Absence of rolling blackouts not due to greater use of diesel — CEO
The winter system outlook presented by Eskom on Friday is the clearest indication yet the state-owned power utility might be turning a corner.
After achieving 32-days of no load-shedding, both the Eskom executive and the minister of electricity Kgosientsho Ramokgopa have assured the country that the absence of rotational power cuts was not linked to an election ploy to garner more support for the ANC.
“The generation performance we are seeing now is not from burning more diesel, it is emerging from the maintenance we have been doing,” Eskom CEO Dan Marokane said on Friday.
Eskom was not “overusing” diesel to keep the lights on, Eskom’s head of generation Bheki Nxumalo said.
In a separate media briefing last week Ramokgopa said Eskom’s performance in the past four weeks was not because it was burning more diesel to run the open-cycle gas turbines (OCGT).
“Some are saying Eskom is burning diesel to improve [the ANC’s] election prospects. This is one of the falsehoods being pedalled.”
According to Ramokgopa, the OCGT utilisation rate had decreased this year. Since the beginning of April, while loadshedding has been suspended, Eskom has spent R1.4bn on diesel to run its emergency diesel-power generators compared with R3.1bn in April 2023.
According to data published by Eskom, the energy generated by diesel-powered OCGTs has decreased significantly in April. By Sunday the OCGTs had generated 198 gigawatt hours of energy compared with 470GWh in April 2023.
Given the improvement in generation performance, contributions from Eskom’s demandside management programme and more renewable energy being generated, the utility was expecting less load-shedding during the winter period compared with 2023.
Marokane said the utility “anticipates to maintain loadshedding to no more than stage 2” between April and August.
Eskom has adjusted the expected generation capacity to be unavailable due to breakdowns by 1,000MW since last year. The base case for winter 2024 now pins breakdowns at a peak of 14,000MW (compared with 15,000MW last year). Under this scenario Eskom will have to implement only stage 1 load-shedding, and this only on five days until end-August.
Marokane said this was indicative of the improvement to the generation fleet.
The worst-case scenario sees load-shedding going up to stage 5, but no higher, during winter.
The most likely scenario was that breakdowns would be maintained at below 15,500MW. This would result in a maximum of 50 days of load-shedding between April and August at a maximum level of stage 2.
The worst-case scenario suggested unplanned breakdowns of 17,000MW (compared with 18,000MW last year) with about 103 days of load-shedding until the end of August at a maximum level of stage 5.
The worst-case scenario for winter in 2023 provided for load-shedding to be implemented on 153 days with a maximum level of stage 8 — this, however, failed to materialise.
“Between April 2023 and March 2024, the reliability of the power plants improved on the back of the generation recovery plan. We saw a year-on-year improvement of 9% in unplanned losses and a 19% decline in unit trips — the latter is very important because it deals with the reliability of the fleet,” said Marokane.
Eskom chair Mteto Nyati said though Eskom had failed to meet the energy availability factor (EAF) — a measure of total electricity generation output as a share of total installed generation capacity — target of 65% that was set by the board for endMarch 2024 in the generation recovery plan, performance in April showed that they were moving towards achieving the 70% target for end-March 2025.
The EAF for April was sitting at 61% compared with 54.5% in March.
Marokane said that while Eskom was “not out of the woods yet” it was encouraging to see the generation performance trend move in the right direction, given the investment that had gone into implementing the generation recovery plan.