Eskom said it was using emergency resources in order to meet Thursday’s electricity demand, saying its power system is constrained.
The troubled utility said it had experienced unplanned outages over the past few days.
The parastatal said it ran open cycle gas turbines on Wednesday night in order to pump water into the dams at its storage schemes.
It said it was waiting for some coal generation units to come back online, but the risk of load shedding was low.
Meanwhile, an Eskom employee will face an internal disciplinary hearing after his arrest for allegedly stealing copper worth over R280,000.
He was arrested with another suspect in the east of Johannesburg on Tuesday.
The pair is currently behind bars and will appear in a local court on charges of sabotage and theft.
Eskom’s Motlhabane Ramashi said: “It is a true inconvenience in providing a reliable supply to our customers. We lose supply and we lose money.”