In a statement issued in Abuja, the system operator confirmed that grid stability has been normalised after what it described as a partial collapse of the national grid, which occurred at about 2:01 p.m. on Monday. NISO added that investigations are currently ongoing to determine the precise cause and sequence of events that led to the disruption.
Preliminary findings, according to the operator, indicate that the disturbance was linked to the tripping of several power-generating units as well as critical 330 kilovolt (kV) transmission lines. The incident had a significant impact on electricity supply in many parts of the country.
Despite the widespread outage, NISO noted that the Delta generation complex successfully operated on “island mode” at the 132kV sub-transmission level. This allowed continued power supply to areas including Oghara, Amukpe, Benin and Efunrun, with a combined generation of 114 megawatts from four units at the Delta Thermal Power Station.
The operator explained that, in line with established operational procedures, it promptly activated system response measures using its dispatch and monitoring tools at the National Control Centre (NCC) in Osogbo to restore supply and stabilise the grid.
NISO also recalled that the national grid has remained vulnerable following the vandalisation of the Lagos–Escravos–Lagos gas pipeline on December 10, an incident that led to reduced gas supply and a shortfall in power generation nationwide. This, it said, further weakened the grid and contributed to its fragility.
Reassuring the public and stakeholders, the system operator pledged its continued commitment to proactive grid management and the application of best operational practices. It emphasised that appropriate measures would be put in place to forestall future grid disturbances and ensure the stability and reliability of the national electricity network.