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Science Forum

  1. 18 Mar '14 18:40 / 3 edits
    This sounds like a possible significant advance for tidal power esp in shallow water:

    http://phys.org/news/2014-03-wing-harvest-tidal-energy.html

    it doesn't give a detailed breakdown of cost so I don't know how it really economically compares with wind power although it does say:

    "...they have shown that their device gathers power as much as two to four times more efficiently than existing hydrokinetic systems
    ..."

    And the video link says "flowing water has a power density that is 1000 times that of wind" -but is that at the same speed? if so, that isn't a fair comparison because wind generally can move faster than a tidal current! Still, it sounds like it is economic.

    The same video link also says "the global tidal resource is estimated at 2.5 TW" -I don't know how that compares with the global power consumption of electricity. Anyone?
  2. Standard member sonhouse
    Fast and Curious
    18 Mar '14 20:33
    Originally posted by humy
    This sounds like a possible significant advance for tidal power esp in shallow water:

    http://phys.org/news/2014-03-wing-harvest-tidal-energy.html

    it doesn't give a detailed breakdown of cost so I don't know how it really economically compares with wind power although it does say:

    "...they have shown that their device gathers power as much as two to fou ...[text shortened]... .5 TW" -I don't know how that compares with the global power consumption of electricity. Anyone?
    I think that puts it at about 5%, I think the ww use of power is something like 50 Tw, 24/7 so 50 times ~8000 hrs, about 400,000 terawatt hours per year.
  3. 19 Mar '14 08:19
    Originally posted by sonhouse
    I think that puts it at about 5%, I think the ww use of power is something like 50 Tw, 24/7 so 50 times ~8000 hrs, about 400,000 terawatt hours per year.
    well, 5% would be a good contributor to renewables at least. Not a bad start! the rest can be made up with other renewables. I think there is a lot of potential for ocean current power ( http://en.wikipedia.org/wiki/Marine_current_power ) which doesn't rely on tides and, of course, has the advantage of being even more regular and predictable than tidal because it is just constant and steady. But I don't have a breakdown of costs of that either so I don't know how to compare.
  4. Standard member sonhouse
    Fast and Curious
    19 Mar '14 13:10
    Originally posted by humy
    well, 5% would be a good contributor to renewables at least. Not a bad start! the rest can be made up with other renewables. I think there is a lot of potential for ocean current power ( http://en.wikipedia.org/wiki/Marine_current_power ) which doesn't rely on tides and, of course, has the advantage of being even more regular and predictable than tidal because ...[text shortened]... and steady. But I don't have a breakdown of costs of that either so I don't know how to compare.
    But potential is not actual. When they say you can get terawatts from the ocean, you would be talking millions of these devices or more. That is not going to happen. My guess is economics would bottom them out at a few gigawatts max. The power from one nuclear station.

    That said, the more diversity in energy the better. The real solution will involve many different kinds of energy from solar to nuclear and everything in between like converting plant cellulose to energy and maybe if we are extremely lucky, cold fusion and even luckier, hot fusion which has several programs researching different ideas there like Tokamak Vs inertial laser and the Z pinch machine.

    Personally I think it would be utterly cool if the cold fusion dudes prove to be vindicated, that would literally give power to the people!