Why Clean Solar Panels?
Solar panels work by allowing light into the solar cells. The more light that hits a panel, the more power it will generate. Due to the upwards angle of solar panels, they are more prone to bird droppings and a build-up of general dust and dirt that does not wash off with just rain. This reduces the amount of light hitting the panel and reduces its output. As the projected energy figures claimed by solar panel manufacturers and installers are based on the optimum performance of clean solar panels, this build-up of dirt can adversely affect the panel’s ability to meet those projections. So it is important to clean solar panels in order to protect and maintain your investment
Some solar panel manufacturers and installation companies have made solar panel cleaning a condition of their warranty. Should you have problems with your solar panels, if you do not have proof of regular solar panel cleaning by professionals, your solar panels may not be covered by the warranty
Why Rainwater Will Not Clean Your Solar Panels
A good way to illustrate why rainwater will not clean solar panels is by looking at your car windscreen. If you didn’t clean your windscreen for 6 months, how much visibility would you lose? If left, the grime on your windscreen would accumulate. Even if the car is rained on, the rain contains airborne dust particles that settle and attach to the surface after the rainwater evaporates. The whole of your solar panel is in exactly the same condition as the edge of your car windscreen because they are both exposed to the same elements. Visibility through your windscreen is lost due to the loss of light. Therefore, the same principles hold true for solar panel cleaning.