Just three power stations – Tutuka, Kendal and Duvha – accounted for 44%, or nearly half, of all Eskom plant breakdowns in the 12 months to March.
This emerged at the utility’s state of the system briefing earlier this month. On average, Tutuka had 2 256 megawatts (MW) of generation capacity unavailable for the most recent financial year which ended in March. Kendal had an average of 1 613MW of generation offline, while Duvha had 1 139MW unavailable.
Together, this totals 5 008MW. If Eskom was to fix these clearly broken power stations – likely both from an engineering (plant) and human resources point of view – and restore just half of these amounts offline, this would be enough to plug the shortfall that Eskom currently has during the evening peak.
Eskom confirmed to Moneyweb that the main contributors to outages across the fleet – boiler (20%), turbine (17%), draught plant (14%) and generator (10%) – were consistent at these three worst-performing plants. It says “in addition, outage slips and trips were also significant contributors at Tutuka”.
Tutuka near Standerton, with nominal capacity of 3 510MW, is Eskom’s worst-performing power station by some margin.
That an average of 2 256MW of generation was offline due to breakdowns – referred to as unplanned capability loss factor (UCLF) – means only a third of the station (two of its six units) was online, on average, during the 2021/22 financial year. This figure excludes any planned maintenance.
This month, Eskom confirmed two incidents of sabotage at the plant.
In the first, a cable to unit five was severed which delayed its return to service. This was discovered the same day that “the control air pipe supplying the turbine systems had been cut with a power tool and the entire bend removed”.
It was reported that the latter was done just outside of the view of CCTV cameras. The acts were reported to police.
In a statement, Eskom said it believed “these were deliberate acts of sabotage by someone who had access to the site where only employees have access and knows the security features in the area quite well”.
Last August, Eskom suspended seven managers at Tutuka. In the last financial year, it reportedly suspended 20 employees on matters related to “theft and collusion” after the apparent theft of R1.3 billion in spares from the power station during the year.
Kendal and Duvha
At Kendal, near Emalahleni, nominal capacity is 3 840MW (from installed capacity of 4 116MW). The 1 613MW of “average” generation capacity lost to breakdowns equates to around 42%.
The number at Duvha, also to the south of Emalahleni, is similar. It has nominal capacity of 2 875MW and the capacity offline for unplanned reasons averaged 39% for the last financial year.
Duvha has already permanently lost 575MW of capacity. Duvha Unit 3, which exploded in 2014, was originally meant to be replaced. Eskom forecast this to be “recovered” in 2019/20. The utility received an insurance payout of R4.2 billion for the incident in 2015. The recovery project was cancelled in around 2018.
The return-to-service date for Unit 2 at Duvha – which was already six months overdue, apparently due to several ‘mistakes’ that kept delaying progress on restarting the unit – was delayed further earlier this month when it was discovered that the incorrect oil had been used.
The top performers
By comparison, at Eskom’s two best-performing large coal-fired power stations – Lethabo (3 558MW of nominal capacity) and Matimba (3 690MW of nominal capacity) – the average amount of generation offline due to unexpected breakdowns equates to 10% and 13% of capacity respectively.
This is very close to Koeberg’s average unplanned losses, which equated to 9.6% in the most recent financial year.
Eskom has previously said the recent suspicious incidents (at Tutuka and Duvha, as well as another at Hendrina) are the difference between it having enough generation capacity and being forced to implement load shedding.