NISO Debunks APGC's Claims on Lagos Voltage Incident

The Nigerian Independent System Operator (NISO) issued a statement on Friday, clarifying that a voltage disturbance in Lagos on June 25, 2026, was misrepresented by the Association of Power Generation Companies (APGC). NISO described the event as a local voltage instability that was promptly contained, preventing a nationwide collapse.

They criticized APGC for presenting an incorrect interpretation of the operational realities, noting that temporary fluctuations in frequency and voltage were fully anticipated and managed according to the Nigerian grid code. NISO stated that the normal operational frequency range is between 49.75 Hz and 50.25 Hz, and during the disturbance, the frequency briefly dropped to 47.50 Hz and rose to 51.50 Hz for 15 seconds.

They also pointed out that APGC's claims did not acknowledge the temporary reduction in generation as a protective measure. NISO reaffirmed its role as the statutory body mandated to monitor the security of the grid and warned stakeholders against relying on unverifiable data.