Eskom hopes to keep load-shedding at stage 2 during winter as SA marks 30 days of no planned power cuts

Eskom is hoping to keep load-shedding capped at stage 2 during winter as the utility marks a significant milestone of 30 days without power cuts, but the country is “not out of the woods” yet.

Eskom's new group CEO Dan Marokane, who started on March 1, led a briefing on the state of the grid and the power supply outlook over winter at Eskom's Megawatt Park offices on Friday.  

Marokane was joined by Eskom's heads of generation and distribution Bheki Nxumalo and Monde Bala and CFO Calib Cassim. 

Reflecting on performance last winter, Marokane said this remained “within the forecast frequency range” of stages 3 and 4 anticipated at the time.

He noted the frequency and intensity of load-shedding over the past year has declined and the utility spent 50% less on burning diesel during April 2024 compared with the same period last year. Eskom's energy availability factor (EAF) is at 61%.

Speaking about this year's forecast, he said: “For winter 2024 the likely scenario from our assumption is load-shedding will be maintained in stage 2 at most. In the extreme case where unreliability increases, that component may go occasionally [to] stage 5 but we think on the basis of what we see, the performance of the fleet, most [likely] load-shedding will stay in stage 2.

“This is on the back of a decrease in the baseline unreliability capacity of 1,000MW which is what we use for our baseline assumption. Over the winter period, work continues and we are targeting to reduce the unplanned losses by a further 1.7GW.”

This will be from a combination of 1.3GW partial load reduction driven by generation and a host of initiatives by the demand side, he said.

In this scenario, unplanned outages will hover at about 15,500MW with 50 days of load-shedding in total. Eskom also predicts spending R8.8bn on diesel during this period. In the best case scenario, load-shedding will be capped to five days at stage 1 with unplanned outages expected to be 14,000MW.

In the worst-case scenario, which will be if Eskom's outages exceed 17,000MW, the country will experience 103 days of load-shedding, mostly at stage 5. The utility will spend R16bn on diesel.

Recapping on last winter's performance, Marokane said unplanned losses averaged about 16.5GW between April and August while load-shedding ranged between stages 3 and 4, with a maximum of stage 6.

“What is really changing as we go into this season's forecast is the base level of unplanned capacity loss factor numbers is lower by 1,000MW and when you understand the capacity we have, it doesn't look like a big number, but when you understand the implications in levels of load-shedding, to be able to bank that capacity is an important aspect.

“How did we get there? When you look at the time period between last winter and now you can see the reduction in unplanned losses. A 9% drop [and] this is mostly coming from the priority stations that were targeted as focal points. We also had the benefit of the earlier return of the four Kusile units that were out.”

Marokane attributed the load-shedding milestone to a “culmination of interventions that started a year ago”.

“We wanted to make sure that moment does not go unnoticed. It is important that we build on it, that the confidence of our teams increases from that perspective and in that way we can move towards doing this as a daily routine,” he said.

Nxumalo focused on the utility's execution of the generation recovery plan which over the past year focused on monitoring the performance at Eskom's “flagship” power stations (Medupi, Lethabo, Matimba and Peaking) as well as at its problematic stations, which include Tutuka, Duvha, Majuba, Kendal and Koeberg.

Kusile once formed part of the latter group but has since been removed after the recovery of several units.

The recovery plan started in April last year and is being executed over two years, with a focus on a range of issues, including raising the EAF to 70% in 2025. The target for the one-year mark was 65% but Eskom fell short of it, according to board chairperson Mteto Nyathi.

Nxumalo said Medupi unit 4 was expected to return in September while Kusile unit 5 will go into operation in June. Koeberg unit 2 is expected back in September.

“Those are all big machines that when they come back will help us for the summer preparations,” he said.

On the demand management side, Bala said the utility was focused on reducing demand by an additional 382MW through four key areas.

“We've got 191MW on the supplemental demand response [and] we have introduced a concept called load-limiting where we targeted specifically the residential sector to come up with a scheme that says we don't have to load-shed.

“With that scheme we have achieved 150MW and the balance of that is made up of the energy efficiency and load management,” he said.

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