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View Diary: The simple innovation that could make wind power a big player (230 comments)

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  •  Fonsia, it's not ground up that gets the bats (4+ / 0-)
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    Agathena, jam, Fonsia, raincrow

    they're sensitive to bariatric shock....

    LBJ, Lady Bird, Anne Richards, Barbara Jordan, Sully Sullenberger, Ike, Drew Brees, Molly Ivins --Texas is no Bush league! -7.50,-5.59

    by BlackSheep1 on Tue Jan 22, 2013 at 12:07:02 PM PST

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    •  And noise polution. They put little whistles (1+ / 0-)
      Recommended by:
      raincrow

      on the edges of the blades to divert flocks of birds, disorients the bats.
      And though the blades on modern turbines are spinning slowly, the tips are moving nearly the speed of sound. But worse,  99% of the time it's not there, 1% of the time it is, and it's moving! Site placement is a real challenge for windpower and one of the reasons huge installations far away from their users are a problem. Distant unpopulated areas with good steady wind characteristics are too often also flightways.
      There are better designs in development, more bird friendly and they are better suited to smaller/closer.

      If I ran this circus, things would be DIFFERENT!

      by CwV on Tue Jan 22, 2013 at 12:54:08 PM PST

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      •  I beg to differ (7+ / 0-)

        1. I've worked on over 2,000 MW of wind and I've never heard of putting whistles on blades.

        2. The tip speed of the GE 1.5-77 (the most popular utility scale turbine in the US) is approximately 80 m/s or less than 25% of the speed of sound.

        Javelin, Jockey details, all posts, discontinue

        by jam on Tue Jan 22, 2013 at 01:06:41 PM PST

        [ Parent ]

      •  CwV, your comment that the tips move (1+ / 0-)
        Recommended by:
        raincrow

        at nearly the speed of sound just doesn't sound right.

        I searched the internet and came up with this quote from wikipedia.

        A wind turbine is designed to produce a maximum of power at wide spectrum of wind speeds. All wind turbines are designed for a maximum wind speed, called the survival speed, above which they do not survive. The survival speed of commercial wind turbines is in the range of 40 m/s (144 km/h, 89 MPH) to 72 m/s (259 km/h, 161 MPH). The most common survival speed is 60 m/s (216 km/h, 134 MPH).
        http://en.wikipedia.org/...

        That is roughly 1/6th the speed of sound.  Do your sources differ?  Is wikipedia just wrong on this?

        We cannot solve our problems with the same thinking we used when we created them. Albert Einstein

        by theotherside on Tue Jan 22, 2013 at 01:25:20 PM PST

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        •  different thing entirely (3+ / 0-)
          Recommended by:
          badger, KenBee, raincrow

          survival wind speed is the max wind speed that the turbine can withstand without damage - i.e. hurricane force winds.

          Tip speed is how fast the very tip of the blade is going. For example, a turbine with an 80 m rotor diameter spinning at 20 RPM has a tip speed of 84 m/s (187 MPH). The tip of the blade goes around a 250 m circumference circle in about 3 seconds.

          So, it's 1/4 the speed of sound, not 1/6 the speed of sound.

          Javelin, Jockey details, all posts, discontinue

          by jam on Tue Jan 22, 2013 at 01:38:33 PM PST

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          •  Fast enough to hurt if it hit you (3+ / 0-)
            Recommended by:
            Agathena, PrahaPartizan, raincrow

            At a truck stop in Indiana, I saw a single blade about 100 feet long on a wide-load truck. The fat end was 9 feet in diameter and hollow, all composite material, a beautiful and very impressive casting. Out toward the tip there were little,  1 inch high, fins, like guitar picks, embedded in the edge, a whole bunch of them in the outer 30-40 feet.
            I followed up with a friend that is way into wind (working on getting Cape Wind installed) and his explanation was that they were high pitch whistles that didn't carry very far but were audible to birds far enough out that they would avoid the danger zone.
            I can't remember how much RPM I was figuring for at 100 foot radius, but it was a shock to come up to such a high number.
            Even 1/4 mach is really moving and as I said, the intermittency is the real danger, the birds don't see it coming.
            The spiral cone design eschews that problem, it's always visible in the space.
            Please don't get me wrong, I'm all for weaning us off of Petro, all for renewables and the sooner the better. Just the jobs factor alone is worth it, but I also see some problems with current technologies and promise in some that are in the pipeline.
            I guess I mostly have problems with the Big/Distant approach. It concentrates the power, literal and figurative, in the hands of major corporations where small/close can be more equitably distributed.
            Big lossy systems offend my pennypinching soul and the ecological damage of big transmission lines present problems.
            There is no easy answer.
            There are much better answers than we have now.

            If I ran this circus, things would be DIFFERENT!

            by CwV on Tue Jan 22, 2013 at 02:36:15 PM PST

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    •  Ah, see, that's why I asked the original question (4+ / 0-)

      I see references to this problem on bat websites (yes, there are bat websites), but never anything specific.

      I wonder if this problem can be solved. Hope we don't have to choose between birds and bats!

      Thank you for the information!

      Enjoy the San Diego Zoo's panda cam! Now with new baby panda! And support Bat World Sanctuary

      by Fonsia on Tue Jan 22, 2013 at 01:06:59 PM PST

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