Hybrid Power Systems
Hybrid power systems are basically a combination of the three other power systems. The inverter has multiple input options (grid / solar / generator).
The inverter will provide excess power produced by panels to the load and, should there still be excess, the feed goes into the grid.
At night the inverter runs from batteries or the grid, depending on battery power available.
Should the grid fail during the day, the batteries will continue supplying the load.
You can also connect a generator to the system to assist in charging batteries should the panels and grid be insufficient.
This power system is basically off grid with a much smaller battery bank which makes this option more feasable than an off grid system.