Yep, the old modules were heavier, had a thicker frame, and most
importantly: much less total surface area. The old 75 w modules were
less than 7 sq ft, compared to almost 18 sq ft of a new 60 cell module.
2-1/2 times the forces on even thinner metal.
Not that I want to go back to the good ol' days, but I think the
industry got a little too thin on the frame, or at the least, we need a
beefier hardware solution for bottom mounted arrays on open frames in
high wind locations. I'll send a pic of our fix, once we try it.
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760
On 1/12/2017 6:01 PM, Dana wrote:
Bottom side bolt up. But they were 1995 Solarex remember the weight of
those frames!
----------------------------------------------------------------------------
Dana Orzel - Great Solar Works, Inc - C - *208.721.7003*
NABCEP # 051112-136 : Idaho PV Licence # 028374
E - *d...@solarwork.com* - Web - www.solarwork.biz
"Responsible Technologies for Responsible People since 1988"
*P*Please consider the environment before printing this email.
*From:*RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org]
*On Behalf Of *Ray Walters
*Sent:* Thursday, January 12, 2017 5:22 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Solar World Wind Damage
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:re-wrenches-boun...@lists.re-wrenches.org] *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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