Eskom’s load-shedding problems shown in one graph

Professor Anton Eberhard has shared Eskom’s energy availability factor (EAF) chart from 2000 to 2023, which shows a rapid decline over the last four years.

The EAF shows the percentage of time the power station was available for use when it was needed. It is a core measure of performance for any power utility.

When the EAF declines, a power utility has less generation power to serve South Africa’s electricity needs.

In Eskom’s case, its average EAF declined from 70% in 2019 to around 54% in 2023. It is so low that there is insufficient generation power to meet demand.

The result is load-shedding, where the demand is artificially reduced by switching off energy distribution to certain areas.

To end load-shedding, Eskom needs to significantly improve its EAF or add more generation capacity to the grid.

In January, Eskom chair Mpho Makwana said they had embarked on a turnaround journey to improve plant performance and reduce load-shedding.

He said it would take at least two years to improve the EAF to 70%. He set targets of 60% EAF by 31 March 2023, 65% EAF by 31 March 2024, and 70% by 31 March 2025.

The government is upbeat about increasing Eskom’s EAF and ending load-shedding in the time frames laid out by Makwana.

Earlier this month, the cabinet released a statement which welcomed the improvement in Eskom’s EAF, which it said “is now closer to 70%”.

Electricity Minister Kgosientsho Ramokgopa also said Eskom could maintain a much lower stage of load-shedding due to the improvement of the EAF.

Ramokgopa said Eskom is much closer to achieving its target of 70% EAF and that it has been consistent on an average of 60% for the past 14 days.

However, the short-term improvement in Eskom’s EAF, although welcome, should not be seen as a long-term trend.

Energy analyst Chris Yelland said Eskom’s EAF is still on a downward trend when considering the year-on-year change.

“The latest Eskom week-on-week energy availability factor is nowhere near 70% and is reported officially today by Eskom as 58.31% for Week 26 of 2023,” he said.

He added Eskom’s year-to-date EAF is 53.77%, down significantly from 59.35% for the same period in 2022.

“The government’s messaging that the energy availability factor is heading upwards and is close to 70% is just not true,” he said.

Although there has been an increase in EAF over the last few weeks, this is not strange and happens every year.

“As we head into winter from summer, the energy availability factor always rises towards a peak in the middle of winter. It then declines towards the summer months,” Yelland said.

“What we are seeing at the moment is following a similar trend with a rising EAF heading to the peak of winter.”

Therefore, the increased EAF is not unexpected, and the rise is still lower than last year.

Eberhard echoed Yelland’s view, saying as South Africa is again facing stage 6 load-shedding, it’s instructive to be reminded of the long-term trend in performance.

He said there are no short-term miracles with Eskom’s ageing power station fleet, which are more prone to breakdowns and require increased maintenance.

Eberhard shared a chart of Eskom’s EAF from 2000 to 2023, which shows the rapid decline over the last four years.

Eskom energy availability factor