The grid-connected pv system is connected to main public grid and works only when the grid is available. The generated solar energy is used to power the loads in the building and the surplus is fed onto the public grid. When the pv system is not producing enough electricity to power all loads in the building, for example at nights, and raining days, then the electricity is supplied by the grid as usual.
How grid-connected PV system works?
The solar modules produce DC electricity when sunlight is available. This electricity is fed by cables to an inverter via a DC-switch. The inverter converts this DC electricity to AC electricity which is compatible with the connected grid. The AC output of the inverter is connected to the main fuse box in the building via an AC-switch. The energy is then consumed by the loads in the building and the surplus is fed onto the public grid.
In some countries, the grid company buys this electricity from the owner of the pv system and sell it to other customers.