The rapid growth of stochastic sources of renewable sources has caused crowding out of conventional units from work at the basic to peak hours and intermediate. The increase in the failure frequency of steam blocks is connected among others with the change of their function in the electrical power engineering system saturated with sources at stochastic character of the work. While planning load distribution between conventional and unconventional sources, environmental and economic issues cannot only be taken into consideration. This problem should be dealt with in a comprehensive way. Technical - economic aspects of work of sources at stochastic nature of work as well as the aspects of work of the entire power system must be included. The article describes a mathematical model that allows to carry out a multi-criteria comparative analysis of collaboration scenarios of hybrid power generation system with the national electricity system based on the conventional energy sources. The model defines four evaluation criteria of considered scenarios: additional fuel usage by hybrid power generation system, the unit cost of electricity generation by the hybrid power generation system, the emission of carbon dioxide during work and the degree of capacity utilization of power ordered by the consumer. (C) 2018 Elsevier Ltd. All rights reserved.