Eskom breakdowns exceed load-shedding threshold

Eskom has reported that breakdowns at its power plants were at 15,137 MW on Friday afternoon, over the threshold at which it previously warned that stage 2 load-shedding may be necessary.

Despite the high unplanned outages and icy weather conditions in parts of South Africa, Eskom said available generation capacity was enough to meet peak demand.

Eskom said it had 30,703 MW of available capacity, plus an additional 720 MW from Kusile Unit 6, allowing it to meet the expected peak evening demand of 28,810 MW.

It explained that although Kusile Unit 6 was not yet in commercial operation, it had been contributing to the grid since 23 March 2025.

Eskom said its winter outlook remains valid. It indicated that load-shedding would not be necessary if unplanned outages stay below 13,000 MW.

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

In addition to breakdowns exceeding the 15,000 MW threshold on Friday afternoon, Eskom’s unplanned outages averaged 14,696 MW over the last week, well above the 13,000 MW warning level.

However, Eskom said its power system remains stable and continues to demonstrate resilience in response to increased electricity demand.

“While occasional system constraints are experienced and managed, sufficient emergency reserves are in place and are strategically deployed to support demand during morning and evening peak periods,” Eskom said.

“To further enhance grid stability, Eskom plans to return a total of 2,450 MW of generation capacity to service ahead of the evening peak on Monday, 30 June 2025.”

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 20–26 June, planned maintenance averaged 3,789 MW. The Energy Availability Factor (EAF) ranged from 60% to 64%, with a month-to-date average of 60.61%.

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 29.36% for the financial year to date (1 April to 26 June 2025).

This was higher than the 27.25% UCLF during the same period last year, which Eskom attributed to delays in returning 995 MW of capacity from planned maintenance, including 800 MW from Medupi Unit 4 since 1 June 2025.

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 declined slightly to 11.37%. However, this figure remains higher than the 6.21% recorded during the same period last year. The weekly OCGT load factor declined from 9.12% to 7.25%.

“Diesel usage is expected to decline as more units return to service from long-term repairs and maintenance activities are reduced, increasing available generation capacity,” Eskom assured.

Year-to-date, Eskom spent approximately R4.76 billion on fuel for the OCGT fleet. Eskom said its diesel expenditure was still within budget for the current financial year.

OCGTs have generated 810.24GWh during the current financial year. This is higher than the 442.65GWh generated during the same period last year.

Eskom said its year-to-date EAF has shown an upward trend, reaching 58.47%. However, this is still lower than the 61.19% recorded during the same period last year, primarily due to an increase in breakdowns.