Power utility Eskom needs people to cut their power usage by 10 percent to keep the country's electricity supply running, it said on Thursday.
"We urge all South Africans to partner with us to keep the lights on," it said in a statement.
"If all our customers can save 10 percent off their electricity usage, this will make it significantly easier to manage the power system during this challenging time."
Eskom previously warned that the power system this year would be "particularly challenging" and said it would issue news bulletins on the state of supply.
Available capacity to meet Thursday's peak demand was 34,618 megawatts (MW) while demand was forecast at 31,168 MW.
Current planned maintenance stood at 4461 MW with unplanned outages at 3678 MW.
On Wednesday, peak demand of 31,108 MW was met by available capacity of 32,601 MW.
On Monday, peak demand of 30,282 MW was met by available capacity of 30,742 MW.
Peak demand for the rest of this week was forecast at 31,303 MW on Friday, 29,762 MW on Saturday and 29,205 MW on Sunday.
The performance of the system had improved since Monday, but during the course of Wednesday, the supply from Cahora Bassa, in Mozambique (1500 MW), was lost for approximately two hours, Eskom said.
Although supply was restored, the system remained constrained and customers were reminded to use electricity as efficiently as possible. (Sapa)
