1. A control system for controlling a parameter associated with operation of a fossil fuel fired power generating unit, said control system comprising: means for receiving data signals from a plurality of sensors for sensing the parameter associated with operation of the power generating unit, said plurality of sensors located in different regions of the power generating unit; an optimization system comprising: (a) a model for predicting the parameter sensed by the plurality of sensors, the model comprising: a plurality of inputs for receiving input values associated with manipulated variables and disturbance variables associated with the power generating unit, and a plurality of outputs for providing a plurality of output values associated with controlled variables, said plurality of output values indicative of predicted values for the parameter sensed by the plurality of sensors, wherein each of said plurality of output values is respectively associated with each of said plurality of sensors; (b) an optimizer for determining optimal setpoint values for each of the manipulated variables by accessing said model to minimize a cost value of a cost function while observing at least one constraint associated with operation of the power generating unit, said cost value affected by the value for each said manipulated variable, wherein said optimizer determines the optimal setpoint values in accordance with at least one goal and the at least one constraint associated with operation of the power generating unit; and means for controlling operation of the power generating unit using the optimal setpoint values for the manipulated variables.