What Eskom has to sacrifice to cap load shedding at stage 4

The latest data on Eskom’s plant performance shows a steep rise in user demand and unplanned outages – so the utility has had to cut planned maintenance to keep load shedding from escalating.

Independent energy analyst, Pieter Jordaan, noted that the data shows that over the past three weeks, Eskom has repeatedly cut its planned maintenance schedules to boost the energy availability factor (EAF).

System data for week 44 (ending 5 November) shows that Eskom’s performance deteriorated significantly compared to the improvement seen in the prior period.

This was seen when Eskom broke away from its nine-day load shedding suspension – a neat trick it managed to pull off by doubling its use of diesel generators and taking advantage of lower user demand – and implemented stage 2 and stage 3 load shedding on rotation.

“Following several weeks of improvement, the past fortnight saw practically all of the metrics correct to their 5-year linear trends,” Jordaan said. “A return to typical demand in week 44 exerted too much pressure on the generating fleet, causing the blackout rate to spike.”

Eskom’s acting CEO Calib Cassim has made it clear that the group’s goal is to cap load shedding at stage 4, and to go further and suspend outages during the day.

This is the state of affairs as of 5 November, with load shedding on a rotation of stage 2 in the evenings and suspended outages during the day.

The group’s summer plan has also been set on having a ‘base case’ scenario of keeping load shedding maxed out at stage 4, premised on having breakdowns and outages not exceeding 14,000MW.

However, the data shows that Eskom has very little manoeuvrability when it comes to maintaining this dance.

When the group saw a spike in breakdowns and a rise in user demand from cold weather, it had no choice but to cut planned maintenance to make sure load shedding did not escalate.

During a briefing to update the public on the Energy Action Plan on Sunday, 5 November 2023, Electricity Minister Kgosientsho Ramokgopa described the inconsistency in generation performance as “unacceptable”.

“We have done exceptionally well over a period of three months [but] I think the ball has been dropped here,” he said.

“As a result of these failures, and this is something that is receiving attention, we’ve gone back to about 17,000MW [of breakdowns], and this is totally unacceptable, I must say.”

The minister has been talking up the improvements at Eskom – particularly the ailing utility’s improved energy availability factor (EAF), which touched 60% for the first time this year in recent weeks.

However, the data shows that the battle against load shedding is far from over, with EAF dropping again to 54.6% and continuing the long-term downward trend.

According to energy experts, the reality is that Eskom’s fleet is highly unpredictable, and breakdowns can happen at any time.

Read: Eskom expands big plan to cut load shedding in residential areas