A power generation system includes: a first gas turbine system including a first turbine component, a first integral compressor and a first combustor to which air from the first integral compressor and fuel are supplied, the first combustor arranged to supply hot combustion gases to the first turbine component, and the first integral compressor having a flow capacity greater than an intake capacity of the first combustor and/or the first turbine component, creating an excess air flow. A second gas turbine system may include similar components to the first except but without excess capacity in its compressor. A control valve system controls flow of the excess air flow from the first gas turbine system to the second gas turbine system. A cooling fluid injector may be coupled to the excess air flow path for injecting a cooling fluid such as water or steam into the excess air flow.