The analysis of the world electric-energy balance revealed the advantage of steam turbine plants. An increase in their efficiency through the improvement of the initial parameters runs into difficulties associated with creation of new materials. The efficiency increase that results from the final pressure reduction requires an improvement of the circulating water supply system. The aim of this work is to determine the effect of the water-cooling tower on the electric power station profitability. This goal was reached by the creation of a mathematical model of the water-cooling tower and turbine plant with a condenser connected to each other. The calculations were made for two types of cooling tower fill packing: asbestos cement sheets and mesh elements made of polyethylene. Further, according to it, the vapor condensation temperature was determined. The latter affects the vapor discharge in the condenser, the capacity of the turbine plant and the temperature of the cooling water at the condenser output, i.e. at the cooling tower input. The novelty of this work consisted of consideration of the interaction between the cooling tower and turbine plant. Significance of the obtained results lies in the fact that, taking into account the reciprocal influence of the turbine plant and cooling tower, the efficiency of the fill packing replacement turns out to be major comparatively to the case without considering this influence. The replacement of the fill packings the half-a-year average temperature of condensation will become lower by 2.34 °С, electricity production increases by 41.72 GWh.