Feeding power into the grid involves conversion of the DC-voltage from the PV-array to grid compatible AC-voltage by “inverting” DC to AC. This unit feeds power into a standard 240 VAC split phase electrical system or two legs (phase to phase) of a 208 VAC, 3-phase commercial, industrial or institutional facility’s electrical system that is connected to the electric utility grid. If the PV system and inverter are providing the same amount of electrical power that the facility is using then no power is taken from or fed into the utility grid. If the facility is using more power than the PV system is providing, then the utility grid provides the balance of power. If the facility is using less power than the PV system is generating, then the excess is fed into the utility grid.
Be sure to look into local regulations regarding net metering/inter-connection in your local area. Note that some utilities need to change their revenue kWh meter for proper net metering measurement or incentives/billing.