Good news about load-shedding – but crunch time coming

Eskom’s week-on-week energy availability factor increased by 8% over the last two months, but the next month will be crucial to see whether this trend is sustainable.

Energy analyst Chris Yelland shared the latest Eskom energy availability factor (EAF), which showed a 3% week-on-week increase.

Electricity Minister Kgosientsho Ramokgopa also highlighted that there had been a 7% improvement in the EAF of the fleet, with a 1% equalling roughly 477MW of output.

This has resulted in an additional output of over 3,000MW, equating to four load-shedding stages.

The key focus for Ramokgopa now is stabilising the supply of electricity and ensuring that the increased EAF is maintained.

“I think it is a significant movement. A green shoot,” Ramokgopa said, “The fact that for a period during the week in winter, you have had instances of no load-shedding is significant”.

The short-term increase in Eskom’s EAF is good news and helped the power utility to reduce its load-shedding intensity.

However, big weekly EAF changes are not uncommon and do not necessarily guarantee a long-term improvement in Eskom’s plant performance.

Yelland highlighted that despite the improvement in recent weeks, Eskom’s EAF is still 4.5 percentage points below the EAF of 62.7% for the same week last year.

There is, therefore, a declining downward trend in Eskom’s EAF when compared to the same period in 2022.

Another observation is that the energy availability factor increased by 7% over the same period last year before a rapid decline of 6 percentage points over the next month.

Yelland previously explained that 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 EAF in 2023

The chart below, courtesy of Yelland and EE Business Intelligence, shows Eskom’s EAF for the first 22 weeks of the 2023 calendar year.