” If one panel goes bad the entire string would go down”
Got like 10 strings here, various inverters. 120 panels total on property. Never had one panel go bad — yet. 12 years on some this fall.
That also depends on how they wire them (parallel or series).
I've had 32 panels for 2 years (May 2021) and 32 more for almost a year (Aug 31, 2022). Those 64 panels max the capacity of the 8 inverter strings, perhaps because my panels are newer (total 20kW). Never had a problem. Not even had to clean them (perhaps because they're on my roof which has a steep pitch, and perhaps because a few times every winter we get ice, which supposedly helps clean the panels as the ice melts in the morning). I'm sure the day is coming when I'll at least have to rinse them off, and perhaps clean them with a rubber squeegee.
One of the reasons I haven't had problems is we rarely get hail here (the story in this article), and when we do get hail it's small-size. Maybe if I lived in hail prone areas it wouldn't be worth getting solar. Of course, solar wouldn't be worth getting anywhere if the Dims didn't have their stupid war on energy.