Under the Load Following strategy, when a generator is needed, it produces only enough power to meet the demand. Load following tends to be optimal in systems with a lot of renewable power that sometimes exceeds the load. Load following is abbreviated "LF" in the tables on the Results page.
On the Controller page, check the "Allow diesel-off operation" box if the system can maintain stability without the generator running. This option is only viable if there is a generator in the system that can be turned off. Some systems require a generator to maintain bus voltage and frequency. If the system includes a "grid-forming" component other than the generator, you can deselect this option. HOMER then turns the generator off if the load can be supplied with other sources.
Checking the "Allow generators to operate simultaneously" box only affects the operation of systems that include two or more generators on the same bus. If you check this box, HOMER allows multiple generators on the same bus to operate at the same time whenever necessary. Otherwise, multiple generators on the same bus must operate one at a time.
Checking the "Allow systems with generator capacity less than peak load" box allows HOMER to recommend a generator sized below the peak load if that load can be more optimally met with the assistance of other sources (i.e., battery). If you uncheck the box labeled "Allow systems with generator capacity less than peak load" then HOMER will consider a generator sized below the peak to be infeasible. For example, if you uncheck this box, HOMER would consider a 2kW fuel cell would be considered infeasible for a system with a 4 kW peak load.
See also