050910 Electricity pylons carry power from Cape Town's Koeberg nuclear power plant July 17, 2009. South Africa will need 20 gigawatts (GW) of new power generation capacity by 2020 and would require double that amount a decade later to meet rising demand, the country's power utility said September 7, 2009. Picture taken July 17, 2009. REUTERS/Mike Hutchings (SOUTH AFRICA ENERGY BUSINESS)

Eskom has started raising red flags on power use and urged commercial and private consumers to reduce electricity consumption by 10 percent.

The power utility said if everyone saved 10 percent, it would reduce consumption by about 3 000 megawatts, enough to power Johannesburg.

Yesterday Eskom published its first weekly system status bulletin aimed at keeping the country up to date on developments in the supply and demand for power.

Since last year the utility has been publishing quarterly bulletins, which it said would continue. The initiative follows public panic after Eskom issued a warning earlier this week about the risk of load shedding.

The power supplier said capacity available to meet last night’s peak demand was 34 618MW while demand was forecast at 31 168MW.

It said current planned maintenance stood at 4 461MW and unplanned outages at 3 678MW.

Eskom said the system had improved since Monday, when it issued the warning.

On Monday, the peak demand was 30 282MW while available capacity was 30 742MW. By Tuesday, the available capacity had increased to 31 840MW while peak demand was 30 753MW.

On Wednesday, peak demand of 31 108MW was met by available capacity of 32 601MW. The company forecast that the peak demand for today would be 31 303MW and this was expected to decrease slightly over the weekend to 29 762MW on Saturday and 29 205MW on Sunday.

Eskom had asked its biggest customers to reduce electricity use and had interrupted the power supply to some.

Eskom has a special arrangement with BHP Billiton allowing the utility to cut off supply to the operator of the Bayside and Hillside aluminium smelters without any notice, if need be.

Eskom spokeswoman Hilary Joffe said that, according to the terms of the contract, the utility could cut the power for up to two hours a week.

“So we always make use of that throughout the year, but we make more use of it when the system is very tight.”

BHP Billiton South Africa spokesman Johnny Dladla said: “This causes a loss of production at these smelters to ensure national consumer demand can be met. We work closely with Eskom to do all we can to protect the supply to our smelters, and other operations.”

Dladla said the company would not disclose the financial loss it incurred as this was confidential information.

Joffe said Eskom also had arrangements with other big customers. “We use what we call the ‘demand market participation’, where we pay them to switch off,” she said.

Joffe said the utility wanted to push for a compulsory energy conservation scheme and some customers had already signed up voluntarily.

Since 2008 BHP Billiton has reduced its base-load power consumption at its smelters by 10 percent. Dladla said the contractual load shedding was in addition to this reduction.

“We have and will maintain that position in South Africa as a contribution to mitigating our country’s power crisis.”

Anglo American said it would make the required adjustments when necessary.

Eskom has compiled power saving tips for the energy intensive industries, which include the regular examination and maintenance of boiler systems, the use of electronic ballasts for lighting and the power factor correction of plants. Power loss could also be reduced in feeders, transformers and distribution equipment. - Londiwe Buthelezi