Cape Town - 121022 - South African power utility Eskom has applied to more than double the price of its electricity over the next five years. The state-owned utility said it has applied for a 16 percent annual increase for five years from April 2013 to March 2018. Many South Africans are struggling with the current cost of electricity. Pictured is teacher Michael Guzana with his son Hluma Guzana. Reporter: Yolisa Tswana PICTURE: SUPPLIED

Johannesburg - It’s cold. Koeberg is still off. And on Thursday night there’s one hour when Eskom really needs you to switch off whatever you can.

That hour is 5.45pm to 6.45pm.

That’s the “peak within the peak” of the daily power usage.

On Thursday morning, Eskom called on all customers to reduce power, saying it needs a reduction of at least 10 percent to manage demand and avoid load shedding.

Eskom’s Andrew Etzinger said that Koeberg’s Unit 2, which is off for planned refueling, was due to have returned to service about 10 days ago but has been delayed so it’s still off. Eskom hopes Koeberg will be back online early next week.

The daily evening peak of 5pm to 9pm is always the most difficult time for Eskom, as that’s when people go home, turn on the lights and cook a meal. Power usage jumps about 3500MW during the evenings.

Etzinger said the “peak within the peak” was 5.45pm to 6.45pm.

Tonight’s peak is expected to be tough for Eskom, as it’s dark earlier in the evening, the weather is colder, and businesses are still operating. Friday, Saturday and Sunday nights are usually a little easier as the business demand is less on those evenings.

“Thursday night is the time of greatest concern,” said Etzinger.

And that Thursday night peak hour is the most crucial hour until Monday night.

“Our reserve margin at that time is going to be practically zero.”

Etzinger called it a “power constraint” rather than a “power emergency”.

He said Eskom has spoken to the big customers and got some to agree to cut during Thursday’s evening peak, which will save about 400MW.

“They will be dropping that during the evening peak,” said Etzinger.

The Star