Eskom says it does not plan to implement load-shedding on Tuesday as some of its generation units have returned to service.

"Emergency reserves are at adequate levels," said the power utility in a statement on Monday evening.

"However, the generation plant remains unreliable and unpredictable, and the possibility remains that load-shedding may be implemented at short notice, should there be major changes in the performance of the  generation system."

It said unplanned outages or breakdowns were at 11,372MW at 4pm on Monday, while planned maintenance was 4,737MW.

"Eskom reminds South Africans that there is a possibility of increased load-shedding over the next 18 months as we are conducting critical maintenance to restore the ageing plant to good health," it added, urging customers to use electricity sparingly.