How Long Do Solar Panels Last?

As part of my investment calculation that I am putting together I need to know how long solar panels can last.

I am borrowing a book from a friend of mine called “Photovoltaics Design and Installation Manual” by Solar Energy International published in 2004 that says:

“Durability. Most PV modules available today show no degradation after 10 years of use. It is likely that future modules will produce power for 25 years or more.”

I did some more research and found that it depends on the type of panel used. Here is a quote from BoatUS site:

“ Over time, all solar cells have a tendency to degrade slightly under the suns rays. Crystalline panels have a
much slower degradation factor than thin film and will therefore continue to produce energy for a longer period
of time. Warranties will reflect this: crystalline panels are often guaranteed from 20 years to lifetime. Thin film panels receive shorter warranties (usually from 2-5 years), but have been known to still be putting out a charge for up to double that time.”

I decided to take a look at some warranties, for the Sharp NE-165U1 solar panel it says:

“25 year limited warranty on power output”

Depending which way I go, having a 25 year warranty sounds pretty good. I am sure in 25 years solar panels will be a bit more efficient and need to be replaced.