Georgia identifies preliminary cause of nationwide blackout

Georgia's National Energy and Water Supply Regulatory Commission (GNERC) has identified a possible transmission line failure as the preliminary cause of the nationwide blackout that struck the country on July 24, while investigations into the incident remain ongoing.

According to the regulator's initial findings, the Georgian power system unexpectedly disconnected from the Azerbaijani electricity grid at 00:10 while the two networks were operating in synchronisation, Caliber.Az reports per Georgian media.

Once isolated, Georgia's grid was unable to maintain system stability, with frequency and voltage falling sharply. The resulting cascade of automatic shutdowns at power stations triggered a nationwide loss of electricity.

GNERC said the chain of failures may have originated from the 110 kV Geguti transmission line, owned by Energo-Pro Georgia, which connects to the Kutaisi 220 substation.

The regulator also said the Georgian State Electrosystem shared responsibility for the incident, arguing that the system operator should have recalculated relay protection and automation settings before the full modernisation of transmission infrastructure. Such measures, GNERC said, could have reduced the risk of the grid automatically separating from Azerbaijan's power system.

The investigation is continuing in two directions. Authorities are seeking to establish the exact cause of the disconnection from the Azerbaijani grid and to determine whether Georgia's electricity system is capable of operating reliably in an isolated mode.

The blackout marked the first in a series of major power disruptions across Georgia last week. On the morning of July 25, the country experienced a second widespread outage, leaving many regions without electricity. The disruption halted metro services in Tbilisi, affected water and internet supplies, and brought rail transport across the country to a standstill before electricity was restored by around 10:30.

GNERC launched an emergency investigation on July 24, while Georgia's State Security Service has opened a parallel inquiry under legislation covering suspected sabotage. The authorities have not yet reached final conclusions on the cause of the incidents.

By Aghakazim Guliyev