There is a feature on the Cycle Charging dispatch strategy design page that states “Allow systems with generator capacity less than peak load.” When the box is unchecked, does HOMER consider any system with a generator sized below the peak (for example a 2kW fuel cell + PV + battery + grid with a 4kW peak) to be infeasible, or just a grid-only system with the generator sized below the peak (2kW fuel cell + grid with a 4kW peak) to be infeasible? 

HOMER considers any system with a generator sized below the peak (for example a 2kW fuel cell + PV + battery + grid with a 4kW peak) to be infeasible. If the box is checked, HOMER will find feasible solutions with a generator less than peak load (+ a big battery). However, once you uncheck the box, HOMER doesn't find any feasible solutions, even though there is a battery included in the model that could serve the load.