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  1. #1

    Default Electric aircraft in the near future? I don't think so.

    I knew that you would find the following interesting - taken from "How The World Really Works" A scientist's guide to our past, present and future, by Vaclav Smil.

    How soon will we fly intercontinentally on a wide-bodied jet powered by batteries? News headlines assure us that the future of flight is electric - touchingly ignoring the huge gap between the energy density of kerosene burned by turbofans and today's best lithium-ion (Li-ion) batteries that would be aboard these hypothetically electric planes. Turbofan engines powering jetliners burn fuel whose energy density is 46 megajoules per kilogram (that's nearly 12,000 watt-hours per kilogram), converting chemical to thermal and kinetic energy - while today's best Li-ion batteries supply less than 300 Wh/kg, more than a 40 fold difference. Admittedly, electric motors are roughly twice as efficient energy converters as gas turbines and hence the effective energy gap is "only" about 20 fold. But during the past 30 years the maximum energy of batteries has roughly tripled and even if it were to triple that again densities would still be well below 3,000 Wh/kg in 2050 - falling far short of taking a wide-bodied plane from New York to Tokyo or from Paris to Singapore, something we have been doing for decades with kerosene-fueled Boeings and Airbuses.
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  2. #2
    Senior Member piroska's Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    Yes, they seem to be concentrating on short trip planes. For obvious reasons.....
    Imagine a flat battery on a large plane while over the ocean and miles to go....
    Ex-pctek

  3. #3
    Wrinkly Member! B.M.'s Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    And the good news is all these Electric Cars and Trains and Planes will be powered by Electricity produced by Coal.
    Global Warming is Mann made.

    Do not regret growing older. It is a privilege denied to many.
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    The problems we face today are because the people who work for a living are now outnumbered by those who vote for a living.

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    tweakedgeek tweak'e's Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    even short flights with mid size is out of the question. there is small aircraft, ie 5 people, that can do really short distance. but thats about it.
    one thing is aircraft safety means they must have enough fuel on board to go to alternate airport or return. that drastically reduces your range.
    then theres the all important what happens in a crash or a forced landing.

    its all BS talk to make ev cars look better than they are.
    Tweak it till it breaks

  5. #5
    Retired old codger kenj's Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    Being electric, they would need a very long lead?

    Ken

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    Wrinkly Member! B.M.'s Avatar
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    Wink Re: Electric aircraft in the near future? I don't think so.

    Quote Originally Posted by kenj View Post
    Being electric, they would need a very long lead?

    Ken
    No, they're fueled by a Whim.
    Global Warming is Mann made.

    Do not regret growing older. It is a privilege denied to many.
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    The problems we face today are because the people who work for a living are now outnumbered by those who vote for a living.

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    Computer Technician wainuitech's Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    Shouldn't really be a problem, think about it, theres Hybrids in cars where the engine actually charges the battery, the neighbours have two electric, one a Leaf they have to charge nightly, the hybrid never gets charged as its engine can charge when its moving, so shouldn't be that hard to have a Airplane generate the forward motion and the few hundred km of wind into a generator that recharges the batteries.

  8. #8
    Retired old codger kenj's Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    Aah, perpetual motion? Have you cracked it?

    Ken

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    Wrinkly Member! B.M.'s Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    Quote Originally Posted by wainuitech View Post
    Shouldn't really be a problem, think about it, theres Hybrids in cars where the engine actually charges the battery, the neighbours have two electric, one a Leaf they have to charge nightly, the hybrid never gets charged as its engine can charge when its moving, so shouldn't be that hard to have a Airplane generate the forward motion and the few hundred km of wind into a generator that recharges the batteries.
    : :
    Global Warming is Mann made.

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    The problems we face today are because the people who work for a living are now outnumbered by those who vote for a living.

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    Computer Technician wainuitech's Avatar
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    Default Re: Electric aircraft in the near future? I don't think so.

    Quote Originally Posted by kenj View Post
    Aah, perpetual motion? Have you cracked it?

    Ken
    Exactly, some bright engineer can design something, they have a similar but smaller device now on all planes called a Ram Air Turbine, that if the plane loses all engine power it drops down into the airflow and generates power
    the RAT will power vital systems (flight controls, linked hydraulics and also flight-critical instrumentation
    So shouldn't be that hard to design a wind powered charger. ( prob not to good for a helicopter if its hovering )

    If the battery is self charging in theory it could stay up indefinitely.

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