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Understanding Solar Panel Degradation Rate

Updated: Dec 1, 2021

If you’re in the market for solar, understanding how solar panels work, the types of panels available, and their lifespan is important. Degradation refers to the reduction in solar panel input over time. Research from the National Renewable Energy Laboratory shows that solar panels have a median degradation rate of approximately 0.5 percent each year, although the rate could be higher in hotter climates. This means that energy production declines by a certain small percentage each year. As an example, if the solar module degrades at the 0.5 percent rate each year, by year 20 it will produce 90 percent of the energy it produced the first year it was installed.

So why do solar panels degrade? Exposure to the elements and to UV rays contribute to degradation. However, the degradation rate is also affected by the quality of the panels themselves, how they’re installed, and maintenance to remove debris that can affect energy production.

The quality of the solar panels depends on the materials used for frame and solar cells. Beware of lowball prices for solar panels; if low quality components are used, the solar panels may damage easily. Another factor is careful installation. Panels on a rooftop must be placed at an optimal angle and properly connected. Regular maintenance can also extend the life of solar panels. Keep panels clear of debris and inspect them for cracks or other damage after adverse weather events, such as a hurricane, hailstorm, or heavy snowfall.

Finally, check the warranty for the solar energy system. What does it cover and for how long? For example, Ion Solar Pros offers the SunPower® EquinoxTM system, a complete home solar energy system backed by the only 25-year warranty that covers your WHOLE system, not just the panels. Inverters, racking, labor and power production are guaranteed with a 25-year warranty, and monitoring hardware is guaranteed with a 10-year warranty. There’s no need to deal with different manufacturers’ policies and warranties should issues ever arise.


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