Sri Lanka’s National System Operator (NSO) has instructed all PV system owners to disconnect their installations from the grid following a nationwide blackout caused by instability in the electricity system on Oct. 17.

The NSO said PV systems had to remain disconnected until further notice to support grid restoration efforts.

According to local media reports, the NSO attributed the outage to unspecified instability in the transmission network, which disrupted electricity supply at around 11:45 a.m.

The NSO confirmed the restoration at around 7:50 p.m. local time, with electricity supplies returning to most areas. It is not clear, however, if PV systems could resume power injection.

Sri Lanka experienced a similar nationwide blackout on Feb. 9, 2025, when the Ceylon Electricity Board (CEB) identified high solar PV penetration as a major contributing factor.

According to a CEB investigation published in April 2025, the blackout was triggered at noon by a fault at the Panadura grid substation. At the time, solar PV accounted for more than 50% of electricity demand, leaving the grid with insufficient system inertia to withstand the disturbance. The resulting voltage drop and cascading disconnections led to a nationwide blackout.

At the time, the authorities also instructed rooftop solar system owners to disconnect their installations from the grid during restoration efforts.

Sri Lanka’s rooftop PV capacity reached 1.94 GW by the end of 2025, following rapid growth in installations and generation.

Sri Lanka’s daily electricity demand stood at approximately 58 GWh to 60 GWh in March 2026, equivalent to an average continuous power requirement of around 2,400 MW to 2,500 MW.

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