Abstract: An optimization and control system for a utility plant that uses fan based air cooled condensers controls the operation of the power generation system at the plant in conjunction with the operation of the air cooled condensers so as to run the power plant at an optimum operating point associated with minimizing or reducing the cost energy produced by the plant. The optimization and control system includes an optimizer having a numerical solver that determines values for a set of control variables associated with an optimal operating point of the plant and an expert system that oversees and modifies the control variable settings prior to providing these settings to a plant controller. The numerical solver uses an objective function and one or more models of plant equipment to determine the operating point of the plant that minimizes the cost per unit of useful energy generated by the plant.