South Africa faces dark days

Eskom’s unplanned capacity loss factor has reached levels that the power utility warned would cause widespread load-shedding.

Last month, Eskom released its winter 2025 outlook, which provided guidance on the grid’s stability and expected load-shedding levels.

It said load-shedding is not expected if breakdowns, also known as the unplanned capacity loss factor (UCLF), remain below 13,000 MW.

It further warned that if outages increase to 15,000 MW, load-shedding would return and that South Africa faced a maximum of 21 days out of 153 days at Stage 2.

Bad news for South African households and businesses relying on Eskom power is that the unplanned capacity loss factor is exceeding 15,000 MW.

Between 13 and 19 June 2025, the average level of unplanned outages reached 15,076 MW, above the 15,000 MW level Eskom warned about.

It significantly exceeded last year’s figure for the same period by 3,144 MW and surpassed the base case estimate of 13,000 MW by 2,076 MW.

Eskom explained that this increase is primarily due to delays in restoring Medupi Unit 4, which is undergoing a long-term recovery project, and Tutuka Unit 1.

Unplanned outages stood at 29.23% for the financial year to date, which is 1.7 percentage points higher than the 27.51% during the same period last year.

Due to the higher-than-expected unplanned outages, the year-to-date energy availability factor (EAF) was 2.83 percentage points lower than last year at 58.25%.

To put the EAF in perspective, Eskom had a target of 70% EAF by March 2025 to ensure load-shedding was a thing of the past.

However, it missed this target by a wide margin, which is why South Africa faced load-shedding again this year.

The high unplanned outages also forced Eskom to burn a lot of diesel to run its open-cycle gas turbines (OCGTs) and avoid power cuts.

The year-to-date OCGT load factor stands at 11.73%, much higher than the 5.78% recorded during the same period last year.

Eskom spent approximately R4.51 billion on fuel for the OCGT fleet, generating 768.64GWh. This is higher than the 378.75GWh generated during the same period last year.

It stated that diesel usage is expected to decline as more units return to service following the completion of long-term repairs and maintenance activities.

Eskom added that, despite the high use of OCGTs, diesel expenditure remains within budget for the current financial year.

The charts below show Eskom’s unplanned capacity loss factor and how much the company spent on diesel.

Eskom unplanned capacity loss factor (UCLF) in MW

Eskom Diesel Spend in R billion