First off, it's essential to follow the manufacturer's guidelines as to what cleaning agent you should use and how often you should clean them. Most manufacturers recommend cleaning them every 6-12 months, depending on your location, the panel's orientation, and how dirty your panels are. Always use a non-abrasive cleaning agent, like a specialized solar panel cleaning solution, and a soft brush to avoid scratching the surface. If you live in an area with a high amount of dust or pollution or in an industrial area (photo above is near a horse ranch), it's essential to clean your solar panels more frequently. Consider installing a self-cleaning system that uses water to rinse off dirt, dust, and other debris from the panels. Although it's not recommended due to high cost and potential for water damage to your home.