BALANSING OF POWER AND ELECTRICITY IN THE ELECTRIC POWER SYSTEM WITH RENEWABLE ENERGY SOURCES BY CRITERIONAL METHOD

Abstract

This article considers the features of the development of renewable energy sources in electrical networks. The main changes in the functional properties of power systems, which include a significant reduction in electricity consumption, change in the structure of electricity consumption, rapid increase in the installed capacity of solar and wind power plants. Electricity consumption in 2020 is almost halved compared to 1990 (from 227 to 119 billion kWh) and as a consequence the share of semi-peak thermal generation, which gave the power system basic flexibility, has significantly decreased (from 71 % in 1990 to 35 % in 2020) and at the same time the share of nuclear generation, which operates in base mode, has increased (from 25 % to 51 %). In particular, consumption by industry with a stable load schedule, decreased (from 146 billion kWh (64 %) to 49 billion kWh (42 %)). At the same time, the demand for electricity by the households, whose consumption profile of which is characterized by significant daily unevenness and sensitivity to meteorological factors, has significantly increased (from 21 billion kWh (9 %) to 37 billion kWh (31 %)). Therefore, the article analyses the preconditions for the problem of flexible generation and explores possible ways to solve them. The optimal composition of electricity generation for Ukraine in the period 2021–2025 is proposed, which provides for the preservation and even increase by optimizing the repair campaign of the share of electricity production by nuclear power plants, the introduction of additional 2–2.5 GW of highly flexible generation and up to 2 GW storage systems (taking into account the pumped-storage power plant), as well as a gradual evolutionary decline in both installed capacity and electricity production by semi-peak coal-fired power plants and maintaining a policy of decarbonisation to ensure its own energy security. A comprehensive approach to compensating for the instability of renewable energy sources generation has been developed, which consists in minimizing the cost of power redundancy in various available ways. The problem of cost optimization for ways to compensate for the instability of renewable energy sources generation is solved by the method of criterion programming. The impact of each backup method on total costs is determined using sensitivity theory.