How TCN Plans to Evacuate New Generation Capacity


In a new blueprint prepared by German power consulting firm, Fitchner GmbH, the Transmission Company of Nigeria recently opened up on how it intends to transmit incremental electricity that will be wheeled out by existing and proposed power plants in the next 20 years, writes Chineme Okafor

It was not exactly clear if the TCN had ever put up in a clear-cut manner or plan how it would transmit the volume of electricity expected to be generated from Nigeria’s new or expanded brownfield power plants on a long term basis, until recently.

Based on its past record as the weakest link in Nigeria’s power market, the TCN had always attracted severe reproach as a company with a lack of preparation for the future. Even with the appointment of an international contract manager who ran its affairs for the first three years of power sector privatisation, the TCN still fumbled and was unable to guarantee the market a stable transmission network.

While it still hasn’t overcome the challenges of transmitting electricity generated in the country without instability, or even executed transmission projects without unnecessary challenges, the TCN has however initiated a new process that could see to its placement of priorities in its job of making sure the various distribution networks get the amount of electricity due to them without interruptions.
At a recent meeting in Abuja, the TCN unveiled a plan to expand its transmission network across Nigeria for the next 20 years.

It said the plan – a 20-year Transmission Expansion Master Plan, was developed with funding from the World Bank, by a German-based power consultancy firm, Fitchner GmbH.
With this plan, TCN said it would continue its expansion works on the country’s transmission network to be able to evacuate circa 28,000 megawatts (MW) of power that would generated in the country by 2035.

The 20-year plan
The master plan was handed over to the Minister of Power, Works and Housing, Mr. Babatunde Fashola, at a ceremony in Abuja by the immediate past Interim Managing Director of the TCN, Mr. Usman Mohammed, after Fitchner signed off on it.

It reportedly cost the World Bank about $2million to execute, and was conceived in 2009 after a national load demand study was done by another power consultancy firm, Tractebel of Belgium.

In their presentation of the plan, the Fitchner team led by Dr. Oprea Liliana, a power systems operations expert, explained that while Nigeria’s power generation grew by 6.3 per cent in the last 40 years, it was expecting demand for and generation of power to hit 28,000MW by 2035.
The team noted that in 2020, 2025, and 2030, Nigeria should be generating 10,000MW, 15,000MW, and 23,000MW, respectively.

Out of this, it also said that 387MW, 1540MW, 1830MW, and 2000MW are expected to be sent to consumers in the West African Power Pool (WAPP) between 2020, 2025, 2030, and 2035, respectively.
It also made recommendations on what should be done across the power value chain to keep the plan in progress and effective, adding that on the average, Nigeria should be adding 1500MW of electricity generation capacity to its grid annually, while expansions in gas supply and distribution infrastructure should be in consonance.

It equally had factored in it future electricity generation capacities like the 3050MW Mambilla hydro power plant and other generation capacities, in addition to recommending that Nigeria was better served by its existing 330 kilovolt (kV) transmission lines.
According to it, the first priority for the TCN within 2020 would be to resolve the overloads occurring under normal operation of its 132 kilovolt (kV) lines in Alagbon-Ijora, Omoku-Rumusoi (DC), and Ibom IPP-Ikot Abasi.

As a next priority, the plan stated that the TCN must reinforce 23 of its overloaded lines currently under N-1 contingencies by either re-conducting them to higher rating conductors.

It equally added that in addition to the transmission projects proposed and undertaken by the Japanese International Cooperation Agency (JICA), new transmission lines in the North East Ring: Damaturu-Maiduguri, Gombe-Damaturu, Gombe-Yola, Yola-Jalingo and Jos-Gombe; North West Ring: Kainji-Birnin Kebbi, and 330kV Kaduna-Kano, should be done within 2020.

Similarly in 2020, it indicated that the 330kV lines in Akangba-Alagbon, Ugwaji-Abakaliki, Osogbo-Arigbajo; 132kV lines in Ayede-Ibadan North, New Agbara-Agbara, Ogojo-Redeem, and Birnin Kebbi-Dosso should be executed as priority projects.
Further, the plan recommended for the immediate upgrade of 14 numbers of 330/132kV 3W and A/T transformers which audits disclosed are overloaded above their 100 per cent rating megavoltage amp (MVA) operation.

It also requested for the upgrade of 25 numbers 132/33kV and 132/11kV transformers which are overloaded above their 100 rating MVA operation, in addition to the upgrade of 10 numbers 330/132 kV 3W and A/T, 25 numbers 132/33 kV and 132/11kV transformers currently overloaded above their 85 per cent rating MVA operations.

According to it, the most critical 330kV substations to be looked into by the TCN are those at Benin, Omotosho, Sapele, Alaoji and Afam IV. These substations, it explained have respective fault levels ranging from 34.9 kilo ampere (kA) to 25.7kA for a three phase bus-bar fault.
The 132kV substation in Ikeja West with a fault level of 29.6kA, was also listed as a critical transmission facility to be looked into in the plan.

In 2025, the plan recommended that parts of the 330kV North West ring lines: Birnin Kebbi-Sokoto, Sokoto-Talata Mafara, Talata Mafara-Gusau, Gusau-Funtua, Funtua-Zaria; parts of the 330kV North East ring lines: Damaturu-Maiduguri, Gombe-Daimaturu, Gombe-Yola, Yola-Jalingo, be continued if they were not implemented by 2020.

It also included in the 2025 timeline the 330kV lines for Mambilla evacuation, and they include Mambila-Jalingo, Mambila-Wukari, Wukari-Makurdi, Wukari-Lafia, as well as 330kV Olorusongo-Arigbajo, Katsina-Daura, Daura-Kazaure, and Shiroro-Kaduna lines.

Further for 2025, it explained that the 132kV lines which are overloaded under normal operation but require reinforcements would be the Ogijo-Shugamu, Dadinkowa-Kwaya Kusar, PHCT Main 1-PHCT Town 2.
It added that since a number of under voltages were encountered in the dry season peak case, and also in order to meet the N-1 security criterion, the Shiroro-Tegina, Tegina-Kontagora, Kontagora-Yelwa, Yelwa-Yauri, Ganmo-Ilorin, Obajana-Egbe, Omotosho-Ondo, Benin-Irrua, Irrua-Ukpilla, Ukpilla-Okene, Shagamu-Ijebu Ode, Dakata-Gagarawa, Gagarawa-Hadejia, Dakata-Kumbotso, Birmin Kebbi- Dosso lines be reinforced.

For transformers upgrade in 2025, it said 20 numbers 330/132 kV 3-W and A/T transformers which are overloaded above their 100 per cent rating MVA operation, and 51numbers 132/33 kV and 132/11 kV transformers also overloaded above their 100 per cent rating MVA operations would need to be upgraded.
It identified the Benin, Omotosho, Azura, Egbin and Benin 330kV substations with fault levels ranging from 54.3kA to 42kA for a three phase bus-bar fault, as the critical substations to be looked into within this phase of the plan.

Considerations for network expansions

Justifying the need for the TCN to embrace the network expansion plan, the document noted that it had factored in the need to increase network transfer capacity, security of power supply, integration of renewable energy sources into Nigeria’s energy mix, effects of transmission losses, and technical resilience of the transmission system in developing its recommendations.

Similarly, Fashola, said that with the plan, the TCN would be expected to continue to improve its capacity to wheel out generated electricity in the country, adding that cases of stranded power would be dealt with by the new plan.

According to him, “the government has given the TCN a mandate to improve its capacity to deliver its responsibilities to the Gencos and Discos. That mandate has not stood alone, it has been followed by policy approvals, and it has been supported by a budgetary commitment.”

“The real story why we are here today is that there is now a plan to address how TCN progresses. We gather to receive a 20-year transmission expansion masterplan and we do it with all our stakeholders. You have heard very detailed analysis of how this plan will become reality and even Mambilla which construction has not started is factored in the plan, and presentations about what each Disco would do, how the plans of the Gencos would affect what we want to do,” he stated.

In terms of finance for the expansion plan, the TCN indicated that it has various funding windows from donor agencies to support its annual incomes from the national budget. It listed the $200 million JICA finance, $272 million from Agence Française de Développement (AFD), $200 million from the African Development Bank (AfDB), $500 million Exim Bank loan, $486 million from the World Bank, and $210 million from the Islamic Development Bank (IDB) as some of the funding windows it has in view for the expansion plan.

“This masterplan establishes the basis of the TCN transmission rehabilitation and expansion plan under which several donors are supporting TCN, and that plan, we have actually advanced some of them. For example, the one that is supported by the World Bank – we have actually done the negotiation, I think it would go to the board very soon.

“The one by the AFD – the Abuja transmission scheme, the procurement has gone very far, and the other aspect, the northern corridor, we are doing the pilot aspect of the feasibility studies and it would also go for appraisal before the middle of this year.
“And that is the same thing for JICA project between Ogun and Lagos, and the northern corridor and the north-east transmission projects. These are the basis of why we are doing what we are doing. We are strengthening transmission system under this programme using in-house capacities,” Mohammed explained in this regards.