Johannesburg - Eskom urged South Africans on Thursday to save electricity to reduce demand on the grid.
"We urge all South Africans to partner with us to save 10% of their electricity usage, especially during peak periods, from 17:00 to 21:00," Eskom said in a system status bulletin.
"This will make it significantly easier to manage the power system during this challenging time, while also enabling us to do planned maintenance to ensure the reliability of our plant."
As of November 1, the capacity available to meet the day's evening peak demand was 33 088 MW (including open cycle gas turbines) while demand was forecast at 31 648 MW.
Planned maintenance stood at 3 956 MW and unplanned outages were at 5 026 MW.
Peak demand for the rest of this week was forecast at 30 215 MW on Friday; 28 838 MW on Saturday and 29 074 MW on Sunday.
Eskom said it continued to make progress with its programme of planned maintenance "but the system remains tight".