Evironmental footprint

edited August 2012 in General
As I did preorder the Model S I of corse end up discussing with a lot of people about it. Most common argument of other people is, that the enviromental footprint is just as high as with a gas car. My google search only dig out the following article:

In the end the article say that if a gas-car emits 60 to 80 mpg (in the german article the say between 3-4 liters of gas) the Gas car will be just as 'enviromental friendly' as the electric car. For this calculation the take the normal energy mix which you get when you don't get a eco-friendly package.

What I just don't get is, that everywhere it's stated that the electric engine is way more effective than a gas one. That enerergy made in any plant is more enviroment friendly than burning it in the car. The study also shows that the battery inpact on the footprint is only 15% of the vehicle...

so how can it end up right beside my 5 year old prius? wich would burn 4.3l of gas theoretically. For me that just doesn't make sense.. but then they are probably smarter than I am.

Are there any other studies?
What do you guys think?


  • edited November -1
    Christian - Here is the original report your link refers to (in English):
    The report includes energy used to produce the whole car. The efficiency of energy used when driving plays a smaller role in this particular study.

    If you look at the details there you can also see that some assumptions made are conservative.
    Other points to consider are:

    1) If you drive a Tesla Roadster behind a Prius (exactly the same way) across a test track where the Prius reaches the 4.3l/100km (55 mpg US) you mentioned, your Roadster would have consumed about the equivalent of 1.4 liters of Mogas (140Wh/km) and that with a car with incomparably more performance. If you drive the Roadster behind a Ferrari across the same track representative for his nominal consumption of 15 l/100km (16mpg US) you would still have only used the energy equivalent of 1.4 l/100km. So you would have consumed about 10 times less. Even allowing for generation and distribution of electricity will leave the Roadster very much ahead. So it all depends on the comparisons chosen.

    2) In real life cars with combustion engines rarely achieve their nominal tested consumption. A lot of mileage is done e.g. with cold engines in urban traffic. I have not found a good report quantifying these effects across the fleet, but they are thought to be substantial. See e.g. (in German).
    More calculations and estimates I have gathered here:

    - Alfred
  • edited November -1
    EVs may well be terrible "enviromentally". Environmentally, however, they're excellent. W<b>h</b>ich does make sen<b>s</b>e.

    Much of your spelling, on the other hand, ...

  • qwkqwk
    edited November -1
    Much of the information on the web is biased, so take that with a grain of salt.

    <p>I use the common sense technique.

    <p>To make gasoline you have to find, drill,pump from ground, transport from middle east, pipe from tanker, REFINE, pump to trucking point, truck to gasoline station, pump in your car.

    <p>That is very much energy wasted which no one factors in when using this calculation.

    <p>Then ann ICE also uses more fuel to warm up to temp, and it idles. Two energy wasting steps electric cars avoid.

    <p>As far as manufacturing goes, they also forget that an ICE needs fuel filters, oil filters, OIL, air filters, spark plugs, Spark plug wires, cap&rotor, belts, clutches, fuel pumps, alternators, starters etc. When you take all this into account, the ICE looks worse and worse.

    <p>Of course none of these studies take this into account, because they are probably sponsored by...............
  • ggrggr
    edited November -1
    Here's an analysis by a colleague of mine of the environmental impact of emissions of Grid EVs versus ICE. Because power generation plants are either very efficient, or (hydro, wind, geothermal) cause no emissions at all, the bottom line is that electric vehicles cause about 1/20th of the pollution per mile traveled. (This doesn't count manufacture, only running.)
  • edited November -1
    Sorry for my spelling, but it's even bad in german so don't expect anything else in english ;)

    Well if the study takes in account that you have to dig for certain materials from the battery i of corse think that they do the same for the ICE car... but it's not really clarified wath they take in account for the ICE Ccar.

    Like I said I drive a prius myself, and I can confirm that you almost never achieve to get the claimed usage of fuel. Actually I drive almost the worst possible way for a hybrid. I go to the highway for 10 minutes, with cold engine, and thats it. I end up having 6.4 litres. If i drive longer distances it gets way better.

    I assume too that with the EV we will not get the same distance as they claim on one load.
  • edited November -1
    <p>Depends almost completely how your drive. With moderate speeds you can drive Roadster over 300 miles. In slow city traffic nearly 400 miles. In 75-80mph freeway less than 200 miles.

    <p>Those EPA range calculations need to be taken as they are: estimates using certain parameters. If you know how much and what way your driving differs from those parameters you can estimate how far you can expect to drive with one charge. That, and then there is a very accurate battery charge meter that can show you your range in few mile tolerance.
  • edited November -1
    Most people I have spoken to don't think that an electric car has a "fuel gauge". This myth has got to be eradicated.

    About the cold engine, in an electric, this matters little. The batteries, however, cannot run cold. That is why Tesla's vehicles have a battery warmer and cooler that keeps the battery at the optimum temperature.

    Please buy a Tesla and sell that Prius. Question, what is the max range of a Pruis and what is the average mileage of a Prius in your experience?
  • edited November -1
    Actually, the batteries DO run cold in the Roadster; they just don't permit regenerative braking (charging) until the battery pack warms up.
  • edited November -1
    I did not know that. I do know that performance is greatly reduce by too cold batteries. I have lots of experience using RCs in the winter. The same car or plane that does 20 min. a charge in the summer will do 5 min. or less in the winter if it is not kept warm before use. Thanks for more info.
  • edited November -1
    So far I have not seen any significant impact on the range due to low temperatures, at least at -9C. I plan to try it at colder temperatures when I have the chance.
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