Megaprojects: Zaramagskaya HPP

My wife and I are power engineers, graduated in 1993 from the Ural Polytechnic Institute. Therefore, we regularly visit all the power stations we see, regardless of the method of energy generation. They couldn't miss the Zaramagskaya hydroelectric power station. First of all, it's beautiful! Secondly, this is a very unique mega-project that I would like to talk about.

Most recently, on February 4, 2020, Zaramagskaya HPP-1 was officially put into operation in North Ossetia. The long-awaited launch of the megaproject - after all, the construction of the Zaramag hydroelectric power station cascade (the cascade also includes the Golovnaya hydroelectric power station, which was launched on September 18, 2009) began back in 1976.

But it immediately became the largest power plant in the republic and the third most powerful hydroelectric station in the entire North Caucasus.

Fig.1. Golovnaya hydroelectric power station with a daily regulation basin

The Zaramagskaya HPP uses a dam-diversion scheme for water pressure. That is, water pressure is created using a dam and diversion in the form of a tunnel or channel for water. The length of the tunnel (attention) is more than 14 kilometers!

The trick of the hydroelectric power station cascade is that the Ardon River, for 16 kilometers after leaving the Tual Basin, creates a height difference of more than 700 meters. These conditions are ideal for creating a cascade of stations using a diversion scheme. The energy workers took advantage of this.

Fig. 2 Diagram of the entire cascade of Zaramag hydroelectric power stations

Zaramagskaya HPP-1 is located in the area of the village of Mizur, Alagirsky district of North Ossetia on the Ardon River (a tributary of the Terek River) and together with the Golovnaya HPP, which was launched on September 8, 2009, it now forms a unique hydropower complex of the Zaramagskaya HPPs.

Fig.3 Reminder about the national hero Kostya Khetagurov

They work in pairs. The Head Hydroelectric Power Station supplies sand-free water to the diversion tunnel of the Zaramagskaya Hydroelectric Power Station-1. The Golovnaya HPP is also unique in many ways; for example, the seismic resistance of the dam is 11.25 points when the seismicity of the area is 9 points.

Fig.4 Zaramagskaya HPP-1

When designing Zaramagskaya HPP-1 and scheduling, unique engineering solutions were used. For example, a diversion tunnel 14,262 m long was built, the longest hydraulic tunnel in Russia and one of the longest tunnels in our country as a whole. It is thanks to it that a record high water pressure is created - 609 m, which drives the largest bucket-type turbines in our country.

Fig.5 Reservoir

RusHydro knows how to choose locations for its megaprojects! The capacity of Zaramagskaya HPP-1 is 346 MW; it will generate about 842 million kWh of electricity per year. Thanks to its power and high maneuverability, it will qualitatively improve the reliability of energy supply throughout the North Caucasus region, and will also open up new opportunities for growth. The construction budget amounted to 35 billion rubles.

The construction of Zaramagskaya HPP-1 was carried out under extremely difficult conditions. After every meter of penetration, after drilling and blasting the rock, it was necessary to quickly lower the formwork and begin concreting the structure, otherwise the rock would crumble. The gravity method of laying concrete was also used. Suffice it to say that no one has worked in such conditions in Russia.

Fig.6 Temple near the reservoir

The next report on unique power plants will be devoted to the megaproject for the construction of the Krasnoyarsk hydroelectric power station, which I visited last week.

As a summary, a quote from Viktor Astafiev, who was born in these places (Krasnoyarsk hydroelectric power station):

PM Excellence is actively involved in the country's energy projects, using its experience in managing large-scale projects and megaprojects.