Sri Lanka suffers six-hour nationwide blackout as grid fails; excess solar generation suspected

Sri Lanka suffered a six-hour nationwide electricity blackout on Saturday after the national grid tripped, possibly because solar power generation exceeded consumption, officials said. The country was without grid power from around noon until dusk, when supplies were restored in stages across the island of 22 million people (AFP via Malay Mail).

Energy Minister Anura Karunathilaka said the cause remained under investigation, but engineers suspected an imbalance caused by high solar generation while demand was muted on a weekend holiday. He urged rooftop solar owners to disconnect their systems “in order to support the restoration efforts”.

The outage was reported at around 11:45am local time, the National System Operator (NSO) said, as reported by Ada Derana. The NSO expected the national grid to be fully restored by around 6.30pm local time.

There was conflicting official guidance on the trigger during the day. The energy minister had pointed to a suspected breakdown at the Upper Kotmale Power Station, but the NSO later denied reports of plant breakdowns, saying operational hydropower plants remained online to help restore supplies (Anadolu Agency).

It is the second grid-wide collapse in little over a year: in February 2025, solar generation exceeding consumption on a sunny Sunday knocked the grid out for more than six hours. Sri Lanka has an installed solar capacity of just over 3,000 megawatts against daytime demand of 2,000–2,500 megawatts, and tax concessions encouraging consumers to sell surplus solar power back to the grid have created imbalances the utility is struggling to manage.