Eskom reports that, as of Friday, the weekly average breakdowns at its power stations was 13,628 MW. For nine weeks in a row, average breakdowns have exceeded the power utility’s 13,000 MW “safe” threshold.

While breakdowns were lower this week, the state-owned power utility reported a significant increase in open-cycle gas turbine (OCGT) usage.

Despite the high unplanned outages and icy weather conditions in parts of South Africa, Eskom said the power system remained stable and continues to show resilience in meeting the winter demand.

“While occasional system constraints do arise, they are effectively managed, with sufficient emergency reserves available and strategically deployed during morning and evening peak periods,” it said.

Eskom said its winter outlook, published on 5 May 2025, remains valid. The winter outlook stated that load-shedding would not be necessary if unplanned outages stay below 13,000 MW.

However, if outages rise to 15,000 MW, stage 2 load-shedding would be probable, albeit limited to a maximum of 21 days out of 153 days.

Eskom said breakdowns stood at 13,380 MW on Friday, with an available generation capacity of 30,195 MW, which was sufficient to meet the evening demand of 28,346 MW.

The power utility said its weekly average unplanned outages were 1,525 MW higher than the same period last year. Curiously, it did not report its year-to-date average unplanned outages.

“To further enhance grid stability, Eskom plans to return a total of 3,470 MW of generation capacity to service ahead of the evening peak on Monday, 14 July 2025,” it stated.

In recent weeks, Eskom has reduced the amount of scheduled maintenance conducted on power plants to ensure sufficient capacity to meet demand.

During the week of 4 to 10 July 2025, planned maintenance averaged 4,418 MW. The Energy Availability Factor (EAF) ranged from 60% to 62%, with a month-to-date average decreasing to 62.07%.

EAF is a measure of generating capacity available from Eskom power plants relative to their installed capacity. It takes breakdowns and maintenance into account.

The Unplanned Capability Loss Factor (UCLF), which measures the capacity lost due to breakdowns, was 29.44% for the financial year to date (1 April to 10 July 2025). This was higher than the 27.03% UCLF during the same period last year.

Eskom diesel usage

Another important indicator of whether there is a danger of load-shedding is Eskom’s open-cycle gas turbine (OCGT) load factor.

OCGTs are diesel-powered stations that Eskom uses to help balance the grid and as emergency generation units to keep load-shedding at bay.

The year-to-date load factor for OCGTs increased slightly to 10.78%. This figure remains higher than the 5.87% recorded during the same period last year. The weekly OCGT load factor increased from 2.41% to 11.92%.

“Although diesel usage is within budget, it is expected to decline as more units return to service, increasing available generation capacity,” Eskom said.

Year-to-date, Eskom spent approximately R5.26 billion on fuel for the OCGT fleet, generating 892.42 GWh. This is higher than the 485.39 GWh generated during the same period last year.

Eskom reported that its year-to-date EAF has increased to 58.83% and remains lower than the 61.74% recorded during the same period last year, primarily due to an increase in breakdowns.