Late on Thursday night Eskom announced that rotational power cuts would continue until at least 05:00 on Friday morning, when the situation would be "reviewed".
The utility terminated load shedding at 05:00, but said it would restart at 09:00.
The overnight cuts will give it time to marshal emergency resources, it said, which it hopes will limit load shedding in coming days.
Eskom said that unplanned breakdowns are currently above 12 500 MW, which amounts to more than a quarter of its nominal generation capacity.
While it did not say which power stations had been impacted by unplanned breakdowns, it specified that coal handling had not been affected by wet conditions in some arts of the country. If heavy rain persists, however, it could begin to impact coal handling and further decrease generation capacity,
The power utility recently said no load shedding was planned until March, although load shedding could be implemented if absolutely necessary, as Fin24 reported.