How Long Do Solar Panels Last?

On average, solar panels will last 20-25 years or even longer, but power output might slowly decrease over time.

If asked how long solar panels last, most solar enthusiasts will say, long enough to pay themselves off and then some! More importantly though, is how much power will solar panels produce as they age. Most are rated to have some percentage of output at some number of years. Like 80% output at 20 years.

Here are some important points to remember as you consider how long your solar panels will last:

  • Glass and aluminum framed panels normally about 25 years. Flexible glue down panels tend to last only 2-4 years before the burn up.
  • Some of the earliest solar panels installed in the history of solar technology have been reported to last up to 50 years!! (Of course, with some loss of performance over time.)
  • Solar panels installed in 1993 are reportedly still putting out around 110 watts.
  • Worst case scenario, assume your panels might loose 1% per year or so. In reality, they’ll lose less than that, but that is a decent estimate if you are projecting figures.
  • Even second hand panels from 8 years ago have been reported to have the same output now at 41 amps in direct sunlight, even when mounted on fence panels in the garden! My guess it they will still be useful after 20 years adding one or two more.
  • Once you start, you’ll find yourself addicted to solar panels! After you start, you will be doing this for the rest of your life with no plan on stopping.