State-owned power utility Eskom says the Energy Availability Factor (EAF) of its generation plants fluctuated consistently between 69% and 73% between September 5 and 11, with the month-to-date average currently at 71.64% and above the 70% mark.

During this period, planned maintenance increased, averaging 4 624 MW, as Eskom enters the summer period, the utility says.

Year-to-date, planned maintenance has averaged 5 243 MW, accounting for 11.17% of total generation capacity. This reflects a slight decrease from the previous week and a 0.7% rise compared to the same period in the prior year.

Unplanned losses from breakdowns remain significantly below the 10 000 MW threshold, recorded at 7 394 MW.

“This reflects sustained structural improvements in plant performance driven by the ongoing implementation of the Generation Recovery Plan.”

Additionally, the open-cycle gas turbines (OCGTs), or diesel generators, maintained a load factor of 0.001% for the second consecutive week. Diesel spend remained well under the allocated budget during the period from April 1 to September 11, Eskom says.

Further, between April 1 and September 11, the Unplanned Capability Loss Factor (UCLF), which reflects the percentage of generation capacity lost owing to unplanned outages, further decreased to 26.53%.

The UCLF showed a week-on-week improvement of about 0.4%, although it remains about 1.2% higher than the 25.38% recorded during the same period in the prior financial year, Eskom notes.

Additionally, to further strengthen grid stability, Eskom is planning to return 2 835 MW of generation capacity to service ahead of the evening peak on September 15 and throughout the coming week, it adds.

“The sustained technical improvements have ensured a reliable power system, meeting more than 97% of electricity demand since the beginning of the financial year. Only 26 hours of loadshedding were recorded between April 1 and September 11.

“This upward trend reflects growing stability and improved reliability across the generation fleet,” Eskom says.

Further, these figures exclude Kusile Unit 6, which has been contributing 720 MW to the national grid since March 23. Although not yet in commercial operation, the unit is expected to reach that milestone this month, it adds.

Meanwhile, the available generation capacity currently stands at 28 776 MW, while the electricity demand expected during the night of September 15 is 25 181 MW.

Over the past week, unplanned outages averaged 8 826 MW, which is significantly lower than the 10 915 MW recorded during the same period last year, and which represents a 2 089 MW year-on-year reduction in breakdowns.

Further, the year-to-date EAF increased to 61.8%, excluding the 720 MW contribution from Kusile Unit 6.

However, this figure is below the 63.61% recorded during the same period last year, mainly owing to a 1.2% year-to-date increase in unplanned maintenance and 0.7% year-to-date increase in planned maintenance compared with the previous year, Eskom says.

The year-to-date load factor for OCGTs has decreased to 7.45%, which reflects a 0.33% decrease compared with the preceding week.

However, this figure remains higher than the 4.30% recorded during the same period in the prior year.

From April 1 to September 11, Eskom spent about R5.9-billion on fuel for its OCGT plants, generating 1 000.91 GWh of electricity.

While there was no notable increase in expenditure over the past week, the electricity generated represents a significant rise compared with the 578.14 GWh produced during the same period in the prior financial year.