The Norochcholai coal power plant will remain disconnected from the national grid for several days following Saturday’s countrywide power failure, as authorities continue to follow safety procedures after the incident.
The National System Operator (NSO) said the 810-megawatt plant had been shut down as a precaution after the sudden power outage on October 17 and would not be reconnected to the grid until the necessary safety measures were completed.
The temporary loss of 810 MW of generating capacity would be managed through careful electricity supply arrangements to minimise the impact on consumers over the coming days, the NSO said.
It said the prevailing rainy weather was expected to help sustain hydropower generation at high levels, while a projected decline in electricity demand would further ease pressure on the system.
The countrywide blackout occurred at around 11.43 a.m. on October 17 after a generating unit disconnected from the national grid, creating an imbalance that caused the entire power system to collapse within less than 30 seconds.
Restoration efforts began shortly afterwards. By 12.11 p.m., major hydropower generating units had been brought back online and the power system was restarted simultaneously in four separate sections.
The restoration process was complicated by small-scale power generation facilities that were not under the direct control of the system control centre. However, electricity supplies were progressively restored through the activation of distribution feeders from 12.37 p.m.
By around 3 p.m., power had been restored to essential services, including major hospitals, water treatment plants and the airport.
Grid substations across the country had been reconnected by around 5 p.m., restoring electricity to the majority of consumers, the NSO said.
The operator stressed that the sudden disconnection of a generating unit as a safety measure was a normal occurrence at power plants. However, such a disconnection resulting in a complete collapse of the national power system was not considered normal.
An internal investigation has, therefore, been launched to establish the sequence of events that led to the islandwide outage and determine its underlying causes, the NSO said.