How Long Do Solar Panels Last? A Detailed Review

Installing solar panels is a major financial decision, so it’s important to get an idea of how long you’ll continue to see a return on your investment. Though there is no definitive answer to how long solar panels will last – freak accidents or major storms do occur infrequently – it’s safe to expect returns for decades to come. Extensive research has shown that most panels will continue efficiently producing electricity for at least 30 years, and most will likely still be generating for years after!

Warranties

A good baseline for module longevity is about 25 years, which is the average performance guarantee warranty for most panels provided by the panel manufacturers. The majority of performance warranties on the market guarantee 90% of maximum output at ten years and 80% at 25 years. Many manufacturers also offer a workmanship warranty that covers any defective panel parts for the first ten years of operation. Better yet, many of Solar.com’s installers go above and beyond the industry standard by offering a 20+ year workmanship warranty. In addition to manufacturer and performance warranties, we also offer a Solar.com production guarantee. We trust so strongly in our solar provider partners and our own system designs that we offer the industry’s only triple coverage warranty, the TriGuard Guarantee.

You can also rest assured in knowing it’s highly unlikely that you would ever have to invoke your warranty. A 2017 study examining installations between 2000 and 2015 found an annual median failure rate of just five out of 10,000 panels. Trends forecast that the failure rate will continue to decrease with increasing technological advancements, which seems especially promising when considering that the failure rate was twice as high between 1980 and 2000. Similarly, the annual degradation rates of solar panels, which measures how much production efficiency they lose per year, is also decreasing. In fact, a recent study by the National Renewable Energy Laboratory (NREL) found that the median degradation rate for today’s panels is just 0.5 percent per year, meaning that after 40 years the panels would still be producing electricity at 80% output.

Environmental Impact

Keep in mind that the climate conditions in which you live can positively or negatively impact the lifespan of your solar panels. Modules installed in cold climates with extreme snow loads and high wind often degrades more quickly than their counterparts in more temperate climates. However, panels in intense desert climates often have the highest levels of degradation and may even produce less efficiently on extremely hot days.

Modules are most effective when the temperature of the panels themselves is in the range of 59 to 95 degrees Fahrenheit. Within this range, they are often even more effective at the lower end. Because panels tend to heat up more than the actual ambient temperature (akin to how a car’s glass will trap more heat on a hot day), they’ll produce less efficiently even as outside temperatures reach levels within the upper bounds of the range. However, experts have found that module installations that allow for airflow underneath panels, rather than flush mounting on roofs, can be extremely effective at maintaining panel efficiency in hotter climates. Furthermore, though your panels may not be producing as efficiently on these extremely hot days, they are still generating energy!

Maintenance

Solar panels require very little maintenance to continue producing at optimal efficiency; however, removing debris like dirt, leaves, and bird droppings can improve your module’s output. We recommend cleaning your panels once every three months. If you have tilted panels and live in a more temperate climate, your system will likely be washed by the rain and you might not need to do quite as much cleaning. Panels in desert climates may require a greater amount of cleaning due to the accumulation of dirt and debris.

Check out our SolarBook video on Solar Panel Maintenance

It’s generally best to clean your panels in the morning or evening on cooler, overcast days. On hot days, the water will quickly evaporate from your panels and dirt may remain instead of getting washed away. If there is a great deal of debris on your module, you’ll need to make sure to remove it before proceeding. One of the easiest ways to keep your panels clean is by rinsing them down with a hose. However, you should never use hot water on cold panels. Additionally, refrain from utilizing products like RainX or rock salt, as well as metal or abrasive products. These can scratch the panel’s glass, leave streaks, or stain – all of which end up decreasing the production efficiency. If your panels are accessible, soapy water and a soft brush or good sponge are generally all that’s necessary to remove buildup.

In most cases, it’s unnecessary to remove snow from your panels because it will eventually melt or fall off. However, for heavy layers of snow, using a leaf blower first can be an effective option for removal. Other options include spraying your panels with lukewarm water and using a long pole with a squeegee attachment. As always, safety is of utmost importance. Many homeowners will find that they can clean their panels from the ground by using a hose. If panel maintenance ever requires you to climb on your roof, please use caution!

To learn more about how long do solar panels last, maintenance, or anything in the world of energy independence, please feel free contact us.