Renewable energy penetration has been greatly increasing in these years and photovoltaic (PV) energy seems to be one of the main renewable source, widely and easily available. To valuate with good accuracy PV energy production usually designers need complicate software tools. In this paper a simple method to estimate the PV plant Yearly Energy production is presented. The proposed method employs only the available data of the PV plant (as location and PV nominal power). The analytical method presented here can be a profitable tool for design engineers in planning PV considering different locations.