Deputy Minister of Energy and Mineral Resources Reveals Cause of Sumatra Blackout: Transmission Network Struck by Lightning

According to him, the lightning strike disrupted the stability of Sumatra’s power system, causing widespread blackouts across various regions. “The issue lies with the transmission network, which was struck by lightning in Merangin. This lightning strike affected the stability of the system,” Yuliot said during an interview at the DPR RI building in Jakarta on Monday, 25 May 2026.

He explained that northern Sumatra’s power system has traditionally relied heavily on electricity from the south. When the disruption occurred, the entire system was affected, triggering a widespread blackout. “Thus, when the disruption happened, the entire system went down,” he said.

The blackout in Sumatra began on Friday, 22 May 2026, at approximately 6:44 pm WIB, and was fully restored by Sunday, 24 May 2026, at around 5:00 am WIB. Yuliot stated that the restoration process was carried out gradually, as the power system had to be restarted piece by piece.

The government and PT PLN (Persero) prioritised restoring power from sources that could be quickly brought back online, including hydroelectric plants (PLTA), geothermal plants, diesel-powered plants (PLTD), and gas-based generators. Steam-powered plants (PLTU), however, required longer to resume operations, taking approximately 12 hours.

The Ministry of Energy and Mineral Resources has deployed a team to the field to investigate the cause of the disruption and ensure the restoration process proceeds optimally. “As coordinated with PLN, electricity supply has been fully restored,” Yuliot concluded.