Since you ask:
Thoughts:
- Even though it seems you probably paid more attention than most to the installation, IMO only, after the accident, part of the problem was not digging in and refusing further work without either replacing or checking/resting the affected panels.
- Even so, any damage, especially small damage caused by an impact such as you describe may not be detectable with immediate testing and only show up as f(time) making early detection less reliable.
- Then, believing (or inferring from what a salesperson says) that Sunpower monitors and gives due diligence to what their warranty infers about monitoring is something I wouldn't and don't rely on personally, in writing or otherwise.
- As for field welding/repair, the simple solution from both a cost and practical matter would seem be replacement of the failed unit(s).
- However, the situation is perhaps/likely complicated by the idea that the X-345 panel is no longer officially made, although there are Sunpower panels that are dimensionally and electrically similar that may be acceptable as replacements. BTW, used X-345 panels are available on the net for ~ $150.
- Do you have documentation to support your claims ?
- Seriously, ever been to small claims court ?
- Warranty is indeed 10 years. If you're under that, you'll still have a claim.
- As you probably know, persistence is king when getting vendor attention and resolution to problems. I'd call them 1X/day. Been there, done that. Always get names and times when you and keep notes.
Just don't get snarky or unprofessional.

BTW, I've had a Sunpower system running since 10/13/2013 and appreciate that S.P. made a good product but IMO only, their support and professionalism sucked. I gave up relying on them for anything like what they appeared to offer long ago.
Good product, lousy to useless support.

One other thing, and not specific to this thread, but I bought a (rebuilt) replacement inverter some time ago for when mine craps the bed.
Yours and my panels are positively grounded and most new string inverters won't work well with the old positive ground panels. Just sayin'.

Good luck.

I did request the panels be checked and they did that both on the ground before installation and then again after installed. Once everything is installed and performing within spec there is not much you can do. Refusing install would be dicey, especially when there is a warranty in place. Lets just say I wouldn't expect a small claims judge to understand the damage to electronics but would expect him to understand a warranty is in place and the product was performing as promised.

Documentation - must have 200 pics of the installation but none of the fallen panels. They picked them up immediately. I'm lucky I was there to see it. Which is why I engage in a 6mo. email campaign so I could get in writing them acknowledging the event and having to return to the warehouse for another panel and cc: in Sunpower corporate.

With you on salesman, but after 8yrs. I stopped checking everyday. That part of the sales presentation was me trying to get some kind of dedicated wifi monitoring hardware so I could just look at it from my desk, but they wanted a ridiculous amount and opted to just make a shortcut in my browser to log in. Like I said after a few yrs of checking....and lost net metering is likely under 150, so...

Field repair, exactly my point. I think the installer "on purpose" didn't record the serial numbers of the fallen panels, because I constantly asked for that in the emails and was never provided. Now its biting them and Sunpower in the rear as if they want to fix this problem in one truck roll they need to replace all the panels or risk doing a piecemeal as the panels die one by one. I definitely don't pay labor thru 2025 but after I'm sure they are going to try to stick me with it. It should be classified as a product defect (SP on the hook) or in the least install defect (Installed on hook).

Yes panels are around aftermarket. My understanding SP and installer keep a small inventory on the side. Same with SMA and their inverters, but bottom line is if they can't provide an exact match, my understanding is they have to provide the next closest substitute when under warranty, which is why I went with the extended warranty with SMA. Making the panels and inverter both 20yrs. I figured back then in 20yrs at the pace things are changing it will be a whole new technology anyway and if not I'll buy the spare then. I lurked on Ebay for the first couple of years at my inverter, wasn't worth it and do I buy the exact same inverter or one that allows me connect a battery. If I decide on battery, definitely not going with a wall pack but to use a EV. I already have about 3yrs banked with my utility company thanks to the 1to1 net metering agreement. I'm basically waiting for the ice car to die but am itching to start talks with EV West as they have quite the waiting list and want to make sure they have customers that are doing this.

Yes, positively grounded I did read that somewhere awhile back when I was brushing up on DC vs AC coupling. Since I have DC on the roof I think I'll go with the efficiency when its time to cross that bridge.
Thx

Has anyone heard of UKT diodes?

Sunpower sub contractor came by, turned off the system, opened up the black box on the back of every panel and cut out all the bypass diodes and closed up the box.
Then disconnected the seried panels in each of my 3 arrays and connected into with MC4 chain the "UKT diodes".

I just discovered a few moments ago "UKT" is not a type of diode as the Sunpower rep. was using it, but the name of a chinese company. I found it on ebay and spare you the trip over there.

UKT - Ebay description
Brand Suzhou UKT New Energy Technology Inc.
Current Output 20-29 A
Current Type DC
Model PV-JB12
Features Corrosion Resistant Resistance Properties Corrosion Resistant, Waterproof, Weatherproof Application Commercial, Home/Garden

Introducing a high-quality PV junction box from Suzhou UKT New Energy Technology Inc. This DC current output device is perfect for both commercial and home/garden applications. It boasts corrosion-resistant and waterproof properties, making it durable for all weather conditions. With a current output of 30-39 A, this PV junction box is a reliable choice for any electrical setup. The features of this device include its corrosion-resistant properties and the ability to withstand harsh weather conditions. This product is a must-have for any alternative energy supplies or home improvement needs.
https://www.ebay.com/itm/134874722926 I tried to both attach, url and insert photos into this message and no luck. Sorry just half to go to ebay if you need a look.

So basically worthless description and maybe not any diodes in it, however....
After the tech left I went back up and put a heavy furnature blanket over the first row of cells and only saw a small drop, then moved it over to the last row of cells and saw the same drop. I was expecting that blocking the last row would knock out the whole panel as there are no longer any bypass diodes in the panels to divide it up into 3 sections. But I'm suspecting the drop i did see was larger than if the OEM 3 bypass diodes where still in play.

I then covered the whole panel (1st panel) in the string and of course saw a drop. Then moved the blanket to the last panel and covered it, expecting it to knock out the whole array but over 50% came thru. Sorry no specific numbers, having to go up and down the ladder to look at the inverter and when returning noticed the wind lifted off a corner of the blanket half the time was frustrating and mobile apps have a 15min delay. Should probably order a MC4 splitter and bring up my meter and do it that way.

My conclusion is Sunpower has permently altered (downgraded) my panels and they will be unable to perform as well as OEM panels. (I no longer have the performance I purchased). This will obviously affect Annual Production numbers and guarantees. (But I don't want to wait that long or have to fight at the end of every year to be reimbursed for lost 1.0 Net Metering credits and argue about how they are calculating it.) They have basically moved the diodes to in between the panels. A liitle shade on the leading edge now will effect "reduce" the whole panel 66% more than it did before. This was because the Sunpower branded SMA string inverter was giving, "Check DC generator, Electr, arc detected." messages. And this is their fix. Actually "not" because of the inverter but because there is likely some kind of design flaw in the diodes making them fail.

Anyone else having these errors/issues. Feel free to contact me here. I going to demnad they replace the panels as they did not make it clear what they were doing. I asked for details and specs regarding the "UKT diodes" a month prior and they said they don't have info on them. I asked multiple times how can they not have specs on parts they are using to replace other parts. They convienently left out the part where "its not their part, but made by some Chinese company". But you know they have the spec sheet as they had to approve it.

Thank you.

Very interesting but probably not surprising activity from Sunpower or their installers.