The 330 kV “Gardabani” transmission line is an interconnection between the power systems of Georgia and Azerbaijan. It was commissioned in 1958 and connects the Gardabani-500 substation in Georgia with the Aghstafa substation in Azerbaijan. The total length of the transmission line is 64 km, 21 km of which is located within the territory of Georgia. The transmission line has a thermal transfer capacity of 250 MW. Within Georgia, the line consists of 60 transmission towers equipped with АСО 480 steel-reinforced aluminum conductors.
In accordance with the 2019–2029 and 2020–2030 Ten-Year Transmission Network Development Plans of Georgia, JSC UES Sakrusenergo was assigned to reconstruct the existing 330 kV Gardabani transmission line by converting it into a double-circuit transmission line.
Considering the current technical condition of the line, it became necessary to improve the reliability and operational resilience of the Gardabani transmission line, one of the most important high-voltage transmission lines within Georgia’s power system, while simultaneously increasing its transmission capacity. To achieve these objectives, in March 2020, JSC UES Sakrusenergo received an assignment from the Ministry of Economy and Sustainable Development of Georgia to carry out the switchover of the double-circuit 330 kV “Gardabani 1 and 2” transmission line at the Georgia–Azerbaijan border during the first decade of May 2020.
The Design and Construction Department of JSC UES Sakrusenergo prepared the detailed design and cost estimate documentation for the project, which successfully passed the technical review and expert examination conducted by the Levan Samkharauli National Forensics Bureau.
Implementation of the project required the installation of two new towers (No. 63 and No. 64) of the double-circuit 330 kV “Gardabani 1 and 2” transmission line near the Red Bridge border crossing, in the vicinity of Kapanakhchi Village. The project also included the connection of the conductors and the optical ground wire from Tower No. 64 to Tower No. 158 of the double-circuit 330 kV “Gardabani 1 and 2” transmission line, which had been constructed on the territory of Azerbaijan within the border zone.
It is noteworthy that the implementation of this assignment coincided with the outbreak of the global COVID-19 pandemic, which also significantly affected Georgia. On 11 March 2020, the World Health Organization (WHO) declared the spread of the novel coronavirus (COVID-19) a pandemic, and a state of emergency was declared throughout the territory of Georgia. The situation was further complicated by the fact that the project site, located in Marneuli Municipality, was declared as a red zone due to the increasing number of COVID-19 cases, resulting in severe restrictions on movement within the region. These circumstances created unforeseen challenges both for the Sakrusenergo personnel engaged in the construction works and for the company’s management, which was responsible for supplying the field personnel with the necessary equipment, materials, and food supplies. Consequently, successful implementation of the project while meeting the established deadlines became a significant challenge for the Company.
The works related to the switchover of the double-circuit 330 kV “Gardabani 1 and 2” transmission line at the Georgia–Azerbaijan border were carried out under strict preventive measures, including daily health monitoring of all personnel involved in the project.
Despite the declaration of the state of emergency and the restrictions imposed throughout Georgia, all essential materials and equipment—including foundations, tower structures, insulators, line hardware, conductors, and other construction materials—were procured, delivered, and made available on schedule through efficient planning and prompt execution.
The tower foundations were completed and the transmission towers were erected within an exceptionally short period. Each tower weighed approximately 32 tones. It should be noted that towers of this size and weight were erected in Georgia for the first time using the hinge-raising (pivot erection) method, marking a significant engineering achievement for the country’s transmission infrastructure.
By 10 May 2020, the newly constructed double-circuit 330 kV “Gardabani 1 and 2” transmission line had been successfully connected on the Georgian side from Tower No. 64 to Tower No. 158, located within the territory of Azerbaijan.
The switchover works for the double-circuit 330 kV “Gardabani 1 and 2” transmission line at the Georgia–Azerbaijan border were completed entirely by the personnel of JSC UES Sakrusenergo.
The reconstruction of the 330 kV Gardabani transmission line, together with the development of the associated transmission infrastructure, has significantly enhanced the reliability and resilience of the line. The project has also improved the reliability of the synchronous operation of the power systems of Georgia, Azerbaijan, and Russia, while increasing the cross-border power transfer capacity from 700 MW to 1,000 MW.