Eskom will implement Stage 2 load-shedding between 10:00 and midnight on Wednesday, and between 05:00 and midnight from Thursday to Sunday.
The power utility said the load-shedding was due to the breakdown of four generation units on Wednesday morning, which contributed to the capacity constraints.
"A generation unit each at the Kendal and Matimba, as well as two units at the Matla Power Station broke down [on Wednesday] morning. This reduced generation capacity by 2 400MW, adding to the ongoing capacity constraints. There has been a delay in returning to service a unit at Kusile Power Station, which is now expected to return to service tomorrow. We currently have 3 630MW on planned maintenance, while another 15 277MW of capacity is unavailable due to breakdowns," Eskom said in a statement.
"Eskom cautions the public that as the shortage of generation capacity persists, the system will continue to be constrained with an elevated risk of load-shedding over the coming weeks."