Rooftop grid tied pv system also known as Grid back feeding system, in this system the solar system connected to the utility grid or power supply lines along with the existing loads. When the solar system starts producing electricity it gives first priority by supplying the electricity to the existing utility loads, Once satisfied with the existing load, excess generated electricity will be exported or feedback to the grid. There are no batteries connected in this system to store excess energy for power backup during power shutdowns, but grid itself act as a Virtual power storage bank by taking all the excess exported generation. Incase of insufficient power generation (during cloudy days and In nights) from solar system to loads, then excess required energy will be imported from the grid. Electricity flows in dual directions (forward &reverse) in this system, hencetechnically called as import and export mechanism. At the end of every month electricity billing will be done based on “Net Units” only. Export units will be deducted from Import units, excess exported units will add or carry forward for the next month billing. This net units will be recorded by "Solar Net meter"