The Nigerian Independent System Operator (NISO) says a voltage disturbance at the Gombe transmission substation was responsible for Tuesday’s partial national grid collapse that disrupted power.
In a statement on Wednesday, NISO clarified that while the incident affected parts of the country, it did not cause a total system collapse, contrary to some media reports.
“The incident only affected part of the national grid; therefore, it was not a total collapse,” NISO said, noting that some transmission lines and generating units tripped during the event.
The system operator disclosed that the voltage disturbance quickly propagated across the transmission network, affecting several substations beyond Gombe before stabilization measures were implemented.
According to NISO, the disturbance spread to the Jebba, Kainji, and Ayede transmission substations, while some transmission lines and generating units tripped during the incident.
Corrective actions were, however, immediately deployed and restoration efforts were completed within a few hours, stabilizing the system and returning electricity supply to normal.
“The national grid has been fully restored, and electricity supply across the affected areas has since returned to normal,” the operator said.
Nigeria’s power grid has experienced recurring disturbances in recent years. In 2025, the national grid collapsed multiple times, with the last incident recorded on December 29.
Tuesday’s incident is the second grid collapse in 2026.