The problem of economical dispatch of condensing power units oil the basis of fuzzy information about units' characteristics is considered in the paper. The goal of optimization is minimization of maximum losses caused by uncertainty and fuzziness of the initial information. The paper introduces fuzzy models of characteristics, presents a mathematical model of the problem, the conditions of optimality and the method of solution. Some examples of calculations are presented. Especially important is economical dispatch of power units at coal and oil shale-fired power plants.