DEN states gradual recovery key to restoring Sumatra's electricity supply

The restoration of Sumatra’s electricity system following an interconnection transmission disturbance must be carried out gradually and with caution to maintain power system stability until supply returns to normal. Given the interconnection spans thousands of kilometres and involves numerous power plants and transmission networks, the relatively swift recovery demonstrates effective management.

National Energy Council (DEN) member M Kholid Syeirazi stated that large-scale interconnection restoration cannot be done instantly as all system components must be synchronised stably.

“Large-scale power system restoration must be conducted with utmost care. The goal is not merely to restore power quickly, but to ensure the system returns to normal safely and reliably,” Kholid said in a statement on Sunday 31 May 2026.

He explained that in an interconnected system, frequency stability is the primary indicator of balance between power generation and customer load. When a major disturbance occurs and several power plants disconnect from the system, frequency can drop sharply, triggering a cascading effect on the power grid.

“If recovery is done too quickly without proper synchronisation, the risk is that frequency drops again, causing power plants to disconnect once more. This must be avoided,” he explained.

Therefore, the restoration process is carried out gradually and methodically to maintain synchronisation between power plants, in terms of frequency, voltage, and phase angle.