Solar Panel Cleaning

Why Should You Clean Your Solar Panels?

Over time airborne dust particles, bird droppings, tree sap and pollution will accumulate with the effect of creating shading on the cells which will prevent sunlight reaching them and thereby reducing their output performance.

Additionally lichen can and does form on panels which creates hard shading and can result in "hot spots" which will reduce the panel's life. If left unchecked lichen will continue to develop and grow until they have completely covered the panel.  Lichen can be removed from solar panels but to do so is not as straightforward as you might think - whilst glass may feel very smooth to the touch it is, in fact, pitted and very rough when put under a microscope. Lichen blooms makes the most of this and attach themselves to the pits in the glass and, because of the way it forms a strong bond with the glass, it becomes very difficult to remove. It is far better to keep your panels reasonably clean and prevent any lichen growth than to try and remove it once it has taken hold and is thriving.

Are  Solar Panels Self-Cleaning and Maintenance Free?

No, generally speaking this is a misconception. When solar panels were first introduced some years ago the solar panel industry did indeed tout them as being self-cleaning as most had a hydrophobic coating which means that water droplets cannot stick to the surface and rolls off the panels. More recent panels may have a hydrophilic coating which does actually help more by chemically breaking down any absorbed dirt which is then washed away by rainfall. However, in reality neither of these coatings are 100% self-cleaning and maintenance free. Neither will remove bird droppings or tree sap, nor prevent the formation of lichen. The coatings have a life span that is usually measured in years (about 5 - 7 years) and the manufacturers of those coatings will tell you that, in order to keep them working efficiently and  gain the maximum life from them,  they need to be maintained and cleaned periodically.

Rain alone is not enough to ensure solar panels remain free from a build-up of dirt throughout the year, let alone the lifetime of the panel.

Manufacturers DO NOT recommend the use of harmful chemicals or detergents to clean solar panels. However, they do advise regular cleaning using pure, deionized water, which will preserve their limited warranty and help to maintain the optimum output performance of the panels. Using hard, untreated, water will leave marks behind on the solar panels containing mineral deposits which will feed and help lichen to thrive, especially in hard water areas.