If you have recently purchased a solar panel system, you might wonder if cleaning them is necessary. After all, ensuring your panels operate at peak efficiency will allow you to rely as little as possible on grid power.
We saw recently that solar panels completely covered in snow won’t work very well. But you may wonder how much the buildup of dirt will negatively affect your panels.
And if you do have to clean them, you may not know how often (or even how) cleaning is necessary. Thus, we will answer those questions in this post.
Is Regular Cleaning Necessary?
The good news about solar panels is that it isn’t really necessary to hose them down every week like you do your car on a weekly basis. While dirt can form on solar panels over time, it usually isn’t enough to reduce their power output too much. It may not be a bad idea to wash your panels once a twice a year, but washing them weekly would probably be overkill.
There have been a few different studies of the effect of cleaning solar panels. Some have found that cleaning them only increased efficiency by a few percent. On the other hand, Google conducted an experiment that showed that cleaning their panels increased efficiency by 36 percent. This was the result after 15 months of continuous operation with no cleaning. However, a big caveat here is that these panels are completely flat, meaning they don’t really allow rain to run off and wash away dirt.
So, how often you should clean your solar panels comes down to, in part, how beneficial it is for your system. The only way to determine this may be to run your own experiment. Try leaving them alone for a year, checking your efficiency, then check again after a cleaning.
However, keep in mind that Google results seem to be an outlier based on what I found, which isn’t too surprising since solar panels are often tilted. It seems that it’s more typical for cleaning your solar panels to increase efficiency by a few percent.
There are a number of variables that could affect how beneficial cleaning is. For example, do you get a lot of rain? What is the angle of your panels? There are so many things that could impact efficiency that you should test your own system.
That being said, it is likely not worth it to hire someone to clean your solar panels. So, yes, don’t do that.
Does Rainfall Clean Solar Panels?
I hinted at this above, but rainfall certainly can clean your solar panels to a certain degree. However, if you live in the desert, rainfall will obviously not help as much as it would in a more tropical climate.
Plus, we saw above that flat solar panels may need to be cleaned more often than those that are tilted. It’s worth noting that Google’s flat solar array is at the headquarters in Mountain View, California. That city only receives 16 inches of rain per year compared to 38 inches per year on average nationally.
Thus, rain can clean solar panels, but it depends upon where you live and the setup you have. In some cases, rainfall won’t be nearly enough.
Check For Debris
Other than a full-blown cleaning, something you may want to do more frequently is to check for any debris that may have fallen. Even leaves or other small objects can obscure your solar panels. Of course, it’s easy to check if you have ground-mounted solar panels, but not as easy for rooftop solar panels.
Nevertheless, if you are capable of doing so, checking your solar panels occasionally for anything that may be obstructing them will help ensure maximum efficiency.
How Do I Clean My Solar Panels?
I mentioned above cleaning your solar panels like you would your car, and that is actually similar to how you will probably clean them. However, you should check the panels’ documentation first to be sure there are no special instructions.
Other than that, cleaning them is pretty simple indeed. You can simply spray them down with a hose or, if necessary, use soap and water, again, just like you would when cleaning a car. Again, the biggest issue may be reaching the panels if they are mounted on your roof.
The Bottom Line
Cleaning your solar panels is a fairly simple process. It’s something you should try to do at least yearly if possible to maintain the best possible efficiency. How much it will actually help depends on a number of factors. That being said, in most cases, an annual cleaning will improve efficiency by a few percent.
Cleaning your solar panels should be fairly easy, but be sure to check for manufacturer instructions. If you have rooftop panels and scaling the roof is dangerous, you may decide to hire someone. Just keep in mind that what you pay may be quite expensive for how simple they are to clean.