South African power utility Eskom said it would implement “Stage 2” scheduled power cuts from 1600 until midnight local time (1400 to 2200 GMT) on Wednesday and Thursday due to a shortage of generation capacity.
Eskom said in a statement that there had been a delay returning several generation units to service, while others had broken down.
The struggling state-owned company suspended scheduled electricity outages 11 days ago, following several weeks of regular power cuts that prompted public anger and hampered businesses.
Eskom has an ageing power station fleet comprised mainly of coal plants that are highly prone to faults.
Government efforts to add additional capacity have been slow, and this year a record among of electricity is set to be cut from the grid.