Solar PV Pocket Calculator. It helps to make the preliminary calculations of the basic elements of a photovoltaic solar system, starting from one of these values: -Consumption or daily demand -Total power of the panels -Battery bank capacity. Then, to perform the calculation, you will also need to enter the Photovoltaic Power (solar irradiation) of the installation area, the system voltage, the expected autonomy, the maximum discharge and the efficiency of the batteries. The output will display