The Nigerian Independent System Operator (NISO) has attributed recent changes in power allocations to Distribution Companies (DisCos) serving Lagos, Abuja and the northern corridors to multiple transmission line outages and changes in network configuration.

In a statement signed by its management on August 30, 2026, NISO said the outages reduced available transmission capacity at different times, forcing adjustments to power allocations to keep the interconnected Nigerian Electricity Supply Industry within secure operating limits.

‎NISO explained that the availability of electricity generation does not automatically guarantee that power can be delivered to a particular load centre, as power transfer also depends on the capacity and availability of transmission infrastructure and the prevailing network configuration.

In the Lagos complex, NISO said successive outages on the Olorunsogo-Ayede 330kV Line 1, Benin-Egbin 330kV Line 1 and Benin-Omotosho 330kV Line 1, alongside the prolonged outage of the Osogbo-Ikeja West circuit, reduced transmission capacity into the Lagos axis. It consequently curtailed allocations to Eko Electricity Distribution Company, Ikeja Electric and the Sakete international supply.

The operator said the northern corridor was also affected by the tripping of the Shiroro-Mararaba 330kV Line 1 between August 24 and 26, which constrained supplies to Abuja and other northern areas. It added that the simultaneous tripping of the Shiroro-Mando 330kV Line 2 and Mando-Jos 330kV Line 1 at 6:47 a.m. on August 27 significantly reduced transmission supply to Jos and the North-East.

According to NISO, the Mando-Jos line was at the time the only available transmission circuit serving the Jos and North-East areas, while the Apir-Lafia 330kV Lines 1 and 2 had remained out of service for an extended period due to faults. The situation led to revised and curtailed allocations to Kano, Kaduna, Jos, Yola and other affected areas to maintain system security.

‎NISO further reported that the Shiroro-Katampe 330kV Line 1 and Gwagwalada-Katampe 330kV Line 1 tripped simultaneously at 3:55 a.m. on August 29, temporarily constraining supply to the Abuja axis. The two circuits were restored at 7:25 a.m. and 7:20 a.m., respectively, allowing the affected transmission capacity to be recovered.

The operator stressed that outages on critical transmission circuits can affect power delivery beyond the immediate location of an incident because of the interconnected nature of the national grid. It said recent allocation changes were therefore driven by transmission constraints and network configuration, rather than generation availability, adding that temporary redispatch, load curtailment or revised DisCo allocations may be necessary to prevent wider system disturbances.