A system and method for increasing the responsiveness of a duct fired, combined cycle power generation plant (12) via operating one or more gas turbine engines (14) at a part load condition less than 100 percent load, one or more steam turbine engines (16), and one or more supplemental burners (18) providing additional heat to a heat recovery steam generator (20) upstream from the steam turbine engine (16) is disclosed. The combination of the steam turbine engines (16) and supplemental burners (18) operating together with gas turbine engines (14) at a part load condition enables the system to quickly change output to accommodate changes in output demand of the duct fired, combined cycle power generation plant (12). By operating the one or more gas turbine engines (14) at a part load condition, the gas turbine engines (14) are able to be used to increase net output of the combined cycle power generation plant (12) faster than relying on increasing output via duct firing.