Evaluation of environmental dispatch strategies

Several strategies have been proposed for the dispatch of electric power according to environmental objectives. These environmental dispatch strategies are of significance to the power industry because of the current national concern with environmental quality. Historically, power system generation has been scheduled (dispatched) to minimize cost. In the mathematical programming formulation cost is then the objective function. However, in an environmental dispatch strategy, the objective is the minimization of an environmental or an environmental-economic function. Inherent in all environmental strategies is the utilization of system generation diversity, both in the operational and geographic sense, and it is to be expected that "cleaner" generating units, i.e., those that emit less pollutants, be utilized more fully under these strategies. An important application of environmental strategies is the control of SO2 emission from fossil-fired units. In this paper a methodology is presented to evaluate environmental strategies for SO2 control through computer modeling. Application of the more promising environmental strategies to a realistic power system is presented and preliminary results are compared with regard to environmental and economic effects. The economic dispatch strategy is used as the reference case.