Sunday, June 3, 2012

The Tesla S is Dirtier Than a Prius Hybrid



The Tesla S is Dirtier Than a Prius Hybrid




The boys at Teslacle have provided some ammunition for the Green Machine. They have provided a computer simulation of the range the Tesla S will attain with the 85 kilowatt hour battery pack and using the EPA’s new 5 cycle test method for electric vehicle operation.



I quote from Tesla below:



“New EPA Rating Procedures: 5-cycle vs. 2-cycle

When the Tesla Roadster was certified, the EPA only used a 2-cycle test that was carried out under conditions of 75 degrees Fahrenheit ambient temperature and with varying acceleration rates and driving speeds for both city and highway tests topping out at 60 mph.

Recently, the EPA incorporated three additional cycles into their tests that push vehicles to greater limits. The additional cycles added as part of the new “5-cycle test” include a cold driving cycle that requires heater use, a hot weather cycle with air conditioning operation, and a high-speed cycle (reaching 80mph) with rapid accelerations.

We are very pleased to report that Model S has exceeded our initial range expectations by about 20 miles and has achieved a Roadster equivalent 2-cycle range of 320 miles and a 5-cycle range of 265 miles.”



Ok we have that the S attained a range of 265 miles with 85 kilowatt hours of batteries. This is 321 watt hours per mile of DC power. Power is generated as AC at the power station and with transmission and distribution losses as well as the conversion of AC power to DC power we must add 15% to the watt hours per mile to calculate the energy usage in AC current. Therefore 369 watt hours of AC power are needed per mile for the Model S under the more realistic 5 cycle EPA test. The average 1,000 watt hours of power generation in the US emits 1.2 pounds of CO2. Therefore the CO2 emissions of the Tesla Model S that will go on sales later this month are 0.443 pounds per mile. A standard hybrid Prius gets 48 miles per gallon (source EPA) and a gallon of gas emits 19.564 pounds of carbon dioxide (source WRI). Therefore the standard hybrid Prius emits 0.408 pounds of CO2 per mile. Of course there are added emissions to explore, produce crude oil, transport crude oil and refine the crude into gasoline. Likewise there are added emissions to mine coal and transport the coal to the power station, or to explore, produce, compress, and transport natural gas to the power station, or mine uranium, enrich uranium and transport the uranium to a power station. On this basis let us stick with the simple analysis above where the Tesla Model S emits approximately 10% additional CO2 per mile than a Prius Hybrid.

Mr. Obama and Dr. Chu I am therefore asking you to give a Federal tax credit of S7,500 to each person who purchases a Prius Hybrid just as you give this amount to each person who purchases a Tesla Model S. Actually the tax credit for the purchase of a Prius Hybrid should be $8,250 to account for the additional emissions of carbon dioxide the Tesla Model S puts into the atmosphere. If Mitt becomes the president next year I am sure he will listen to my sage advice. Now I am really dreaming. Mitt will simply triple the tax credit for the rich person who buys the Model S and will tell the purchaser of the Prius Hybrid to walk more frequently if they want to save money. Mitt Antoinette will stand on the portico of the White House and tell us we are bloody fortunate to have a guy who knows business in charge of the country and Wonder Bread is good for us. Our Morton’s fork choice is between a private equity guy with green in the bank and a guy who is green between his big ears even after almost a full term in office. I doubt I will ever have enough money again to eat at Morton’s Steak House. God Bless America while we the 99% eat pink slime!!! In a couple of years Wendy’s will bring out a new ad on Facebook groups targeted to the senior citizens that has an octogenarian who asks “where’s the pink slime?” Folks we are in a burger joint of a Presidential race that serves only buns made of Wonder Bread and there is no meat.

7 comments:

  1. Lindsay, good entry. It is a great reminder of how easy it is to calculate the impact. Paul

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  2. This is a great entry. I think people need to start talking about total energy.

    Tesla's apparently are always consuming power and owners must always keep it plugged in when not driving. There are plenty of stories floating around the interwebs about Teslas consuming their batteries to depletion. For some reason, Tesla allows their batteries to drain to 0, which everyone from laptop owners to engineers know is a no-no for lithium ion. Having overseen development of rechargeable batteries before, omitting what is called under-voltage protection that disconnects the batteries from the load when they reach a minimum voltage, is ludicrous. The circuitry is small and cheap, and almost every battery manufacturer recommends it at the specification phase. Once the battery has discharged to 0, you now own a very large and expensive paperweight.

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