Solar Pensacola
Panama City Beach Solar Residential

How Often Should I Clean My Solar Panels?

When someone gets a new rooftop solar installation in the Northwest Florida area, they always ask “how often do I need to clean my solar panels.”

Solar panels get dirty primarily from wind-blown dust and pollen. As panels get dirtier, their output declines.  A light dusty film may only cause a 5 percent output decline. However, when panels get very dirty — perhaps in an agricultural area or location that does not get regular rainfall — the output decline can be greater than 20 percent. A good heavy rainstorm will usually wash away most of the accumulated soiling.

I use the term “usually” because on panels that are tilted at about 5 degrees or less, the rain may leave a puddle of muddy debris along the lower edge of the panel. When this puddle dries, sometimes a thick layer of dirt accumulates along the lower row of cells. Depending on the design of the system, this small accumulation of dirt can cause a very significant decrease in output.

So the answer to the question: “how often should I clean my solar panels” really depends on three factors: your location (does it rain regularly or only during certain months), the tilt angle of your panels (steeply tilted panels tend to stay much cleaner than panels that are close to horizontal), and the amount of wind-blown dust and pollen.

Compass Solar Energy suggests that solar customers in the Florida Panhandle clean their solar PV panels once a year just to be sure that they are getting the best possible solar output.