To estimate the power generation of the photovoltaic power generation system, it is necessary to know the peak sunshine hours at the place where the system is installed (the total solar radiation received on the photovoltaic module surface is converted into the number of hours under irradiance of 1000W/m2), the system efficiency, and the system installation capacity.

For example, a 10kW photovoltaic grid-connected system, the installation location is Beijing, the peak sunshine hours are 4 hours, and the efficiency of the

photovoltaic grid-connected system is about 80%, so the daily power generation calculation formula of the system = module installation capacity× peak sunshine

hours× system efficiency = 10×4×0.8 = 32kWh, about 32 kWh