Johannesburg - The risk of rotational load shedding remained high for Tuesday morning, power utility Eskom said.
"The probability of rotational load shedding remains high for [Tuesday] as a result of a shortage of capacity due to a number of generating units still out of service due to breakdowns. The applicable stage of load shedding will be communicated early [on Tuesday] morning," Eskom said on Monday night.
"Customers are reminded to treat all electrical points as live during load shedding."
Eskom implemented Stage 4 load shedding on Monday, which was terminated at 10.11pm.
Stage 1 requires 1000MW, Stage 2 requires 2000MW, Stage 3 requires 3000MW and Stage 4 calls for 4000MW to be rotationally load shed nationally at a given period, the power utility said.
"Load shedding is conducted rotationally as a measure of last resort to protect the power system. We continue to appeal to residents and businesses to use electricity sparingly during this period. Please switch off geysers as well as all non-essential lighting and electrical appliances to assist in reducing demand."
On Monday, the Eskom board said the power utility would urgently embark on an in-depth audit of its systems. The board had a meeting with its executive management and the Public Enterprises Minister Pravin Gordhan.
The board called an urgent meeting with its management and Gordhan following the unexpected introduction of power cuts at 1 pm on Monday.
"The initial schedule was to implement stage 2 load shedding on Monday as a result of generation shortages over the weekend and constraints in diesel supply. However, earlier today, Eskom implemented stage 4 load shedding," the power utility said in a statement.
The board, which was provided with a detailed analysis about the breakdowns in its new build programme and the older power stations, after the meeting assured South Africans of a systems and operations update within the next 24 hours.
The immediate cause of the problem, as well as challenges of the new build and old power stations, were under discussion in the meeting that took six hours.
The board said it will undertake an "in-depth audit of the entire system to ensure that every technical problem is understood at a granular level and to avoid unexpected crises as seen today".
“We remain uncomfortable about the stability of the generating system but will keep the country informed of our progress over the next few days in providing better assurance about electricity supply," chairperson of the board, Jabu Mabuza, said.
But by Monday night, "four units had returned to service and it is expected that the remaining three will be back to service by tomorrow morning", the power utility said.