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When are you going fully electric?

Discussion in 'Motors' started by Ricochet J, Aug 23, 2018.

  1. b0rn2sk8

    Mobster

    Joined: Mar 9, 2003

    Posts: 4,056

    You are confusing efficiency and total potential energy and potential energy per kilo. They are all very different things. Yes petrol has way more potential energy per kilo but creating it and using it is incredibly inefficient. You lose huge amounts of that potential energy through the extraction, refining, transportation and combustion of that fuel.

    Think of it this way, 1 US gallon of fuel has approximately 33kWh of energy and gets the average american car 35 miles. 33kw in an electric car will go over 130 miles in something like a Kona, Ionic or Model 3 and over 100 miles in something like a Model S. This also completely ignores the extraction, refining, transportation and combustion of that fuel. Electricity generation and battery charging is considerably more efficient than producing petrol.

    https://cleantechnica.com/2018/03/10/electric-car-myth-buster-efficiency/
     
  2. satchef1

    Mobster

    Joined: Apr 17, 2009

    Posts: 3,822

    MJ/kg is the specific energy held by a battery. It has nothing to do with efficiency.

    On efficiency, there is absolutely no contest. EVs are in a completely different league to petrol or diesel.
     
  3. Simon

    Capodecina

    Joined: Oct 21, 2002

    Posts: 22,403

    Location: Berks / Moscow

    What is ‘battery efficiency’ then ? I am quoting you. In the context of a vehicle is it not weight efficient way of storing
     
  4. Jonnycoupe

    Capodecina

    Joined: Oct 19, 2002

    Posts: 11,545

    Location: N.Warks

    God we’ve gone down this road again...
     
  5. satchef1

    Mobster

    Joined: Apr 17, 2009

    Posts: 3,822

    efficiency
    /ɪˈfɪʃ(ə)nsi/
    noun

    The ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in.

    [​IMG]

    Electric cars use considerably less energy to travel the same distance. That is efficiency. Internal combustion engines aren't very efficient at all; the vast majority of the energy present in Petrol is simply wasted.
     
  6. Simon

    Capodecina

    Joined: Oct 21, 2002

    Posts: 22,403

    Location: Berks / Moscow

    Oh dear I seem to have made one comment earlier about the energy density of fuel and now we end up comparing Electric motor vs ICE efficiency as some sort of battery proof point.

    Batteries are rubbish energetic storage devices compared to liquid fuel. However I see this post could be argued so I will suceed in advance as generally apples are more green than oranges.

    Ps your chart above seems to look at getting crude oil out of the ground but completely ignores battery manufacture and raw material mining. It’s also rubbish as it can’t decide if it should be talking about petroleum or gasoline (petrol in the U.K)
     
  7. Jonnycoupe

    Capodecina

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    Posts: 11,545

    Location: N.Warks

    Driveline EV is way better but I bet you now, amusingly, battery compared to fuel tank the fuel is way more efficient.... you put 50L in and have maybe 49.95L litres to use. You need to put a lot more than 50kWh in.
     
  8. satchef1

    Mobster

    Joined: Apr 17, 2009

    Posts: 3,822

    Ok. We'll go bigger. Life-cycle vehicle analysis:

    https://www.google.com/url?sa=t&sou...FjADegQIBxAB&usg=AOvVaw2X_SnVumXjL8QVF0Sado_n
     
  9. Jonnycoupe

    Capodecina

    Joined: Oct 19, 2002

    Posts: 11,545

    Location: N.Warks

    Page 24 has a Honda Insight plugged into the grid with an ironic “I drive a clean car”. Oh dear.

    Let’s not switch the thread to a usual
    Google egurgitation exercise. I’m looking forward to the Honda Urban EV later in the year.
     
  10. Simon

    Capodecina

    Joined: Oct 21, 2002

    Posts: 22,403

    Location: Berks / Moscow

    I still said energy density of batteries is miles away from fuel. Petrol stations at full wack are like a power station.

    I’m not sure why people are making other points to argue with now. I was simply highlighting a fact that I found interesting when I first heard it and it shows how much needs to change for EV to mass adoped.
     
  11. Simon

    Capodecina

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    Location: Berks / Moscow

  12. satchef1

    Mobster

    Joined: Apr 17, 2009

    Posts: 3,822

    You're still mixing up efficiency with energy density and specific energy.

    I know batteries cannot store as much energy by weight, or by volume. I am not arguing the contrary. It's you that keeps switching terms every other post.

    The primary disadvantages of EVs are range and refuelling speed. Both relate directly to specific energy. But that isn't efficiency. Weight is a factor of efficiency, but nothing more.

    Because that's a like-for-like comparison. Petrol to Battery & Electricity isn't. Why would you factor in the main source of pollution and inefficiency from an EV drivetrain and ignore the same from a petrol car?

    Petrol is 100% efficient, if you never burn it. But stick it in a car, and around 5/6ths of the stored energy is wasted.
     
    Last edited: Jan 6, 2019
  13. b0rn2sk8

    Mobster

    Joined: Mar 9, 2003

    Posts: 4,056

    I have been pretty impressed with how Tesla Auto Pilot has been progressing lately. Navigate on nav where it takes highway exits in the satnav route automatically seems to be coming along nicely.

    https://www.youtube.com/watch?v=UBee9tmrY64
     
  14. satchef1

    Mobster

    Joined: Apr 17, 2009

    Posts: 3,822

    You missed the joke then I take it? Look again.

    It's a drawing of a car that's connected to an oil power station, spewing out pollution, with the caption "I drive a clean car".

    The source of that study isn't pro-EV. It's a research group representing European oil producers. Far from being propaganda, it was intended as advice to the oil industry on how seriously they should take EV environmental claims.

    While found via Google, it's the specific document that I was looking for rather than just a random one I stumbled across. I could have gone with a source like The Guardian or Electrek, but both are too easy to dismiss as being partial.
     
    Last edited: Jan 6, 2019
  15. Simon

    Capodecina

    Joined: Oct 21, 2002

    Posts: 22,403

    Location: Berks / Moscow

    The insight mk1 is not a plug in hybrid
     
  16. Jonnycoupe

    Capodecina

    Joined: Oct 19, 2002

    Posts: 11,545

    Location: N.Warks

    Exactly I expect accuracy. Atleast chose a plug in-hybrid not arguably one of the cleanest self charging hybrids on planet earth. I’ve had one just like that for the last 10 years.

    I did get the joke, my use of the English language allowed me to use the word ironic to highlight the joke without needing a sentence to explain it...

    Doesn’t matter if that EV is not clean, it can get cleaner as power stations are upgraded and grid mix changes. Unlike any ICE.
     
  17. satchef1

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    Fair enough. But it's not like they drew the image; the source is in the bottom right corner. Personally, I just saw a car, and I think it's perfectly plausible that the author(s) saw the same, or simply thought is was humorous.

    It's fairly inconsequential to the findings of the research though. There's no shortage of studies like this, all coming to the same conclusion; EVs are cleaner and more efficient than the existing fleet of motor vehicles. The trade-off is range and refuelling speed (the primary areas that manufacturers are currently concentrating on).
     
  18. Simon

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    The detail is what matters in studies like these though
     
  19. satchef1

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    Posts: 3,822

    Want me to source a different study that states the exact same thing? There's no shortage of them.

    Or shall we just accept that a stock image in a report is inconsequential to the findings of a study?
     
  20. Simon

    Capodecina

    Joined: Oct 21, 2002

    Posts: 22,403

    Location: Berks / Moscow

    Thing is. If people try and prove something by just throwing a lid of info over the fence them I’m inclined they don’t understand it or can’t be bothered to summarise.

    Ultimately EV future needs green power to work. But what if that green power could go into a liquid instead