From what I understand all panels come with a 25 year warranty because that's the federally mandated minimum warranty, and that there are panels twice as old st

From what I understand all panels come with a 25 year warranty because that's the federally mandated minimum warranty, and that there are panels twice as old still operating today. Unless they do something foolish like coat the panels in a plastic that degrades under direct sunlight, I don't really see why panels shouldn't last for quite a long time. Does the silicon itself take UV damage or something?