•Blackout
Fresh concerns have emerged over the health of Nigeria’s national electricity grid following last week’s major disturbance on the Lagos transmission corridor, with power sector experts warning that the country’s transmission infrastructure is dangerously overstretched, underfunded and increasingly vulnerable to collapse.
The alarm follows the recent outage triggered by voltage instability on the Benin–Egbin 330kV transmission line, which disrupted bulk power supply to Lagos and surrounding areas, reports Daily Independent.
Although the Transmission Company of Nigeria (TCN) has since restored the Benin–Egbin line and continues repair work on the Benin–Omotoso 330kV line, industry stakeholders insist the incident exposed deeper structural weaknesses in the national grid.
An infographic released by the Association of Power Generation Companies (APGC) painted a troubling picture of grid instability on June 25, 2026.
According to the real-time grid performance data, frequency fluctuated sharply between 49.00Hz and 51.65Hz, far outside the healthy operating range of 49.5Hz to 50.5Hz.
Experts note that such a wide 2.65Hz swing threatens turbine lifespan, governor stability and protection systems.
Generation also fluctuated significantly from 2,543MW to 4,416MW, representing a 1,873MW swing within the same period. APGC classified this as a high-risk condition, warning that reserve margins remain inadequate and system collapse risks elevated.
Voltage readings were even more alarming, rising from 298kV to 380kV, compared to the normal operating band of 330–345kV.
Analysts said the 82kV spread indicates severe instability, with under-voltage conditions pointing to weak grid sections and over-voltage suggesting reactive power imbalance and poor Automatic Voltage Regulator coordination.
APGC consequently classified both frequency and voltage risks as critical, describing the grid as “highly volatile.”
Power sector analyst, Kunle Kola Olubiyo, said the incident should not be viewed as an isolated fault but as evidence of long-standing failures in transmission planning, maintenance and protection.
According to him, many of Nigeria’s system protection devices — including frequency relays and other grid safety mechanisms — have become obsolete or defective.
“We have frequency relays, system protection schemes and protective devices, but many are obsolete and failing to operate effectively,” he said.
Olubiyo argued that poor investment in transmission expansion and maintenance has left the grid vulnerable to cascading failures, particularly during system stress.
He further alleged that TCN owes local contractors about N350 billion for projects executed over several years, with many emergency repairs reportedly carried out on credit and without immediate budgetary backing.
According to him, delayed payments have weakened contractors’ ability to respond quickly to infrastructure failures.
He questioned government funding for transmission infrastructure between 2023 and 2026, insisting there must be greater transparency around budget allocations for grid maintenance and expansion.
Another industry stakeholder, Joy Ogaji, raised concerns over the impact of repeated transmission upgrades.
She questioned whether line upgrades and transformer installations across the country have translated into measurable improvements in power availability.
“Have we tracked to know whether all these line upgrades and transformer installations have actually enabled more power delivery or megawatt addition?” Ogaji asked.
Technical discussions around the incident also focused on the possibility of transformer bushing arcing or flashover as a contributing factor.
Electrical experts explained that bushing arcing occurs when high-voltage electricity discharges across insulation surfaces due to contamination, moisture, insulation failure, overload, switching surges or poor earthing.
Signs of impending failure include oil leaks, overheating, crackling sounds, carbon tracking and corrosion.
Analysts noted that operating a 330kV transmission system at 380kV without adequate reactors or control devices significantly raises the risk of overcurrent, overheating and insulation breakdown.
Experts also identified several systemic gaps in Nigeria’s transmission network, including weak or ineffective SCADA systems, inadequate spinning reserves, poor vegetation management, obsolete circuit breakers and weak black-start capability.
Olubiyo likened the state of many transmission substations to “driving a heavy-duty truck without brakes, horn, lights or engine cooling.”
Industry stakeholders are now calling for an urgent national grid stress test, a full technical audit of transmission assets, and comprehensive overhaul of the electricity protection scheme.
They warned that unless obsolete infrastructure is replaced and serious investments made in transmission safety and expansion, grid disturbances may become more frequent.
For many analysts, the Lagos disturbance has reinforced an uncomfortable reality: Nigeria’s generation challenges are only part of the power crisis.
The bigger problem, they argue, may now lie in the wires, substations and protection systems meant to keep electricity flowing. Without urgent intervention, experts warn, the national grid could remain one major fault away from another widespread outage.
