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 of each kilowatt-hour of energy or other useful 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. As part of determining the optimal plant operating point, the numerical 
solver may determine the number of fans to run within the air cooled condensers of the plant and / or the speed of the fans to use in the air cooled condensers in conjunction with the amount of fuel to 
burn in the boiler, the desired temperature of the steam at the input of the 
steam turbine, etc., all required to produce a given amount of power (load demand) at the particular environmental conditions currently experienced at the plant. The 
expert system may modify these outputs by determining which fans to actually use at any particular 
time based on, for example, the availability of or the operational status of the fans, the wear of the fans and fan motors, etc.