How GenCos gas cuts caused blackouts

The start of 2018 wasn’t pleasant for the country as the 5,222 megawatts (MW) peak electricity generated in December 2017 was reduced to 0mw over shortage of gas to power plants, and subsequent collapse of the national grid. In this piece, the Daily Trust analyses the causes and the attempts by the federal government to […]

The start of 2018 wasn’t pleasant for the country as the 5,222 megawatts (MW) peak electricity generated in December 2017 was reduced to 0mw over shortage of gas to power plants, and subsequent collapse of the national grid. In this piece, the Daily Trust analyses the causes and the attempts by the federal government to resolve the constraint.

The Transmission Company of Nigeria (TCN) on January 2, 2018 announced that a fire incident on the gas pipeline supplying six Generation Companies (GenCos) in the western part of Nigeria triggered a sudden collapse of the grid.

The grid was restored afterwards but the six GenCos had their gas supply cut off and had to shut down. The GenCos’ operational output of 1,143MW as at when the fire incident occurred was lost.

Lagos and other states in the West had their electricity load allocation cut down across about three Distribution Companies (DisCos). Electricity customers in the axis said they observed a dip in the power supply to their installations and had cried out for federal government’s immediate intervention.

The Nigerian National Petroleum Corporation (NNPC) said the incident was due to a bush fire that affected the Escravos Lagos Pipeline System (ELPS) around Okada in Edo State.   

The Federal Ministry of Power, Works and Housing in a statement said the incident led to the loss of 3,182 MW of electricity across the six affected GenCos. 

The affected GenCos include 1,320MW Egbin GenCo and 60MW Paras GenCo in Lagos State; 676MW Olorunsogo NIPP GenCo and 338MW Olorunsogo GenCo in Ogun State. The others are 450MW Omotosho NIPP GenCo and 338MW Omotosho GenCo in Ondo State.

The Nigerian Gas Processing and Transportation Company Ltd (NGPTC) had to shut down the pipeline supplying gas to the plants to avert further inferno due to the gas product being conveyed, it said.

“The sudden loss of generation due to interruption in gas supply from these stations caused the national transmission grid to trip off around 8:00pm January 2, 2018,” the ministry admitted.

However officials of TCN, which controls the grid, said along with some other GenCos they worked to restore operation of the national grid after which the hydropower GenCos and other unaffected GenCos will increase production to minimize the impact of the loss.

The ministry had appealed to electricity customers to be patient while it overcomes the temporary setback as it waited for the restoration of the pipeline.

Daily Trust confirmed that another system collapse occurred on Wednesday, less than 24 hours after the initial incident this year.  

The spokesperson of TCN, Mrs Ndidi Mbah, said the second electricity system collapse occurred in the afternoon after the Odukpani-Ikot Ekpene 330 kilovolt (KV) line transmission line tripped off and stopped power generation from Odukpani Generation Company (GenCo) near Calabar in Cross River State.

Daily Trust reports that the two system collapses occurred at less than 24 hours interval. Independent data obtained from the Nigeria Electricity System Operator (NSO) shows that the peak generation of electricity was at 4,710MW on Tuesday being the first day of work in 2018, before the system collapsed after the frequency rose to a high 50.75 Hertz (Hz). 

Officials at the transmission section of the power sector said the national electricity grid would have withstood the Odukpani GenCo trip off if generation along Western region was available.

As a result of the intermittent collapse, TCN in a statement said Lagos State and other areas in the western region may experience cut in electricity supply so that the power line to the region could carry less energy load to avoid collapsing the electricity grid again.

“It would not be safe to put higher loads on the Lagos-Benin and Lagos-Osogbo 330kV lines because of its impact on the Grid stability. A 330kV line carrying her load could trip and cause system collapse. Therefore TCN may not carry enough load to Lagos,” the company said in the statement.

While the collapsed caused a dip of the national grid to 0.50MW, on Tuesday, the second collapse occurred Wednesday afternoon when peak generation was improving at 3,906MW. The power system crashed to 51MW before it was restored Wednesday night, it was learnt.

As at that period, TCN said the Nigeria Gas Company (NGC) had indicated that a contractor was mobilised to reconstruct the affected segment of the Western Gas Pipeline within 24 hours, so that gas supply to Omotosho, Egbin, and Olorunsogo I and II GenCos could be restored.

However, the pipeline was not fixed within the 24 hours but lasted till last Sunday, our reporter gathered. By Monday, the Minister of Power, Works and Housing, Mr Babatunde Fashola announced that the pipeline had been restored and that gas supply would subsequently be resorted to the affected GenCos.

Fashola, who spoke at the 23rd power sector meeting in Lafia, Nasarawa State, said the pipeline was restored on Sunday, which was about six days after the incident occurred.

He said with the restoration, the affected power plants including Olorunsogo and Omotosho GenCos had started getting gas and would ramp up generation in few days and the grid would bounce back to what it was before the fire incident.

Fashola said: “I am happy to inform Nigerians that as at last night (Sunday), the Nigerian National Petroleum Corporation (NNPC) informed us that repair have been completed. We thank and commend them for their response. What remains is to test the lines and restore pressure and supply to the GenCos.”

Same pipeline in fresh explosion – NNPC

Ten days after the ELPS was burnt by bush fire and restored on Sunday, NNPC on Thursday reported that the same pipeline has been ruptured again by an explosion.

A statement by its spokesman, Ndu Ughamadu, said the fresh incidence occurred along Egbokodo-Omadino, in Warri South Local Government Area of Delta State. 

NNPC said its Group Managing Director, Dr. Maikanti Baru, has directed that repair works should be executed immediately on the pipeline.

The GMD further directed that gas supply from other sources like Oben, Oredo, Sapele, Ughelli and Utorogu be stepped up to augment any shortfalls as repair works have commenced on the pipeline.

The Escravos pipeline supplies gas to power plants, in addition to feeding the West Africa Gas Pipeline System (WAGPS). 

The new incident will still cause a hitch to the national grid, with attendant power outages until gas supply to the GenCos around the western region which feed from the pipeline is normalised, Daily Trust observed.

The latest data on electricity generation obtained on Thursday from the NSO shows that the national grid bounced back to 4,623MW peak electricity generation on Wednesday. This was about two days after Fashola announced the restoration of gas supply to the six GenCos affected.

The peak generation as at Thursday morning stood at 4,372, which was a far improvement from the 3,600MW attained the previous week when the first pipeline fire occurred.

The latest 4,372MW peak generation was recorded earlier before NNPC announced the fresh explosion to the pipeline.

Records were not immediately available on if the same six GenCos were affected and would be shutting down immediately.