While gas shortage was largely responsible for the poor electricity experienced in the country last year, power generation is now being hampered by frequency management occasioned by distribution companies’ load demand.
Line constraints, according to the latest data from the Federal Ministry of Power, Works and Housing, left 1,693.9 megawatts of the nation’s power generation capacity idle as of 6pm on Thursday, down from 1,904.5MW on Wednesday.
With gas constraints affecting 290MW, the unutilised electricity generation capacity in the country stood at 1,983.9MW on Thursday, compared to 2,314.5MW the previous day.
Plants affected by line constraints were given as Geregu I (161MW), Omotosho I (114MW), Olorunsogo I (152MW), Omotosho NIPP (120MW), Olorunsogo NIPP (170MW), Ihovbor I (244,2MW), Sapele NIPP (225MW), Odukpani NIPP (117MW), Afam VI (240MW) and Shiroro (150MW).
The nation generates the bulk of its electricity from gas-fired power plants, while output from hydro-power plants makes up about 30 per cent of total generation.
The total national power generation stood at 3,971.8MW as of 6am on Thursday, down from the peak of 5,074.7MW recorded on February 2, 2016.
Eight of the nation’s 26 power plants did not generate any megawatts of electricity on Thursday. They were Sapele I, Afam IV & V, Alaoji NIPP, Gbarain, Ibom Power, AES, ASCO and Rivers IPP.
Generation from Egbin, the nation’s biggest power station located in Lagos, stood at 387MW as of 6pm on Thursday, down from 1,085MW on March 15, 2016.
The Managing Director/Chief Executive Officer, Niger Delta Power Holding Company, Mr. Chiedu Ugbo, said the power plants built under the National Integrated Power Project scheme had suffered from load rejection by Discos.
He said in an interview with our correspondent recently, “All the NDPHC power plants in technical terms are available. For installed capacity, I think we are somewhere around 3,000 megawatts, but deliver far less than this figure.
“It’s not so much a function of gas this time; it is a function of Discos picking load, the so called load rejection. So, if Discos don’t pick load, it impacts on the grid stability. What I generate must be equal to what the consumer takes, provided the transmission is good. If the consumer doesn’t take what I generate, it falls back on transmission and that is the frequency challenge you often hear.”
According to him, transmission frequency must balance at 50 hertz, and it can go to 50.2Hz or around 49Hz but it mustn’t be beyond this range.
“And so if there is a lot of power in the system, it gets heated and trips off,” Ugbo said.
The nation’s power grid recorded a partial collapse on Wednesday, October 18, the third time this month. It has recorded 14 total collapses and nine partial ones so far this year.
The grid collapsed 29 times last year, the highest since 2011, as the quantum of spinning reserve aimed at forestalling such occurrence remained low.
In the whole of 2014 and 2015, the grid collapsed 13 and 10 times, respectively, with four partial collapses each.
The five power stations meant to provide spinning reserve did not have any available reserve on Thursday as of 6am, the data showed.
The power stations are Egbin, Delta, Olorunsogo II, Geregu II, and Omotosho II, with combined contracted reserve of 295MW.
Spinning reserve is the generation capacity that is online but unloaded and can respond within 10 minutes to compensate for generation or transmission outages.