INDEF: Phased Recovery Critical for Restoring Interconnected Power Grid Post-Blackout

The recovery process for Sumatra’s power grid following an interconnection disturbance follows a similar pattern to major global blackouts, prioritising system stability through gradual, cautious, and measured recovery stages. Abra Talattov, Head of INDEF’s Centre for Food, Energy and Sustainable Development, said global experiences show modern interconnection disturbances can rapidly escalate into cascading failures or domino effects when system frequency drops and supply-demand balance is disrupted. He added that similar patterns emerged in major blackouts across the United States, India, Spain, the UK, and South Australia, all triggered by transmission issues or interconnection instability. “In large interconnection systems, the most challenging phase is typically the recovery process. Operators must ensure frequency, voltage, and synchronisation between generators remain stable to prevent the recovering system from collapsing again,” Abra stated. He cited the 2003 North American blackout, which escalated into a systemic failure causing over 100 power plants to disconnect from the grid. In India’s 2012 blackout, the interconnection disruption spread due to regional load imbalances. In Spain and Portugal in 2025, recovery was carried out gradually to maintain system stability after a voltage surge triggered a major outage on the Iberian Peninsula. Similar patterns occurred in Pakistan and Turkey, where system operators had to carefully synchronise power plants to prevent further disruptions during grid re-energisation. Abra noted that global experience shows the recovery phase is often the most critical, as synchronisation errors during power plant restart can trigger follow-on disruptions or even a second blackout. He explained that thermal power plants, such as PLTU, require longer recovery times due to technical steps including boiler heating, frequency synchronisation, and operational stabilisation before fully resupplying the interconnected grid.