One of the most sustainable, inexhaustible and “clean” sources of electricity is photovoltaic solar energy that can be used for instant consumption while the surplus might be delivered in the power grid or stored in (local) batteries. In the study here presented, we analyze a usual, medium-sized household. The input data of the here developed application are the geolocation, the roof surface facing south, the geometric dimensions of the available individual solar panel, its installed power capacity and the (previous) electricity consumption for an entire calendar year. As output data the application will provide the total number of solar panels that can be placed and the total amount of energy produced in a year, for different values of conversion efficiency (solar energy-electricity, respectively DC power-AC power). Depending on these assessments, the user can decide whether is efficient to become a prosumer or opt for local storage of additional energy produced during solar peak irradiance hours.