Eskom warned that there is a high risk of stage 1 rotational load-shedding from 5pm to 10pm on Thursday as a result of a "shortage of capacity" due to the loss of generating units at some of its power stations.

Stage 1 allows for up to 1,000MW of the national load to be shed to prevent the collapse of the power system country-wide.

Eskom said on Thursday the winter plan it recently shared with the public indicated that the power utility expected to implement 26 days of stage 1 load-shedding during the winter period, depending on the level of unplanned breakdowns.

"Based on the winter plan, Eskom has successfully managed to go through five days without load-shedding, where stage 1 load-shedding would have been implemented," Eskom said in a statement.

Eskom asked residents and businesses to use electricity sparingly to beat the winter peak in demand.

"By rallying together we can contribute to a saving of up to 5,000MW, which is equivalent of one unit at a power station. Please switch off geysers as well as all non-essential lighting and electricity appliances to assist in reducing demand."