What is the best way to clean solar panels?

Clean solar panels mean money in the bank for our clients. It is really that simple: a cleaner solar (or Photo Voltaic panel) collects more energy and therefore yields higher monetary returns. According to the National Renewable Energy Laboratory (NREL), about 7% energy is lost annually from soiling of solar panels in the United States, while that number can be as high as 50% in the Middle East. Most solar panel manufacturers recommend cleaning of solar panels at least once a year but many solar panel owners may wait until there is a noticeable drop in energy production. Because of the temperature fluctuations and moisture that can affect the panels, dirt and grime might become cemented onto the solar panel surface.

Figuring out the best method for cleaning panels can be tricky. Solar panels in the South Western USA must contend with dry dusty conditions which bakes dirt onto the surface, while panels in the South East may be covered with mildew in the more humid climate. Panels may be a part of a vast solar field, or just a few panels on top of a carport (which is very common here in Phoenix). Additionally, solar panels are delicate and can be damaged by cleaning with high water pressure or harsh chemicals (see below list). Another consideration is the potential danger to workers in close proximity to electricity, gas and water– a dangerous combination!

According to DualSun (a French solar panel manufacturer), this is one list of “What to avoid when cleaning solar panels:”

  • Certain cleaning products can damage the solar panels and should therefore be avoided:
  • Hard water. It can leave white residue that diminishes photovoltaic output.
  • Abrasive sponges. They may scratch the panels.
  • Very cold water: Using very cold water on a warm panel can result in thermal shock and permanently damage the solar panel.
  • Very high-pressure water. This can damage the joints in the panel frame. Kärcher-type high-pressure cleaners must therefore be avoided.
  • Solvents and detergents. Such products may damage the surface of the solar collectors.
Dual Sun, “What to avoid when cleaning your solar panels”

Yesterday we had a great conversation with the folks (Ed and Jordan) over at Sunbrush USA who sell some amazing products to help clean solar panels. Their flagship product is the Sunbrush TrackFlex (see picture) uses softened water and soft, rotating bristles which gently yet effectively clean the panels without chemicals. The amazing Washtronic system applies firm yet gentle pressure to clean the panels.

Sunbrush's Trackflex system
Sunbrush’s TrackFlex system features a Washtronic system that keeps a gentle yet constant pressure over the entire panel surface without damaging the panels.
an example of a sunbrush cleaning a solar panel field.

Where might spray drones fit into world of solar panel cleaning? Clearly, for larger fields that are evenly spaced and allow for tractor access, the sunbrush model is the way to go. However, for panels on residential buildings, carports and in difficult-to-access locations, spray drones offer a cost-effective solution.

We are not the first company to explore the use of drones for cleaning solar panels. In fact, one company in Israel, Airobotics, is advertising the use of automatic docking drones to clean solar panel fields, as explained in this post. However, this model necessitates the buying of expensive equipment that is stationed at each solar field. Our spray drones come to you with our trucks outfitted with the latest in temperature and pressure controlled equipment, when you need us and how often you need us to. We recommend our quarterly cleaning maintenance packages to keep your panels clean throughout the year, at a reduced cost. Call us at 1-888-264-0225 for a no-cost quote today!