You simply don’t know what you’re talking about.
Eight nof my panels are 15 years old, and their plastic is as soft and flexible as the day I bought them. The sun never gets to the bottom of something that is attached to a roof.
So you think that the plastic in those solar panels never grow old enough that the panels have to be replaced??? If that is so, given their popularity, then why do communities have special rules regarding the disposal of these panels.
How long do solar panels last?
Solar photovoltaics slowly lose their generating capacity. Although some solar panels are still working satisfactorily 40 years after installation, the conventional view is that most will dip below 80% of their rated capacity within about 20 years. This will vary slightly between manufacturers and between different types of silicon.
http://www.scitizen.com/future-energies/how-long-do-solar-panels-last-_a-14-2897.html