The appeal follows a major grid imbalance experienced on Friday (May 30), which resulted in power outages across several parts of the country, including Colombo. According to the NSO, the disruption was caused by an unexpected drop in electricity demand during the Vesak holiday period, coupled with a significant increase in electricity generation from rooftop solar systems.
Officials said the sharp decline in demand, which fell well below forecast levels, created operational challenges for the national grid as solar power generation remained high during daylight hours. The resulting mismatch between electricity supply and consumption led to instability within the power network.
In response, the system operator requested rooftop solar users to temporarily disconnect their systems until 3:00 p.m. on Friday. Authorities also disconnected several 33 kV feeders in areas with high solar penetration as part of efforts to restore balance to the grid.
These measures enabled officials to gradually stabilize the network and fully restore electricity supply to affected areas by approximately 2:15 p.m.
With electricity demand expected to remain low throughout Sunday due to the extended holiday weekend, the NSO has renewed its appeal for public cooperation. The operator stated that voluntary deactivation of rooftop solar systems during the specified period would help prevent further disruptions and reduce the need for additional feeder disconnections.
