From Victor Osula, Abuja
The Nigerian Independent System Operator (NISO) has announced the full restoration of electricity supply nationwide following a system disturbance that partially collapsed the national grid on Monday, December 29, 2025.
According to NISO, the disturbance occurred at 14:01 hours (2:01 p.m.), involving the simultaneous tripping of several generating units and critical 330kV transmission lines.
This led to a widespread blackout, with major providers like the Abuja Electricity Distribution Company (AEDC) and Ikeja Electricity Distribution Company (IE) experiencing significant power losses across their networks.
NISO noted that the fragility of the grid was exacerbated by the earlier vandalism of the Lagos–Escravos gas pipeline on December 10, 2025.
This act of sabotage had already severely limited the gas supply to thermal power stations, reducing overall generation capacity prior to the collapse.
Despite the broader system failure, the Delta generation complex successfully transitioned into “island mode” at the 132kV sub-transmission level.
This technical maneuver allowed for continued electricity supply to the Oghara, Amukpe, Benin, and Efunrun substations, maintaining a total of 114 megawatts (MW) from four units at the Delta Thermal Power Station while the rest of the country was in darkness.
NISO emphasised that its National Control Centre (NCC) in Osogbo promptly initiated recovery measures using advanced dispatch and monitoring tools.
By Tuesday morning, December 30, supply had been stabilized across all regional hubs.
The System Operator stated that investigations into the exact sequence of events leading to the disturbance are ongoing.
While supply is restored, NISO affirmed its commitment to proactive grid management and the implementation of measures to prevent a recurrence of such disruptions.
