On Grid System
Grid tie (also known as grid-intertied or utility-interactive) systems are intended to operate in parallel with an electric utility.
During the daylight hours, the system generates power, offsetting the consumption of electricity from the utility and cutting electric bills. The balance of the kWh required by your loads is automatically drawn from the input lines.
If the PV panels are producing more electricity than you are using, the system will feed the surplus of the energy back to the utility. (Not yet in Pakistan).
PV Modules (Solar World)
Grid Tied Inverter (SMA, ABB, Schneider)