Johannesburg - Eskom on Monday urged South Africans to save at least 10% of their electricity usage during peak hours.
"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," the power utility said in a system status bulletin.
Total demand on Monday evening was forecast to reach 31 392 megawatts. Capacity available to meet the demand was at 34 022MW, including open cycle gas turbines.
Eskom said it continued to make progress with its programme of planned maintenance, but the system "remained tight".
Peak demand for power is between 17:00 and 21:00.
In March, the parastatal also called on the country to save 10% of their electricity usage.
Click here to learn how to conserve electricity.
The National Energy Regulator of SA (Nersa) assured parliament last month that Eskom would not be bankrupted by the decision to increase electricity tariffs by 8% over the next five years.
Eskom had requested a 16% a year price increase.
Nersa told MPs the increase allowed would still enable Eskom to continue paying its loans for capital projects.
Last month Public Enterprise Minister Malusi Gigaba said South Africans should brace themselves for what could be the most difficult winter as electricity supply remained constrained.
He made the announcement during an energy saving campaign.
Gigaba urged the public to continue with basic electricity saving habits like switching off geysers during peak hours.
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