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Wind Design

October 17, 2011, 4:41 pm

I am curious why one would create a windfarm where the majority of the generators are right in the turbulence / wake of another windmill?  Wouldn't you want to stagger these?

Category: Energy

10 Comments

  1. SB7:

    On land-based wind turbines the heads rotate, so I assume they do on nautical ones as well. If so, perhaps the prevailing winds are not typically parallel to the rows.

    October 17, 2011, 4:57 pm

  2. me:

    Actually, what you want is this: http://www.gizmag.com/wing-7-flying-wind-turbine-makani-power/20109/

    Kind of nice to occasionally see some actual innovation.

    October 17, 2011, 5:04 pm

  3. ZZMike:

    Does anybody know why groups of birds fly in V formation?

    SB7: Just looking at the photo, it doesn't look like the rows are staggered. To our credit, most land-based wind farms are.

    October 17, 2011, 7:32 pm

  4. John Moore:

    Errr... for the most part, it would seem to depend on what direction the wind is blowing. Admittedly, the grid layout is probably the least optimal, but I doubt it is that less efficient that that which is optimal. Or perhaps, the changes induced in the windfield by the upstream fans is just not significant, even if it does make dramatic pictures.

    The real question is: what fool built that many windmills instead of an oil well or two?

    October 17, 2011, 8:26 pm

  5. Punkster:

    What is an 80% efficient wind mill? Isn't the theoretical maximum 57%?

    October 17, 2011, 9:54 pm

  6. Punkster:

    @ZZMike The birds are drafting each other, which reduces the drag and makes it easier for them all to stay aloft for longer periods.

    http://en.wikipedia.org/wiki/Drafting_(aerodynamics)

    October 17, 2011, 9:57 pm

  7. Rick:

    Why would the developer care about wind turbulence or efficiency? The purpose of a wind farm is to harvest tax dollars.

    October 18, 2011, 3:09 am

  8. gn:

    Re: birds in V formation: It is not drafting so much as flying in the updraft created behind and just outside the span of the bird in front of them.

    [msaero-on]There is circulation created around the wing itself to force the air over the top to go faster than the air over the bottom and thereby attach the flow to the trailing edge. This circulation cannot just end at the tip. Instead the tip sheds a vortex that trails behind the wingtip and essentially creates downflow inside the span and upflow outside the span if you are behind it. Same reason you see cool vortexes trailing of wings of jets, etc.[/msaero-on]

    October 18, 2011, 7:39 am

  9. Matt:

    http://www.eurekalert.org/pub_releases/2011-07/ciot-wpp071311.php
    http://dabiri.caltech.edu/publications/Da_JRSE11.pdf
    Here is a link to a introduction and the paper of a Caltech study about how smaller vertical wind turbines might be able get more energy output per area than larger horizontal ones. It looks specifically at turbulence and its affect on efficiency.

    October 18, 2011, 7:56 am

  10. greg:

    They are staggered, just imagine viewing them from any other angle. I'd assume these 'unique' conditions affected the wind, and this isn't direction. And yes, the heads will rotate to be perpendicular to the oncoming wind.

    October 19, 2011, 3:45 pm