When you invest in a new feature of your home, you expect it to last a long time. It’s an investment. It’s a large outlay of money. And if you’re thinking about buying a solar energy system, a question in the back of your mind could be how long the solar panels will last.

Generally, solar panels keep on working as long as they’re not seriously damaged by weather or impacts. They often come with a 25-year warranty because some have lost a part of their efficiency by that time. But they still keep working after 25 years!

Do Solar Panels Go Bad?

Of course, scientists and engineers have come up with a term for solar panels losing some of their efficiency: solar panel degradation rate.

This rate can increase in certain situations, such as extremely hot weather. And solar panels at different levels of quality can have different base degradation rates. Certain chemicals in the panels naturally break down over time, becoming less potent.

But what does this mean in real numbers? Here are some sample degradation rates and what they would mean for you:

  • 0.30% Per Year: This rate means that a solar panel loses about one-third of 1% of its efficiency each year. After 25 years, this adds up to a loss of 6.96%. The electrical output of that panel after 25 years would be 93.04% of its first year of output.
  • 0.50% Per Year: Expect a loss of one-half of 1% of a panel’s efficiency each year. After 25 years, it could lose 11.33% and produce 88.67% of its first year of output.
  • 0.80% Per Year: Expect a loss of four-fifths of 1% of a panel’s efficiency each year. After 25 years, it could lose 17.53% and produce 82.47% of its first year of output.

 

You can think of these three levels as premium, good, and budget tiers of solar panels. Keep in mind that after 25 years, panels in the first two tiers will still produce around 90% or more of the electricity you expect.

3 Tips to Make Solar Panels Last Longer

If you’re asking how long solar panels last, you realize they won’t last forever. They may need some care, like anything else in our lives—like vehicles, floors, and roofs. And there are ways that you can help to extend their lives:

  • Buy Them Right: Buy your solar panels from an installer that has a great reputation for both superior initial installations and ongoing customer service. Get warranties that cover damage and defects, with a guarantee of a certain level of energy output.
  • Get Regular Checkups: Have your qualified service person check on your solar panels on a regular schedule. They’ll look for any problems with wires, racks, and related equipment. Allowing a professional to perform the checkup ensures that you don’t accidentally damage your solar panels and void your warranty.
  • Keep Foreign Materials Off: You can perform any necessary landscape maintenance to prevent leaves and branches from falling on your solar panels—and carefully pick off anything that does fall on them. You could also install a critter guard system to keep animals away.


Solar panels don’t go bad, exactly. They often lose some of their efficiency after 20+ years, but they will continue to work, lasting 30 years and longer. These and similar questions have interesting answers that we love to talk about. Contact Smart Wave Solar to learn more or to set an installation appointment.