HOMER Grid 1.9

The generator minimum load ration is the minimum allowable load on the generator, as a percentage of its rated capacity. Specifying a minimum load does not prevent the generator from being shut off, it simply prevents it from operating at too low a load. This input exists because some manufacturers recommend that their generators not be run below a certain load.

As an example, this number is set to 30%. If the required power from the generator is 40% of its capacity, it runs at 40%. If the required power is 15%, it runs at 30%, with the excess power either serving the deferrable load, charging the batteries, or being dumped. If no power is required from the generator, it is turned off.