The Nigerian Independent System Operator (NISO) has dismissed claims by the Association of Power Generation Companies (APGC) over the June 25 disturbance on the national electricity grid, describing the group’s publication as misleading and not reflective of the actual operational events.
In a statement issued on Friday, NISO said the APGC’s interpretation of the incident failed to accurately capture the operational circumstances surrounding the disturbance, stressing that only NISO is legally mandated to operate, monitor and provide official information on the National Grid.
According to the system operator, the June 25 incident was a localized voltage instability in the Lagos region, which was promptly detected and contained through coordinated operational interventions, preventing it from spreading to other parts of the national grid.
NISO explained that electricity system frequency and voltage are expected to temporarily fluctuate during disturbances before corrective actions restore normal operations. It noted that the Nigerian Grid Code permits temporary frequency deviations under stressed conditions and requires generating units to remain connected during such excursions to support system stability.
The operator said it was technically inaccurate to interpret temporary frequency or voltage fluctuations as evidence of a grid collapse or system failure, as such occurrences are anticipated and managed through established control, protection and restoration mechanisms.
It further stated that the temporary drop in power generation recorded during the incident resulted from the activation of generator and network protection systems, as well as deliberate operational measures taken to safeguard the integrity of the grid and prevent cascading outages.
NISO maintained that the swift stabilization and restoration of electricity supply demonstrated the effectiveness of its emergency response procedures.
The agency urged the public, electricity market participants and policymakers to rely solely on official communications from NISO for verified information on grid operations and system events.
Reaffirming its commitment to the Nigerian Electricity Supply Industry (NESI), NISO pledged to continue ensuring the reliability, security and stability of the national grid through strict adherence to the Nigerian Grid Code, transparent communication and internationally accepted system operation practices.
