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I think I may have found a renewable energy source

  1. Sep 14, 2016 #1
    Hello guys so I have this idea of mine which I can't get my head around and I need someone to tell me why it won't work, so let's say you have a fully pressurised tank of air and you blow that pressurised air at a turbine connected to a generator, ovisously the generator will then start to create a voltage and when connected to a battery it will charge it, what if you then use that charge from the battery to spin a motor that spins a piston which then repressurises the tank and it creates a cycle again, and also the pressurised air tank at this point is still got some of it's original pressurised air left inside and it won't get used up so fast, think how long it would take to empty a full can of deodorant, also the generator is a 3000w genarator spinning at 2000RPM and the motor is only 200w also spinning at 2000RPM, and even if you include all the losses such at heat, mechanical movement on friction and even sound, then the generator could be outputting let's say 2500w and that's still enough power there to supply the motor, you know what I mean, thank you guys and I hope someone can help me out here, thank you.
  2. jcsd
  3. Sep 14, 2016 #2


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    Do the calculations and conclude that it doesn't work. You can't lift yourself off the ground by grabbing your hair.
  4. Sep 14, 2016 #3


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    Violation of conservation of energy. It won't work.

    You cannot simply throw numbers around. You need to do the math to calculate the energy or power in each step of the process and see what you have available for the next step.

    It is not.

    Thread locked.
  5. Sep 14, 2016 #4


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    I know the thread is already locked, but i'll be more specific about where you went wrong:
    RPM is totally meaningless here. What you are missing in your energy balance accounting is the very electrical energy you are using and producing! 500W of friction and other losses means the generator requires 3500W of mechanical power to turn it. Quite obviously, a 200W motor does not produce 3500W of mechanical power.
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