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.
  • edited November -1

    Please let us know how the cold test goes.
  • edited November -1
    @Samuel H

    Don't know what you mean about the max range.. you mean the pure electric? I guess if you're lucky you'll get 2 miles and you have to drive around 40 km/h and not accelerate too much. But then that hybrid never was ment to drive on pure lectric, the electric motor should help the Gas Motor to avoid peaks... so it's just a cool feature to drive in silent mode throu the parking lot.

    Like I said my average is around 6 litres per 100 km. But that's me only driving short range distances on a highway. If I do longer trips, even on the highway I'm often under 5 litres.

    The Model S is defenitely high on my priority list, but it will all depend on the price here in europe. It's an expensive car and it's really close to what I'll be able to spend then. but yeah, can't wait until it comes out.
  • edited November -1
    I meant what is your range in hybrid mode using electric and gas in concert for max efficiency. Sorry didn't make myself clear. In other words, how far can you theoretically drive in your Prius?
  • edited November -1
    The standard mode is 'hybrid', wich means the ICE gets some support from the Electric motor and stores some engergy when riding down and breaking. This results in a lesser gas consumtpion compared to a ICE car the same size.

    additionally you can drive a very short distance (2-4km), in very slow speed (40km/h) in pure electric wich makes sence in parking lot's or stop and go traffic. The energy comes from the same 'small' battery. The battery itself is never charged it get's its energy a bit from regen braking and most of it from the ICE.

    So in the end it's just Gas consumptions. The prius has a 45L tank wich means:
    If I use the stated 4.3l / 100km I'll get 1046.5 km

    My average over the year is 6l / 100km = 750 km

    Long range trips were around 5.3l / 100km = 850 km

    But like I said, the 'range' kinda is limited as in the end It's a gas car. you refill it in 5 min. and you boldy go where everybody else also go...

    If you drive long distances my
  • edited November -1
    I heard somewhere that the Prius could only go 130 miles/209 km.
  • edited November -1
    You have heard wrong then. Prius has big enough fuel tank to have range of somewhere in 1000km range.
  • edited November -1
    70-80 mph is quite fast for European roads (autobahns etc. excluded). 50-60mph average would be closer to truth in Europe. That gives you a lot more range.

    BTW 11 gallons = 48 liters, Planar energy 1.2kWh/L batteries give you 57.6kWh, which means ~260mile range for Roadster using battery that is no bigger than Prius gas tank. Double that and have same range as Prius without filling tank/recharging battery.

    ChristianG 4.8L/100km with Prius is quite possible. One of my friends has average 5L/100km with Saab 9-5 (basically same car as one of the Cadillac models for you Americans). All you need is a very steady driving style and he does that semi-naturally. No excess gas usage, no revving in high gears, anticipating slowdowns etc. One of the most relaxing person to drive with. (not at all like my other drive-a-lot friend, that makes you grip the handles like if they are your only hope between this life and the abyss)
  • edited November -1
    I rented a Prius last year for a week and drove nearly 2,500 miles. Most of the driving was in the 70 - 80MPH range. My average MPG for the entire trip was ~ 48. Not willing to run out of gas I didn't push the empty needle too far. I usually filled up after about 400 miles. I believe the gas tank was about 11 gallons - 11*48 = 528.
  • edited November -1
    Well the way I think of it is; gas cars can only run on gas, which is very environmentally unfriendly. However electric cars can run on electricity made for fossil fuels OR sustainable sources like solar or hydro or wind etc.
    So electric cars have the potential to be environmentally neutral, minus the parts production etc.
  • edited November -1
    Not neutral. Electric cars are much more efficient. Even powered by coal their carbon footprint is a fraction of a gas car.
  • edited November -1
    Unusual thoght maybe but wonder if we looked at whole planet and do studies on if their are any ways we could have hydroelectic grid worldwide. Hydroelectric seems very environmentally friendly to me, again know there would be daunting challenges but that is what high tech people have thrived on historically speaking.
  • edited November -1
    @Timo those are imperial gallons. 11 US gal = 41.6 liters.
  • edited November -1
    How do you know which gallons those are? Are you "Tesla 940" with new username?
  • edited November -1
    Google works pretty well: Hydroelectric power
  • edited November -1
    I know that it's possible to come close to the said 4.3l / 100km... BUT my ride to my work does not allow it. It is a short ride, 10km and it's only highway (fast 120km/h). Driving short distances is very bad for the prius. If you drive longer it starts getting better like I said. But if I drive longer it's Highways again...

    Like it's stated in the article it causes many problems too, however if you do it on a smaller scales there some pretty good ways to get 'some' power. Like taking a river and only take part of the water to make the energy. Only little land is flooded by water and the eco system is untouched. Buuuut it's not nearly as efficient as the big damn-lakes.

    A very promising way to get energy beside Wind and Solar Power is this ... even as it too may cause problems it sounds pretty cool.
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