The Nigerian Independent System Operator (NISO) has said the national electricity grid collapsed on Friday following the simultaneous tripping of multiple 330kV transmission lines and the disconnection of several power generation units.
According to The Telegraph, the collapse caused electricity generation to plunge from more than 4,500 megawatts to as low as 24 MW by about 1:30 p.m.
All 23 power plants connected to the national grid reportedly lost output during the incident, resulting in zero power allocation to the country’s 11 electricity distribution companies.
In a preliminary statement issued on Saturday, NISO said the system-wide disturbance occurred at about 12:40 p.m., triggering a total outage across the interconnected network.
“The Nigerian Independent System Operator 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,” the operator said.
NISO explained that preliminary operational reports indicated the disturbance was caused by the simultaneous tripping of multiple 330kV transmission lines, along with the disconnection of some grid-connected generating units.
“These events collectively contributed to the system collapse at the time indicated,” the statement added.
The operator said restoration efforts began shortly after the collapse.
“Following the outage, system restoration activities commenced at about 13:15 hours, in accordance with established grid restoration and recovery procedures,” NISO said.
Electricity supply has since been restored to Abuja, Osogbo, Benin, Onitsha, Sakete, Jebba, Kainji, Shiroro and parts of Lagos, while restoration efforts continue in other parts of the country.
NISO also confirmed that an investigation into the incident is underway.
“A detailed investigation into the root and contributory causes of the disturbance is currently ongoing,” the operator said, adding that the full restoration and stabilisation of the grid remains a top operational priority.
