Power supply fully restored after national grid collapse – NISO

Power has been fully restored across Nigeria after the country’s electricity grid experienced a partial collapse on Monday, December 29, 2025, the Nigerian Independent System Operator (NISO) has confirmed.

According to NISO, the system disturbance occurred at 2:01 pm, causing a sharp drop in electricity generation from about 4,800 megawatts to just 139 MW by around 3 pm. The outage affected power supply in many parts of the country.

In a statement late Monday, the system operator said the disruption was triggered by the tripping of several generating units and key 330 kV transmission lines, which weakened the already fragile grid.

NISO also noted that lingering gas supply challenges — linked to earlier vandalism on the Escravos–Lagos pipeline — had previously reduced fuel availability for thermal power stations, making the grid more vulnerable to disturbances.

Despite the setback, the Delta Generation Complex isolated itself from the main grid and continued to supply electricity to some substations, while emergency response measures were activated at NISO’s control centre in Osogbo.

By evening, coordinated recovery efforts succeeded in restoring power nationwide and stabilising the system.

NISO said it will continue investigations into what exactly caused the disturbance and will implement measures to reduce the risk of future collapses.

The system operator reassured Nigerians of its ongoing commitment to improving the stability and reliability of the national grid.