By Dotun Ibiwoye
Efforts to boost electricity supply in Umuahia and its environs recently received a boost with the establishment of a N3.4billion substation in the Abia State capital.
The installation of the 2 x 40MVA, 132/33kV DC Transmission Substation in Umuahia brings to an end a 10 year hard work to tackle the problem of electricity in the state capital and its environs.
The Federal Executive Council in 2001, awarded the contract for the construction of Umuahia 2 x 40 MVA, 132/33kV Transmission Substation to Messrs Valenz Holdings Limited, a fully indigenous company at the cost of N500.30million ($7.06m)
One of the advantages of the Umuahia Transmission Substation is that on completion, it would serve as the backbone for four other 40MVA, 132/33kV substations at Okigwe, Mbaino, Ohafia and Arochukwu, all of them targeted at improving power supply in Abia State and the South-East geopolitical region.
Federal and state collaboration
At the inauguration of the substation, the Minister of Power, Prof. Bart Nnaji, noted that there were several processes involved in thedistribution of power, which he said was not solely a federal government’s affair, adding that the building of a substation also requiredthe involvement of the state government for several reasons.
The minister also said that the completion of the substation was a good demonstration of how a state government can work with the federal government to achieve great results.
According to him, “We want to notify Nigerians that the states and the federal government can embark on a project like the substation and achieve a good result. The state government provided the land for us to build this substation which will definitely boost socioeconomic activities in the state. The line is only able to deliver about five megawatts of power allocation, out of which two megawatts are lost during transmission.”
He noted that the completion of the project meant little unless power is transmitted to the people, adding that the government spent over N3.4billion on the project.
Nnaji sid the streaming of the substation would save residents of Umuahia and its environs the problem of erratic power supply, and the Geometric Power Plant, a private initiative at Osisioma, near Aba, would begin to provide power to the area by the end of 2012.
The Executive Governor of Abia State, Chief Theodore Orji, argued that the state’s economy has been revitalized; adding that this would also impact some parts Imo State that are connected to the substation.
He gave the assurance that his administration would check the dangers posed by the activities of miners of kaolin, which is capable of leading to the collapse and failure of the substation structures and equipment.
Scope of contract
The contract awarded to Messrs Valenz Holdings for the construction of the substation covered the design, manufacture, supply,delivery to site, erection and commissioning of all materials/equipment needed for the installation of the Substation.
The initial cost of the project was $4.59 plus N151.81m, but was however, reviewed due to additional work, which pushed the value to$7.06m plus N500. 300m.
The 132k V double circuit transmission line from Alaoji 330/132k V substation to Umuahia was awarded at a cost of $4.06 + N737.32ms, but was later reduced to $3.3m + N677.54m.
During the process of design, the consultants observed that the rehabilitation of Alaoji 132kV switchyard was essential for operational flexibility and stable supply to stations connected to it i.e. Umuahia 132kV substation and the four downstream 132kV stations that would feed from it.
The rehabilitation work was, however, not included in the original scope of the project. Also, it became imperative to change the design of the Umuahia substation from a single bus bar to a ring-bus arrangement, to ensure operational flexibility, reliability and future extension economically, which led to the first revaluation of the contract.
The Chief Executive of Valenz Holdings, Mr. Bonny Odiri, noted that “The surface was not wide enough; the earth was cut more thanfour meters down to get it to desired width, before construction could start. Furthermore, the soil sample test revealed soft clay soil with low bearing capacity, bringing forth the challenge of further cutting, backfilling and compacting before getting a workable space.
“Another major challenge was inadequate funding for the budget appropriation in the early years of the project, which stalled the project.
After completion of the substation, there is a transformer capacity of 80MVA, two 132kVlines and 6 x 33kV out-going feeders.
Before now, power supply to Umuahia and neighboring communities had been through a very long 33kV line from Aba with about 5MWs of power allocation.
Due to losses along the line, only about 3MW and 25kV would be available for distribution. The result was poor electricity supply to a very large consumer population.
For the Chief Executive Officer, Transmission Company of Nigeria, TCN, Mr. Olusola Akinniranye, completing the project was very challenging particularly with regard to the construction of the transmission substation and the complementary transmission line from Aba to Umuahia.
He also said decried the activities of Kaolin miners, saying, “We have situations like this in other parts of the country where people virtually dig laterite right under the tower, thus disturbing the foundation.”