Nowadays, energy companies operate under the conditions of a high competition due to the wide integration of intermittent generation in energy production process, the fluctuation of electricity and prices of fuel, increased demands to energy efficiency and its production flexibility. For saving leading position, the energy companies must take appropriate steps in a timely manner as a reaction to the reasons of competitiveness mentioned above. In line with the proposed methodology, the installation of electric boiler at combined cycle gas turbine power plant is evaluated for the reducing of production costs and increasing of its competitiveness, operating under the condition of open electricity market and located in the area with low share of intermittent generation and high level of biomass energy sources.