The Nigerian Independent System Operator (NISO) said it has successfully maintained stability on the national grid despite experiencing significant generation shortfalls triggered by industrial action by the Petroleum and Natural Gas Senior Staff Association of Nigeria (PENGASSAN).
The strike, which disrupted key operations within the gas supply chain, led to widespread gas shortages, adversely impacting the generation capacity of gas-fired power plants across the country.
According to NISO, power generation on the National Grid fell sharply from over 4,300 megawatts (MW) in the early hours of Sunday, September 28, 2025, to approximately 3,200 MW at the lowest point, representing a substantial reduction in available electricity.
This sudden shortfall threatened to destabilise the grid, raising concerns about potential nationwide blackouts.
In response to this critical challenge, NISO swiftly activated an array of contingency interventions to safeguard the grid’s stability, security, and reliability.
Central to these measures was the optimisation of hydropower resources, with major hydroelectric stations increasing output by over 400 MW.
This strategic ramp-up provided crucial additional capacity, cushioning the deficit caused by the faltering gas-fired power plants.
Furthermore, the System Operator implemented real-time generation dispatch and load balancing adjustments to ensure that supply continuously matched demand while preventing the system frequency from collapsing, which could have led to widespread outages.
Constant voltage and frequency support were also provided through reactive power compensation and rigorous reserve monitoring to maintain the integrity of the power system under strain.
Acknowledging the severity of the situation, NISO also deployed demand-side management strategies. Selective load shedding was introduced as a last resort measure to avoid total system breakdown, enabling a controlled and fair distribution of available power.
These carefully calibrated efforts helped avert the risk of a system-wide blackout, particularly protecting critical infrastructure and essential services.
The National Control Centre, led by NISO management, praised the timely and effective response that minimised disruption and ensured continuous power supply amid unprecedented operational challenges.
The episode underscores NISO’s commitment to proactive grid management, operational excellence, and adherence to global best practices in electricity system operations.
NISO reaffirmed its dedication to guaranteeing a secure, stable, and reliable electricity supply that supports economic growth and improves lives nationwide.
