[en] One of the possible manners, to reduce the losses in consumption of electrical energy in Complex Electro-energetic Systems is inventing of optimal solution on a lot of problems which exists in exploitation of CEES (Complexual Electro-energetic Systems), as so as in theirs starting that and in theirs exploitation in CEES, independent of consumption in EPS (Electric Power System). In all this very important is the insuring of optimal exploitation of Power Plants with minimal economic deficit and minimal energetic deficit. In this paper will be proposed concrete example of exploitation of two Power Plants, which one of them is Thermal Power Plant and the other is Hydro Power Plant, and by the way was calculated their necessary optimal working time independent of consumption in Power Grids. It is analyzed regular using of Primary energetic sources in exploitation of Thermal and Hydro Power Plants with maximal saving water in HPP and maximal saving fossil fuel in TPP. (Author)