Eskom said it was extending scheduled power cuts until Saturday because of a shortage of generation capacity.
Eskom regularly enforces outages over faults at its coal-fired power stations that hold back economic growth in Africa’s most industrialised nation.
In a statement, Eskom said it would cut up to 2 000 megawatts from the national grid in what it calls “Stage 2 load shedding”, from 9 a.m. (0700 GMT) on Tuesday until 5 a.m. (0300 GMT) on Saturday.
“While Eskom teams have successfully returned a unit each at the Kusile, Matimba and Arnot power stations during the early hours of this morning, further delays in returning other units to service have exacerbated the capacity constraints,” the company said in Tuesday’s statement.
On Sunday it had warned of power cuts planned for the nights of Monday and Tuesday.