Tubular towers and PV mounting [RE-wrenches]

[Jeff Clearwater, Village Power Design]

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Hi Hugh & Matt & Ian,

Well I'll defer to your judgement, Hugh, as you have much more wind 
experience than I.   I learned about resonance to close to the hard 
way - so I may be overly cautious about it.    However 2-3 KW are 
liable not to be attached at just one point on the tower.  If they do 
go with a guyed tower then you'd probably want to attach a guy at the 
top and bottom of the array attachment points.

And whether it's  freestanding or guyed, I still would still 
recommend at least a phone call to the engineers at Rohn.  They've 
been really helpful to us on such questions.

Best,

Jeff C.



>At 1:02 AM -0500 16/11/03, Jeff Clearwater, Village Power Design wrote:
>>With two loads pushing from the side you can get some complicated 
>>resonance action.
>
>If the PV array is located at a guy attachment level then the side 
>loading will not be an issue in terms of pipe bending loads.  The PV 
>array will not introduce vibration into the structure either.  All 
>that remains is the mass of the array and its effect on tower 
>resonance.  Once again, if the array is at a guy level then it is 
>hard to see that extra mass at this nodal point would have any 
>significant effect.
>
>>- don't guess - hire a structural engineer to stamp this one!
>
>I would say it depends on the customer.  It's an extra expense, and 
>in my opinion hardly justified.  But some jobs have plenty of money 
>for that sort of stuff.  It's known as covering your @&5#.
>
>If your wind turbine is "maxing out" the tower, then later on 
>someone will be looking for an excuse for failures, but the mistake 
>was to use a turbine that behaves like that to begin with.
>
>--
>Hugh
>
>in Edinburgh
>http://www.scoraigwind.co.uk/
>
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-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jeff Clearwater
Village Power Design Associates
http://www.villagepower.com
Sustainable Energy & Water Solutions for Home & Village

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Founder:  Ecovillage Research, Development, and Demonstration Program:
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