I definitely think this would have helped. It's a strange thing to consider... If a rail were added, would there be another failure point, like the roof attachments, which would probably be a worse scenario? It's hard to tell. There is a economic limit to how hardy we make these systems. At a certain point, any installation will fail. Who's to say a small tornado didn't pluck a system? I guess we have to consider what an acceptable loss level is. It's no different than other building products like roofing and windows. I have seen roof tiles stripped from a home and an identical adjacent home with solar panels completely undamaged. It's luck of the draw.
On Fri, Sep 15, 2017 at 10:07 AM, Glenn Burt <glenn.b...@glbcc.com> wrote: > I wonder if a third rail would have prevented many of these escapees. > Not even attached to the structure, just to every module. > > *Glenn* > *Sent from my 'smart' phone so please excuse spelling and typographical > errors.* > > ------ Original message------ > *From: *Ray > *Date: *Fri, Sep 15, 2017 9:43 AM > *To: *re-wrenches@lists.re-wrenches.org; > *Cc: * > *Subject:*Re: [RE-wrenches] Hurricane damage to solar arrays > > What was the pressure rating for the modules that got sucked off the > racks? Also, is it possible that flying debris caused some of the random > location module failures? > > Ray Walters > > Remote Solar > > On 9/14/17 1:53 PM, Jason Szumlanski wrote: > > More early anecdotal data... > > We are finding NO anchors pulled out of roofs, regardless of roof type or > attachment type. That is clearly not the failure point. We also see no > attachment to L-foot or L-foot to rail issues. And contrary to my > expectation, we see no t-bolt failures. What's happening? The panels > themselves are flexing (bowing) sufficiently to work their way right out of > the mid-clamps. This applies both to Unirac's older 1-inch space clamps and > newer 1/4 inch bonding mid-clamps. > > This attached pictured system had panels on a north roof pitched very > slightly to the south. We had northeast hurricane winds in this area, and > the way the wind went under these panels was obviously what caused the > panels themselves to fail. This is an essentially flat roof commercial > application. It was bad luck to have the wind direction from the northeast > corner (the NW edge of the eye wall passed right over this area). But we > are seeing similar results on residential pitched hip and gable roofs in > terms of the failure mode. > > What's interesting is that there is no rhyme or reason to where in the > array we see damage. I have seen absolutely no catastrophic damage on a > residential roof - just one or 2 modules mostly. And the missing module can > be on the lower edge, upper edge, or right in the middle of the array. More > often than not, the t-bolt and mid-clamp assembly is still sitting right > there in the channel of the Unirac Solarmount rail, but a module is > missing. It's quite freaky. > > And much like tornado damage I have seen on TV, houses adjacent to each > other have very different fates. We have a new community (100+ homes slated > for solar) with about two dozen homes completed, and just one home had a > panel pop out in the middle of an array. It was gently deposited onto the > adjacent panel with absolutely no damage and the DC leads still connected > to the microinverter. > > One issue we are facing is that when panels fly off, something has to give > with the DC leads to microinverters. No panel leads have been broken so > far. In most cases, the MC4 connectors simple un-snap somehow - no loss of > crimped connectors. We have a few cases of leads ripped out of the > microinverter case completely. The microinverter bracket is badly bent on > many microinverters, indicating that there was tremendous force until > something gave up. I am extremely hesitant to reuse these microinverters > because the force on the DC input leads must have been huge. I think we are > going to insist on microinverter replacement when replacing modules in > these cases. > > Hopefully I will have more, but not too much more to come. It looks like > we did very well here (as an industry). There are spotty issues, but it's > far from the catastrophe that kept me up for multiple nights before and > after Irma. Then again, many people have not returned home yet. > > Jason Szumlanski > Florida Solar Design Group > > > > On Wed, Sep 13, 2017 at 6:18 PM, Jason Szumlanski <jason@ > floridasolardesigngroup.com> wrote: > >> [image: Inline image 1] >> I'm based in Fort Myers and we cover the hardest hit areas from Irma. We >> are in the "stuff" right now, so I'll make this brief until I have more >> time, which might be a while. We are seeing quite a bit of minor damage and >> some major damage. We're getting calls from all dealers' customers and a >> couple of our own clients. We have several homes with one or two panels >> dislodged. There is no rhyme or reason. Some are middle of arrays, some on >> edges. Panels are ripped right off rails, leads ripped from microinverters. >> Strangely, it looks like the panel j-box connection and MC4 connectors >> survived better than the microinverter end of the DC leads. Amazingly, we >> have several panels that were blown onto driveways, other roofs, and pool >> cages with NO DAMAGE except frame scrapes. Very weird. We haven't seen a >> shattered panel yet, but it's early. >> >> I'm heading to a self-storage facility tomorrow where there are three >> 25kw systems on different buildings. Two buildings are unscathed. One >> building lost ALL of the panels apparently. Tornado? Hard to say. >> >> So far (other than the 25kw I have not evaluated) we have not seen a >> single fastener pulled out. All of the failures are panel top and mid >> clamps at this time. Anchor and rails remain intact. Possibly installation >> errors? Possibly sheared off T-bolts? Hard to tell and we may never fully >> know. >> >> We generally require 48 inch spacing between anchors into trusses for >> engineered systems. The pullout values are pretty high. It looks like the >> attachment points into the roof are not going to be the failure point in >> the systems in Florida, but there is a LOT of work to be done still. It's >> going to be a very interesting few months ahead! >> >> >> Jason Szumlanski >> Florida Solar Design Group >> > > > On Tue, Sep 12, 2017 at 3:09 PM, James Rudolph <jamesrudolp...@gmail.com> > wrote: > >> Aloha Everyone, >> I was just wondering how all the PV arrays did during these storms? >> Does Florida have higher pull out values and wind designs for their >> PV/H20 systems? >> Is there any thing the rest of us could learn from all this? >> Photos? >> >> >> Mahalo Nui Loa, >> >> *James B. Rudolph* >> >> *Hawaii Unified* >> *Director of Energy* >> >> *ES Electrician # 10816* >> >> *NABCEP Certified PV Installer # 091209-155 <091209-155>* >> >> *80* >> >> > > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > <https://mailtrack.io/trace/link/ed32727b631169b3de8d81ebb18b8a246e6503e6?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=3cd190d69f6faa97> > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > <https://mailtrack.io/trace/link/3a15fd176aebb630fe34c7d7c9bcc625a508efe6?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=e7412e53270d9893> > > List rules & etiquette:www.re-wrenches.org/etiquette.htm > <https://mailtrack.io/trace/link/30777a085e514daa764fa265954c414d5af4f512?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=4dae9d699883317e> > > Check out or update participant bios:www.members.re-wrenches.org > <https://mailtrack.io/trace/link/16a1d99842dcc0b7e03b50d0892a78045772066e?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=42563c628760a38d> > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > <https://mailtrack.io/trace/link/ed32727b631169b3de8d81ebb18b8a246e6503e6?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=3cd190d69f6faa97> > > List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches. > org/maillist.html > <https://mailtrack.io/trace/link/3a15fd176aebb630fe34c7d7c9bcc625a508efe6?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=e7412e53270d9893> > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > <https://mailtrack.io/trace/link/30777a085e514daa764fa265954c414d5af4f512?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=4dae9d699883317e> > > Check out or update participant bios: > www.members.re-wrenches.org > <https://mailtrack.io/trace/link/16a1d99842dcc0b7e03b50d0892a78045772066e?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=42563c628760a38d> > > >
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