The Nigerian Independent System Operator (NISO) has confirmed that Tuesday’s national grid collapse was traced to a voltage disturbance at the Gombe transmission substation.
The system operator disclosed this in a statement issued on Tuesday while providing updates on repair and restoration efforts.
According to NISO, the incident resulted in a partial system collapse, marking the second grid disturbance recorded in 2026.
NISO said electricity supply across the affected areas has since been fully restored following immediate corrective actions by its technical teams.
NISO explained that the disturbance originated from the Gombe transmission substation before spreading to other parts of the network.
The agency stressed that the incident did not amount to a total system collapse, contrary to reports by some media organisations.
“The national grid has been fully restored, and electricity supply across the affected areas has since returned to normal.”
“The incident only affected part of the national grid, therefore not a total collapse,” NISO added.
“The event was accompanied by the tripping of some transmission lines and generating units, resulting in a partial system collapse.”
The system operator said restoration efforts commenced shortly after the disturbance and were completed within hours.
NISO disclosed that the voltage disturbance quickly propagated across the transmission network, affecting multiple substations.
The disturbance impacted power infrastructure beyond Gombe before stabilisation measures were implemented.
The voltage disturbance spread to the Jebba Transmission Substation.
Kainji Transmission Substation was also affected.
Ayede Transmission Substation experienced disruptions as the disturbance propagated.
Some transmission lines and generating units tripped during the incident.
According to NISO, corrective actions were immediately deployed to stabilise the system and restore normal grid operations.
Nigeria’s power grid has continued to experience recurring disturbances in recent years.
In 2025 alone, the national grid collapsed multiple times, with the last recorded incident occurring on December 29.
Tuesday’s incident represents the second grid collapse recorded in 2026.
The latest disturbance was classified as a partial system collapse.
Data obtained from the NISO showed that power generation dropped to zero megawatts at about 11:00 am on Tuesday.
Voltage instability remains a key trigger for grid disruptions.
The repeated grid failures continue to highlight ongoing operational and infrastructure challenges within Nigeria’s power transmission network.
