JOHANNESBURG - Eskom has implemented stage 3 power cuts from Friday at 2 p.m.
The power cuts will run until 5 am on Monday.
The power utility says the decision was taken after it lost 2,700 megawatts in the past 14 hours.
Unit 2 at the Koeberg power station was taken offline, and bad weather affected two units at the Kusile power station.
Eskom says higher levels of planned outages are expected in preparation for winter.