How long do the panels last?
Solar PV panels installed today could still operate in 100 year’s time.
Their longevity is as great as the operating conditions thrown at them. The same panel on your roof might be out the Arizona desert and suffer from great heat in the summer and extreme cold. In some places like Guernsey, extreme winds or other places like Japan, large hailstones.
Panels have rigorous product certifications.
As of May 2020, most panels have product warranties of 10 to 12 years with a warranty on output of 25 years.
As you can see “a solar panel has two warranties: a performance and product or equipment guarantee. A solar panel's performance warranty will typically guarantee 90% production at 10 years and 80% at 25 years. An equipment warranty will typically guarantee 10-12 years without failing.” - https://news.energysage.com/shopping-solar-panels-pay-attention-to-solar-panels-warranty/