Eskom is implementing stage one power cuts on Saturday, it said.
The rolling blackouts started at 8am and would continue until 10pm.
The power utility said it had initially planned to implement stage two power cuts but some generating units that had to undergo maintenance had come back online overnight.
This meant that fewer people would be impacted by power cuts in the country at a time.
Stage one allows for up to 1000MW of the national load to be cut, stage two for up to 2000MW, and stage three for up to 4000MW.
Stage one rolling power cuts would also be implemented on Sunday.
“However, any unexpected changes on the power system could lead to a change in the load shedding stage,” Eskom said. SAPA