On 5 January 2021, at about 5:41 pm, a power shortage in the Integrated Power System of Central Asia of about 800 MW destabilised the parallel operation of the North-South electricity transmission in the Unified Power System (UPS) of Kazakhstan. As a result, the emergency automation disconnected three 500 kV and one 220 kV overhead line of the North-South electricity transmission in Kazakhstan to prevent damage to the equipment. Ultimately Zone South of Kazakhstan UPS and the Central Asian IPS were islanded with frequency of 49.1 Hz.
According to current data, the load shedding affected Almaty, Zhambyl, Kyzylorda, Karaganda, and Turkestan oblasts of Kazakhstan and amounted to 959 MW.
Thanks to the efficient work of the KEGOC personnel at 5:51 pm the normal operation was restored in Karaganda oblast, and at 5:58 pm Zone South was synchronized with the UPS of Kazakhstan and the integrity of the power system of Kazakhstan was restored. At 6.15 pm all load shedding restrictions were lifted.
The source of trouble was in the Uzbek power system, where two 450 MW combined cycle power units went down at Talimarjan GRES power plant, and generation at a number of other power plants was decreased.