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Magnetic cheap energy?

  1. Oct 7, 2008 #1
    Hey guys,
    I have not taken a course in magnets, so I cannot provide specifics, and this idea might be completely insane. However, my brother was asking me about the idea that magnets could power a turbine, condense a spring, whatever, that would generate heat, and would make energy. The idea is similar to most other power plants and ideas, like nuclear fission how the reaction spins a turbine to create energy, except that it would be a magnet powering it. He works at a hospital and knows that MRI machines use really high powered magnets and it doesn't cost alot to run, so he figured maybe running high powered magnets to run a turbine could create cheap and very safe/environment friendly energy.
    Personally, it seems to me that the energy put in to power the magnet would be similar to the energy output, but like i said, I dont really know.

    Please any advice would be great, I dont mind at all if you just destroy the idea, because like i said, i thin it sounds kind of foolish, but he is curious, and I am too a little bit.

  2. jcsd
  3. Oct 7, 2008 #2
    Nice try...It's pretty much perpetual motion, won't work. Sorry
  4. Oct 7, 2008 #3
    I thought MRI's cost a lot to run. Magnets are up to like 3 Tesla, which requires a lot of current through the magnets. You can do that either through pumping a lot of power into it, or cooling the magnets to make them superconducting.

    Neither is really cheap as far as I can tell.
  5. Oct 8, 2008 #4


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    MRI machines do cost a lot to run. I did a project involving cooling this MRI machine: http://www.fonar.us/su_siting.htm

    Altogether, it demands more than 150 kW. That's about $15 an hour plus the monthly demand charge of about $2000.

    If the machine is running half the time during the work day, that would be about $3200 a month to run it.
  6. Oct 8, 2008 #5


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    Consider this: how does compressing a spring once generate energy? A magnet is basically just a spring with a different relationship between force and distance. Conservation of energy applies.
  7. Oct 8, 2008 #6

    Chi Meson

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    There is a huge "yada yada yada" in the middle of that one.

    And, when the turbine spins to "create energy," it doesn't. It transforms the kinetic energy of the spinning turbine into electric energy (electric current). ANd to do this you spin coils of wires through, guess what? Magnetic fields! So you'd save a lot of time by using your high powered magnets to spin around a coil of wire, instead of using them to turn the turbine first. And what's going to spin those magnets (they must move you see, otherwise no current is created)? Use something like an MRI machine? IT needs an electric current. So plug it into the current that your spinning magnets are creating, and there is your PPM! Except it doesn't work, since friction, heat, noise, and other nonconservative effects remove energy from the system, and the machine grinds to a halt in...what, seconds?
  8. Oct 8, 2008 #7
    Spinning magnets in a field is an electric motor. It is not practical to use an electric motor to turn a generator cause there is loss and they are sort of the same thing. Kinda like using a big fan to spin a windmill to create power. It will work, but its gonna cost you.
  9. Oct 8, 2008 #8


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    Staff: Mentor

    It seems like we have an answer, so I'm closing.
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