With regular rain, the solar panels are generally self-cleaning.
However, when there is little rain, the panel tilt is minimal, or they are located in a dusty area (e.g. near farms or vineyards), or if there are other factors that might dirty the panels (e.g. bird droppings), it may be a good idea to clean the panels once every year or two.
Dirty solar panels can reduce the solar system’s performance by up to 25 percent, which means a decrease in the electricity produced and your return on investment.
If the solar panels are easily and safely accessible, we recommend trying cleaning them yourself!
Avoid cleaning them when the weather is hot since the water can evaporate quickly and leave streaks. Best time to clean them is early in the morning before the sun gets hot.
Make sure to shut down the system before you start cleaning, use a good quality soft brush and squeegee on a long enough handle with an extension, make sure your hose can reach the panels, and use an environmentally safe detergent (e.g. mild dishwashing soap).
However, you still may want to hire someone to do the cleaning. You can consider hiring a handyman, a window cleaner or a solar company to do the work.
Green Stock Solar provides solar panel cleaning service in Napa County and the North Bay Area.
One advantage of hiring Green Stock Solar to clean your panels is that we will also do a visual check-up of your solar system.