How long do solar panels last?

PV modules can be expensive and when you purchase them, it’s only natural to be interested in exactly how long do solar panels last. The general answer is 25 years — that’s the average lifespan of a system. However, there is a lot to talk about here: let’s dig into the subject of solar panels aging deeper.

Factors affecting the service life of solar panels

When talking about the life of solar panels, it’s important to understand that solar panels lose a bit of their power every year. The first year when the panel is exposed to the sun for the first time is the roughest: a module can lose 2-5% of its power due to so-called Light Induced Degradation (LID). After that the panel loses around 0.7-0.8% every year. There are brands whose panels show the degradation rate as low as 0.25% per year, like REC and Panasonic.

The service life of your panels is at least 25 years on average almost no matter what, but some external factors can shorten or prolong it. For example, hot and dry climate speeds up the aging process of PV modules, therefore solar installations in deserts lose around 1% of their output every year. On the contrary, panels love cold and sunny climates. Solar panels endure harsh weather conditions pretty well, but it doesn’t mean that hail, strong winds, hurricanes or tornadoes are good for modules. Shading decreases the output of your modules and can lead to development of hot spots. Hot spots are cells that heat up more than the others and they potentially shorten the lifetime of a module.

Obviously, the higher the quality of panels, the longer is their lifespan. Panels made by manufacturers with good reputation are less susceptible to cracking or hot spots development. Generally, brands issue a 25 year warranty for performance and a product warranty can vary from 10 to 25 years.

Keep the panels away from debris and other damaging materials.

Proper installation is very important for solar panels. Before putting panels on the roof, it’s a good idea to perform a shading analysis: inspect the installation site and take into consideration all objects that can potentially block the sunlight for solar panels. Some states encourage creation of solar easements between neighbors. An easement is a contract that prevents your neighbors from growing trees on their land that can potentially block the sun from your array.

Obviously, you shouldn’t keep any materials that can be harmful for your panels on the roof or in the yard, if your installation is ground-based. In the fall when leaves are falling down, a leaf blower is a great tool to keep panels clean from debris. In the winter snow loads can be problematic. If panels are tilted enough, snow may just slide off, but otherwise you’ll have to clean it for better exposure of panels to the sun. Birds love nesting under panels so you can also get critter guards which are essentially metal nets for your modules.

Is it possible to extend the life of solar panels?

You don’t have to do much to prolong the lifetime of your system — PV modules are almost maintenance-free to begin with. It is recommended to wash your panels every year, especially if your panels are installed on the ground. While rain does take care of the dirt on the modules, it doesn’t clean them completely. The dust eventually turns to mud and lowers the production significantly.

Cleaning panels is easy and you can approach it like cleaning windows — just don’t use soap or any cleaning supplies that might react with the glass and aluminium frame. Soap leaves residue and raises the reflectivity of a surface. If the performance of your panels decreases, it might be a sign that it’s time for cleaning.

Aside from cleaning, occasional visual inspection is recommended. Always check the connection as most problems stem from there. Check the integrity of modules. Discoloration usually doesn’t affect the performance, unless some cells are darker than the others: that might be a sign of hot spots. It is recommended to invite a certified electrician from time to time to take a look at your array. Overall if your panels are high quality, you take good care of your panels and are lucky, they can serve for up to 50 years.

When should I change my solar panels?

So if the warranty runs out and panels have already lost a fair share of their performance, does it make sense to change them? Well, it’s really up to you. As long as panels bring in the energy, there is no necessity to remove them. The thing to keep in mind is that you have to detach your old panels from the roof first and usually you’ll have to call for special services for that. A house with solar panels also costs more on the retail market.

However, there are different situations and sometimes replacing old panels can be a reasonable idea. For example, you may find a really good deal on new modules. Or old panels lost their color and don’t look good on your office building anymore. Or electricity bills become too high and it’s essentially time to invest in a new solar system. If you are into DIY, old panels may still serve you for some small project.