The Nigerian Independent System Operator (NISO) said the national grid experienced a system disturbance at 11:20 a.m. on Wednesday.
Earlier, the Abuja Electricity Distribution Company (AEDC) announced a power outage affecting its franchise areas. The AEDC said the outage was due to a loss of supply from the national grid, which occurred on Wednesday.
NISO, in a statement signed by its management, said the disturbance was caused by the tripping of a generation company (GenCo), resulting in a significant load drop that cascaded to other GenCos, leading to a system disturbance.
“The Nigerian Independent System Operator (NISO) informs the general public that the national grid experienced a system disturbance at 11:20 hrs on 10/09/2025.
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“The disturbance was caused by the tripping of a GenCo, resulting in a significant load drop, which cascaded to other GenCos, leading to a system disturbance,” the statement said.
NISO said it immediately commenced restoration of the grid at 11:45 a.m., beginning with supply to Abuja from the Shiroro power plant, adding that substantial restoration has been achieved across the country.
NISO assured that a full investigation into the incident is underway to determine the immediate and remote causes.
READ ALSO: AEDC reports power outage due to national grid disruption
“A full investigation into the immediate and remote causes is underway. The outcome (s) of the investigation report would determine the remedial and proactive actions to be taken to forestall future occurrences.
“We crave your indulgence to bear with us as restoration is still ongoing,” it said.
NISO is in charge of electricity system operations, managing load allocation from generation companies to distribution companies and eligible customers.
This latest disruption adds to a series that has raised concerns about the stability of Nigeria’s electricity system, with over 100 grid collapses reported in the past decade.

























