Electric cars are a pipe dream

Discussion in 'General Science & Technology' started by Syzygys, May 20, 2010.

  1. billvon Valued Senior Member

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    The best available supercaps are the Maxwell caps, which max out at about 7.4Wh/kg. A good Panasonic 18650 li-ion cell is around 200 Wh/kg.

    If you are going by "what people claim" there are a lot of claims out there that improve on lithium energy chemistries; one recent one claimed 1550 Wh/kg. However, I have been seeing these claims for 10 years now and they almost never pan out. The only technology I've really seen work is silicon anode, which gives a modest improvement - 20 to 40% - in specific energy.

    I think it would be great to develop higher energy densities in capacitors or lithium ion batteries - but lithium ion batteries are, currently, much higher energy than capacitors. (Which, of course, is why they are used in EV's.)
     
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  3. Randwolf Ignorance killed the cat Valued Senior Member

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  5. billvon Valued Senior Member

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    Well, again, I was talking commercially available products. Comparing research samples to research samples would result in far higher capacities for both capacitors and lithium chemistry batteries.
     
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  7. elte Valued Senior Member

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    That's what I mean. I'd like cars to be way smaller and lighter. Something like eight feet long and 500 pounds.

    A big reason I bicycle besides not having to wait at all (and besides exercise) is because it works much better carrying most things things like food than public transportation. Load the bike up at the store front and unload it right at the home door. Don't have to walk with the stuff.
     
  8. DrZygote214 Registered Member

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    Not a bad point about carrying loads on the bike too insteada walking. But "not having to wait at all"??? You still have to wait...at cross streets, don't you? If everyone rode a bike instead of drove, I imagine bike streets and intersections would be necessary and you would have to wait a lot more. If everyone drove a car that was 8 ft and 500 lbs, well, we would all be doing the same amount of waiting in traffic as we do today.

    If the goal is to minimize time, then waiting for the bus should be indistinguishable from waiting at an intersection. It's all the same kind of time wasted, so the only question should be which one wastes more time? There are express busses in some cities that can get you across town just as fast as a car. So what if you have to wait 5 minutes for it? You just plan your walk so that you arrive at the bus stop a lil before the schedule, and the good cities make it a part of the driver's job to NOT depart early even if he arrives early.

    If everyone rode such busses, traffic would be way, way less, and commute times would be decreased even further, plus the gas and accident savings, etc. The occasional late bus is nothing in comparison to the time spent in rush hour 5 days a week (and twice each of those day for the average worker).

    I know shopping is a pain to carry bags on public transport. The good cities also let you carry a bike on the bus one way or another, so there's the possibility of getting the best of both worlds.
     
    Last edited: Feb 14, 2015
  9. elte Valued Senior Member

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    Busses can be useful for some people, and it is good that they are an option.

    It depends on where bicycling that determines how much waiting is necessary. Sometimes there are side routes that can get around waits that bigger vehicles can't use. Often times the bike doesn't have to wait long at a light if the coast is clear.

    I'm not sure how a bike loaded with heavy cargo would get onto a bus, but maybe there are special busses.

    Have you seen videos of the Chinese riding their bikes? Almost no one is waiting and there are loads of bikes all over the street.

    If everyone had very small cars, they wouldn't feel like they have a mini living room to cruise around in, and so would tend to drive less. Really small cars would take up less space on the roads which would ease congestion, given that most cars carry just one person.

    Personally, public transportation is added stress that I would rather avoid even if it happens to use more time to ride the bike.
     
  10. billvon Valued Senior Member

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    Here in San Diego, buses carry bikes via racks in the front. Pretty easy to load and unload.
     
  11. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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  12. Futilitist This so called forum is a fraud... Registered Senior Member

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    Electric cars are still a pipe dream.
     
  13. billvon Valued Senior Member

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    I have one; it works great. Indeed, at our company, one of the biggest complaints is that there aren't enough chargers to go around. We just installed another 38 charger parking stalls and already people are demanding more.

    So you may be dreaming about them, but other people are actually building, using and supporting them.
     
  14. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I can't find the link, but earlier today read Tesla had best car sale month ever - more than 1000 cars.
     
  15. Futilitist This so called forum is a fraud... Registered Senior Member

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  16. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    No, we are not. You were more nearly correct when starting the apocalypse-soon thread. There you just got the time scale very wrong. I. E. it is true on decade time scales that the average cost or oil is and will continue to rise, as the "low hanging fruit" is picked. Sugar cane alcohol has many advantages over gasoline, including lower cost per mile driven, fully renewable as is solar energy stored, and net zero (or initially slightly negative) CO2 releases.

    Reason it is not already the main liquid fuel for cars is that its production is very local and widely distributed. I.e. impossible for 5 or so large corporations to monopolize and control, like they do petroleum. If physics and economic rationality controlled the choice of energy systems for transportation, as you argue, then our cars would be using that alcohol, not gasoline, but powerful vested interest like to keep control of our transport fuel and are still doing so.

    Electric cars are currently to expensive for the masses to afford, in large part because of the cost/ battery size/ range relationship; but with Musk's GigaFactory, now in costruction and Tesla, soon to make available lower cost EV, at about $35,000 or less, the current use of gasoline will greatly drop. Your argument that the world must run on petroleum as physic proves that is nonsense.
    Your physics and /or entropy mandates world must run on oil is no more valid than the same argument applied to wood 200 years ago is.

    Currently EVs mainly run on fossil energy (converted to electrical energy, with over all efficiency of energy delivered to the Car's motor of less than 30%); but this is rapidly changing. Much faster than the change from wood to petroleum was. Solar cell capital cost per watt capacity continues to fall rapidly. So the solar to electric energy they make is at least doubling each year now.
    I. e. China ALONE will install three times more solar cell generation in 2015 than the US installed in 2014! China also leads the world in the two other forms of solar energy (Hydro-electric and wind), because it is working hard to end its terrible pollution problem, and ALREADY closing coal fired generation near the urban areas, where electric or human powered bikes etc. clog the streets.

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    No "red tape" to cut here - The CCP just commands and it is done.
     
    Last edited by a moderator: Apr 27, 2015
  17. Futilitist This so called forum is a fraud... Registered Senior Member

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    That is not my argument.

    I never said the world must run on petroleum. I said the world currently runs on petroleum. Petroleum will reach the dead state as an energy source in about 5 years or so according to the Etp model. That is not enough time to make a useful switch to alternatives, even if they could be scaled up, which is not certain.


    ---Futilitist

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  18. exchemist Valued Senior Member

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    To claim we will be out of useable petroleum in 5 years is the most daft prediction I have ever seen on this forum from someone who is not obviously certifiable. The oil price has just dropped because we have it coming out of our ears, thanks to the shale revolution and the geopolitical reaction to that. Do you really think that the price would be low if we were all going to run out of it within 5 years? If that were true, governments and utilities would be stockpiling it like crazy, forcing the price up, shares in oil companies would have gone through the floor and Saudi Arabia would not be pumping their remaining reserves as if there were no tomorrow.

    Even the ETP model you are touting, by this apparent crank B W Hill, does not claim the mythical "dead state" will be reached until 2030. There is no conceivable argument for saying this will run out or become unuseable in 5 years time.

    Suggest you look instead at a proper ETP model, by a reputable energy organisation, here: http://www.iea.org/etp/etpmodel/

    You will notice it reaches rather different conclusions, does not make the idiotic assumption that the role of petroleum is fixed and immutable, and does not involve any preposterous claims about thermodynamics. In fact you may notice that a lot of this model is about energy substitution of various kinds. Where is the discussion of energy substitution in Hill's model?
     
    Last edited: Apr 28, 2015

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