[RE-wrenches] Hurricane damage to solar arrays

Jason Szumlanski jason at floridasolardesigngroup.com
Sat Sep 16 07:07:01 PDT 2017


Here is a photo indicative of the bent mounting plates.

[image: Inline image 1]






On Fri, Sep 15, 2017 at 6:37 PM, <solar1online at charter.net> wrote:

> Jason,
> Thanks for the preliminary failure analysis of the latest hurricane
> damage. Do you have any photos which shows the bent mounting plates for the
> micros? Wouldn't that be an indication of the force applied before
> something gave up? Good call to get new micros when the leads and their
> attachments may have been compromised.
> TIA,
> Bill Loesch
> Saint Louis, MO
>
>
> -----------------------------------------
> From: "Jason Szumlanski"
> To: "RE-wrenches"
> Cc:
> Sent: 14-Sep-2017 20:26:09 +0000
> Subject: Re: [RE-wrenches] Hurricane damage to solar arrays
>
> 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 <jamesrudolph99 at 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*
>>>
>>> *80*
>>>
>>>
>>
>
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