Grid-Connected Systems in Off-Grid Mode
The inverter can be used in off-grid, backup or self-consumption systems. Depending on the system, additional energy sources may be available (e.g. diesel generator, utility grid or others).
Inverters in grid-connected operation mode, are used to increase self-consumption. In off-grid mode, there are such systems that are connected to a diesel generator, the utility grid or both at the same time.
The use of diesel generators in off-grid systems is the classic application of Sunny Island systems. If available, the utility grid can also be used for this application. The grid within a system can be setup in different ways:
with utility grid as an energy reserve or grid as generator
with utility grid as the main supplier of loads (with or without PV plant)
with utility grid as the main supplier of loads with Diesel generator (w/o PV plant)
Larger systems require further components and are more complex. They are not considered here.