What’s the greenest car? A short guide to vehicle emissions

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A guide to vehicle emissions of four petrol cars and electric vehicles using four different types of electricity (coal, oil, gas and solar).

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Shrink That Footprint

Vehicle-emissions1

 

A few months back I did a post called The World’s 7 Greenest Vehicles.  It only included one car.  Since then a few readers have emailed to ask if I could do a similar comparison, but for cars only.  So here’s a very brief guide to vehicle emissions.

In the graph above I’ve compared the full vehicle emissions of four petrol cars (20, 30, 40 and 50 MPG) to that of an electric vehicle using four different types of electricity (coal, oil, gas and solar).  In each case I include the emissions from vehicle manufacturing plus the full scope of petrol and electricity emissions. What a wonk might call well-to-wheels plus manufacturing.

The results are pretty clear.  The better the fuel economy of a petrol car the lower its emissions.  For the electric car the major difference is the source of electricity.  The lowest emissions by a distance is the electric car using solar electricity. I’ve chosen solar (45 g CO2e/kWh) because there is high co-ownership of solar and EVs, but the emissions would be just as low using hydro, nuclear, wind or any other low carbon electricity.

That’s it, very brief as promised.  Diesel is slightly better than petrol but has a particulate problem. Do you think electric cars are going to be the low carbon vehicles of the future?  How about next-gen biofuels or hydrogen fuel cells?  For more on vehicle emissions check our posts on electric vehicle emissionsyour driving emissions and the world’s 7 greenest vehicles.

 

 

Source: Shrink That Footprint. Reproduced with permission.

 

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7 Comments
  1. Coaltopia 5 years ago

    Probably need to understand where the car is made and then how often the EV battery has to be changed. The Suzuki Alto is still probably one the best cars you can own in this country for life-cycle emissions.

  2. Martin 5 years ago

    What an utterly facile and non-sensical article.

    MPG? What gallon? Imperial or US?

    Distinguish between petrol cars with different fuel efficiencies, yet gloss over the significant efficiency differences of electric cars?

    Basing emission intensity and “greenness” solely on CO2 emissions?

    Ignoring the environmental damage of uranium mining and the radiation emission problems of nuclear power stations?

    Stating that diesel has a particulate problem while recent research suggests that “[n]ew Gasoline Direct Injection (GDI) petrol engines for cars emit more cancer-causing particles than modern diesel engines [..]”?

    Come on Renew Economy, you can do better than that. If you have to republish, be a bit more selective or add some critical sense.

    • Lindsay Wilson 5 years ago

      Hi Martin, this article is deliberately simple because it helps engage a type of reader that doesn’t generally bother with long winded studies. If you are interested in sensitivities to embodied energy and energy use please check out the full report: http://shrinkthatfootprint.com/electric-car-emissions
      On units and diesel vs petrol I take your point. Lindsay

    • JonathanMaddox 5 years ago

      I didn’t see nuclear power stations mentioned. Until now.

  3. JonathanMaddox 5 years ago

    Where’s wind? 🙂

  4. Peter Castaldo 5 years ago

    I think the top graph does very little to discuss or provide a genuine comparison. What type of gas was being used convention or fracked gas. Each well would give quite different results. Which coal type is being used brown or black and what if someone buys only green energy? We can pitch for whatever fuel we want with this approach. If I retrofitted a car that was to be scrapped with a battery system and only used my solar panels to charge them that would win by a mile I suspect.

  5. suthnsun 5 years ago

    2 points
    For a car purchaser – buy an electric car and ensure an ultra low emission energy supply ( costs no more if it can be organised) it’s the best you can do as a consumer (if a bike won’t do)

    For a car manufacturer – learn how to make an ultra low emissions ev. Increased consumer demand can only feed back more opportunity to do this. QED ( ev or other renewable storage technologies for transport are the only option)

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