Combustion turbine peaking units typically are used to meet peak power demands for short periods of time when system demands are highest. For summer-peaking utilities, these conditions occur during hot, humid weather periods. The hot weather conditions that increase the peak demand also degrade the combustion turbine output and heat rate (Figure 1). The thermal storage inlet cooling system that was installed on the MS7001B gas turbine at the Rokeby Peaking Unit Site was designed to increase the output of the turbine during these periods.