A standard utility-scale solar farm might use about 500-1,000 gallons of water per megawatt annually for cleaning purposes. The cleaning process usually involves spraying panels with deionized water to remove dust, bird droppings, and other debris that can reduce energy production. In general, all solar power technologies use a modest amount of water (approximately 20 gallons per megawatt hour, or gal/MWh ) for cleaning solar collection and reflection surfaces like mirrors, heliostats, and photovoltaic (PV) panels. Some advanced solar facilities even employ robotic cleaning systems and hydrophobic panel coatings that further reduce water. Unlike coal or nuclear plants that consume millions of gallons daily for cooling, solar panels typically use only a fraction of that water annually for maintenance. (A megawatt-hour is about what a typical California household would consume in six or seven weeks. In both soaking/cleaning and rinsing steps, the H2O was cast onto the panels. In comparison, when both soaking and rinse. Solar panels conserve water through various methods, such as not using water during operation, not using water for cooling systems, and using only enough water for running office bathrooms and washing.