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with little time to seek out the proper links, i'd like to point out that there is a global slew of work being done on "swimming foundations" as the Germans say.  In the US, the original offshore designs from the 70's were floating.  In fact, the entire turbine support structure was allowed to swim with the wind, eliminating expensive yaw bearings and motors.

Currently, NREL investigated several designs, and has evolved what they believe is optimal.  in Norway, a large floating project is supposed to begin construction next year (this year?).  Italy tried to build a smaller test program several years ago, which to date hasn't gotten "afloat."  The floating tripods pictured above may have come from a design developed in the Netherlands, at the turn of the century, which likely predated the principle power designs.

There's more under development under the radar, for sure.  the rest of the world really doesn't have the giant pool table we affectionately call the North Sea.

I guess i'd have more respect for ocean offshore development in the US if they were already moving toward 15-20 Gigs/Yr on land, increasing annually, and with the concommitent investment on transmission.  The Great Lakes?  Hmmm, got an open mind there.

"Life shrinks or expands in proportion to one's courage." - Anaļs Nin

by Crazy Horse on Sat Feb 21st, 2009 at 07:39:35 AM EST
adding, there are some sound engineering/cost reasons to go with a tripod foundation, but most of the research says to put the turbines in the middle.  i have not investigated these pictured at all.

"Life shrinks or expands in proportion to one's courage." - Anaļs Nin
by Crazy Horse on Sat Feb 21st, 2009 at 07:42:26 AM EST
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I'd guess and say that the foundation rotates to face the wind, because it seems like it would be easier for an active ballast system to work if each leg of the tripod was normally in roughly the same orientation to the wind.

In the picture, each of the turbines are oriented to face the other two legs of the tripod, but whether that is the design or it just happens to be illustrated with the wind coming in from that direction is not clear.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Sat Feb 21st, 2009 at 01:32:04 PM EST
[ Parent ]
Most of the modern floating structures are catenary to some degree, so they can't really orient to the wind freely.  Check the NREL studies, they're all public on the net.

"Life shrinks or expands in proportion to one's courage." - Anaļs Nin
by Crazy Horse on Sat Feb 21st, 2009 at 01:50:44 PM EST
[ Parent ]
catenary - the curve theoretically assumed by a perfectly flexible and inextensible cord of uniform density and cross section hanging freely from two fixed points

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Sat Feb 21st, 2009 at 02:26:57 PM EST
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Nope.



"Life shrinks or expands in proportion to one's courage." - Anaļs Nin

by Crazy Horse on Sat Feb 21st, 2009 at 04:04:43 PM EST
[ Parent ]
Or rather,



"Life shrinks or expands in proportion to one's courage." - Anaļs Nin

by Crazy Horse on Sat Feb 21st, 2009 at 04:07:15 PM EST
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... stress that they don't fall over even when the wind is coming from the direction where it would seem most likely to tip over.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Sat Feb 21st, 2009 at 04:51:15 PM EST
[ Parent ]
In projects i've worked on, we came up with a maximum laydown angle of 17 degrees, meaning from the normal vertical, in 120 kph winds.  beyond that, we detuned the turbines to keep the angle upright (no greater than 17 degrees).  We have no real world data on whether that was the correct decision, but even if wrong, we don't lose much energy if we have to derate sooner.

"Life shrinks or expands in proportion to one's courage." - Anaļs Nin
by Crazy Horse on Sat Feb 21st, 2009 at 05:16:17 PM EST
[ Parent ]
... not about engineering, when talking about the details in an "artists impression" drawing.


I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Sat Feb 21st, 2009 at 06:55:20 PM EST
[ Parent ]
... is when the "Electricity Superhighway" additions to bring High Plains wind power to market have been made, since the Time of Day profile for the High Plains and the Great Lakes are quite different from each other, so adding the Great Lakes to the Dakota, Kansas and Texas Panhandle resources ought to provide a valuable reduction in the Time of Day variance of the system.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Sat Feb 21st, 2009 at 01:38:12 PM EST
[ Parent ]

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