The blackout in the North

As the blackout in the North enters its 10th day, the economic loss due to the outage will be incalculable. This is the first time in the era of grid-connected electricity in the country that such large swathe of territory with more than half of the country’s population will be affected by a power outage […]

As the blackout in the North enters its 10th day, the economic loss due to the outage will be incalculable. This is the first time in the era of grid-connected electricity in the country that such large swathe of territory with more than half of the country’s population will be affected by a power outage for days, if not weeks, on end. To start making any cost calculation for the outage while it lasts will be premature but there is no doubt it will run into billions. The priority for now is for TCN to sort the problem and restore service.

The past few weeks have been a difficult period for electricity consumers in the country when the national grid collapsed and took almost three days to restore. It is even more difficult for consumers in the northern states who have continued to remain in blackout after the electric power grid had been restored. It was not until TCN released a statement days later that the reason for the continued outage became clear.

System collapse is a topical subject in Nigeria—so much is said but so little is understood about it—tongues are beginning to wag since the last occurrence. TCN has its hands full at the moment hence no one expects that it will have time to finish analysis of the situation and release the sequence of events for the causes to be known, but given the discovery of the tower collapse along Shiroro–Kaduna transmission line as well as the other fault along Ugwuaji–Makurdi line, it is possible, even probable, that those were the triggers for the events that led to the system collapse.

Acts of vandalism on national economic infrastructure have become a fact of life in Nigeria. It was oil installations in the 1990s. Electric power infrastructure is now the prime target.   

Nigeria has been struggling over the past several decades to power the economy and increase electricity access. Financing has been one of the biggest challenges. Whether the country recognises this threat or not, it has to factor in insecurity among the top risks for both power project development and O&M.

In the last few years, insurgents in the North East, by their relentless destruction of the 330-kV line from Gombe to Maiduguri, have made sure that the citizens of that region do not enjoy uninterrupted power. TCN has been struggling to cope with the rate of attacks on power transmission infrastructure, so much so that NNPCL had to come to the rescue by building an emergency power plant at Maiduguri—a simple-cycle gas turbine with an installed capacity of 50 megawatts. That has been the saving grace. That the relief has lasted so far is probably because gas for the MEPP is being supplied in trucks.

The case of the Shiroro–Kaduna line is not dissimilar; it traverses a thickly forested area infested with bandits whose violent conduct is of utmost savagery. And just like their fellow partners-in-crime in the North East, Boko Haram, the bandits have added transmission line vandalism to their nefarious activities. This has raised the level of risk for maintenance work on the line. Consequently, the reliability of this critical transmission line to the economy of the North is now very low. The prevailing outage is the outcome of their latest act of terror.

This now leads us to measures for a solution. The first, is the fundamental one of security upon which the survival of the nation depends, so calls on the government to secure the country cannot be overemphasised.

Specifically, if the government can stop attacks on oil installations in the Niger Delta when such vandalism posed a serious threat to the Nigerian economy, it can do the same for its power supply infrastructure. No one will tell the government what to do or how to do it, by whatever means—carrots or sticks or both—it knows better.

As is usual, a lot of suggestions have come forth following the last system collapse, with some recommending a radical restructuring of the national grid. With all due respect, I’m not one with them. The prolonged blackout in the North has vindicated my position—the national grid should be strengthened, not balkanised.

You cannot have regional or isolated grids when, as in the Nigerian case, only a few of them will have any source of generation, to be self-sustaining. To be sure, the North American power system, of United States and Canada, as well as the European one,  comprised a sort of power pools or regional grids but all of them are interconnected by tie-lines to supply load imbalances which cannot be accommodated internally and have to be made up from external sources, across system boundaries so to speak. So, viewed globally, they are all one large interconnected grid.

The Nigerian power system is still evolving and until it reaches a stage when substantial generation capacity exists in different regions of the national grid to support islanding, such measure as presently being proposed will spell doom, to say nothing of its being a recipe for chaos.

Such subdivisions are applied in large systems with power flows in several hundred thousand, for ease of energy management. At any rate what quantum of power flow does the Nigerian system handle to justify such measure even in the future?

The crux of the matter is that implementation of the country’s power system development plan had been poor, or at best haphazard; everyone knows this — that’s what has led to privatisation and the mess we find ourselves in presently. This blackout in the Northern parts has been a long time coming!

We have to recognise and accept that powering an economy the size of Nigeria’s requires a strong national electricity grid. Other energy sources and systems are necessary complements.

Power engineering professionals must not tire in enlightening people’s ignorance that the electric power grid is not an imposition but the result of evolution of the power system globally, to satisfy the needs of industrialisation and economic growth.

The 330-kV national grid came into being in Nigeria when Kainji Hydroelectric Power Station came onstream in February 1969, to transmit the power from the dam to the load centres across the country. The backbone of the system comprised Kainji–Jebba; Jebba–Kaduna (via Shiroro); Jebba–Oshogbo; Oshogbo–Akangba (Lagos); Oshogbo–Benin; and Benin–Onitsha, transmission lines. Other power stations and transmission lines were added as the network developed into the large complex system it had become today.

Except for the triangular loop formed by Oshogbo, Lagos and Benin, the 330-kV high-voltage transmission network in Nigeria had been essentially radial—in other words, it didn’t have the redundancy of an alternative pathway for power flow from the power stations to the load centres (cities, towns, industries, etc).

It is pertinent to point out that the idea of a national grid (the connection of all power stations in a country to a common transmission network) is a universal one and arose from the need to pool power generation resources for reasons of economy.

It happens that energy resources for bulk power generation in Nigeria (and elsewhere) are found in remote locations—gas resources in the Niger Delta and hydro resources in parts of the North-central region, but all quite some distance away from the load centres, making the construction of long transmission lines necessary, with all the attendant consequences.

For long, the architecture of the country’s transmission network had not substantially changed from the radial configuration, its fragility being all the more critical in the Northern section which, in crisis situations as this one, is rendered into a virtual electrical island without a source of generation—the main node at Kaduna is supplied from a double circuit, 330-kV line from Shiroro; single-circuit transmission lines connect the major load centres (transmission substations) at Kano, Jos, and Gombe; with later extensions to Maiduguri, Yola, and Jalingo. Even when things are normal, power transfer capability of the two lines from Shiroro is no more than 1,200 megawatts.

Apart from power supply availability, power quality is also an issue in the North due to limitations associated with long transmission lines. It’s no surprise that restoration following a system collapse becomes prolonged.

It wasn’t until the last few years that the preexisting transmission line project, from New Haven to Jos via Makurdi (now rerouted through Ikot-Ekpene and rechristened Ugwuaji–Makurdi–Jos) , which had been a permanent feature of the FGN budget since 1996, was taken over by NDPHC and completed in 2017, thus providing much needed access to gas-fired generation resources in the south-eastern axis—effectively opening an additional pathway for power flow to the North, via the Jos node. This underscores the significance of the newly constructed but yet to be commissioned double-circuit transmission line from Kaduna to Jos, as the existing Kaduna – Jos (single-circuit) transmission line is underrated and would constitute a bottleneck.

To conclude on a happy note, despite the grim picture painted about bulk power transfer to the North, one would say things are looking up—there have been positive developments pertaining to the transmission network in the last few years. The construction of a double-circuit transmission line from Shiroro to Abuja in 2002, apart from improving power supply to the FCT, has created further opportunities for opening new pathways for power flow to the North in particular, and for network redundancy in general.

One of those positives is the siting of a large, gas-turbine combined cycle power plant at Geregu (Ajaokuta) in Kogi State with an associated double-circuit transmission line, Ajaokuta–Lokoja–Gwagwalada (Abuja). With the already existing transmission line from Benin to Ajaokuta, the potential for a third pathway for power flow to the Northern axis has been created. This potential can be exploited by constructing a transmission line from Abuja to Kaduna.

Perhaps, the need for constructing that line has been reinforced by NNPC’s decision to build three gas-turbine combined-cycle power plants rated at 1,350 MW, 900 MW and 1,350 MW at Gwagwalada, Kaduna and Kano respectively, all of them to feed from the AKK Gas Pipeline now under construction. Work on the Gwagwalada plant is already underway.

The NNPC, for all its failure to supply affordable fuel to the country, deserves commendation for this initiative; if the economic fortunes of the country are to get a real boost, it is projects like these that that the FGN should implement.

One last thing worth mentioning, as part of efforts to improve reliability of power supply in the North, is to make moves to correct the flaws associated with power evacuation from the newly completed Zungeru Hydroelectric Project—the plant has since been delivering power to the national grid, but through a corridor that is constrained, with the result that the country doesn’t quite reap the full benefits of the power plant’s energy production. One way to maximize the power evacuation from the Zungeru plant is by constructing a double-circuit transmission line to Kaduna. This is also in line with TCN’s Transmission Rehabilitation and Expansion Plan.

 

Engineer Abdul-Aziz is a former CEO of Shiroro Hydroelectric Power Station