Eskom is facing an uncertain future in terms of load-shedding as its energy availability factor (EAF) continues to decline.
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.
Energy analyst Chris Yelland posted Eskom’s latest energy availability factor numbers, which showed that its week-on-week EAF for week 28, 2023, stands at 56.28%.
This is the second week Eskom’s energy availability factor declined, which is in line with the trend seen in previous years.
Yelland further highlighted that the EAF for the first 28 weeks of 2023 stands at 54.00%, 5.28 percentage points lower than the EAF of 59.28% for the same period last year.
Simply put, the energy availability factor decline means it has less generation power to serve South Africa’s electricity needs.
The lower EAF means that Eskom is experiencing significant electricity shortages this winter.
In July, the shortfall ranged between 2,708 MW and 6,929 MW, which forced Eskom to implement stage 6 load-shedding and significant load-curtailment.
Apart from the immediate challenge of getting through winter without hitting stage 8 power cuts, Eskom also has a longer-term challenge.
In January, Eskom chair Mpho Makwana said they had embarked on a turnaround journey to improve plant performance and reduce load-shedding.
Makwana set targets of 60% EAF by 31 March 2023, 65% EAF by 31 March 2024, and 70% by 31 March 2025.
Eskom’s plan to end load-shedding was to reach a 60% EAF by March 2023 and improve it to 65% by March 2024 and 70% by March 2025.
Unless Eskom succeeds in increasing the reliability of its generation fleet, South Africa should expect many more years of load-shedding.
The latest data shared by Yelland showed that Eskom’s EAF is on a declining downward trend, which has been the case for the past five years.
The EAF is based on the average performance of 90 generators in Eskom’s electricity generation fleet. “You cannot maintain or fix them simultaneously,” he said.
What this means, mathematically, is that the EAF is a continuum. There cannot be a discontinuity – also known as a step change – in the EAF trend.
“To increase Eskom’s EAF, there must first be a slowdown. It then has to bottom out, stabilise, and start to rise. This process will take several years,” he said.
Eskom’s EAF data for the first 28 weeks of the year confirmed that Eskom’s targets are misguided. In fact, it is only getting worse.
It is nearly impossible for Eskom to reach the 65% EAF target by March 2024, which means that load-shedding will likely continue for years to come.
Eskom energy availability factor
The chart below, courtesy of Yelland and EE Business Intelligence, shows Eskom’s EAF for the first 28 weeks of the 2023 calendar year.
Eskom energy availability factor since 2000
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.