How Long Do Solar Panels Last?
Some or all of the mortgage lenders featured on our site are advertising partners of NerdWallet, but this does not influence our evaluations, lender star ratings or the order in which lenders are listed on the page. Our opinions are our own. Here is a list of our partners.
Solar panels generally last 20 to 30 years with proper care and maintenance, — although you may be lucky enough to get up to 50 years in some cases.
Generally, solar panels don’t just stop working all at once. They degrade gradually as part of normal wear and tear at an estimated rate of about 0.5% each year, according to research from the U.S. National Renewable Energy Laboratory, a federal lab focused on researching and deploying renewable energy sources. By the time you’ve had your solar panels for 20 years, you can expect them to be functioning at about 90% capacity.
Other factors can also negatively impact solar panels and shorten their useful lives, including:
High temperatures. Extreme heat can harm solar panel performance and damage the panels.
Dirt, debris, stains and foreign objects. Solar panels work best when nothing inhibits the amount of sunlight they receive. Common items like bird droppings, leaves and dirt sitting on solar panels will make them less efficient. Using strong chemicals and detergents to clean solar panels can stain and damage the panels.
Cracks and breakage. Solar panels have a protective layer of tempered glass, but if this layer is cracked or broken, the panel can become damaged, and performance declines. Small cracks can occur due to temperature changes, hail, heavy snow, wind, pressure and humidity — as well as improper packaging, transporting, handling and installation.
Leaks. Once cracks occur, the original waterproof nature of solar panels is compromised. When water gets inside, performance suffers and the panel can short-circuit.
As a homeowner, you'll decide when replacing older less-efficient solar panels with newer ones is worthwhile.
How to make solar panels last longer
These steps will help you get the longest possible life out of solar panels:
Choose good quality solar panels from a reputable brand. If you live in a place with high temperatures, hurricanes or other extreme weather, make sure your solar panels are designed and tested to withstand these conditions.
Only use an experienced and reputable installation company. Since panels can be damaged during installation by mishandling, be sure your installer has experience and knows what they are doing. A good installer will see that your panels are installed at the proper angle, which improves efficiency and helps dirt and debris slide off, preventing damage.
Trim overhanging trees. Trimming trees near your roof allows more sunlight to reach your panels and helps prevent life-shortening damage from falling branches.
Keep an eye on your system. Check your solar panels regularly for damage and obstructions. If you have a home security system, you can do this safely by pointing one of your security cameras at your panels. It’s also wise to monitor your panels’ power generation frequently, to see how much efficiency they’re maintaining over time. Catching and addressing problems early can extend the life of a solar panel system.
Perform regular maintenance. You can clean solar panels gently with a garden hose, or with a soft sponge or cloth and mild detergent. You can also hire someone to clean your solar panels for you; often, the company that installs your panels offers cleaning services for a fee. Remember that you can’t walk on your solar panels, and never use harsh detergents or abrasive materials to clean them.
Solar panel warranties: What to know
There are three major types of solar panel warranties:
Product warranties: Sometimes referred to as equipment or materials warranties, product warranties protect against manufacturer defects in the product, such as panel failures, cracks, moisture or other damage (as opposed to normal wear and tear). These warranties typically offer 10 to 25 years of protection.
Power warranties or guarantees: These warranties guarantee that your solar panels will maintain a specified percentage of electric power production during the warranty period. This percentage varies between manufacturers, and it makes sense to look for a warranty with the lowest degradation rate guarantee you can find. Power warranties are typically offered for 25 years.
Workmanship warranties: These warranties protect against damage that occurs during the installation process and typically cover five to 25 years.
If you have issues with your solar panels, filing a warranty claim is a good first step to getting the necessary repairs and replacement parts. But know that you can unintentionally void these warranties by:
Using improper methods to clean your solar panels, such as harsh chemicals.
Installing the solar panels yourself.
Not addressing/reporting damage and other issues promptly.
DIY repairs to your solar panels.
Hiring outside contractors (as opposed to someone manufacturer-approved) to repair your panels.
How do you dispose of solar panels?
Currently, there aren’t any U.S. federal laws that direct you to recycle solar panels, and the U.S. National Renewable Energy Laboratory estimates that the vast majority of solar panels aren't recycled at the end of their useful lives. Many discarded solar panels end up in landfills, which is a concern because solar panels contain toxic materials that harm the Earth — as well as valuable items that could otherwise be used to create new solar cells.
If your solar panels have outlived their usefulness, here are some options to dispose of them responsibly:
Recycle: You can search for places that recycle solar panels in your area, or find companies that offer this service.
Sell or donate: Just because your panels are no longer producing enough electricity for your needs doesn’t mean they’re completely useless. They may still be a good fit for off-the-grid use and smaller homes, as well as certain schools, hospitals and nonprofit organizations that don’t require as much power. You can also donate solar panels directly to a registered charity like Good Sun, which takes care of transport and disposal, then repurposes the panels in schools and low-income communities in the U.S. and developing countries.
Replacing your solar panels: Some additional considerations
If your solar panels are nearing the end of their useful lives, there are a few things to consider before choosing a replacement:
Do all of your panels need to be replaced? If some of your solar panels are still operating efficiently, talk to your solar panel provider about replacing parts rather than investing in a whole new system. If your panels are old, however, it may be challenging to find replacements that are a good match.
What’s the condition of your roof? If you’ve decided to replace your whole roof solar panel system, it’s a good time to inspect your roof and make sure it’s still in good condition before mounting new solar panels. If you need a new roof (or will require one in the next few years), you’ll want to take care of that before installing your new system. And if you’re replacing your roof, you may also consider solar shingles (which can do double duty as a roof) as a replacement for aging solar panels.
Would refurbished solar panels make sense? If budget is a concern, refurbished solar panels may be a more affordable option, since they’ve been professionally restored, and cost considerably less than new panels. Some may even come with a limited warranty. The downside is that refurbished panels often don’t last as long as new ones.
