Solar panels for your home are a fairly expensive initial investment. In fact, one of the many things you need to know about solar systems before installing them is that while they can save you money, it can take years to break even. Knowing this, you may be wondering how long solar panels last on average. If they’re just going to break down or malfunction after a few years, well, that changes the perspective, doesn’t it? The good news is that the United States Environmental Protection Agency (EPA) says that with proper care, a quality set of solar panels has a useful life of 25 years or more. This gives you time to recoup costs and even save money before having to make replacements or upgrades.
Keep in mind, however, that the lifespan of a solar panel depends on several factors. Most relevant is the panel type: silicon solar panels with mono- and polycrystalline cells are expected to last 25 years or more. Thin-film panels last about 10 to 20 years, according to EcoFlow, but this is improving with modern innovations. Despite the longevity gap, you need to understand the difference between thin film and monocrystalline before deciding which one is best for you.
Another thing to note is that solar panels generally don’t stop working. Instead, they can operate at maximum efficiency and technological relevance over a period of years, what EcoFlow calls “useful life.” At this point, it may be more beneficial to upgrade for practical and financial reasons, but not necessarily because the panels themselves stop producing electricity completely. Panels degrade slowly over time, but in a network made up of multiple panels working collectively, it’s not that bad, at least not until it reaches a point where it is – hence the lifespan estimate ranges.
How quickly do solar panels degrade?
Researchers at the National Laboratory of the Rockies (NLR), formerly the National Renewable Energy Laboratory (NREL), analyzed data from a large group of photovoltaic (PV) systems across the United States to understand degradation and found a median performance loss of 0.75% per year. The researchers also found that in warmer temperature zones or climates, the loss of efficiency was doubled. So installation location, average temperatures and climate can all impact lifespan, in addition to the type of panels or materials used.
But what does this actually mean for residential systems? To put it simply, each year, your panels lose on average 0.75% of their efficiency, producing even less electricity. So in the first year they would produce 100%; the second year they would produce 99.25%; at the end of the fifth year, they would produce 96.25% and after 30 years, their efficiency would be less than 80%. Remember that degradation may be more or less significant depending on the climate and the quality of the panels. In some areas, and with higher quality panels, for example, the degradation rate could be as low as 0.30% per year, which would maintain operational efficiency well above 90%, even 25 years after installation. You can also help increase the overall utility of your system over time by following the 20% rule for the solar panels you have installed.
What type of maintenance and care is required?
Solar panels are overall low-maintenance investments, but that doesn’t mean you should neglect or ignore them, especially if you want them to continue operating at peak efficiency. Generally speaking, you should clean your panels between two and four times a year. It depends on the season, what debris might be in the area (such as the buildup of heavy tree cover or pollen), and how and where the signs are installed. If they are tilted, for example, rain can help wash away debris naturally, but if they lie flat, more dirt can accumulate on top. Homeowners make many mistakes with solar panels, but not scheduling regular cleanings is a big mistake.
Many solar panel companies do not recommend cleaning the panels yourself. This is dangerous if they are mounted on a roof, and if you are doing it from the ground with tools there is always a risk of damaging the panels. Damage caused by sloppy maintenance and cleaning of solar panels is also generally not covered by limited warranties.
Depending on the system and type of features you have, you can monitor the efficiency or output of your solar panels, often using an app or power delivery device of some sort. But you should also be able to tell how clean the panels are just by looking at them. If you notice any dust, debris, or embedded materials, you will probably want to have them cleaned. If your meters are showing low output power and your panels are still relatively new, this also requires cleaning.
