Deputy Minister of Energy and Mineral Resources Says Sumatra Blackout Triggered by Lightning Strike

JAKARTA - Deputy Minister of Energy and Mineral Resources Yuliot Tanjung stated that the Sumatra blackout was caused by a lightning strike on transmission lines.

Yuliot explained that although the lightning-struck transmission line was located in Merangin, Jambi, the incident affected electricity flow to northern Sumatra, which experienced the blackout.

“Regarding the electricity incident in Sumatra, the issue involves transmission lines struck by lightning in Merangin. This lightning strike impacted system stability,” Yuliot said at the DPR Building in Senayan, Jakarta, on Monday, 25 May 2026.

He added that when the system shuts down due to lightning, it must be restarted one by one, and the government is working to restore power, though the process takes time.

“First, hydroelectric (PLTA) and geothermal plants, followed by diesel (PLTD) and gas-fired plants. Technically, coal-fired plants (PLTU) require about 12 hours to restart. The Ministry of Energy and Mineral Resources has deployed field teams to inspect the situation, and we are pleased to confirm that, as coordinated with PLN, full restoration has been achieved,” Yuliot added.

Areas affected include Aceh, North Sumatra, South Sumatra, and Jambi.

PT PLN (Persero) CEO Darmawan Prasodjo said the initial indication of the fault was on the 275 kilovolt (kV) transmission line between Muara Bungo and Sungai Rumbai, Jambi.

“This is an initial indication that a 275 kV transmission line between Muara Bungo and Sungai Rumbai in Jambi was affected by weather-related issues,” Darmawan said during a press conference in Jakarta on Saturday, 23 May 2026.

The transmission line fault caused the system to disconnect from Sumatra’s power grid, leading to supply-demand imbalances in several regions.

PLN explained that some power plants experienced oversupply as power flow was interrupted.

“The power plants automatically disconnected from the system, or in public terms, they shut down automatically,” Darmawan said.

On the other hand, areas losing power supply faced shortages.

PLN stated this triggered a domino effect across Sumatra.

“The transmission line fault had widespread effects on parts of Sumatra’s transmission system, causing frequency drops due to heavy generator loads and triggering cascading outages in multiple areas,” Darmawan said.