Johanensburg - Eskom’s grid is getting dangerously close to the brink of a shutdown and with winter here it’s going to get worse.
The utility has repeatedly asked households to reduce their peak-demand electricity usage, pointing out that blackouts could cripple businesses and industry and compromise investor confidence.
The system is teetering.
On Monday the available power supply only just met peak demand by a margin of 0.45 percent, according to the latest available figures from Eskom - making it the third closest the grid has come to a shutdown this year.
The minimum reserve margin targeted is 15 percent, according to a 2008 Department of Public Enterprises report.
The closest the grid has come to the brink of collapse was on May 13, when the margin stood at just 0.17 percent, followed by last Thursday’s margin of 0.39 percent.
Although Eskom has encouraged its customers to reduce their consumption throughout the day, it has asked for a focus specifically on the peak period between 5pm and 7pm when the system is at its most vulnerable.
“If you switch off between 5 and 9 (pm), it will make a difference,” said Eskom spokeswoman Hilary Joffe.
During peak periods, demand went up by 2 000 megawatts (MW) or more, she said.
“That’s the output of almost one large power station.”
In the past Eskom has done maintenance during summer, but this year for the first time it has to perform work during the cold months.
“We just can’t afford not to, there is planned maintenance we have to do,” Joffe said.
And with the weather expected to get colder in the next few weeks, the system will be under even more strain.
A cold front is expected to move from the Western Cape to Gauteng by Sunday night and temperatures will drop - minimums for both Pretoria and Joburg on Monday will be 6°C, the average minimum temperature for May based on the South African Weather Services’ figures between 1990 and 2009.
The average for the past week has been 25°C in Pretoria and 23°C in Joburg, according to SA Weather Service forecaster Dipuo Tawana.
“If we get a sudden cold front we will definitely be asking large and small clients for their help,” Joffe said.
Eskom chief Brian Dames has warned that there is a high risk of blackouts this winter that would cripple business and industry and compromise investor confidence.
Dames said winter months placed heavier demands on the power grid, but this winter the utility was running at a higher risk than usual.
This was partly because power stations had been run hard to meet demand, leaving insufficient time to do essential maintenance. Power stations had become volatile, with increased breakdowns.
“If we continue along this path, we risk the possibility of a widespread and unplanned power outage that would cripple businesses of every size, undermine our quality of life and compromise investor confidence in South Africa for years to come. Eskom cannot allow this to happen,” Dames said. As winter approached, Eskom usually wound down its maintenance programme to bring more power stations online to meet the increased demand. But this winter, the utility would have to take at least nine units offline at several power stations for extensive overhauls.
If the lights were to stay on, South Africans would have to cut electricity usage drastically, particularly between 5pm and 9pm, when there was a huge surge in demand.
“Eskom calls on all South Africans to pull together and switch off every non-essential item during these hours, particularly geysers, which consume large amounts of electricity,” Dames said.
“Demand for electricity jumps sharply on winter evenings as people come home from work and switch on heaters and other appliances and we see a jump of 3 000MW or more in just an hour.
“That means we have to keep capacity available in winter just to meet this peak between 5pm and 9pm, capacity which we could otherwise be maintaining.”
Dames said households should also switch off pool pumps and all non-essential lights.
How to keep the lights on
Geysers: Turn down to 60°C and switch it off when you leave for work. Insulate geysers and pipes with specialised blankets. Take a shower instead of a bath and only use warm water if it is necessary. Solar geysers and heat pumps can cut heating costs by up to 67 percent.
Heating: Use a blanket or jersey instead of heaters. Use heaters with a short warm-up time and a built-in thermostat if needed. Only heat rooms in use. Insulated ceilings save up to 40 percent heat loss from a home.
Pool Pumps: Only run the pump outside peak times (6am-9am and 7pm-10pm) and use a pool cover. Cleaning pump filters to keep it operating efficiently.
Lighting: Switch to energy saving bulbs which use about 80 percent less electricity and last between six and eight times longer than traditional bulbs. Use motion-sensor security lights.
Appliances: Switch off appliances at the wall, as standby on certain electronics such as TVs or DVD players can use up to half the electricity they would if they were switched on.
Kitchen: Ensure your oven door is closed until the food is done and switch off hot plates before the food is done as they retain enough heat to finish cooking. Only boil as much water as you need in the kettle and let hot food cool down before refrigerating it. Replacing the seals on the fridge will make the appliance use less energy, as well as making sure the fridge is not packed to the brim.
Laundry: Only use the washing machine for full loads. Use the warm water setting and reduce temperature from 90°C to 60°C when washing bed linen to cut back on the amount of electricity you use.
The Star