Fresh concerns surrounding the stability of Nigeria’s national electricity grid emerged this week following operational reports indicating that the power system routinely operated outside prescribed frequency and voltage limits throughout October, despite power plants utilising 85 percent of their available generation capacity. ​
Data on grid operations for the month reveals that system frequency repeatedly drifted outside the standard grid code threshold of 49.75 Hz to 50.25 Hz, while voltage levels suffered severe fluctuations across key transmission corridors.
The systemic instability occurred even as thermal and hydro generation facilities ramped up output to supply higher energy volumes, exposing critical structural vulnerabilities in the nation’s transmission and distribution networks. ​Speaking at an energy stakeholders’ briefing in Abuja on Tuesday morning, Engr. Abubakar Suleiman, Director of Transmission Systems at the Transmission Company of Nigeria (TCN), addressed the operational strain. ​
“Operating at 85 percent generation availability is a commendable operational milestone for our power plants, but the grid’s inability to maintain steady frequency limits under high load stresses the urgent need for enhanced automated control systems and spinning reserves,” Suleiman stated. ​Industry engineers point to a combination of compounding technical operational failures that drove October’s instability.
Chief among these issues is the persistent absence of functional contracted spinning reserves, which left the national grid exposed to sudden load rejections and frequency spikes. Furthermore, severe transmission interface congestion repeatedly hampered the wheeling of bulk power from generation hubs in the south to primary demand centers in the north.
The system was further destabilised by uncoordinated load shedding and load rejections by electricity distribution companies, which continually disrupted real-time system frequency equilibrium. ​Engr. Folake Arowolo, Chief Technical Officer of the Association of Nigerian Electricity Distributors (ANED), emphasized the necessity of coordinated system operations during a press conference in Lagos on Wednesday afternoon. ​
“When power plants push output to 85 percent capacity without flexible grid regulation and adequate equipment at the distribution interface, frequency overshoots are inevitable,” Arowolo noted. “Resolving this requires joint real-time monitoring between TCN and distribution networks.”
​Industry analysts and power sector regulators have warned that operating the national grid outside nominal voltage and frequency thresholds drastically heightens the risk of widespread equipment damage and partial or total system collapses.
The National Electricity Regulatory Commission (NERC) is expected to issue a formal performance directive later this month outlining corrective measures, including mandatory compliance with Grid Code standards and the enforcement of auxiliary service provisions by power generation firms.
