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Can electricity be made from diesel?

  1. Jul 18, 2008 #1
    I went to a traveling carnival a few weeks ago, and I noticed that the carnival had several generators to power the rides. My guess is the generator ran off either diesel or gasoline in order to make electricity, although the electricity from the generator might have came from a battery.

    Can a generator without a battery create electricity from diesel fuel?

    Can a generator without a battery create electricity from gasoline?
  2. jcsd
  3. Jul 18, 2008 #2


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    The method of turning the generator (or alternator) doesn't matter.
    It can be diesel, gasoline, water power, or even a hand crank.

    Generators have a residual magnetic field that allows them to self excite.
    If for some reason the generator becomes completely demagnetized then a battery or some other electrical source is required to remagnetize it.
  4. Jul 18, 2008 #3


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    Some have permanent magnets as well for the initial excitation.

  5. Jul 19, 2008 #4
    notime and stewartcs,

    I'm guessing that the diesel fuel is to start an engine in order to create mechanical power. The generator then turns the mechanical energy into electrical energy. Is this correct?

    I am not sure what you mean when you say that some have permanent magnets for the initial excitation. Do you mean that a magnet is used to start the engine?
  6. Jul 19, 2008 #5


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    The diesel fuel is the chemical energy source for the mechanical energy (the prime mover in a generator) that will be converted into the electrical energy.

    In order for the generator to produce useable electrical power, the armature must be excited by a separate field. The field poles are energized by residual magnetism, an external source such as a battery, permanent magnets, self-excitation, or possibly some combination.

    Here is a little info on field excitation:


    To get the prime mover rotating, you'll need some type of starter. This may be another electrical source such as a bus (electrical bus that is), batteries, air, etc.

    Hope that helps.

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