By Iyunade Grace
The Nigerian Independent System Operator (NISO) announced that power supply has been fully restored to all parts of the country after a system disturbance led to a partial collapse of the national grid on Monday, December 29, 2025. The incident occurred at 14:01 hours, tripping several generating units and critical 330kV transmission lines, and affecting electricity supply across parts of the country.
According to NISO, preliminary reports indicate that the disturbance was caused by the tripping of multiple power generation units and transmission lines, resulting in a widespread impact on electricity supply. The Abuja Electricity Distribution Company (AEDC) and Ikeja Electricity Distribution Company (KEDC) reported significant power supply losses across their networks.
The Delta generation complex successfully isolated itself from the national grid and operated in island mode, ensuring continued electricity supply to Oghara, Amukpe, Benin, and Efunrun 132kV substations, with a total generation of 114 megawatts from four units at the Delta Thermal Power Station.
NISO promptly initiated system response measures using its dispatch and monitoring tools at the National Control Centre in Osogbo, leading to the full restoration of supply nationwide. Investigations into the cause and sequence of events leading to the system disturbance are currently ongoing, and appropriate measures will be put in place to prevent future occurrences.
This incident is the latest in a series of grid collapses recorded in recent years, highlighting the fragility of Nigeria’s power infrastructure. The Lagos-Escravos gas pipeline vandalism on December 10, 2025, had earlier reduced gas availability to thermal power plants, contributing to the grid’s weakness.
NISO reassures Nigerians of its commitment to proactive grid management and the application of best operational practices to ensure the stability and reliability of the National Grid.
