Eskom is battling to restore stability to its generation fleet as breakdowns once again skyrocket to record levels. At lunchtime on Tuesday, the utility had 16 985MW of capacity offline due to breakdowns. In addition, 5 446MW of its fleet was not available due to planned maintenance.
This means 22 400MW of generation capacity is offline. Eskom has total installed capacity of 49 020MW, which means that 46% of this is not currently available. Things are worse in the coal fleet, with more than half the capacity – 53% – not online.
On Tuesday morning a conveyor belt failure at Kendal power station, near the N12 between Johannesburg and Emalahleni, triggered a sequence of events which ultimately saw three units tripping. This loss of nearly 2 000MW of capacity necessitated the implementation of Stage 4 load shedding at short notice from its planned recovery in Stage 2. Kendal is one of the company’s three worst-performing power stations.
Eskom’s three worst-performing plants responsible for nearly half of all breakdowns
Never mind winter, load shedding is likely to get much worse from September (May 2022)
Load shedding was first implemented last Tuesday as Eskom’s generation unit endured what COO Jan Oberholzer on Monday called a “disastrous week”. A total of 42 generating units had tripped during the week – some more than once.
The crisis is being exacerbated by the late restart of Koeberg’s unit two which was supposed to return to service in June. This date has been pushed back repeatedly. It was last online more than 10 days ago. Issues with the control rod have meant the unit has not been able to ramp up to full capacity since efforts at restarting it begun last month. Oberholzer told the media on Monday that trips of this nature are normal after a control rod has been replaced.
This means approximately 900MW of dependable capacity – equivalent to one stage of load shedding – has been offline since January. This, together with the chaos caused by illegal industrial action in June and July which saw load shedding pushed to Stage 6, meant Eskom has been forced to run marginal coal units harder.
Those chickens are now coming home to roost.
Read: Load shedding here for a year or more – Eskom COO
54 hours of diesel later
To avoid higher levels of load shedding on a weekend, where demand is lower than in the week, Eskom burned diesel at its OCGTs for 54 continuous hours from Thursday (September 8) at 16:00. By 21:00 on Saturday (September 10) it had run out of diesel. This as it battled to replenish upper dams at its pumped storage schemes and scrambled to restore coal capacity.
Eskom has spent R7.7 billion on diesel for its open cycle gas turbines (OCGTs) since April because it must frequently run these outside of evening peak periods.
It has effectively exhausted its annual diesel budget halfway through the year. Its use of its own OCGTs has been fairly constant at a load factor of 16% for most of this year to keep the lights on. The load factor of OCGTs run by independent power producers (IPPs) is at 11% since April.
In the last seven days, the load factor for its OCGTs is above 32%. This means that, on average, it has been operating these at a third of their capacity for the last week. For IPP OCGTs, the load factor in the last week has been 25%.
Supply constraints – in other words trucking the diesel to the plants – mean it can only physically burn a maximum of R2.4 billion a month. Sourcing that amount of the fuel and finding the cash to pay for it is a more practical limitation.
The National Energy Regulator of South Africa (Nersa) only approved a load factor for the diesel turbines of 3% for this financial year, which is going to mean a tremendous fight next year over whether it can recover this.
A bigger looming problem is where Eskom is going to find another R7 billion for diesel for the rest of the year. It was provided with ‘fiscal support’ (read: a bailout) of R21.9 billion in Finance Minister Enoch Godongwana’s February budget. By July, Eskom’s debt owed by municipalities stood at R49.1 billion – an R8.2 billion increase since September 2021. The total amount was only R9.5 billion in 2017.
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Shoddy maintenance = unavailability
Oberholzer also admitted on Monday that the work done by Eskom and its contractors’ maintenance team is simply not up to standard. He said that units will often break down shortly after undergoing maintenance. This is due to a “lack of skills” both internally and at contractors. One might describe this skills crisis at the utility as ‘acute’.
Read: Eskom’s maintenance work not yielding results: Oberholzer
The coal fleet has not been able to generate more than 19 500MW sustainably since Friday morning, and last achieved over 21 000MW on Thursday morning.
The total coal fleet is theoretically capable of generating 41 000MW but is currently not able to reach even 48% of this figure.
An energy availability factor (EAF) of anything above 60% this year has been the exception. In fact, the average so far is 59.5%, exacerbated by the outage at Koeberg unit two. However, exclude the impact of illegal industrial action and Eskom’s EAF for the year-to-date drops to 58.9%. This is below the 62% achieved for the last fiscal (to end-March 2022). The EAF budget for FY2022 was 70%.
Currently, there is every chance that Eskom’s EAF for 2022 will be below 60%, bearing in mind that Koeberg unit one will be taken offline imminently (likely once the unit two restart achieves stable operation).
Its latest system status report indicates that load shedding should be expected – in a ‘likely risk scenario’ where 15 000MW is offline due to breakdowns – for all but three of the next 52 weeks.