Eskom has announced that it will implement Stage 2 blackouts from 11am on Wednesday.
The blackouts will continue until Monday morning.
Eskom says this is after further breakdowns of generating units last night.
The power utility says that units at Kusile and Kendal power stations tripped, contributing to the current supply constraints.
Eskom is appealing to citizens to reduce their use of electricity and switch off any non-essential items.
More details on eNCA