Eskom has implemented Stage 2 load shedding between 08:00 and 22:00 on Saturday.
The power utility's spokesperson Khulu Phasiwe says Eskom started the weekend on a poor footing, as generating units lost during the week have still not come back online.
He says earlier this week they lost a number of generating units because of technical faults, and many of those units are not back online yet.
On Thursday Phasiwe said many of Eskom's 27 power stations were experiencing faults.