Economic-environmental scheduling of hydro thermal power systems

The present paper describes a framework for expanding the hydrothermal operation task from traditional cost minimization to also include environmental objectives. The basic idea is to maintain the physical value of the impact through the decision process, rather than assigning a specific monetary value. A trade-off curve, representing all alternative operation policies, is derived by assigning relative weights to the pollutants. The suggested method, which is based on mnultiobjective Dual Dynamic Programming, identifies both minimum cost and minimum emission operation of hydrothermal systems. The main contribution of the approach is to indicate how the operation of a hydrothermal system changes as function of the total environmental weight. The approach is illustrated and discussed in a case study.