The power utility said that if the demand for electricity was not reduced, it may need to implement rotational power cuts.

The constrained conditions means possible load shedding between 5.30pm and 6.30pm.

Eskom said it had enough generating capacity to meet daytime demand, but during the evening peak the electricity demand increased to 36 000 megawatts.

The increase is predominantly due to the use of space heating, geysers and cooking that takes place during this time.

Consumers are urged to delay using electric heaters and ensure that geysers, pool pumps and non-essential lights are switched off during the evening peak.

Eskom has stressed that it will utilise all necessary emergency resources at its disposal to keep the lights on, but should the demand not decrease, load reduction will be implemented as a measure of last resort to protect the national grid from a total shutdown.