The Nigerian Independent System Operator (NISO) has said the industrial action within the gas supply chain between the Petroleum and Natural Gas Senior Staff Association (PENGASSAN) and Dangote Petroleum Refinery and Petrochemicals FZE resulted in reduction in power generation by more than 1,100MW on September 28, 2025.
According to NISO’s Management in a statement in Abuja on Tuesday, available generation in the National Grid fell sharply from over 4,300MW in the early hours of September 28, 2025 to about 3,200MW at the lowest point.
It said: “NISO wishes to notify the public of recent major generation shortfalls on the National Grid, caused by industrial actions of the Petroleum and Natural Gas Senior Staff Association of Nigeria (PENGASSAN) within the gas supply chain.
“These disruptions triggered widespread gas shortages, reducing available generation from over 4,300 MW in the early hours Sept. 28th to about 3,200 MW at the lowest point”.”
It said the development heightened pressure on the grid, prompting emergency measures to stabilise supply and avert a nationwide blackout.
To mitigate the crisis, the system operator said that it ramped up generation from major hydropower stations, injecting over 400MW to cushion the shortfall from gas-fired plants.
The agency said it also implemented real-time load adjustments, frequency support measures, and selective load shedding to preserve operational security.
NISO said it promptly deployed contingency measures to preserve the stability, security, and reliability of the National Grid.
It said the key interventions included: “Hydropower Optimisation: Strategic ramp-ups from major hydro stations, contributing over 400 MW of additional output to cushion the shortfall from gas-fired plants.
“Generation Dispatch and Load Balancing: Real-time load adjustments to match available generation with system demand, while preventing a system frequency collapse.
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“Voltage and Frequency Support: Continuous deployment of reactive power compensation and reserve monitoring to safeguard system integrity.
“Demand-Side Management: Selective load shedding, applied as a last resort, to avert a system-wide collapse and ensure fair power distribution.”
According to NISO, these timely actions enabled the it and National Control Centre (NCC) to minimise the impact of the labour-induced gas shortages, sustain operational security, and maintain supply to critical loads, thereby averting a nationwide blackout.
The system operator reaffirmed its commitment to proactive grid management, operational excellence, and the application of best-in-class practices to guarantee a secure and reliable electricity supply for the nation.
PENGASSAN attributed its latest action to Dangote Refinery’s alleged unilateral action in sacking over 800 staff members for joining the association.
The National Executive Council (NEC) of PENGASSAN held an emergency meeting of all its branches on Saturday, and resolved that members should withdraw all services effective 00:01 on Monday.
The federal government has waded into the face-off between the Dangote Refinery and PENGASSAN .
A meeting chaired by the Minister of Finance and the Coordinating Minister of the Economy, Wale Edun, underscored two recent developments, including the purported suspension of the Naira-for-Crude oil arrangement by the Dangote Refinery, and concerns raised by PENGASSAN regarding the refinery.
