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What’s the Life Expectancy of Solar Panels?

Author: Samuel Beckingham
Updated: Nov 23, 2022
3 minutes read

As solar panels get used, they lose efficiency very slowly over the years. Battered by sunlight radiation, day in, day out, they start to produce less electricity. After a certain point, they become too inefficient to keep, so they are forced to be retired.

Manufacturers will often specify that they will last 25-30 years, but the industry standard for warranties is only 25 years. At 20 years old, a solar panel is expected to produce 96% of its original capacity. The decline in efficiency is so gradual that you shouldn’t notice it happening. This is different for various manufacturers, as high-grade panels will be at 93% after 25 years, while lower quality panels can be as low as 82.5% capacity.

The worst degradation is experienced when the solar panels are installed and first exposed to sunlight. This causes a fixed permanent loss in efficiency between 1 and 5%. This does depend on how solar panels are made, as up to 96% on the market are made from silicon, which is manufactured in such a way that it’s susceptible to this degradation.

Weather conditions have an effect, especially heat, which is why solar panels tell you how well they perform in higher temperatures. Combined with the heat is the cooling effect, which causes tiny cracks to form on the surface of the solar panel. This movement through expansion and contraction steadily lowers the output they can achieve. Solar panels are less prone to degradation through colder weather.

Wind is another element unkind to solar panels over time. Strong winds can cause panels to flex, which is why they can be installed with a rack that will limit strong uplift forces. Any bending of the panels will ultimately cause cracking, even on a microscopic scale, which will limit the total output. Likewise, heavy snowfall can lower a panel’s lifespan. When covered, the panels won’t work effectively, but if snow is removed improperly, the surfaces can be scratched. Any imperfections on the surface will limit a solar panel’s efficiency.

In some cases, solar panels installed in mild climates can last 40-50 years. Efficiencies can be as high as 80% after that time, thanks to advances in solar power technology. The panels themselves won’t stop working, so there is no cut-off point for when you’ll need to replace them. As they normally need no maintenance, they should be effective for many years, even after they’re below optimal levels.

Warranties for solar panels typically last 25 years, which covers a drop in efficiency up to 20%. As even the worst constructed panels only drop to 82.5%, this shouldn’t be an issue. You can rest assured that your solar panels will last for decades, producing renewable energy without much fuss. And in 25 years, the technology would have improved, offering better efficiencies and longer lifespans.