Electricity generation companies (GenCos) in Nigeria, have again raised an alarm over the epileptic performance of the nation’s national grid.
Section 15.3.1 of the national grid code states that the Frequency shall be maintained at 50 Hz. This means that the National Control Centre, overseen by the Transmission Company of Nigeria (TCN), would control the System Frequency within a narrow operating band of +/- 0.5 per cent (49.75 – 50.25 Hz) from 50 Hz, at least 97% of the time during Normal Conditions.
Besides, under System Stress, the Frequency Control on the Power System is expected to be exercised within the limits of 50 Hz +/- 2.5 per cent (48.75 – 51.25 Hz).
But the GenCos told The Guardian that the grid performance from 2015 till date has not met extant regulations.
Indeed, the Executive Secretary, the Association of Power Generation Companies (APGC), Joy Ogaji, said GenCos have been bearing the brunt of the challenge in addition to all other market risks.
“Frequency Deviations out of tolerable zones are not only damaging the GenCos units but are also increasing considerably the maintenance costs close to three times the normal maintenance costs. The intervals between maintenance will decrease and will need longer time for completion with a greater downtime of the generating units; needing extra investment to increase the power plant capacity,” Ogaji said.
However, TCN had said the Nigerian Grid Code Frequency Standard is 49.75Hz and 50.25Hz, while the WAPP Frequency standard is 49.80Hz and 50.20Hz.
It also noted that the National Grid achieved frequency control of between 49.80Hz and 50.20Hz for 64.47 per cent of the time and frequency control between 49.75Hz and 50.25Hz for 85.55 per cent between December 27, 2018 and January 12, 2019.
“The frequency control is the best ever achieved in the history of Nigeria and is also the best in West Africa as at today. The frequency control achieved from January 8-12, 2019, is the best so far by any power utility in West Africa,” a spokesperson for TCN, Ndidi Mba said.
TCN explained that subsequent collapse of the National Grid, as was the case last week, was inevitable due to extant challenges, including lack of commensurate investment by the DisCos.
Meanwhile, the Association of Nigerian Electricity Distributors (ANED), the umbrella body for distribution companies (DisCos), had last year decried the repeated system collapse, stating that TCN’s analogue system caused over 100 electricity grid collapses since the privatisation of the power sector in 2013.
Stating that transmission networks constitute the vital arteries of the entire power value chain, indicating that the industry growth is contingent to development of a robust and a non-collapsible transmission to acceptable technical limits has exposed generator units to perform beyond factory rated capability.
Ogaji said the inability of the system operator to maintain grid stability leads to huge fatigue damage and higher costs. “In addition, operation of these gas turbines far away from their baseloads implies a reduction in efficiency or in other words an increase in consumption of gas by as much as 15-20 per cent, a cost not recognised by Nigerian Bulk Electricity Trading Plc. nor captured in the Multi-Year Tariff Order (MYTO).
“All electrical appliances (thermal and hydro plants) have set conditions under which they function at optimal levels and are designed to operate optimally and efficiently at baseload.”
As a result, GenCos can no longer sustain these costs alone given the level of remittance in the market, which barely covers the operating cost, she noted/
“The only sane thing to do to save the sector from collapsing is for GenCos to adhere to Section 12.6.6 of the Grid code by allowing the generator to disconnect the Generating Unit for reasons of safety of personnel, Apparatus, and/or Plant,” Ogaji said.
