Here is a basic overview on how grid-connected solar power systems work.
During the day when the sun is shining, sunlight falling onto your solar panels/modules is converted into DC electricity (the semi-conductor material in the PV module performs this conversion).
This DC electricity is conducted to a solar inverter which converts this DC electricity into AC electricity.
The solar inverter then feeds this AC electricity into your house’s switchboard.
This AC electricity is then used to power your house.
Any power being produced that is surplus to your house requirements/load will be fed back to the local grid (reverse feed-in).
If there is a power outage from the utility, the EG will switch off and stop operating until the grid is switched back on (this is also a safety requirement discussed under Safety and standards for SSEG installations.)