Eskom announced that it will implement Stage 1 loadshedding between 5 pm and 10 pm on Monday.
The power utility said the loadshedding is due to the loss of two generation units at Kusile, and one each at Kendal and Tutuka Power Stations.
Eskom said these constraints have been exacerbated by delays in returning a unit each at Kusile, Duvha and Malta Power Stations.
Breakdowns currently total 15 570MW of capacity, while planned maintenance is 1 273MW of capacity.
Eskom said the likelihood of loadshedding is high for the rest of the week as the power system remains constrained and vulnerable and Eskom will communicate promptly should there be any changes.
Eskom said these capacity constraints will continue for the foreseeable future and all South Africans are urged to reduce their use of electricity, particularly between 5 pm and 10 pm, when the winter demand is the highest.