While the electricity system is severely constrained, there is a low probability for load shedding this week, Eskom said on Tuesday.
"Since the past weekend, plant performance has deteriorated with unplanned breakdowns reaching a high of 12 500MW before reducing to approximately 11 500MW as at 10am this morning. Eskom is currently using emergency resources, being diesel and pumped water storage to keep the lights on," said the power utility.
While Eskom is using emergency resources, the probability for load shedding is low given the expected return to service of several units.
"With the expected return to service of several units today and tomorrow, and with current diesel reserves, the probability of load shedding remains low for the week, but the system remains constrained until at least Thursday."
Eskom reminded its customers that any unexpected shift, such as additional unplanned breakdowns or the unavailability of diesel or pumped water storage reserves could result in load shedding at short notice.
The utility's Summer Plan which was announced in September said unplanned breakdowns above 9 500MW require the use of emergency resources at a high rate (diesel and pumped water storage generators).
Unplanned breakdowns also increase the probability of load shedding if the supply constraints are sustained for a long duration.
"Our summer maintenance programme is underway, and technical teams are working tirelessly to keep to schedule and bring back generating units from planned and unplanned maintenance."
The utility appealed to residents and businesses to use electricity sparingly.
"Please switch off geysers as well as all non-essential lighting and electricity appliances to assist in reducing demand," it said.