Eskom hit stage 7 load-shedding twice last week despite expectations that power cuts would ease with lower demand.
Eskom officially announced stage 6 load-shedding from Tuesday, 5 September, to Thursday, 7 September.
However, on Wednesday and Thursday, the power utility cut 6,369 MW from the grid, which equates to stage 7 load-shedding.
Eric Shunmagum, Eskom’s senior manager in the group executive generation office, said increased breakdowns and higher planned maintenance caused the higher load-shedding.
Last week, Eskom had planned maintenance of 5,700 MW and unplanned breakdown maintenance of 17,200 MW.
This exceeded the winter targets of 3,000 MW of planned maintenance and 15,000 MW of unplanned breakdowns.
The higher planned and unplanned maintenance left Eskom with an additional 5,000 MW of lost generation capacity.
Another factor contributing to the higher load-shedding was the lower use of open-cycle gas turbines (OCGTs) to conserve diesel.
Shunmagum explained that Eskom has a R30 billion diesel budget, which includes R19.4 billion for OCGTs and R9.5 billion for IPPs.
Eskom has already spent around R10.5 billion in the financial year-to-date, so it must manage its budget to ensure it does not run out of money for diesel.
As such, Eskom runs fewer OCGTs, resulting in more intense load-shedding during increased breakdowns.
The lower-than-expected generation capacity and limited use of OCGTs forced Eskom to implement higher-than-expected load-shedding.
The table below shows Eskom’s load-shedding over the last week.
|Date||Load-shedding||Stage announced||Actual stage|
|Sun, 3 September||4,544 MW||Stage 5||Stage 5|
|Mon, 4 September||5,067 MW||Stage 5||Stage 6|
|Tue, 5 September||5,991 MW||Stage 6||Stage 6|
|Wed, 6 September||6,369 MW||Stage 6||Stage 7|
|Thu, 7 September||6,369 MW||Stage 6||Stage 7|
|Fri, 8 September||5,050 MW||Stage 5||Stage 6|
|Sat, 9 September||3,463 MW||Stage 4||Stage 4|
Eskom EAF decline
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.
In July, Electricity Minister Kgosientsho Ramokgopa said Eskom could maintain a much lower load-shedding stage due to the EAF’s improvement.
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, Eskom’s official EAF data tells a story of deteriorating performance that moves away from the 70% target rather than towards it.
The recent breakdowns resulted in Eskom’s energy availability factor (EAF) dropping to 52% in September. This is much lower than the corresponding period last year.
The EAF for the 2023 calendar year-to-date is 54.52%, compared to 59.78% for the same period in 2022.
It shows that Eskom will need a miracle to reach its 31 March 2024 EAF target of 65% and its 31 March 2025 target of 70%.
The chart below, courtesy of Chris Yelland and EE Business Intelligence, shows the decline in Eskom’s EAF over the last three years.