Eskom declared an emergency on Thursday morning and warned of possible power cuts. Spokesperson Andrew Etzinger said seven days of heavy rain had left coal stocks wet.
"We have asked our large industrial customers, to reduce their consumption by 10%, but it appears this will not be enough," Etzinger said. "Rotational load shedding is a strong possibility."
Eskom appealed to the public to reduce their electricity usage to help ease the demand for power.
Meanwhile, the company urged Free State residents on Tuesday to stop wasting electricity.
"Switch off at any time, and not just at peak times," Moeketsi Mathosa, an Eskom Free State network manager, said on Tuesday.
'Less is more'
As winter approached, people should remember "less is more" with electricity, he told journalists in Bloemfontein. "The less electricity people use, the more electricity will be available to go around."
Eskom Free State general manager Lindi Mthombeni confirmed the national electricity system would be tight this winter. She urged residents not to wait for alert messages flashing on their television screens before saving power.
"We must do something before we get there [alert warnings]."
Mthombeni said maintenance of the national system would continue through winter, and that it was critical all Eskom customers reduce their electricity consumption by 10% ahead of winter.
Eskom has 233 115 customers in the Free State, more than 90% of whom are residential customers. – Sapa