This invention relates to a method and apparatus for increasing the final feedwater temperature associated with a regenerative Rankine cycle, said cycle commonly used in thermal systems such as conventional power plants, whose steam generators are fired with a fossil fuel and whose regenerative Rankine cycle employs a reheating of the working fluid. This invention involves the placement of an Exergetic Heater System in the feedwater path of the regenerative Rankine cycle. The Exergetic Heater System conditions and heats feedwater such that the temperature of the cycle's final feedwater as it enters the steam generator has reached a desired value. The Exergetic Heater System receives its driving steam from an Intermediate Pressure turbine extraction.