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B Harness heat energy

  1. Mar 31, 2016 #1
    Is there a way I could harness heat energy in a drone, if so, how?
  2. jcsd
  3. Mar 31, 2016 #2


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    Hi there
    Welcome to PF :smile:

    energy from where and to use it for what ?

  4. Mar 31, 2016 #3
    @davenn Heat energy from the sun to power the said drone
  5. Mar 31, 2016 #4


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    In order for a heat engine to work, you need a temperature difference. In a drone, you can easily pick up heat, giving you a "warm reservoir". You could try to use the surrounding air as a "cold reservoir", but the thermal resistance between a "heat sink" and air is fairly high (that is why CPU's use a fan).
  6. Mar 31, 2016 #5
    I am trying to build a drone which could be used in African villages and am looking to find a backup energy, in case the battery fails. Solar seems like the predominant choice, but I feel like heat could work really well too, so I need a way of harnessing it.
  7. Mar 31, 2016 #6
    Couple of points. The maximum attainable temperature with Solar flux is 120C. If you consider your cold reservoir at 0C, Carnot's efficiency is 30 percent. Practically it would be much lower. Also heat engines are generally not that light weight. You could better consider Photovoltaic panel instead.
  8. Mar 31, 2016 #7


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    You would never get enough useful energy
    Solar cells would be much better, but you will still have a problem of collecting enough energy to keep a drone flying
    The best you could do would be to use solar power to recharge batteries whilst they are not in use and then swap
    them with the discharged ones from the drone

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