History

Thoughts about consumption of the energy potential of the River Enguri appeared at the dawn of hydroelectric engineering - at the beginning of the XX century. Niko Nikoladze was one of the first who worked in this direction. He invited the specialists who drew up the project. However, this idea could not be realized due to volume of the construction budget and the World War I. Several projects have been prepared in connection with consumption of the hydropower potential of the River Enguri. This was in the 30s, 40s and 50s. Eventually, in 1961, the construction started with the project according to which the Enguri HPP is built today.

Construction of Enguri HPP continued for a long period after the enterprise was put into operation. This doubled the responsibility and the complexity of the task. 3 units were launched at the end of 1978, the fourth - in 1979, and the fifth - in 1980. However, construction of Enguri HPP continued for another 7-8 years and was actually completed at the end of the 80s. Moreover, certain works on the dam continued even with the rehabilitation project. approximately 60% of the arch dam was built by 1980. This means that the underground plant of Enguri HPP was put into operation, and the concreting of the dam was still going on.

Today, everyone agrees that construction of Enguri HPP was a very bold statement in the history of the Georgian engineering and technical thinking. Due to complexity of the idea and the limited experience in this direction, some specialists were skeptical. However, the optimists were also cautious, because they were frightened by the scale of the construction and the complexity of the terrain.

It should be mentioned that Enguri HPP was the first arch dam in the former Soviet Union, after Lajanuri HPP. Therefore, there was no experience in this direction. This led to necessity to involve the foreign specialists. In addition, there was no the Soviet equipment to drill the rocks on-site. That’s why they used Swedish and Finnish equipment, and the Italians and French specialists worked on the design itself.

Despite of the difficulties mentioned above, today Enguri HPP is already a world-class building. The facilities of the hydropower plant are located in the territory of Tsalenjikha and Gali municipalities. In particular, the dam, water reservoir and 10-kilometer section of the 15.5-kilometer pressure tunnel are located in Tsalenjikha, and the remaining part of the tunnel - 5.5-kilometer power joint, underground plant, hydropower units, transformers, air-insulated switchgear and tailrace tunnel are located in the territory of Gali district.

Vardnili HPP Cascade is located in Abkhazia with its full-time regulation reservoir, hydropower plant building and 26-kilometer channel. Nowadays, the main and auxiliary electrical equipment of Vardnili HPP-II, Vardnili HPP-III and Vardnili HPP-IV are looted and out of order. Vardnili HPP-I was kept in proper working order, thanks to dedication of the local specialists. It should be mentioned, that already in 1972, the first unit of Vardnili HPP-I was put into operation. At the same time, construction of Vardnili HPP-II, Vardnili HPP-III and Vardnili HPP-IV was underway. All three of them were located on the aqueduct at a distance of 5.5 km, 10.1 km and 14.9 km from Vardnili HPP-I, respectively.

In addition to complexity of simultaneous construction and operation, the 90s were not easy for Enguri HPP either. It can be said that in this regard, it was really unlucky. First of all, this refers to the war in Abkhazia, which resulted in division of the enterprise into two parts. As is known, the power unit of Enguri HPP - generators and turbines, which generate electricity, are located in Gali district, the main building of the reservoir, the arch dam and a part of the 15-kilometer derivation tunnel - in Tsalenjikha district. When the Georgian military units and the Georgian-speaking population of Abkhazia had to leave the territory during the war in Abkhazia, Abkhazia was emptied en masse. Naturally, some of Enguri HPP staff tried to take their families to the safe place. At that time, the director of Enguri HPP was Giorgi Mikava, who decided not to leave the plant. It was about afternoon of September 29. Already on September 30, there were about only ten people remained at the plant. Thanks to them, the station did not stop.

In this hard time, it was important that the Abkhazians understood the strategic importance of Enguri HPP very well. This is proven by the fact that a special delegation led by Khuta Jinjolia, Head of Abkhazia’s Energy Agency, arrived in Saberio, the settlement of Gali district, to meet with the management of Enguri HPP. The Abkhazians promised them, that no one and nothing would touch them and they could to return the others as well. As employees recall, when they were inside the plant, no one really touched them, but the situation outside was definitely not safe.

In fact, the situation was the same in Vardnili HPP. As a result of the events developed by the end of September 1992, the plant was abandoned by the operational staff. The only person remained here for several days was Shota Sanadze, the director of the enterprise. In the background of the well-known events in Abkhazia, Vardnili HPP-II, Vardnili HPP-III and Vardnili HPP-IV were looted. All three plants operated normally before the war, today, only the building and the channel where the water flows are left.

In parallel with the political situation, the 90s were not easy for the energy system of Georgia in other directions either - nationwide restrictions, the half-darkened capital and the regions in a more difficult situation. At that time, Enguri HPP was of decisive importance. Due to the fuel shortage in the 90s, this period was mainly reflected on HPPs, and 50-60% of HPPs’ output came from Enguri HPP. Besides tariff was so low at that time that supply of electricity at this price was even a kind of social assistance. Today it can already be said boldly, If not for Enguri HPP, development of Georgia’s economy would be hard to imagine at all.

Complexity of the operation process, which accompanied the 90s, was directly proportional to this state responsibility. This was caused by a kind of isolation. In addition, the connections that existed with equipment or spare part suppliers were severed. Between 1993 and 2002, the operation process was very complex. The fee for the generated electricity was so minimal that the staff did not get paid for several months. However, in 1997, the first steps were taken towards rehabilitation of Enguri HPP and the first grant was allocated by the Swiss Government. That is how the new life of Enguri HPP started - with rehabilitation.

Of course, preservation of Enguri HPP in a condition where it could generate even minimum electricity is the merit of the technical staff who were able to do all kinds of repair work on their own. Despite of the fact that in the 90s, the enterprise did not receive even the minimum required funds and therefore, it was not possible to buy spare parts either, the units worked and Enguri HPP provided vital electricity for the country. However, the technical condition of both buildings and equipment was gradually deteriorating. That's why since the beginning of the 2000s, we have reached the stage that Enguri HPP was practically shut down and needed urgent rehabilitation.

The study of the facility in this direction began in the late 1990s. By that time, one out of five units no longer existed in fact. In particular, an empty pit was left at the site of the third unit. The large-scale rehabilitation project of the Enguri HPP was developed in 1998-2001. Major rehabilitation works were carried out in 2003-2014 with the support of the Government of Georgia and the European Bank for Reconstruction and Development (EBRD).

What does the Enguri HPP rehabilitation project mean?

If the technical equipment do not undergo timely maintenance and overhaul, they will automatically appear in such a technical state where they need not overhaul any more, but a larger procedure called rehabilitation or restoration. The same happened with the third unit. Accordingly, the rehabilitation project started, because it could no longer be considered as overhaul or other type of work. The rehabilitation project included immediate and urgent technical operations, which were directly related to generation of electricity. For example, this applied to units, transformers, turbines, etc. This was necessary for putting Enguri HPP into more or less output mode as quickly as possible.

Depending on the scale of the project, the rehabilitation would cover the period of 15-20 years from the beginning. Fulfillment of similar works at the same time was even theoretically impossible. Therefore, it had to be written in phases and it happened. The first phase lasted from 2003 to 2009. It was at this time that three units were rehabilitated, while the rest of the electrical equipment was repaired. In addition, together with rehabilitation of Enguri HPP dam and derivation tunnel, other important works were carried out in 2006. Accordingly, three phases of rehabilitation were completed in 2015, and the fourth phase began in 2016, however certain works were added in 2020-2021. As a result of all these efforts, we got the fact that Enguri HPP and Vardnili HPP-I are working perfectly today.



When will Enguri HPP rehabilitation be completed?

The final stage of the fourth phase of rehabilitation of Enguri HPP includes works to be performed in 2024-2027. Based on technical safety and priorities, technical stability, ensuring seismic stability and completion of diversion tunnel works are decisive in the planned process. In addition, this is the necessity of the accumulated capital works that Enguri HPP needs. This refers to replacement, adaptation, modernization, etc. of a number of electrical and hydromechanical equipment. Construction of roads is also provided here, which is necessary for safe operation and monitoring of the dam.

According to the plan, The final stage of the fourth phase of rehabilitation should be completed in 2026-2027. If everything goes according to schedule, Enguri HPP will not need overhaul in the next 15-20 years. Thus, after completion of the final phase of the fourth phase of rehabilitation, Enguri HPP will go into the mode of ongoing repairs, which will be its natural state.