The size of the solar PV system will vary according to the location of your home and the amount of energy consumed. A 1.5 kW system is the minimum solar system size needed for grid connection. If you have a medium-sized household then it should be enough to take care of 16-25% of your total energy needs. You may want to install a 4-5 kW solar energy system to take care of 100% of your domestic energy needs.