Electricity supply has been fully restored across Nigeria following a system disturbance that caused a partial collapse of the national power grid on Monday, the Nigerian Independent System Operator, NISO, has confirmed.
The disruption occurred on Monday afternoon and led to power outages in several parts of the country. Grid records showed that electricity generation, which had peaked at about 4,800 megawatts earlier in the day, plunged to as low as 139 megawatts by 3 p.m.
In a statement released late Monday night, NISO explained that the incident was triggered by the tripping of multiple power generation units and key transmission assets.
“The National Grid experienced a system disturbance at 14:01 hours on Monday, 29 December 2025, which led to a partial collapse,” the operator said.
“Preliminary reports indicate the tripping of multiple generating units and 330kV transmission lines, resulting in widespread impact on electricity supply.”
The disturbance came against the backdrop of ongoing gas supply challenges caused by the recent vandalisation of the Escravos–Lagos gas pipeline, which has constrained fuel supply to several thermal power plants nationwide.
According to NISO, the gas shortages further undermined the stability of the grid.
“This has further led to the fragility and weakness of the national grid,” the statement said.
Despite the system collapse, the Delta power generation complex reportedly isolated itself from the national grid and continued supplying electricity independently to parts of Delta and Edo states.
“A total generation of 114 megawatts was delivered from four units at the Delta Thermal Power Station,” NISO said, noting that power supply was sustained to Oghara, Amukpe, Benin and Efunrun substations.
The system operator added that emergency response protocols were immediately activated at the National Control Centre in Osogbo to restore supply.
“In line with established operational procedures, NISO promptly initiated system response measures using its dispatch and monitoring tools,” it said.
NISO later confirmed that power had been fully restored nationwide and that grid stability had been re-established.
“Supply has been fully restored to all parts of the country and system stability normalised,” the operator said.
The agency noted that investigations were ongoing to determine the precise cause of the disturbance and to prevent a recurrence.
“Appropriate measures shall be put in place to forestall future recurrence of such major system incidents,” it added.
Nigeria’s power grid has experienced several collapses in recent years, often attributed to gas supply disruptions, ageing transmission infrastructure and operational limitations. NISO, which recently took over system operations following reforms in the power sector, reiterated its commitment to improving grid reliability.
“NISO reassures Nigerians of its continued commitment to proactive grid management and the application of best operational practices,” the statement said.
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