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Edited on Sat Dec-15-07 05:50 PM by nothingtoofear
The US produces and uses 4.0682 trillion kwh/yr of electric energy. The new Telsa Roadster runs on a 53 kwh battery and lasts 245 miles. There are 243,023,485 passenger cars in the US.
If one in ten is replaced with a Telsa Roadster then the amount of energy for one 245 mile charge would be 1,288,024,470.5 kwh. (24,302,349 cars X 53 kwh = 1.288 billion kwh).
Likewise, the average number of miles a year that a driver drives is 12,000 miles. Of course we have to understand that not all 243 million cars on the road are driven that far, but it would be safe to assume that at least 10% of those are.
12,000 miles / 245 miles per charge = ~48.9796 charges per year (or roughly 49 charges/yr).
Therefore, 1,288,024,470.5 kwh X 49 charges = 63,113,199,054.5 kwh/yr or ~1.551% of the present total yearly production.
The problem arises however when more than that amount start using electric cars. If 100% of the population used them then 631,131,990,545 kwh/yr would be necessary or ~15.51% of our yearly production. This would cause the system to experience widespread brown and black outs.
Ways to remedy this... create a second power network solely for the powering of electric cars, use current infrastructure with minor adjustments and major add ons (costing undetermined billions to build new production stations) and / or make sure cars are only charged in off-hours, non-peak usage times (i.e. at night) but this in unenforceable unless the only place you can recharge your car will be at special stations (like gas stations) as to charge cars you would need special voltage anyways. This would be inconvenient at best. And during the summer power outages will still occur because air conditioner usage is still used at night in major cities. Regardless of the way it's done, we would have to find an inexpensive and non-bureaucratic way to transfer power between grids with need and grids with excess. And it has to be watched so that electric companies don't begin price fixing (it is debatable as to whether I should say continue to price fix, particularly on the west coast).
However, we also cannot be fooled that this would be a completely clean energy source. Electricity in the US comes from a variety of primarily non-renewable, carbon releasing sources:
49.1% (1.995 trillion kwh) comes from coal which releases energy at a rate of 2.1 pounds of coal per kwh or 4.1895 trillion pounds (2,094,750,000 short tons, US) of coal a year. And, coal releases an average of 2.86 short tons (2000 pounds in a short ton) of carbon dioxide per 1 short ton of coal expended. With 2,094,750,000 short tons of coal consumed each year, you will expect to emit 5,990,985,000 short tons of carbon dioxide a year already without adding on the new amount for the electric cars.
If coal will be burnt proportionally for the new energy demand for electric cars then: 63,113,199,054.5 kwh/yr X 49.1% = 30,988,580,700 kwh/yr by coal. This would add another
30,988,580,700 kwh/yr * 2.1 lbs/kwh * (1 short ton / 2000 lbs) * 2.86 short tons CO2/short ton coal = 93,058,707.8 short tons (186,117,415,600 pounds, that is: 186 billion pounds) of CO2 extra per year or about 1.55% more per year from coal.
If all cars, instead of just 10%, were to become electric then the following would be true:
930,587,078 short tons of extra CO2 (1,861,174,156,000 pounds, that is: 1.86 trillion pounds) or ~15.5% more by coal emissions than before from coal.
This number only describes the amount of CO2 released by coal however. Petroleum based combustion does make up 21.7% of the total used to create this nation's energy, but it comes in various forms (oil, diesel, natural gas, petroleum coke, and traces of others, which I'm sorry to say I don't have the patience to do all the math for, as each releases CO2 at different rates and each has different mitigating factors such as refining that I also don't want to tackle. It should also be mentioned that I do not account for the CO2 emission created by moving the coal to power plants or mining it in the first place, nor the potential heath hazards of doing so, nor the damage of strip mining on the environment (though it's not widely used).
-HOWEVER-
I must add two more statistics to this demonstration... The amount of carbon emission removed from the atmosphere by not burning fossil fuels in cars (as we are turning over to electric in this experiment).
Scenario: 100% turn over from gas cars to electric Telsa Roadsters (only).
World CO2 emissions each year is 27044Tg, and US emissions is 22% of that or 5,949,680,000,000,000 grams. 14% of US CO2 emissions came from cars. Totaling 918,175,938.5 short tons of CO2 (or 1,836,351,880,000 pounds, 1.84 trillion pounds) in 2006.
If all car owners turn to electric 2008 Telsa Roadsters then the amount of CO2 released will be 1,895,289,360 short tons extra by all electrical sources in proportion for cars in the US. (930,587,078 short tons C02 by coal * 100% of electricity / 49.1% by coal = 1,895,289,360 short tons of CO2 extra by all electrical sources in proportion for cars in the US.)
Therefore, the amount of CO2 emitted from cars TODAY, as we said, is 918,175,938.5 short tons. And the amount that would be released into the atmosphere if everyone traded in their cars for the 2008 electric Telsa Roadster (as described by the manufacturer) and they all worked at optimum conditions is 1,895,289,360 short tons of CO2. That is 977,113,422 short tons MORE CO2 per year. And, the byproducts of coal, heavy metals such as mercury, would also have to be dealt with care.
KEEP IN MIND HOWEVER That there are cleaning processes that can keep much of the emissions that are coal related from entering the atmosphere. It works at a 80-90% efficiency rate, however it can cost up to 41% more energy to do so and cost the consumer up to 91% more money (up to 10 cents per kwh).
SO THERE YOU HAVE IT.
Make your own assumptions and please, if anyone finds something wrong in my math itself don't hesitate to tell me. I know I didn't cite properly, but the numbers are accurate as I saw them from online sources ranging from the DOT to Wikipedia to the US Census website. Honestly I don't feel after this like going back and finding them all again, I hope you understand.
Cheers, NTF
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