Eskom says it will not be able to suspend stage 2 load shedding during the afternoon rush hour on Wednesday, as it is still in the process of replenishing its emergency reserves of diesel and water.
Stage 2 load shedding is set to continue until Thursday morning at 6am, when "the situation will be reviewed".
Suspending power cuts in the morning between 6am and 9am and in the afternoon between 4pm and 6pm is a new initiative intended to lessen the impact of load shedding on commuters. It was announced on Monday.
But the programme is contingent on the availability of spare generating capacity. "The significantly higher demand has meant that the headroom available to accommodate peak traffic is not available," said Eskom in a statement on Tuesday evening. In a subsequent note it said it had no capacity to suspend power cuts during the afternoon.
The utility said it had manage to decrease unplanned outages to 9 817MW on Wednesday morning, the lowest figure in weeks, and just slighlt above its goal of 9 500MW.
Eskom's CEO Andre de Ruyter, meanwhile, said on Tuesday that for the next 18 months there would be an increased likelihood of load shedding as Eskom undertakes delayed maintenance at its power stations.