Can Electric Cars Reduce Emissions?
Editor's Note
August / September 2009
Volume 7 Number 4
Our last issue, which dealt principally with research and technology in the automotive industry, engendered various responses. Clearly, what's happening in that beleaguered industry is of more than passing interest. We'll keep you posted on R&D in the months ahead.
Meanwhile, you may be interested in this letter we received from Vlado Bevc of the Synergy Institute in California. He takes issue with several of the pieces in the magazine.
You write about electric cars and their government-subsidized evolution. There is no doubt that various models and versions of electric cars can be designed and —€”with government subsidy—€”produced and sold. What your articles fail to present is the overall picture as to what effect substitution of electric cars for conventional cars would have on the economy and the environment about which you profess to be concerned. Following is a simple analysis of the effect of the electric cars on the environment, energy management and the specter of global warming supposedly caused by carbon dioxide.
Consider first the environment that is to be "saved." The mass of Earth's atmosphere is about 5.3 billion megatons. The measured amount of carbon dioxide (by number of molecules) is 381 parts per million, that is approximately 3 million megatons. This amount of carbon dioxide varies throughout the year by 6 parts per million, that is by 48,000 megatons. Compared with these numbers all the figures of emissions attributed to human activities are of very little significance. There are 160 million automobiles in the United States (and about 500 million in the entire world). On the average every car in the United States uses about 500 gallons per year. Burning one gallon of gasoline produces 18 pounds of carbon dioxide. All the cars in the United States, accordingly, emit 640 megatons of carbon dioxide annually. Compared to the 3 million megatons of C02 already in the atmosphere this amounts to a mere 1.3 percent of the natural annual variation. Thus removing all the automobiles would have very little effect on the amount of carbon dioxide in the atmosphere.
However, the internal combustion engine-powered automobiles are to be replaced with electric cars. These, too, require energy. The same amount as the conventional cars, to be sure. The energy in one gallon of gasoline is about 37 kWh. Because the efficiency of the internal combustion engine powered cars is about 25 percent we can readily estimate that the energy required for propulsion of electric cars in the United States is about 800 billion kWh. In the year 2005 the annual generation of electrical energy in the United States was 4,038 billion kWh. Accordingly, electric energy generation would have to be increased by at least 20 percent—€¦. "Stewards of the Planet," however, always oppose construction of any new electric power plant. To generate annually 800 billion kWh, 45 nuclear power plants with capacity of 2,000 megawatts would be needed. But "Protectors of the Environment" oppose nuclear power plants. About 72 percent of electrical energy is produced in electric power plants using the so much maligned fossil fuels, the greater part of which is coal. Allocating this amount of fuel to the electrical energy needed for electric cars consider that 576 billion kWh is produced by coal fired power plants. On the average fossil fuel fired power generating plants require 4 kWh of energy to generate 1 kWh. Accordingly, fuel with a total of 2,300 billion kWh of heating content is needed. The heating value of coal is about 4 kWh per pound. Hence 256 megatons of coal are needed. At combustion, that amount of coal produces 940 megatons of carbon dioxide.
We see that in the present economic system and today's technology replacement of 160 million internal combustion engine-powered automobiles in the United States with electric cars would increase carbon dioxide production by almost 50 percent. It would not matter to the environment, really, as pointed out above, but one adopts for the moment the view of the "Guardians of the Environment," the situation would thus be made even worse as far as carbon dioxide generation is concerned.
Theoretically it is true that carbon dioxide could be more easily sequestered at the power-generating plants than in the individual automobiles but sequestration is not used to any great extent at present. Promoters of electric cars also say that the needed electrical energy will be provided by photovoltaic solar electric power generating plants. In 2005 solar electric power generating plants produced a total of 500 million kWh (as compared with the total electric power generation of 4,038 billion kWh). All other options, such as the renewable energy including hydroelectric power generated a total 457.3 billion kWh.
Finally it should be examined if the world resources of lithium are adequate to supply enough of lithium for the storage batteries required by 500 million cars in the world.. While the known deposits of lithium might suffice for batteries of 600 million automobiles the production of batteries would require energy and petroleum products, too. For a car battery containing 35 pounds of lithium each an annual production of 60 million new automobiles would require 1.08 million ton of lithium, which is 50 times more than the current production which amounts to 20,000 tons—€¦.
Agree? Disagree? Vlado Bevc has had his say. You can have yours by emailing us at myturn@innovation-america.org.
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