Influence of the wind energy sector on thermal power plants in the Polish energy system

Wind as a renewable energy source is characterized by rapid growth of installed power in many countries, including Poland, where its share in the electricity production has grown over 25 times in the last decade, now reaching about 10%. Since renewable energy has priority in access to the grid, it forces the dispatchable coal-fired power plants to adjust their load. This causes additional consumption of primary energy due to more frequent shut-downs/start-ups and due to efficiency penalty when operating below nominal parameters. In this paper, actual data on the operation of Polish power plants in several years are analysed. The analysis, together with simulations of performance of the power system without the presence of wind energy, focuses on the influence of wind power plants on the utility ones. The results of simulations are additionally processed using the concept of thermo-ecological cost to compare the operational impact of wind farms on the power system with their investment environmental burden. A conclusion is that current share of wind energy at the level of 10% is enough to have an adverse effect on the coal power plants, but depending on the structure of the power system it may actually increase its overall efficiency. (C) 2020 Elsevier Ltd. All rights reserved.