What kind of PV systems do we know today?
On-grid system
The PV panels are connected to the gird via the inverter. The PV panels are produce power both to the house and to the grid. The sstem can not operate without the grid.
Off-grid system
The PV panels are connected to a battery pack and suuply the house from the battery pack via the inverter. The system can not operate without a battery pack.
Hybrid sstem
It try to combine the on-grid and off-grid systems. Basicly it operates as an on-grid system and use a battery pack to supply the house when the grid is interrapted. The battery pack is necessary for the off-grid operation.