\input zb-basic \input zb-ioport \iteman{io-port 01258319} \itemau{Su\'arez Rodr\'{\i}guez, P.; Bay\'on Arn\'au, L.; Alvarez Vigil, A.} \itemti{Pollution emissions optimization of hydro-thermal systems.} \itemso{Bank, Bernd (ed.) et al., Proceedings of the 3rd international conference on approximation and optimization in the Caribbean, Puebla, Mexico, October 8--13, 1995. Puebla: Benem\'erita Universidad Aut\'onoma de Puebla, 15 p. (1997).} \itemab Summary: This paper examines the applicability of the Ritz method to the optimal environmental dispatching of hydro-thermal systems. The algorithm proposed is aimed to reduce the production of atmospheric emissions such as $NO_x$ and $SO_2$ caused by the operation of fossil-fueled thermal generation. Such a reduction is achieved by including the emissions as a function in the objective of the dispatching problem. The technique may also be applied to the study of other types of emissions or to a combination of objectives. The generic minimization algorithm, which is not difficult to construct on the basis of the Ritz method, has certain advantages in comparison with the conventional methods. \itemrv{~} \itemcc{} \itemut{atmospheric emissions; fossil-fueled thermal generation; minimization algorithm} \itemli{http://www.emis.de/proceedings/3ICAOC/} \end