Hybrid GA/SA algorithms for evaluating trade-off between economic cost and environmental impact in generation dispatch

Two hybrid algorithms, GAA and GAA2, are proposed in this paper for evaluating the trade-off between fuel cost and environmental impact in power generation dispatch with multiple fuels and multiple pollutants. The two algorithms are developed based on genetic algorithms and simulated annealing. The problem is first formulated as a bicriterion optimisation problem. This is achieved by combining the total emission of individual pollutants into a single criterion via the use of relative weights in the objective function. Trade-off curves between total fuel cost and emission of each pollutants are then obtained by solving the bicriterion function at different values of PEC assigned to the total emission. The developed algorithm is demonstrated through an application example in which emission of three pollutants-SO ₂, NO_x and CO₂ are considered. The trade-off curves obtained are useful in assisting operation engineers to determine the appropriate dispatch when both economic and environmental aspects are considered