Why power supply remains poor despite increased generation
Operators of the Kainji and Jebba Hydro Power Plants (HPP) in Niger State have raised their capacities to 20 per cent of the national grid since privatisation in 2013.
But electricity customers in the downstream are still groaning under huge bills under the 11 Distribution Companies (DisCos) as they are yet to reap the benefits of these improvements. Our reporter who visited the plants, located along the River Niger in Niger State, found out that despite the success of the hydro, their output is still constrained by the inability of the DisCos to take the entire power being produced to the customers at households and industries.
The Generation Companies (GenCos) said they were often asked to reduce their generation to stabilise the transmission system because the energy produced is not fully consumed by DisCos, even at the peak of the rainy season when the hydro plants have excess water to generate electricity.
Kainji plant was commissioned as Nigeria’s first HPP in 1968, and Jebba plant came up on April 13, 1985. The two GenCos are under a concession management of Mainstream Energy Solutions Limited (MESL) since they took over the plants on November 1, 2013 after the privatisation exercise.
The Chief Operation Officer (COO), Mr Jose Villegas Garcia, conducted reporters across the 1,338mw capacity plants, separated by a 103 kilometre road distance across the Kainji-Mokwa-Jebba highway.
While Kainji has an installed capacity of 760mw, it cascades downstream to Jebba, which has a 578.4mw generation capacity, culminating in 1,338.4mw. The company manages 14 generating units in the two plants: Kainji has eight installed units, Jebba plant has six.
With just 10 days to the fourth anniversary of the privatisation, Mr Villegas said his firm had restored the original capacity of the two plants to a functional 922mw from the 582mw non-operational plants they met in 2013. He said, “We currently generate an average of 20 per cent of Nigeria’s power through our available capacity of 922mw with nine generating units across the two plants.”
The Kainji plant has 440mw available capacity and Jebba has functional 482mw capacity. Although MESL has done much, it is working to recover the remaining 416mw from five unavailable generating units to reach maximum capacity of 1,338.4mw.
The deficit of 320mw will be recovered at Kainji, and another deficit of just 96mw is required from one unavailable unit at the Jebba plant, Villegas explained.
He said the unavailable unit at Jebba plant was caused by a major fire incident on the generation system on April 21, 2009 before privatization, and that the recovery process has commenced. Plants generate N103bn since 2013 Since takeover in 2013, the Kainji plant has generated 15,962 gigawatt hour (GWh) of electricity. The company’s book for the 2016 financial year shows that it earned N103.005 billion as revenue during the period. The breakdown shows that in 2013, Kainji plant generated 965GWh while Jebba generated 2,657GWh, making a total of 3,623GWh with earned N3.699bn. In 2014, Kainji produced 735GWh and Jebba generated 2,432GWh to make 3,167GWh; they, however, earned N19.820bn.
For 2015, both plants produced 3,708GWh, with Kainji having 1,602GWh and Jebba having 2,106GWh, with which they earned N23.398bn. The plants’ output rose steeply to 5,464Gwh in 2016 as Kainji generated 2,425GWh and Jebba produced 3,038GWh. They doubled their revenue by earning N56.088bn in the year. How we are raising plants’ capacity After the takeover, officials of Mainstream said they completed the rehabilitation of three units 1G5, 1G6 and 1G12 with combined generating capacity of 346mw at the Kainji site.
“Statutory overhaul was not carried out on the generating units at Kainji for over 40 years of its existence, such that most of the units went out of operation service or de-rated over the years,” the management said.
Four other unavailable generating units: 1G7, 1G8, 1G9 and 1G10 of 320mw have been scheduled for rehabilitation, the COO said. At the Jebba plant, the only unavailable unit 2G6 with 96.4mw capacity is also scheduled for rehabilitation.
On its investments, the company said the contract process is ongoing for the Engineering, Procurement and Construction (EPC) to recover two units - Unit 1G7 in Kainji and Unit 2G6 in Jebba in the first phase of the recovery programme. It said the next phase would be to recover Units 1G8, 1G9 and 1G10 at Kainji plant.
The Jebba operation supervisor, Engr. John Onimisi who spoke on the plants’ efficiency said, “Since the takeover, we have been able to institute a maintenance culture with the same staff retained from the former PHCN. Things are done better now and the staff members are much more dedicated to their duties and responsibilities.”
Despite the constraint of utilisation, the total energy generated in the national grid, Mainstream said it would expand so that it could sell power to international customers, including Niger Republic where it already dispatches an average of 160mw daily through the Kainji hydro for the Federal Government.
Kainji plant has four open pits that could take four more generating units of 120mw each. Hence, its Capacity Expansion Programme (CEP) considers adding 480mw to the existing 760mw capacity of the plant. Mainstream said it would execute the project in two phases by installing 240mw in each phase. DisCos’ low power supply affects plants The technical experts at both plants said the transmission frequency stabilised at 50 hertz (Hz) to avoid system collapse and a nationwide blackout from the National Control Centre (NCC) of the Transmission Company of Nigeria (TCN).
However, because the GenCos produce more power now and the DisCos are taking less, the frequency often jumps high to 50.5Hz.
Giving the secret to the high generation during the rainy season, Mr Villegas said the water level reached peak between May and October during the white flood to fill up the 141.73 metre Kainji reservoir capacity and that triggered maximum energy generation.
At the weekend, the water level was at 141.67m, and to protect the dam structure, the spillway for Kainji was opened to discharge excess water. Jebba plant’s water level also rose to 102.9m, which was near the 103.15m maximum mark with the spillway to discharge the excess, it was observed.
Engr. Onimisi said more water level meant more capacity to produce electricity, but, “For a day, we could produce about 11,000 megawatts hour (MWh), but due to the ramp down caused by DisCos’ load rejection, we don’t go beyond 6,000MWh. We are losing about 40 per cent production at both plants from this constraint.”
To maintain optimal water level during the rainy and dry seasons, the Chief Operation Officer (COO), Mr Villegas said, “The new water level management system called the Inflow Forecast System (IFS) will help us maintain adequate water level during the black flood period (dry season) and the white flood period.
“We are training our staff at Kainji plant on that, and it will greatly enhance the efficiency of the two plants once that is in place. The process is costly and is being installed only in few hydro plants in the world,” he explained at Jebba.
With improvement and stability in the DisCos’ network, the over 6,000mw capacity of the GenCos, including those from the three hydro plants will be effectively used to go beyond the 4,500mw capacity at the DisCos’ ends.
However, if there are no immediate interventions at the downstream in spite of GenCos’ improvement, it is likely that the customers who pay hugely for this electricity may not still get adequate supply as outage is prevalent across many urban and rural areas of Nigeria.