Real reason for lower load-shedding revealed

New data from Eskom and EE Business Intelligence shows that lower maintenance and more solar power are behind the decline in load-shedding.

South Africa enjoyed a month without load-shedding – the first time this has happened since 2022.

Many people speculated that this is an election ploy, where Eskom may be burning lots of diesel to keep the lights on.

However, Eskom chairman Mteto Nyati dismissed suggestions that the uninterrupted power supply is linked to the 2024 general elections on 29 May.

He said it resulted from its maintenance strategy, where it took specific generation units offline to fix. This strategy, he said, is starting to produce results.

While this is indeed part of the reason, it does not tell the full story of why South Africans enjoyed a blackout-free April.

Energy analyst Chris Yelland said unplanned breakdowns are, indeed, consistently lower in the first 16 weeks of 2024 compared to the same period last year.

However, it is mainly due to the return to service of 3 x 800 MW units at the Kusile Power Station, which provided 2,100 MW to the grid.

“Unplanned breakdowns remain pretty steady and high this year, at about 30% of Eskom’s generation capacity in commercial service,” he said.

Eskom achieved a higher average energy availability factor (EAF) in the first four months of 2024 than the same time last year, allowing it to reduce load-shedding.

Yelland said the higher EAF trend this year is mainly attributable to the corresponding reduction in planned maintenance outages (PCLF).

The increased EAF and lower load-shedding at the start of the year was, therefore, because Eskom did less maintenance and not lower levels of unplanned breakdowns (UCLF).

Eskom System Operator head Isabel Fick added that increased photovoltaic solar power helped Eskom cut load-shedding in April.

2,800 MW of photovoltaic solar is directly connected to the Eskom grid, with other “behind-the-meter” solar installations of around 5,440 MW.

Fick said the contributions of these solar power plants and rooftop solar installations allowed Eskom to replenish its pumped storage capacity during the day rather than at night.

Eskom can then use its emergency generation capacity – pumped storage and diesel-powered open-cycle gas turbines – over the evening peak when solar energy is unavailable.

When the sun shines most of the day, like in April, it relieves tremendous pressure off the grid. However, things change for the worse when it is overcast or rains, like in March.

The charts below, courtesy of Chris Yelland of EE Business Intelligence, show Eskom’s performance over the last few months compared to previous years.

Cautiously optimistic

Energy analyst Chris Yelland

Yelland said he was reasonably optimistic that South Africa would experience continued reduced frequency and intensity of load-shedding for the rest of 2024.

However, this is barring any major breakdowns, such as that experienced when 3 x 800 MW units were out of service for about a year at Kusile.

He also noted that the 2 x 800 MW units at the Medupi power station were expected to deliver commercial power to the grid in Q3 this year.

Yelland said it was a notable and commendable achievement by Eskom that unplanned breakdowns are stable this year at levels consistently lower than those of last year.

The energy availability fact has also stabilised and not reduced further along the same downward trend as for the last five years and more.

Yelland’s predictions alight with Eskom’s predictions that South Africans may see load-shedding this winter, but it will likely be limited to stage 2 and capped at stage 5.

Eskom presented its Winter 2024 Outlook last week, where CEO Dan Marokane said the utility’s performance over the past year had improved significantly.

This strong performance over the past few weeks has placed the utility in a much stronger position ahead of winter 2024 compared to 2023.

Eskom energy availability factor

Eskom planned maintenance

Eskom unplanned outages


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