A method, including receiving a turbine system operating parameter. The turbine system operating parameter includes an indication of a frequency variation of an electric power system associated with the turbine system. The method includes determining a correction factor to vary the output of the turbine system according to the frequency variation, wherein the correction factor is based on a droop power response and a nominal droop power ratio. The droop power response is calculated based on a gas turbine power output and a speed-load error. The method further includes varying the output of the turbine system based at least in part on the correction factor.