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Can we use counter-rotating rings to generate power on space

  1. Aug 19, 2015 #1
    I was reading a post by spongebob_79 about using counter-rotating rings to generate power and I had a thought. What is the general opinion of using counter-rotating rings mounted to 2 facing sides of a structure and simpily inducing opposite spins on the structures to generate power? Obviously good mechanical designs would need to be in play for it to work correctly and an amount of orbital construction would be needed as well. But, if it could be designed simply, cost effective, and modular then should not it be feasible?
     
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  3. Aug 19, 2015 #2

    Bandersnatch

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    Energy extraction slows down the spin. Inducing spin costs energy. Energy losses in-between mean that you're putting more energy in than you're getting out of it.
     
  4. Aug 19, 2015 #3

    phinds

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    Of course it's feasible if you don't mind spending extra money on totally wasted energy (as Bandersnatch pointed out) used to create the energy that you are "saving" that you could have just created directly.
     
  5. Aug 19, 2015 #4
    I am led to believe the thief you mean is friction? What if the surfaces do not touch and the energy is produced by magnetic induction?
     
  6. Aug 19, 2015 #5

    Bandersnatch

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    No. Friction is the cause of mechanical losses.
    The mere fact that you're extracting energy slows down the spin - i.e. making the electrons move in a wire requires energy.
     
  7. Aug 19, 2015 #6

    phinds

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    There is no such thing as a 100% efficient motor or generator. So,

    fuel -> motor -> spin -> generator -> electricity

    has losses at every stage

    So does

    fuel -> generator -> electricity

    but it has fewer stages in which to incur losses.
     
  8. Aug 19, 2015 #7
    Ok. I understand. I am going to have to do some more research on the input costs v. output results. It just seems to me that in an orbital environment, the input energy to induce and maintain the spin would be less than the output gained in power production of the generator...strange.
     
  9. Aug 19, 2015 #8

    phinds

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    You are now talking about a perpetual motion machine ... free energy. It doesn't work and discussion of this crackpot idea are banned on this forum. I understand that you "get" that it doesn't work, I'm just letting you know.
     
  10. Aug 19, 2015 #9

    berkeman

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    Welcome to the PF.

    Over-unity mechanisms (and perpetual motion machines) are on the Forbidden Topics list in the PF Rules (see Info at the top of the page). We do not discuss them because they are a waste of time to discuss. Please see the links below in the quote from the Rules -- they should help you to understand the issues better. :smile:

    Thread is closed.
     
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