The Nigerian Independent System Operator (NISO) says the ongoing drop in electricity supply affecting Lagos and nearby areas was caused by a major generation failure at the Egbin Power Station.
In a statement issued in Abuja on Thursday, NISO said the incident occurred on April 28, when the country’s largest power plant suffered a sudden operational breakdown that forced its output to drop from about 641 megawatts to zero.
It explained that the shutdown was caused by a failure of the plant’s central compressor and a malfunction in its circulating water pump system, which led to an emergency shutdown of all generating units.
The situation was further worsened by a transmission challenge, including the forced outage of the Osogbo–Ikeja West 330kV transmission line, which limited the evacuation of available power to Lagos and its environs.
According to NISO, the combined generation loss and transmission constraint created a major supply shortfall, making it necessary to implement load shedding to stabilise the national grid and prevent a wider system collapse.
The system operator said: “Egbin power station… experienced a major operational disturbance.
At about 8:21pm on April 28, 2026, the power station recorded a complete loss of generation, dropping from approximately 641MW to zero output.”
It added that emergency grid management measures had been activated, including load reallocation across distribution companies, with priority given to critical infrastructure.
NISO said efforts were ongoing to restore generation and optimise output from other power plants to reduce the impact on consumers.
The operator acknowledged the disruption to electricity supply, especially in Lagos, and assured that stakeholders were working to restore normal supply as quickly as possible.
