You’re thinking of going solar (awesome!) and have a ton of questions (as you should!). One of the common ones many people have is “how long do solar panels last?”

The answer is probably a lot longer than you think! Here are the details you need to know about this. 

How Long Do Solar Panels Last?

Well the answer to that will of course depend on what kind of panel you get, the manufacturer and some other factors. However, in general, solar panels should last you a good 25 to 30 years on average.

But just because they are meant to last for 25 to 30 years, it does not mean that they’ll just all of a sudden stop working one day and you’ll have to replace them. 

No, even after 25 – 30 years, your panels will still function. (Unless there is something wrong with yours that’s out of the ordinary). Instead, after that time period, your solar panels will just not be as good and efficient as they used to be. 

What we mean by this is that their ability to absorb sunlight and convert it to energy will likely degrade after the time period mentioned earlier. This process is called “solar panel degradation rate”. 

Solar Panel Degradation Rate

According to an older study by the National Renewable Energy Laboratory (NREL), the average degradation rate is 0.8 percent each year. But that was almost 20 years ago and things are even better now.

There are certain factors that affect the degradation rate of a solar panel. The climate and, in particular, hotter weather, being a main one. 

However, even then, that 0.8 percent degradation rate did not apply to all solar panels. The degradation rate will vary by the model of solar panel as well as the brand who manufactures/sells them. 

As you can probably guess, the lower the degradation rate of a solar panel, the better. That is because with a lower rate of degradation, your solar panel will keep producing more energy for you for a longer period of time. 

The good thing is degradation rates of solar panels are continually improving thanks to solar panel technology getting better over the years. So degradation rates below 1 percent are pretty normal these days.

What’s a Good Degradation Rate?

What is considered a good solar panel degradation rate? One that is around 0.3 percent every year is really solid. A 0.5 percent solar panel degradation rate is pretty average.

Meanwhile, a 0.8 percent average is not so hot these days. 

Over the course of 25 years, a solar panel with a 0.3 percent degradation rate will only deteriorate by about 6.96 percent. This means that your solar panel will operate at 93.04% of its original capacity after 25 years. 

If your solar panels have a degradation rate of 0.5 percent then, after 25 years, they will operate at 88.67 percent of their original capacity. 

Bottom Line

So, as you can see, if you’re considering solar, you can expect your panels to last for a very long time. And, even then, it’s just that they won’t be as efficient as converting sunlight into electricity for you. But they should still keep working well past the 25 – 30 year mark.

Leave a Reply