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Underwater Power Generation?

Posted by Cliff on from the natural-dynamos-under-the-sea dept.

An anonymous reader writes: "We keep seeing stories here about tidal power, and that's cool, but I don't see how it can be done without a column rising all the way to the surface. So here are the ideas I've got right now." Read on for some interesting thoughts on the subject...

"Keep in mind that the device will probably be housed in a length of 4-inch PVC or ABS pipe, and it needs about 0.5 ma at 1.5 volts:

  • Surge power. Put a couple of funnels back-to-back with a CPU cooling fan-sized turbine and generator in the middle, and run the output through a rectifier and capacitor. But how reliable will those moving parts be after years underwater?
  • Self-winding watch concept. Float the thing tethered to the bottom and install some sort of pendulum inside with a magnet on it, moving through a coil. The moving parts are protected, but will it be enough power?
  • Yank the chain. Again, tether it, but use the varying tension on the tether to drive a dynamo of some sort. Not sure how this would work.
  • Magnetohydrodynamic generator. Like the surge power thing, but using the flow of cunductive seawater through a magnetic field to generate a current. I have no idea how much power this would generate, if any, or how to deal with ion accumulation at the electrodes.
  • Nukes. Anyone got a spare radioisotope thermoelectric generator? Any idea how many smoke detectors I'd need to cannibalize to get enough Americium-241?
The generator need not fit inside the 4-inch cache tube, but it shouldn't be huge, either. It needs to be practical to build, and not terribly expensive. Above all it's got to be reliable and enduring. Any ideas?"

6 of 62 comments (clear)

  1. Cold fusion by Anonymous Coward · · Score: 0, Funny


    Do cold fusion in the sea. It's easy.

  2. I'd love to help you... by Anonymous Coward · · Score: 3, Funny

    But first you need to tell us who you are and why you want and underwater lair.

    1. Re:I'd love to help you... by Rorschach1 · · Score: 3, Funny

      Gah, you've discovered my evil secret! I suppose I may as well give you all the details. I am Man-Ray, scourge of the oceans and destroyer of land-dwellers. Soon, my perpetually blinking submarine LED devices will be placed in all of the world's oceans, a constant reminder of my aquatic domination to those who might venture into my domain! Muahahahahahaha!

      And stay off the lawn, damnit!

  3. Dangerous by 0xB · · Score: 2, Funny


    You do realise that by extracting energy from the sea you will be affecting the currents and temperature gradients, and this will have a knock on effect on the weather?

    You may think 0.5mA is not much, but just wait until Canada turns into a barren desert and then you'll be sorry.

    --
    0xB
    1. Re:Dangerous by Jonny+290 · · Score: 3, Funny

      just wait until Canada turns into a barren desert and then you'll be sorry.

      You sure about that, eh?

      --
      Hey Taco! Looks like you're using the "infinite monkeys and typewriters" scheme to generate Ask Slashdots again...
  4. Bubbles? by n2linux · · Score: 2, Funny

    How about harnessing the power of underwater fart bubble? ;-)