Load shedding
  • Eskom says the latest round of load shedding is due to breakdowns and planned maintenance.
  • It's only going to get worse, says an expert, as Eskom embarks on a huge maintenance program over the summer.
  • The warmer weather also increases the risk of breakdowns in Eskom's largest power stations.
  • There's a strong likelihood of load shedding for the next 18 months to two years as Eskom completes the program.
  • For more articles, go to www.BusinessInsider.co.za.

There will likely be no more load shedding this weekend, Eskom says, after blackouts resumed this week – but that respite seems unlikely to last.

According to Eskom, the latest round of load shedding is due to "an increase in generation unit breakdowns", as well as planned maintenance. The power utility didn't provide any more detail.

This follows electricity rationing during July, despite Eskom CEO Andre de Ruyter’s hope that load shedding would only be restricted to three days during the winter.

And it’s only likely to get worse. Eskom’s own projections for the next three months paint a stark picture.

Eskom’s weekly data shows load shedding remains a possibility until November. In the table above, the last two columns show Eskom’s predictions of power constraints. The second last column shows what Eskom had previously been expecting. The final column – the one which is all so ominously red – shows Eskom’s revised predictions.

“It’s a pretty bleak picture of the next three months,” says Chris Yelland, energy analyst and managing director of EE Business Intelligence. “It doesn’t mean there’s a certainty of load shedding, but that it’s pretty likely.

“No-one knows for certain if load shedding will be necessary, not even Eskom,” says Yelland. “It depends on the randomness of breakdowns. However, Eskom can make predictions based on their experience.”

The likelihood of rationing is despite demand for electricity being lower in 2020 than in 2008, he says. “That’s because of a weaker economy, and rising electricity prices which means people are more likely to use energy such as gas.”

However, there are a bunch of things happening over the short term and long term that make further blackouts more likely, and means they’ll probably keep on happening for at least another 18 months.

In the short term, Eskom’s available generating capacity (the amount of power it can produce) usually declines over summer. The basic reason is that demand for power is lower, so Eskom typically schedules its maintenance for the warmer months.

Eskom’s available power is usually lowest between December 15 and January 15, says Yelland.

Unfortunately, there’s also an increased risk of unplanned outages during the summer. The warmer air can impact Eskom’s dry-cooled power stations, such as Medupi near Lephalale, and Kusile near Balmoral.

“Think of a power station that produces 600MW. Because it’s getting too hot, it can now only produce 500MW,” says Yelland. "It’s almost like a car overheating. You can’t run them flat out.”

“And if Medupi and Kusile, two of Eskom’s largest power stations, have 10% less output, that means there’s a lot less power generated.”

Over the long term, Eskom’s power stations are also getting older. “It’s very normal,” says Yelland. “When plants get older, they break down more often, like having an old car.”

The power utility is embarking on a massive maintenance program over the next few months, although the exact dates are not known; the reliability maintenance programme, as it’s called, was originally scheduled for earlier this year, but was delayed due to lockdown.

For this type of maintenance, Eskom will take some of its generators out of service for around 10 weeks.

“It’s not just a quick fix. It’s like sending a car in for a complete overhaul of the engine,” says Yelland. The entire program is expected to last 18 months.

In addition, Medupi and Kusile have design flaws that need to be fixed, he says. Both have six generators which, if they’re taken out of commission for ten weeks at a time, means 120 weeks – or two whole years – of deep-level maintenance on Eskom’s two largest power stations.

It’s not an exact prediction, of course. “But the data says that, for the next 18 months to two years, there’s a possibility of load shedding, says Yelland. “That doesn’t mean it will happen every single day, but that there’s a high probability of blackouts.”

“They’ve skipped maintenance for years,” he says. “At some point they were going to have to do it properly.”

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