It is important to keep solar panels clean to ensure maximum output. High quality solar panels’ surfaces are made of tempered glass and are easily cleaned with water. Often rain is enough to clean dust and dirt but localized conditions may require more concentrated cleaning methods. Bird droppings, tree sap, and dirt from wind storms are examples where using a mild solution of water and vinegar along with a foam scrub brush will aid in the soil removal. Harsh chemicals should not be used.