Energy from undersea pressure

Discussion in 'Physics & Math' started by Search & Destroy, Feb 16, 2012.

  1. Search & Destroy Take one bite at a time Moderator

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    Hi guys, I was on a long train trip recently and was trying to think up a unique solution to energy on the island I hail from.

    We are very near the deepest trench in the world, and I can even swim to the drop-off where you are looking at reef and in an instant staring into 5000+ foot abyss.

    Is there a way to drop something down there to harness the energy from the pressure?

    My best thought was some kind of turbine that spins and also creates heat, creating a pressure differential. I have no clue on physics, and was wondering if anything like this is possible through chemical, turbine, or some other means.

    Summary:
    Is it possible to drop something 10,000 feet down and harness the energy from the huge amount of pressure?
     
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  3. HectorDecimal Registered Senior Member

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    Hi S&D,
    I would tend to think, "Yes." You might wish to put Deuterium Ice in a search and compare what is going on in that. It is truly not ice, but highly compressed deuterium. You might want to try experimenting with mixtures permeated with deuterium gas and perhaps some host impurity. One thing to consider is compressibility of any materials used, in that layers or using materials that would withstand the pressures. You might try encapsulating a quartz crystal between two copper or aluminum plates then run a couple wires up to your boat or raft.
     
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  5. cosmictraveler Be kind to yourself always. Valued Senior Member

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  7. Aqueous Id flat Earth skeptic Valued Senior Member

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    You can test this idea by standing on a pump handle and developing a pressure, and using it to do work. When the handle is clear to the ground, you will have to lift it and get up and stand on it again.

    If you drop a bellows full of air, with a weight to make it sink, the water pressure will make it do work, such as to turn a turbine. But when the collapse is complete, you have to pull it up and refill it with air. The work you will do by raising and lowering the device will cost you more than you get out of your machine.

    In short, there's no way to create a useful cycle than pushes a piston back and forth, without doing more work to complete the cycle that comes after compression. In this case, you have to push the sea back out of your chamber. So that's the limitation.
     
  8. wellwisher Banned Banned

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    There is energy in the pressure differential between the deep trench and the surface. However, to take advantage of this you need to start at high pressure where all the energy is. For example, say we had a cylinder of gas at pressure P, we create at the surface. We then lower the cylinder using gravity, which does not require energy. Now the gas in the cylinder has a pressure of P+P2. We open the cylinder and release the gas in a pipeline the surface, to retrieve the energy from P2.

    The P2 energy needs to drive our compressor to put the gas back into the cylinder. We also need to get the cylinders back to the surface. We can float them up with some of the residual gas. But this will lower the energy of P2 to P2-P3.

    Another idea would be to generate our gas directly at the bottom, such as electrolysis of water. We add electric energy to some contained water in the trench, to make O2 and H2. This is floated up to the surface, via two pipelines, to gain the energy within the pressure differential between the trench and the surface. We use this pressure to drive a turbine to create the energy for the electrolysis. The H2 and O2 gas become the extra energy.
     
  9. Aqueous Id flat Earth skeptic Valued Senior Member

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    If either of those ideas worked, couldn't you just place something very heavy on them to develop the needed pressure?
     
  10. Aqueous Id flat Earth skeptic Valued Senior Member

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    Nice picture. Looks like they've got it all in Hawaii - wind, solar, wave and geothermal.
     
  11. HectorDecimal Registered Senior Member

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    Have you noticed what the quakes of this era are doing to islands?

    Aside from that, isn't wind power in the discussion hijacking this thread? Obviously the OP isn't written by a dummy who doesn't know about wind power. It was written by someone asking about a new possibility for alternative energy. Besides that, wind power only works when the wind is blowing. The pressure at 2 miles depth will remain constant.

    back to ideas 101...

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  12. Rhaedas Valued Senior Member

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    And there's the problem. There's no change or difference to harness.

    It might make a good OPEC site though, using the difference in temperatures of the upper and lower waters, not the pressure.
     
  13. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    That's OTEC, not OPEC!

    There's one on the Big Island, listed on the wiki article above.
     
  14. Rhaedas Valued Senior Member

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    So much for proofreading. Thanks for the correction.
     
  15. HectorDecimal Registered Senior Member

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    Can you imagine some way to artificially generate a pressure change at that depth?
     

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