Contents I. Introduction
Renewable energy sources (RES), primarily wind and solar, are becoming the basis of "new energy" industry around the world, a powerful tool for decarbonization. At the same time, these sources are characterized by a weather-dependent, variable, non-dispatchable operating mode, a relatively small unit capacity (up to several MW) and a high degree of geographical "distribution" of installations. The integration of wind and solar power plants into the power system creates new requirements for the network infrastructure, the volume and quality of capacity reserves. It also changes the operational modes of conventional power plants. In fact, the boundaries between basis, intermediate and peak power sources are being "blurred", and technical requirements for existing generating equipment are being seriously increased, primarily at thermal power plants. All these "system" effects have their own cost, which can significantly influence the choice of cost-effective scales of structural changes in the power system, technological transformation of its largest segment – the thermal power.
