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Windmills in the Sky

Posted by michael on from the don-kee-ho-tay dept.

An Anonymous Coward sent in: "The BBC is reporting on works of an Australian scientist who has been developing flying turbines that use the stable jet stream at 4.5 km altitude to generate electricity and send it back to the ground via cables."

2 of 13 comments (clear)

  1. Transmission isn't a problem by Spamalamadingdong · · Score: 3
    The cables would have to be awfully thick (hence heavy) to transmit a decent amount of power 3 miles. Then you're wasting power just keeping them up in the sky.
    Not really.
    1. Transmitting power 3 miles, even over lossy cables, doesn't lose much compared to the losses in transmitting power several hundred miles even over low-loss cables.
    2. Keeping the machine in the sky is easy; the rotors develop lift by themselves due to their angle against the wind. You can consider this "wasted power", but it's power that comes from the wind (it's free) and you more than make up for it with the higher wind speeds at the upper altitudes (you get more power from the same size rotor than you would near the ground).
    If the winds aren't high enough to keep the machine in the air and still develop excess power, you just reel it down to the ground and park it. You might use a little power to land it and then to help it take off again, but you make up for that with the power it generates when it's on station. You use external power to run the pumps and fans to get a fuel-burning powerplant started up, so I don't see any big difference between the two.

    I think this is a very clever idea, and I hope that someone can find a way around the air-traffic and bird-strike issues that are bound to arise and make this practical.
    --
    Give a man a fish and he eats for a day.

    --
    Scientists restrict study to entire physical universe; creationist
  2. Problems by Anoriymous+Coward · · Score: 4

    The cables would have to be awfully thick (hence heavy) to transmit a decent amount of power 3 miles. Then you're wasting power just keeping them up in the sky.

    I imagine Australians don't worry too much about stuff falling out of the sky - Skylab & Mir both missed - but I think other, more populated, countries would have a hard time implementing this. Regardless, you have yet more transmission costs once you get to the ground (although obviously this is a problem with well known solutions).

    The jet stream is stable because it is uninterrupted. One wind farm isn't going to change that. Put enough of them up there, though, and you're going to change weather patterns.

    It's a nice idea, but I don't see it being terribly practical.

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