EMP/Solar Flare and PV Solar Panels

Well First I do not think anyone knows for certain, but in the case of solar flares on a off grid home, I do not have any concerns.Time has shown them to be very durable. I believe the amplitude,frequence,and duration of a solar flare that could induce a damaging voltage potential into a panel would have to be of a magnitude so great that I believe it improbable.
I would be far more worried about a lightening strike, direct or close than solar flares. I think its been sense the late 60, and for sure the early 70s that panels have been in service, and I do not know of any loss that can be attributed to solar activity, hail, lightening, kids with rocks, Yes.
Now with that said, if the system is set up to be grid connected then yes I would be concerned, as the incoming power lines "can" (in some cases)bring in a high amplitude induced voltage, but again far greater concern should be the neibour kid who just was given his first pellet rifle.

Now a nuclear emp would likely have the ability to induce significant voltage potentials into any electrically conducting surface. First concern would be proximity to the blast, and I suspect the failure mode of the panel would be due to a induced voltage potential across the p/n junction destroying it. Again not being grid connected would more likely aid survivability. I have no data, to support the estimate I am going to make, but I suspect panels 50 km or more away from the source would be fine (non grid connected). One reason for my confidence in there survivability is in a off grid application the wiring is hooked up to a battery bank of many KWs in capacity, and you can not change the potential across such a large capacity bank instantly. I suspect the bank will act as a buffer to any induced voltages. Also should you anticipate such a event happening just go into the junction box on the panel you wish to protect, and place a jumper on the - and + output. This should clamp or aid in limiting any potential that could be induced into the panel.
As I know of no tests done on panels by a emp my guess is just that, I am sure others will follow.

from what i've seen in research, there is a good chance that those will be fine. i know a guy (no really i know him) he's an engineer, he's done many hours of research and while he's opinion is that they will work, he's put up shield panels as well. he did an "education thing" for a group of us a few years ago, and went over all of this. all i can say is that if there is info out there on the subject he's read it, and he gave us a no BS run of things. he's a prepper, and has tested his alt power set up many times. he's the best resource i know of.

for what it's worth, you don't know me, i can't tell you who he is. . . and i can't share his work (they are for members only, and is copyrighted) he did not charge me a dine for all his work (and he doesn't pay for anything i or others in the group can help him with either) but i'd trust him with this info.