The Nigerian Independent System Operator (NISO) on Tuesday said it averted a nationwide blackout after the national grid experienced significant generation shortfalls due to industrial action by the Petroleum and Natural Gas Senior Staff Association of Nigeria (PENGASSAN).
NISO, established in 2024 as part of the restructuring mandated by the Electricity Act of 2023, manages Nigeria’s national grid and electricity market operations independently of grid infrastructure development. Its core mandate is to function as an impartial and independent entity responsible for system and market operations within the Nigerian Electricity Supply Industry (NESI).
To avert a total system collapse, the agency said it rolled out emergency measures, including ramping up hydropower generation, real-time load balancing, and selective load shedding. It added that available generation dropped from over 4,300 MW to about 3,200 MW at its lowest point due to gas supply disruptions.
NISO explained that it urgently deployed contingency measures to preserve the stability, security, and reliability of the national grid. These included hydropower optimisation, generation dispatch, load balancing, voltage and frequency support, and demand-side management.
‘The Nigerian Independent System Operator (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 of Sunday, 28th September 2025, to about 3,200 MW at the lowest point.
‘Selective load shedding was applied as a last resort to avert a system-wide collapse and ensure fair power distribution. These timely actions enabled the NISO 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 statement read.
The agency reaffirmed its commitment to proactive grid management, operational excellence, and the adoption of best-in-class practices to ensure a secure and reliable electricity supply for the nation.