Keeping your Solar Panels clean from dirt, bird poo and other debris will help insure that your solar panels are not losing anywhere from 10% - 30% in output power capacity! Its important to have your solar panels cleaned with DI water so that you dont have hard water build up on your panels. Leaving dirt on your panels for long periods of time will allow minerals from the dirt to set into the glass thus reducing your power output. It is recommended that you have your solar panels cleaned every six months or bare minimum once a year.