Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electricity in Space

  1. Feb 11, 2007 #1
    First post here, hello!

    Just wondering if I could get a second opinion on something. I'm doing my GCSEs right now, and after learning about the way electricity is generated, I had an idea, but I don't know if it's possible as I'm no expert.

    Electricity is produced when you have a magnet rotating within a magnetic field right? We spend alot of money making the magnets rotate, burning stuff usually to produce the power to turn them. Because of friction of gravity and air resistance and all of that, we have to keep using resources to make power. In space, there isn't gravity and there isn't air resistance. You can push something in space and it will keep on moving forever if it doesn't hit anything. Surely this means you could have a turbine in space, give it one push, and it would carry on turning forever(or until friction stops it)? Wouldn't this be a really cheap way of powering space stations.etc?

    I'm guessing there's some flaw in my plan, as I would've heard about it before if it was pheasable, but I'm wondering what you think...
  2. jcsd
  3. Feb 11, 2007 #2


    User Avatar

    Staff: Mentor

    The flaw in your plan is that by far the largest source of energy loss is the energy required to rotate the magnet against a magnetic field! That's where the electrical energy comes from and the energy required is exactly equal to the energy generated.

    Also, friction forces due to gravity are miniscule compared to the forces being applied to the generator, so internal friction won't change much if the generator were put in space.
  4. Feb 11, 2007 #3
    Oh ok then, I get that, I hadn't taken the magnetism into consideration...

    Thanks :-)
  5. Mar 12, 2007 #4
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook