Eskom's Breakdown Disaster

Despite claims to the contrary from South Africa’s Minister of Electricity, the energy availability factor (EAF) of Eskom’s coal power stations has continued to remain at a dismally low level.

The EAF percentage indicates what proportion of Eskom’s power stations are generating power relative to its total installed capacity. It is an objective measure of how well Eskom’s plants are performing.

In 2021 and 2022, Eskom’s worst years of load-shedding before this year, it recorded average EAFs of 61.7% and 58.1%, respectively. Those were its worst figures on record.

Bar a brief recovery in 2018, the EAF has been declining gradually since 2009 — when it stood at just over 85%.

The Eskom board appointed in October 2022 has been tasked with increasing Eskom’s EAF to 70% by 31 March 2025.

As part of a two-year generation improvement plan, it aimed to bring the figure to the upper 59–60% by 31 March 2023, and 65% a year later.

Mpho Makwana, chairman of Eskom Holdings. Photographer: F. Carter Smith/Bloomberg

This was a tall order, and Eskom’s EAF has continued to decline in 2023.

When EAF declines, load-shedding is more likely as Eskom’s available electricity capacity is reduced.

However, despite record load-shedding in 2023 and near-continuous load-shedding over the past few months, electricity minister Kgosientsho Ramokgopa has made some bold claims about EAF improvements.

For example, during a media briefing on Sunday, 25 June 2023, Ramokgopa said Eskom was gradually approaching the board’s target of 70% EAF.

He also said the EAF had consistently averaged 60% in the two weeks leading up to the briefing.

Kgosientsho Ramokgopa, Minister of Electricity

These claims are refuted by Eskom’s weekly EAF data as collated by energy expert Chris Yelland of EE Business Intelligence.

Yelland has been analysing Eskom’s official weekly average EAF figures over the past few years and plotting it on a graph, which he updates and publishes on Twitter nearly weekly.

The data Yelland uses is accessible to the general public — including the electricity minister — under Eskom’s system status reports on its website.

This graph shows that Eskom’s average weekly EAF has been much lower in the first 34 weeks of 2023 than over the same periods in 2022 and 2021.

In the year to date, there has been no week in which the EAF reached 60%, with the closest being 59.62% in week 23 (5 to 11 June 2023). In the same week in 2022, the EAF was 63.29%.

For the two weeks preceding Ramokgopa’s claim of 60% EAF — week 24 and week 25 (12 to 25 June 2023) — the actual weekly average EAFs were 57.64% and 58.37%.

Even assuming that Ramokgopa used week 23 and week 24’s data, the average would have come to 58.63%.

The graph below compares Eskom’s average weekly EAF in 2021, 2022, and 2023.

The grey line shows the average weekly EAF in 2023 has been trending well below 2022 and 2021

While the graph shows an overall improvement in EAF between week 15 and week 31, it is important to note that this trend is in line with previous years.

The weekly average EAF typically increases in the winter due to Eskom taking less capacity offline for planned maintenance. That is to ensure it can meet winter demand, at least to the best of its capabilities.

The previous years’ trendlines clearly illustrate this. In the year to date, Eskom has failed to cross those lines in any week.

The only two weeks in which Eskom’s weekly EAF in 2023 has been better than in 2022 ran from 26 June 2023 to 9 July 2023.

The main reason for this improvement over last year was a strike that crippled the utility’s ability to do maintenance last year.

In his most recent analysis, Yelland said Eskom’s EAF for the 2023 calendar year to date was 54.52%, compared to 59.78% in the same period in 2022.

In the last reported week, from 21 to 27 August 2023, the EAF stood at 55.32%, compared to 59.78% during the same week in 2022.

Eskom’s data clearly shows that Ramokgopa’s claim of improved EAF was false.

Instead of an improvement in generating capacity, Eskom’s EAF continues to decline.

While the recent upward movement might appear to be a positive sign, it correlates with what happened in previous years.

Until the weekly EAF crosses the trendline of past years, there is no reason to believe that Eskom has reversed its declining fortunes.

MyBroadband asked the minister for comment on the disparity between his claims and Eskom’s EAF data but did not receive feedback by the time of publication.