TCN has been recording a declining trend of system collapse incidences for the last four to five years.

Engr. Sule Ahmed ABDULAZIZ Managing Director and CEO TRANSMISSION COMPANY OF NIGERIA

Sustainable growth in Nigeria

November 8, 2021

Engr. Sule Ahmed Abdulaziz, managing director and CEO of Transmission Company of Nigeria (TCN), talks to The Energy Year about the impact of the Presidential Power Initiative (PPI) on Nigeria’s power network and how both the government and TCN are taking steps to enhance transmission infrastructure. TCN manages Nigeria’s electricity transmission network.

How important will the PPI be for Nigeria’s power network and in what ways will TCN benefit from this programme.

The PPI seeks to consolidate and optimise both transmission and distribution infrastructure, as well as remove bottlenecks at interfaces to improve the free flow of electricity from the generators to load centres. Against this backdrop, the federal government of Nigeria and Siemens, representing the government of Germany, under the PPI developed the Nigeria Electrification Roadmap, which is structured in three phases.
The first phase focuses on essential and quick-win measures to increase the system end-to-end operational capacity to 7 GW. Phase 2 targets the remaining network bottlenecks to enable full use of the existing generation and last-target distribution capacities, bringing the system’s operational capacity to 11 GW. Phase 3 is focused on developing the system up to 25 GW in the long term.
TCN stands to benefit from the PPI through some identified quick-win projects to address TCN/DisCo 132/33-kV interface bottlenecks. It is to be noted that TCN’s wheeling capacity is 8,100 MW today. Addressing the interface challenges will facilitate the free flow of electricity to enable attainment of capacity increases, not just for TCN but also for DisCos and GenCos distribution and generation companies.

Click here for a map of Nigeria’s power infrastructure.

In what ways is the government enhancing the nation’s transmission infrastructure?
The maintenance and expansion of the transmission grid, which includes rehabilitation of existing transmission lines and substations, upgrading of transmission capacity through installation of transformers and associated substation equipment, and the construction of new substations and lines, is an ongoing exercise.
Many projects are ongoing in this regard and are expedited under different financing arrangements. These projects will enhance the grid network by strengthening the 132-kV downstream to deliver more supply to the distribution interface. It also aims at achieving N-1 on some of the 330-kV lines that are not yet looped. Substations will also be upgraded and better interface co-ordination with DisCos more vigorously pursued.

 

What setbacks does TCN encounter within its transmission network and process, and what solutions is it fostering to cover these gaps?
There are a number of challenges TCN faces, which include the need for a functional SCADA system and low government budgetary allocation, delays in the release of approved budgets, bottlenecks in project implementation related to the processing of IDEC and other port-clearing documents, and difficulty in acquisition of land and rights of way for projects.
TCN has been recording a declining trend of system collapse incidences for the last four to five years, from 22 system collapse incidences in 2016 to only four incidences in the year 2020. In 2021, we have had one partial disturbance of the system. This is an indication of gradual improvement in grid stability which is being achieved through the reinforcement of the network and a more rigorous enforcement of the grid code by TCN via the National Control Centre. Also, generating stations are complying more on free governor control of their generators.
On the issue of transmitting available generated power to DisCos, TCN has adequate transmission capacity for immediate needs of the DisCos. The quantity of power to be generated and transmitted in the system is largely dependent on the quantity of power being demanded by the DisCos; the demand side needs to be unlocked to allow for more power to be generated and transmitted.
However, both TCN and DisCos have recently signed a service-level agreement in which the DisCos nominate day-ahead the capacity they want to distribute and where, and it is TCN’s duty to supply them as they request, provided it is not below their multi-year tariff order allocation. This is expected to gradually unlock the demand to allow more power to be generated and transmitted to the end users.

What is TCN’s overarching ethos and what are the functions of its business units TSP, SO and MO?
The role of TCN in the power sector is to cost effectively provide, operate and maintain the required assets, equipment and transmission grid network for evacuating and dispatching high-quality and reliable electricity with minimal technical losses.
However, TCN does this through the three major sectors: Transmission Service Provider (TSP), The System Operator (SO) and Market Operator (MO). Firstly, TSP oversees the development and maintenance of the transmission infrastructure as well as the national interconnected transmission system of substations and power lines and providing open access transmission services. It also maintains the physical infrastructure that makes up the transmission grid and expands it to new areas.
Moreover, SO dispatches generated units in accordance with the least-cost Merit Order, on the basis of nomination by generators, and handles power system emergencies and power system restorations. It also performs demand forecasts, incorporating DisCos’ load nomination; co-ordinates generation and transmission outages; supervises compliance with and enforces the Grid Code and market rules; and tests and monitors users’ equipment to ensure their compliance with the Grid Code, among other activities.
MO, on the other hand, is responsible for the administration of the market and the implementation of the market rules on all participants in the power sector.

In what ways is TCN enhancing efficiency and effectiveness in its transmission operations to ultimately achieve reliability and minimise losses?
Achieving the latest all-time peak of 5,801.6 MW can be attributed to many factors but largely to the effective dispatch of the generators through the transmission grid, strong enforcement of the code through the National Control Centre and the unlocking of demand by DisCos, allowing power to flow to the end users. Also, generating stations are complying more on free governor control of their generators.
We will continue to pursue this path and do all we can to eliminate downtime by pursuing timely maintenance and spares availability and of course, ensure continuous human capacity development. Also, we are executing more projects and reconductoring more transmission lines with higher-capacity conductors, among other measures to ensure sustainable transmission capacity growth.

What recent projects has TCN rolled out to optimise and enhance its transmission network?
TCN has done a lot of projects in the last few years. Within the last 10 months, under my watch, projects undertaken by TCN include but are not limited to: providing redundancy with the construction of a 330-kV tension tower that will shift Egbin-Aja 330-kV Line-4 to proposed Omotosho-Epe 330-kV incoming line terminal gantry. This line had been out for over five years due to faulty GIS, leaving the Ajah substation to be supplied only through Line-3.
We have also constructed a 132-kV bay for the redundant 150-MVA 330/132/33-kV T1A power transformer at the Ayede transmission substation, increasing the capacity available to IBDEC. In addition, we have provided flexibility and redundancy by building the 3Nos. 132-kV bays at Iwo transmission substation for existing transmission line tee-offs.
Likewise, TCN has improved grid stability by recalibration and reconfiguration of transmission lines and transformers protection schemes which have been prone to frequent system disturbances through the setting up of a functional protection department in the head office. This has drastically reduced system collapses.
At present, we are enhancing the Sokoto-Birnin–Kebbi line from 70 MW capacity to 120 MW, as well as the Ikeja West-Alimosho-Ogba-Alausa lines from 120 MW capacity to 240 MW. Also, the Onitsha-New Haven line that would increase its capacity from 680 MW capacity to 1,320 MW, has been awarded.
We have equally completed several new transformer installation projects in TCN substations in Abuja, Kaduna, Jigawa, Lagos and Cross Rivers States, to mention a few. New substation projects like the Gagarawa 2×60 MVA substation in Jigawa State was also completed.
The company has also completed 1×100 MVA, 2×60 MVA, 1×60 MVA and 1×30 MVA transformer projects at the Ogba, Gagarawa, Rumuosi and Iseyin substations among others.
Lastly, there will be a new National Control Centre at Osogbo and Gwagwalada. From here, both of our National Control Centres will be equipped with a state-of-the-art grid control system and all 132-kV and 330-kV substations fitted with [automated] systems for protection and remote control. Also, the SCADA system is being upgraded and modernised.

What collaborative approach has TCN adopted to ensure sustained improvement in the power sector?
The collaborative approach adopted by TCN with GenCos and DisCos has improved synergies by identifying key interface constraints and putting mechanisms in place to solve them and developing SLA agreements to reinforce supply security. Also, TCN is in collaboration with different state governments to acquire the right of way and payments of compensation to persons and communities affected by certain projects.
At the same time, collaboration with host communities has proven to be very effective in the area of surveillance and protection of TCN facilities from the activities of vandals. TCN is seriously pursuing this avenue in view of recent incidents.
Synergy between stakeholders in the sector is a necessary tool for success. The synergy between GenCos and TCN through the use of the free governor mechanism by generators has brought the frequency to the stability range of 49.8-50.02Hz, acceptable by the West African Power Pool (WAPP).

What are the goals and milestones TCN aims to achieve in 2021 and beyond?
TCN expects several positive outcomes from 2021 and beyond, including having an automated grid with fully functional SCADA and EMS, market rules and grid processes completely automated with a commercial-grade software and a reduction in downtimes of equipment and rapid response to maintenance issues.
The company also expects to further increase the capacity of the grid by completing several ongoing critical projects as well as upgrading staff capacity, among other actions.

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