ABSTRACTThe higher specific fuel consumption of present Navy gas turbine generators, when compared to main propulsion gas turbines, has led to the investigation of propulsion‐derived ship service electrical power. Variations in propulsion engine speed require that a generator provide constant frequency with a variable input shaft speed. A fuel use analysis has been conducted of the application of a variable speed constant frequency (VSCF) generator to a four gas turbine twin shaft destroyer. Other considerations are the quality of ship service power with the introduction of power electronics to the generating system and the impact of the new components on system weight, volume, and survivability. Propulsion‐derived ship service utilizing VSCF generators offers to provide substantial benefit to Navy combatant ships through the application of proven technology.