address further in the report. Because of this, charging the battery on the vehicle will generate approximately 42 pounds of carbon dioxide and other greenhouse gasses. Using figures from Blanco (2009) we can see that the Ford (2011a) electric vehicle will get 3.2 miles per kilowatt hour so the electric vehicle will produce .56 pounds of greenhouse gasses per mile. On the other hand, the Ford (2011b) gasoline powered car will get 33 miles per gallon. Coe (2005) states, each gallon of gasoline produce19 pounds of greenhouse gas. This means that the gasoline powered vehicle produces .57 pounds of greenhouse gas per mile. This is a negligible difference under 2% in greenhouse gas production between the two cars.
Storing energy or power in a battery can be inefficient and this inefficiency is not flat or linear. Real world experience with an electric vehicle as described by Wilder (2009) that it requires an additional 26% of power to charge a battery than the battery is capable of holding. According the a study performed by John Stevens and Garth Corey (1996) depending on the current state of a battery, this in efficiency can be as high as 50% requiring two times the amount to top off a battery above 90%.
So if you take the electric vehicle down to the corner store to pick up dinner and back only driving 3 or 4 miles, using 15% of the battery and plug the car back in, it will take nearly 30% of that batteries capacity in electrical power to charge it back to full. These inefficiencies are the reason it takes 29 kilowatt hours to charge a 23 kilowatt hour battery. Also if you increase the voltage and amperage supplied to the battery system such as adding a 240v plug or a 70amp high voltage circuit, you may shorten the life span of the battery. (Brodd, R. & Winter, M. 2004) (Wilder, 2009)
Another reason that electric vehicles are not environment friendly is because of the material that goes into creating the batteries which stores their energy. Lithium (Li) must be mined and then shipped to be refined before then being converted into material that can be used in the production of batteries. According to Ober (2006), the majority of lithium is produced in Chile, but according to Wray (2009) half of the world’s reserves remain untouched in Bolivia. However, once the material is mined from these South American countries it is shipped to South East Asia to be refined and turned into batteries.
This brings us to our next major contributing factor as to why electric vehicles are no friendlier to the environment. In an article by John Vidal (2009) cargo ships produce 5,200 tons of sulfur dioxide per year and 3.5 to 4% of all greenhouse gas emissions. And these batteries are shipped half way around the world and back before they are placed into the car.
So in conclusion, with the current state of electrical power generation in the United States being fossil fuels; along with the inefficiencies and potentially short lifespan of batteries. Plus the fact that the material used to create the batteries must be mined and shipped; refined and shipped again; a pure electric vehicle is no more environmentally friendly than a comparable gasoline powered vehicle and may be much worse for the environment.
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