Systems, Methods, And Apparatus For Modifying Power Output And Efficiency of A Combined Cycle Power Plant

Embodiments of the invention can provide systems, methods, and an apparatus for modifying the power output and efficiency of a combined cycle power plant. According to one embodiment where a combined cycle power plant includes a compressor (110), a gas turbine (105), a combustor (120), and a heat recovery steam generator (110), excess air from the compressor (110) can be extracted and expanded to generate power. The expanded air can then be mixed with at least one combustible fuel to generate a heated combustion product. The heated combustion product can be mixed with exhaust gas from the gas turbine (105) to increase the temperature of the exhaust gas prior to introduction to the heat recovery steam generator (110). This increase in temperature of the exhaust gas from the gas turbine (105) provides additional energy for generating steam and power and improves performance of the heat recovery steam generator (110).