How long do solar panels last? What consumers should know
People interested in adding solar panels to their home or business have probably wondered, “how long do solar panels last?”
Conventional wisdom says solar panels last between 25-30 years. But there’s more that prospective solar customers should know about panel lifespan.
Let’s inspect this topic more closely.
Once you have solar panels installed, they’re relatively maintenance-free. There are no moving parts, and all they need to do is act as a sponge that soaks up the sun’s rays.
But solar panels do degrade over time. That means they slowly start to produce less electricity as they age.
Don’t get too worried though, because the National Renewable Energy Laboratory says panels commonly lose less than 1% of their power output per year. That degradation rate depends on climate, the type of module and other factors.
A .5% degradation rate, for instance, means 20-year-old panels would produce 90% of the power that they did when they were new.
Long-term production is an especially important consideration for solar customers who are concerned with their system’s return on investment. After all, the system may not pay for itself for years after it was installed, and its value is tied to how much energy it can produce to offset electricity bills.
Luckily, the team at Wolf Track Energy factors in module degradation when calculating long-term production figures.
Why do panels degrade?
Solar panels are constantly exposed to the elements. And while they’re rugged devices that are built to last, the weather can take a toll.
Our friends at Solar United Neighbors outlined some reasons why solar panels degrade, including the cycles between hot and cold weather that affect electrical connections, exposure to ultraviolet rays that degrade a component responsible for protecting the solar cells, as well as high humidity that damages cell insulation.
Meanwhile, Solar Power World found that in some cases, low-cost panels failed to stand the test of time. Some came with thinner frames, reducing the amount of aluminum needed to produce a panel. While that may lower the price, the panels would sometimes bend during the freeze-thaw cycle.
A licensed and certified solar installer should be able to identify the right panel for your project.
Warrantied to last
Solar panels often come with two types of warranties. One covers the materials and workmanship of the panels themselves, and the other addresses their panels’ long-term power output.
For instance, Heliene offers a 25-year performance warranty. After a quarter century, it says the actual power output won’t be less than 86% of the labeled power output.
As the NREL points out, solar customers may still use their solar system after the warranty, but the power output is no longer guaranteed by the manufacturer and it will continue to decline.
While solar panels last for a couple of decades or more, they will produce less electricity over time due largely to environmental factors.
Manufacturers have performance warranties that spell out how much power their panels will produce over time. These performance warranties generally last 20-25 years.
A licensed solar installer can help decide which panel makes the most sense for your situation.