Eskom says its expenditure on diesel is within budget despite burning nearly R6bn in fuel to run its open cycle gas turbines (OCGT) in the first four months of the financial year.
The power utility on Friday said between April 1 and August 1, it spent R5.84bn on fuel for its OCGT plant, just over a third of the R17bn it spent in the 2024/25 financial year. For the whole of 2023/24 it spent almost R40bn.
“From April 1 to August 7 2025, diesel spend remains within the allocated budget. The winter outlook, published on May 5 2025, covering the period ending August 31, remains valid,” Eskom said.
It said, however, the use of the OCGT was not linear and was “driven by seasonal demand and when there are occasional system constraints, particularly during morning and evening peak periods”.
“Load-shedding will not be necessary if unplanned outages stay below 13,000MW. If outages rise to 15,000MW, load-shedding would be limited to a maximum of 21 days out of 153 days and restricted to stage 2.”
The utility said in the first week of August, the energy availability factor (EAF) ranged from 62%-70%, “reflecting the fleet’s growing stability and improved reliability”.
Headed by CEO Dan Marokane, Eskom said it planned to return to service 3,280MW of generation capacity ahead of the evening peak throughout this week, as a measure to further strengthen grid stability.
André Lourens, economist at the Minerals Council SA, said while reliance on OCGTs remained high, Eskom had managed to keep diesel expenditure within budget.
“Eskom’s ability to maintain supply is partly dependent on its continued use of OCGTs to manage peak demand,” he said.
While there had been an improvement in Eskom’s operational performance, Lourens said “this progress is tempered by setbacks in Eskom’s nuclear fleet. On July 15 2025, Eskom confirmed further delays in the return to service of Koeberg Unit 1 due to cracks found in the tubing of two of the three newly installed steam generators.”
“Additionally, Koeberg Unit 2 will need to shut down again before its nuclear operating licence expires on November 9 2025 to complete post-replacement testing — raising concerns about the integrity of its newly installed steam generators.”
Eskom, however, said: “The unit’s current operating licence remains valid until November 9 and a shutdown would only be necessary if the licence is not extended. Eskom has submitted the required documentation for long-term operation, which is currently under review by the National Nuclear Regulator. If approved, Unit 2 may continue operating until March 2026, as it has sufficient fuel to complete its current cycle.”
Correction: August 11 2025
This story has been updated to reflect that Eskom had only used about a third of its diesel budget in the reported period, rather than half. It also includes further comment from Eskom clarifying the status of Koeberg’s Unit 2.
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