Integration of RES-based Power Plants into the Unified Energy System of Russia: Problematic Issues and Approaches to Solving Them

Abstract

Recent years have seen mass-scale integration of wind (WPP) and solar (SPP) power plants for capacities ranging from a few to several hundred megawatts into the Unified Energy System (UES) of Russia. Wind and solar power plants for a total capacity of 5.28 GW are to be commissioned by the end of 2024, and around 6.7 GW else are to be commissioned within the next decade. WPPs and SPPs are constructed in the framework of capacity supply agreements, which guarantee the return of investments in the wholesale electricity and capacity market. The aim of the study is to analyze problematic matters concerned with integrating RES into the UES of Russia and to outline a list of first-priority and further steps to be taken for securing the optimal control of power system operation modes under the conditions of a growing share of RES in the mix of generating capacities. In view of the fact that certain power districts operating within the UES of Russia have been islanded for various reasons, the problematic matters of RES integration are analyzed also for these power system operation conditions. Experience gained around the world with integrating RES into power systems is considered, and the RES introduction scales for which certain organizational and technical measures must be developed and taken are ranked. Statistical data from Russian and foreign sources on the reliability indicators of wind farms and photovoltaic systems for various capacities are given. The equipment of modern WPPs and SPPs features high availability indicators; however, it is quite frequently disconnected, which leads to load surges on the adjacent grids and the need to cover the emergency active power shortage by conventional power plants. The article suggests a list of first-priority steps to be taken for correctly integrating RES into distribution grids that will make it possible to avoid grid equipment failures and incidents involving mass-scale loss of power supply to consumers in the course of power system operation. The implementation of the plans that have been set forth will facilitate smooth integration of the growing RES capacities into the UES of Russia, while keeping the ability to control the power systems operation modes. The article substantiates the need of introducing certain amendments to the legislation, statutory, regulatory and technical documents that set out technical requirements for RES equipment, its technological connection to and operation as part of power systems. If implemented in a goal-seeking and stage-by-stage manner, the suggested measures will help rule out excessive disconnections of RES, engage them in control of power system operation modes, guarantee reliable power supply to consumers, and secure safe and reliable performance of the UES of Russia.