Zagorskaya PSP: an "invisible" link in the energy system of Russia

The Zagorsk pumped storage power plant was built on the Kunya River near the village of Bogorodskoye in the Sergiev Posad district of the Moscow region in 1987. Currently, work is underway to put into operation the second stage of the PSPP. This power plant has the status of the largest object of this type in Russia, being an important structural link in the power supply system of the Moscow region and the center of Russia.

First you need to figure out on what principle pumped-storage stations work. Their key benefit lies in leveling the daily heterogeneity of the electrical load schedule. Objects of this type operate in two modes. During the morning and evening peaks of energy consumption, the station generates expensive electricity by discharging water from the upper storage pool to the lower supply reservoir (generator mode). During the period of the night minimum of energy consumption, it takes cheap electricity from the power grid, spending it on the reverse pumping of water into the upper basin (pumping mode). If we think as straightforwardly as possible, then we can draw a not entirely correct conclusion, which is that pumped storage stations are energy unprofitable, since they consume more electricity than they produce. Despite this, they play an important role in large energy systems, which include the Russian one. Thus, the use of a pumped storage power plant is economically extremely profitable, because it contributes to both optimizing the daily load schedule and improving the reliability and quality of power supply.



Currently, there are two full-fledged pumped storage stations in the Russian Federation. We are talking about the mentioned Zagorskaya PSP in the Moscow region and the Kuban PSP in Karachay-Cherkessia. A few more similar stations are part of hydropower complexes, where power facilities of various types operate in a single system. Another ten hydrostorage stations are currently in the design stage.

The first stage of the Zagorskaya PSP (capacity 1200 MW), the facilities of which were put into operation in the period from 1987 to 2003, includes a station junction, an upper storage pool, pressure pipelines, a reversible water intake, and a lower storage pool. The construction of this facility was of an experimental nature, the location of the new station was determined taking into account many factors that had a positive impact on the construction and operational processes. The PSPP is located near the borders of three regions (Moscow, Vladimir and Yaroslavl) in the zone of influence of the powerful energy system Mosenergo. The developed infrastructure of the central part of Russia made it possible to reduce the cost of all issues related to the delivery of the necessary materials and equipment to the construction site. Given the complex economic situation in the country in the nineties of the last century, the full commissioning of the facility was constantly postponed. To complete the construction of the station, Mosenergo had to obtain a loan from the European Bank for Reconstruction and Development in the amount of $50 million. In addition, in the course of work with a certain frequency, emergency situations occurred. So, in 1979, a large ancient landslide intensified at the construction site, which for a long time could not be stabilized, and in 1986 the left retaining wall of the water intake collapsed.

In 2006, in order to further reduce the shortage of regulating maneuvering capacity, for which pumped-storage stations are being created, a decision was made to build the second stage of the Zagorskaya PSP (Zagorskaya PSP - 2). A serious signal for such a step was a major accident in the energy system of the capital in 2005, when several districts of Moscow were completely without electricity for a couple of hours. To carry out construction work at the new power facility, OJSC Zagorskaya GAES-2 (a 100% subsidiary of OJSC RusHydro) was established. At present, it is the state corporation RusHydro that owns both stages of the Zagorsk pumped storage station. This company is the owner of most of the hydropower facilities in our country, and the Russian Federation is its controlling shareholder (more than 60%).

On July 10, 2007, the solemn laying of the first stone in the foundation of the future station took place. Already by 2011, the readiness of the Zagorskaya PSP - 2, the capacity of which was supposed to be 840 MW, reached 50%. It was assumed that in 2013 the first stage of construction will be completed. However, a serious accident made its adjustments to the course of work. As a result of soil erosion, settlement of the station building and flooding of the turbine hall and station site occurred. A little later, the joint commission of RusHydro and Rostekhnadzor came to the conclusion that the designer of the facility, which was the Hydroproject Institute, was indirectly responsible for what happened. It is also worth clarifying that over the six years of work, RusHydro managed to invest about 70 billion rubles in the implementation of this project. A certain part of the funds spent was later reimbursed, insurance payments for the accident amounted to 8,2 billion rubles.

In 2018, the Board of Directors of PJSC RusHydro approved the leveling project for the damaged building. The cost of the work was estimated at 3,15 billion rubles. It was assumed that by 2022 the consequences of the accident would be eliminated, but later a member of the board of the company, Roman Berdnikov, said that a clear understanding of the future fate of the station would not become known until 2023. From the foregoing, we can conclude that at present the prospects for the second stage look rather vague. As is often the case in Russia, the main problems lie in the financing and timing of the project.

Despite this, the currently successfully functioning Zagorsk HPSP-1 allows us to assess the strengths of this type of power facilities. Thus, pumped-storage stations are highly maneuverable compared to state district power plants and nuclear power plants, which allows them to quickly respond to various disturbances in the power system. All this suggests that such stations should be considered primarily as a source of a quickly introduced reserve of active power.