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Underwater Ocean Kites To Harvest Tidal Energy

eldavojohn writes "A Swedish startup has acquired funding for beginning scale model trials of underwater kites, which would be secured to a turbine to harness tidal energy for power. The company reports that the kite device allows the attached turbine to harvest energy at 10 times the speed of the actual tidal current. With a 12-meter wingspan on the kite, the company says they could harvest 500 kilowatts while it's operational. This novel new design is one of many in which a startup or university hope to turn the ocean into a renewable energy source."

11 of 203 comments (clear)

  1. Unintended consequences... by synaptik · · Score: 4, Funny

    Because of the tides, the Earth's rotational energy is being stolen by the moon, which is using that energy to slowly escape from orbit. (This is a diminishing effect over time, that will eventually reach equilibrium.) But when we leach this energy for our own purposes, we are changing the delicate balance of that equation. ...Siphon off too much energy from the tides, and we could either increase the rate at which the Earth is slowing, bring the moon crashing down upon us, or both!

    Won't somebody think of the children? We owe future generations a planet fit to live on and capable of sustaining the future.

    --
    HSJ$$*&#^!#+++ATH0
    NO CARRIER
    1. Re:Unintended consequences... by Yakasha · · Score: 5, Funny

      Won't somebody think of the children? We owe future generations a planet fit to live on and capable of sustaining the future.

      Don't worry, it is being developed by a private company. Private industries regulate themselves.

    2. Re:Unintended consequences... by Amouth · · Score: 5, Interesting

      well based on what i have read - as the moon/tidal effeects work the earth is slowing down and the moon is gaining potential energy related to earths gravity well by moving farther away - assume this is a colosed energy system..

      assume we pull energy out of it.. the moon will come closer to earth (or reduce it's movement away) - so the total energy supply would be the potential energy of the moon in relation to earths gravity well.

      PE = m x g x h

      m = 7.3477 × 10^22 kg
      g = 9.8 m/s2
      h = 363,104,000 m (using it's Periapsis)

      PE = 2.61461968 × 10^32 Joules

      474 × 10^18 = AEC = whole planet annual energy consumption

      PE/AEC = 551,607,527,000 years....

      so the answer is .. keep current rates.. and assume we could get it all from here.. 550 billion years..

      according to this #19
      http://helios.gsfc.nasa.gov/qa_sun.html

      "In about 5 billion more years, the useable hydrogen (not all the hydrogen) will have been converted to helium, and the Sun will start burning helium, and become a red giant."

      if i remember right.. if it goes red giant it will grow larger than 1 AU so it will engulf earth..

      basically.. we could increase energy consumption by a factor of 100 and only then would we be toying with maybe crashing the moon into us before the sun burns us away.

      --
      '...if only "Jumping to a Conclusion" was an event in the Olympics.'
    3. Re:Unintended consequences... by edumacator · · Score: 4, Funny

      God, I love reading the comments on this site.

      I have no idea if you know what you are talking about, but you better believe I will be pulling this shit out at the next party I go to.

  2. sweet by gandhi_2 · · Score: 4, Insightful

    now whales can enjoy the "renewable revolution" like migratory birds and bats do with windmills.

  3. Re:Haha by ColdWetDog · · Score: 4, Funny

    Careful what you ask for. You might get it.

    --
    Faster! Faster! Faster would be better!
  4. Re:Stupid question, but one that's always bugged m by Nadaka · · Score: 5, Informative

    short answers: No, there is. The sun. No.

  5. Sea kites for space travel by T+Murphy · · Score: 4, Funny

    Tidal forces are from the moon, and over time the moon is getting farther away. Clearly, if we harvest tidal energy we will force the moon away faster as it makes up for the difference. If NASA times it just right, we could put people on the moon, launch the moon at Mars and have people walking on Mars just months later. Melt the polar icecaps on Mars, use tidal kites there, and repeat as needed to keep using the moon as our Earth/Mars space shuttle. Add Phobos and Deimos into the mix and space tourism can take off.

    Next, we use the tide from the sun to travel to Alpha Centauri.

  6. You are overlooking the obvious... by postermmxvicom · · Score: 4, Funny

    The solution is obvious. I am selling gravity credits to absolve you of your moon-doom guilt. Each credit you purchase represents energy gathered from sources not directly linked to the moon's potential energy plus some of the profits will be used to fund missions that will increase the moon's potential energy. This gravity offset program will save the earth for our posterity. As the administrator of this program, I will, of course, take a percentage of the sales as compensation. My motives are, however, purely in the interest of the future.

    --
    One last thing: Sometimes I wonder; "Is that someone's signature? Or do they type that at the end of each post?"
  7. Explanation video on YouTube by phiz187 · · Score: 5, Informative

    I was having difficulty visualizing this technology, from the text description. Here is a YouTube video that sheds more light. Spoiler: essentially the tethered kite does figure-8 patterns to continually move the turbine through the water.

    http://www.youtube.com/watch?v=1qCDRj8TE9Y

    --
    Pretend I said something meaningful or insightful here.
  8. Re:dem dang numbers by fava · · Score: 4, Informative

    Thats not how it works.

    The kite is really a steerable sail that moves back and forth across the current, thereby increasing the velocity through the attached turbine.

    An animation is available at http://www.ebase.se/minesto/animation.htm

    fava