Power blackout hits northern Sumatra, restoration underway

By Riko Siahaan

A widespread power blackout hit multiple provinces across northern Sumatra on Friday evening after a major disturbance at a key interconnection transmission substation triggered an automatic shutdown of the regional electricity system.

The outage affected Aceh, North Sumatra, West Sumatra, Riau and the Riau Islands beginning at around 6:15 p.m. local time.

Initial reports indicated the disruption originated from a major transmission grid facility in the Sumatra interconnection system, causing the network protection system to automatically shut down parts of the grid to prevent wider damage.

Restoration efforts were under way as of 7:25 p.m., with PLN emergency teams deployed to the affected facilities.

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According to preliminary restoration estimates, electricity supply is expected to return gradually in stages.

Power supply to parts of Medan, Binjai, Deli Serdang and Pekanbaru is expected to begin recovering between 8:30 p.m. and 9:30 p.m., while broader restoration across North Sumatra and surrounding areas is targeted between 10:00 p.m. and 11:00 p.m.

More remote and mountainous areas could experience longer outages extending until around midnight.

Officials said electricity supply from generating plants had started to re-enter the system gradually as repair work continued.

Editing by Alexander Ginting