Following the breakdown of some of its power generation units over the weekend, the electricity system will remain "severely constrained" until at least Thursday, Eskom said.
In an update after at midday on Tuesday, Eskom said that these unplanned breakdowns, along with planned maintenance, meant that more than 12 500MW in power generation was offline by Monday evening.
Anything above 9 500MW means that Eskom has to resort to emergency power generation: open cycle gas turbines and pumped storage hydro electrical plants. These are very expensive ways of generating power, particularly gas turbines as they require large quantities of diesel. They can only be used for short periods before diesel and water reserves run out.
By Tuesday morning, the situation had improved to 11 500MW of capacity being offline.
"With the expected return to service of several units today and tomorrow, and with current diesel reserves, the probability of load shedding remain low for the week, but the system remains constraint until at least Thursday," Eskom said in a statement.
It said that any additional unplanned breakdowns, or shortage of diesel and pumped storage, could result in load shedding at short notice.
Last month, South Africans suffered five days of load shedding after outages at five units. Eskom also resorted to emergency power generation, but then its diesel stocks started running low, which forced it to shed power.
POWER ALERT 1— Eskom Hld SOC Ltd (@Eskom_SA) November 5, 2019
Date: 05 November 2019
The electricity system is severely constrained, but the probability of loadshedding is low.@News24 @IOL @ewnupdates @TimesLIVE @GCISMedia @SAfmnews @GovernmentZA pic.twitter.com/3a8wSOPoew