As a practical matter, there are not any warranties on solar panels anyway.
Hardly any of the solar panel companies around today existed 20 years ago.
True enough.
But I do have a nice story about one of them that was around for a long, long time and made good on a bad panel - Kyocera.
In 2003, I bought a KC-120 for use when camping. Used it off and on for many years.
In 2020, it developed an open on the buswork between cells. There was some online info that Kyocera had acknowledged this issue, calling it a problem on "solder connections on the buss tabbing" due to their migration to non-lead solder.
I figured "no harm, no foul" and got in touch with them.
They emailed me a warranty claim form which I filled out and returned.
It took a couple months, but eventually I got this from my email contact:
> >
> > Checking the emails KC/QA Japan did approve your warranty claim.
> >
> > I will make sure it ships tomorrow.
> >
They sent a KC-130 as the 120 had been discontinued.
An above and beyond response from a manufacturer that I will never forget.