Johannesburg - Eskom implemented stage two rotational load shedding from 8am on Sunday morning and it is expected to continue to 10pm, the state-owned power utility said.
"In our latest update [on Saturday], we communicated that due to the high unavailability of plant Eskom was unable to build the necessary reserves resulting in high probability of stage two rotational load shedding from [10am on Sunday morning], Eskom said in a statement.
"However, due to a further shortage of generation as a result of units that have not returned to service as expected, stage two rotational load shedding [was] implemented from [8am] and is likely to continue until [10pm]. Eskom would like to sincerely apologise for the inconvenience and uncertainty caused by this."
Generation plant continued to be out on planned maintenance (about 5000 MW) and there was a higher than expected number of units (currently at about 10 000 MW) on unplanned maintenance due to technical faults.
Cahora Bassa hydropower plant was still supplying 700 MW less to the grid as a result of a damaged transmission line which occurred late on Wednesday. Over and above these problems, Eskom was experiencing low diesel reserves due to the continued pressure on the national grid resulting in excessive usage of open-cycle gas turbines (OCGTs).