The Nigerian Independent System Operator (NISO) has attributed recent reductions in electricity allocations to Distribution Companies (DisCos) serving Lagos, Abuja and parts of northern Nigeria to multiple transmission-line outages and constraints on the national grid.
In a statement issued on Sunday, August 30, 2026, titled “Clarification on Recent Changes in Power Allocations Following Transmission Line Outages,” NISO said the reductions were driven by transmission constraints rather than inadequate electricity generation.
The system operator explained that available generation cannot automatically be delivered to every part of the country because power flows depend on the availability and capacity of transmission infrastructure.
Several transmission outages affected the Lagos axis, including the Olorunsogo–Ayede 330kV Line 1, Benin–Egbin 330kV Line 1 and Benin–Omotosho 330kV Line 1.
The prolonged outage of the Osogbo–Ikeja West circuit further reduced the network’s ability to transfer electricity into Lagos.
NISO said the cumulative loss of the circuits lowered transmission capacity into the Lagos axis, prompting reductions in allocations to Eko Electricity Distribution Company, Ikeja Electric and the Sakete international supply.
Power supply to Abuja and parts of northern Nigeria was also affected after the Shiroro–Mararaba 330kV Line 1 tripped between August 24 and August 26, 2026.
The constraints intensified at about 6:47 a.m. on August 27, 2026, when the Shiroro–Mando 330kV Line 2 and Mando–Jos 330kV Line 1 tripped simultaneously.
NISO said the Mando–Jos line was then the only available transmission circuit serving Jos and the North-East, while the Apir–Lafia 330kV Lines 1 and 2 remained out of service because of faults.
To keep the remaining network within secure operating limits, allocations to Kano, Kaduna, Jos, Yola and other affected areas were curtailed.
The Federal Capital Territory experienced a separate transmission constraint on August 29, 2026, when the Shiroro–Katampe 330kV Line 1 and Gwagwalada–Katampe 330kV Line 1 tripped simultaneously at about 3:55 a.m.
According to NISO, the Gwagwalada–Katampe line was restored by 7:20 a.m., while the Shiroro–Katampe line returned to service five minutes later at 7:25 a.m.
NISO said the incidents highlight the interconnected nature of Nigeria’s electricity network, where failures on critical transmission circuits can affect supply across multiple regions.
When transmission constraints limit the safe movement of available electricity, the operator may temporarily redispatch generation, curtail load or revise DisCo allocations to protect system stability and prevent wider network disturbances.
