Roof power plant is the use of plants, public buildings, residential rooftop PV plant resource development. This type of plant size by limiting the effective roof area, the installed capacity of a few kilowatts to tens generally MW; the power generation in place to encourage consumptive, fed directly into the low voltage distribution network or 35kV and below the high-voltage grid; component orientation, inclination and shadow occlusion diversification. Such power plants are currently the main form of distributed photovoltaic applications, mainly in the eastern and southern regions of our country.