Eskom says despite some units having returned to service on Friday evening, Stage 3 load shedding will be implemented from 09:00 on Saturday until 05:00 on Monday.
This, to accommodate the shortage of capacity and to replenish emergency reserves.
Eskom introduced Stage 2 load shedding from Friday evening, a day after President Cyril Ramaphosa announced new energy measures during his State-of-the-Nation address on Thursday.
The embattled power utility said that by 10 pm on Friday, it had lost 11 400 MW as a result of breakdowns.
A further 7 000 MW was lost due to scheduled maintenance.
Eskom says diesel reserves for open-cycle gas turbines and water reserves for the hydro-pumped storage schemes were utilized extensively on Friday and overnight to supplement the shortage of capacity.
It also reminded weary South Africans that rolling blackouts will be around for the next 18 months as critical maintenance continues.
