 Rooftop mounted systems are small compared to ground-mounted photovoltaic power stations with capacities in the megawatt range.Rooftop PV systems on residential buildings typically feature a capacity of about 5 to 20 kilowatts (kW), while those mounted on commercial buildings often reach 100 kilowatts or more.The urban environment provides a large amount of empty rooftop spaces and can inherently avoid the potential land use and environmental concerns.