Eskom on Wednesday said that stage 2 load-shedding would continue on Thursday.
In a statement, the power utility said the electricity system was "severely constrained".
"While Eskom today and yesterday [Wednesday and Tuesday] successfully returned three generation units to service, a further three units tripped, two of which have returned," the statement read.
The rotational power cuts are expected to continue for the rest of the week, Eskom warned.
"As the aged generation infrastructure is unreliable and volatile, this constrained power system is expected to persist for the rest of the week, particularly as the cold front hits."
