Let’s get the obvious out of the way first, aesthetics. When that Charleston dirt, pollen, mildew etc. builds up on solar panels it stands out. Another reason to clean solar panels but less obvious is it can significantly improve efficiency. Studies have shown that dirty solar panels can loose up to 50% of their efficiency compared to clean solar panels. Google did an interesting study several years ago with their 1.6 mW solar installation in California. The first cleaning was performed 15 months after installation, and they found the output doubled. Eight months after the first cleaning they were cleaned again, and the solar panel efficiency increased again by 32%. These increases in efficiency can save you a lot of money over a small period of time.
The quick answer is that the rain will help to a small degree. One way to illustrate how rain is not very effective in cleaning solar panels in Charleston and elsewhere is to consider the windshield of a car. If you did not clean your windshield for 6 months how much loss in visibility would you have? If left alone the grime on your windshield would build up and here in the Charleston area it would eventually turn green. At a minimum it takes the back and forth of the windshield wipers to get the debris off the windshield. Rain alone is not very effective for cleaning solar panels not even a hard Charleston rain.
Here in the Charleston area there are many elevated homes and hard to reach areas. At ambassador we are known for efficiently accessing difficult to reach areas. Once we have the access, cleaning a solar panel is much like cleaning a window whether it be with a squeegee or water fed pole with the proper water filtration system.
Every six months is a good rotation to get on in order to insure good performance. A visual inspection should tell you when it’s time for the next cleaning. If you can visibly see debris on the solar panels then the efficiency of the panels will increase with a cleaning.
Solar panel cleaning costs will vary depending on the difficulty to access, how many panels are being cleaned and how many separate areas the panels are located. Here at Ambassador we offer free quotes so if you just give a few bits of info we can often have you a price during a five minute phone call.