Chris & Dana;
Our site is a mountain in Wyoming and does have some focusing effects,
so maybe 170 mph is possible. Are your arrays using top down clamps? I
think that is apparently stronger, also possibly the 2011 Sanyos look to
have beefier frames. However, I looked at their spec sheet and they're
only rated at 60 PSF (less than the SWs). From my measurements here of
Solar World 4.0 frames, I'm seeing a flange thickness of approx 1.3 mm,
while an old Siemens SP 75 has 1.8 mm thick metal.
I'm coming up with a fix for the Solar Worlds: 3/4 x 3/4 Stainless steel
Angle fits just inside the lip of the module, and will distribute the
forces more evenly. The question then is, are we just going to lose the
glass next? Anyone have a currently available module that is beefier?
I may recommend we swap the whole array out, if we are indeed exceeding
the design of the Solar Worlds.
Thanks,
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 1/12/2017 2:39 PM, Chris @ The Oasis wrote:
Wrenches: We have a ~70KW ground mounted array on the Rocky Mountain
front near Choteau, MT. Springs winds are not unusual with 150 to 175
MPH gusts. The system was installed in 2011 (with Sanyo 215W
modules). No problems yet; we certainly over-engineered the racks,
knowing what high winds there are!
Chris Daum
Oasis Montana Inc.
406-777-4309
406-777-0830 fax
www.oasismontana.com <http://www.oasismontana.com>
------------------------------------------------------------------------
*From:* RE-wrenches [mailto:[email protected]]
*On Behalf Of *Ray Walters
*Sent:* Thursday, January 12, 2017 2:16 PM
*To:* RE-wrenches
*Cc:* Sefchick, Steve
*Subject:* Re: [RE-wrenches] Solar World Wind Damage
Hi Bill;
Solar World customer support did come through yesterday with flying
colors. They got hit by a big storm in the North West. Right now
though, they are saying that we exceeded the 64 PSF rated loading to
the back of the module. I've pointed out that that would correspond to
over 170 mph winds, so I'm not quite ready to concede the warranty.
Their engineering team is reviewing my information.
As always, the Wrench list experience is invaluable. Are 170 mph
winds possible, outside of a tornado or hurricane?
*Whether or not Solar World stands by their product in this extreme
situation, I definitely stand by my installations.* I'm taking a snow
cat up to replace and reinforce the modules next week, then hopefully
get a little help from my supply chain after. My repair costs will be
many times the cost of one replacement module anyway.
Yes, the 33 mm vs 31 mm refers to the module thickness. I don't have
a version 2.5 frame to check the flange metal thickness, and it is
conspicuously absent from the specs. I have a good micrometer, and I
will compare metal thicknesses of several module brands, because with
all the cost cutting, many module manus seems to be using thinner
metal lately. As Jay pointed out, we're bolting much bigger modules
down with much weaker flanges, and the same hardware we used on a 75 w
module, so its not entirely surprising to start seeing high wind failures.
R.Ray Walters
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