The Nigerian Independent System Operator (NISO) said the national grid experienced a system disturbance at 12:40 p.m. on Friday.
Earlier, electricity distribution companies (DisCos) announced a power outage affecting their franchise areas. The DisCos stated that the outage was caused by a loss of supply from the national grid, which occurred on Friday afternoon.
NISO, in a statement signed by its management, said the disturbance was caused by the tripping of multiple 330kV transmission lines, alongside the disconnection of some grid-connected generating units.
“The Nigerian Independent System Operator (NISO) wishes to inform the public that at approximately 12:40 hours on Friday, 23 January, 2026, the national grid experienced a system-wide disturbance, which resulted in a total outage across the interconnected network.
Preliminary operational reports indicate that the disturbance was associated with the simultaneous tripping of multiple 330kV transmission lines, alongside the disconnection of some grid-connected generating units,” the statement said.
These events, it said, collectively contributed to the system’s collapse at the time indicated.
Electricity supply restored
Following the outage, NISO said system restoration activities commenced at about 1:15 p.m., in accordance with established grid restoration and recovery procedures.
NISO said electricity supply has been successfully restored to Abuja, Osogbo, Benin, Onitsha, Sakete, Jebba, Kainji, Shiroro, and parts of Lagos, while restoration efforts are continuing progressively in other parts of the country.
“A detailed investigation into the root and contributory causes of the disturbance is currently ongoing. The full restoration and stabilisation of the grid remains a top operational priority,” it said.
NISO is in charge of electricity system operations, managing load allocation from generation companies to distribution companies and eligible customers.
This latest collapse adds to a series that has raised concerns about the stability of Nigeria’s electricity system.
