Mega power stations flawed
Eskom’s mega power stations, Medupi and Kusile, which were intended to alleviate SA’s power constraints, have a multitude of serious design and technical flaws that are impeding their operation.
The poor performance of the new stations is a key reason why Eskom is still unable to meet the country’s energy demands despite adding 3,200MW of capacity to the grid since 2015.
Eskom’s current installed capacity is about 38,000MW.
The utility went into stage four load-shedding mode on Monday, dropping 4,000MW from the grid, the largest-ever amount that it has needed to shed to keep the grid stable.
Load-shedding takes place when demand exceeds supply and customers are dropped to avoid the grid tripping.
Two of the six generating units that failed on Monday, causing the jump to stage four, are at Medupi.
Eskom, which supplies more than 95% of SA’s electricity, says the main problems at Medupi and Kusile are the fault of the main contractor on the boilers, Japanese conglomerate Mitsubishi Hitachi Power Systems Africa (MHPSA).
It is not the first time that Hitachi’s work on Medupi has been found to be defective.
In 2013, 10,000 welding faults were discovered when it failed to heat-treat the welds.
In 2015, it failed the crucial steam test, which is a necessary step before commissioning.
Hitachi and Mitsubishi Heavy Industries merged their power activities in 2015 to form Mitsubishi Hitachi Power Systems Africa.
Hitachi’s award to build the boilers has always been controversial due to its partnership with the ANC’s investment company, Chancellor House.
It was fined by the US Securities Exchange Commission in 2015 for allegedly paying the ANC front a $1m [R13.84m] success fee and $5m [R69.21m] in “dividends” in connection with the Medupi and Kusile contracts.
A multiplicity of faults have been identified common to both Medupi and Kusile.
In its updated tariff application to the National Energy Regulator of SA (Nersa), Eskom lists seven technical and design problems.
● The boiler design results in high temperatures which the spray water system cannot adequately cool, leading to frequent tripping.
● The design causes excessive ash accumulation and ash bags must be frequently replaced. This causes ash blockages, frequent tripping and load losses.
● None of the coal mills, which pulverise the coal going into the burner, meet technical specifications, meaning they must be serviced twice as frequently as normal.
● The gas air heaters, which capture waste heat and transfer it to combustion air, enhancing the efficiency of the boiler, do not meet technical requirements.
● The dust handling plant, which is vital for safety, environmental and occupational health reasons, requires more frequent maintenance due to high ash accumulation, leaks and the scarce availability of spare parts.
● The computerised control system frequently fails, causing plant trips, and does not meet technical requirements.
● There is a high number of vibrations on the cooling loop.
Several of these problems are adversely affected by poor coal quality, according to the Eskom presentation.
The presentation also lists a shortage of skilled people and unavailability of spare parts as an eighth factor negatively affecting Medupi and Kusile.
The problems have meant Medupi’s unit 6 (which was the first of three commissioned so far) has barely reached 60% of its capacity since June 2018.
The remaining two units perform at about 70% capacity.
In response to questions last week, Eskom chief operating officer Jan Oberholzer laid most of the problems at the door of Mitsubishi Hitachi Power Systems Africa.
Eskom has assembled teams of specialists to rectify the major defects and technical workstreams have been established with contractors.
“Eskom will attempt to resolve issues in terms of the contracts and may institute legal proceedings only should contractual resolution not be possible,” Oberholzer said
“It is Eskom’s position that the contractor will fix and pay for the faults.”
Mitsubishi Hitachi Power Systems Africa spokesperson Nicolas Meyer said the company did not wish to comment.
In another blow to the plants, it was reported by EE Publishers on Monday that Clyde Bergemann Africa – a main contractor to Eskom for the ash handling systems and a sub-contractor to Mitsubishi Hitachi Power Systems Africa – has filed for business rescue.
Employees walked off the site at Medupi and Kusile after they were not paid for January. After a comfortable few months we were rudely awakened with Stage 4 loadshedding on Monday. And, whether or not we listened to President Cyril Ramaphosa’s state of the nation address last week in which Eskom’s woes featured prominently, the reality of the mess we are in is clear to all when loadshedding of this magnitude hits us.
Nelson Mandela metro in addition also had to contend with heavy rain, thunder and lightning on Monday, making the lack of electricity in certain areas even more hardhitting.
Eskom says these outages are a last resort to protect the power grid from total collapse but also warns that capacity problems – and with that, further loadshedding – could continue until April or possibly later.
Ramaphosa made it clear in his Sona address that the government would tackle the issue of state institutions mismanaged over many years, giving a broad outline of how Eskom will be remodelled and split into three state-owned entities.
However, that is small comfort for the average household in the immediate future.
We must appreciate that, though Ramaphosa has said the government would step in to support Eskom’s balance sheet, he has also warned that the process should be done “without burdening the fiscus with unmanageable debt”.
We hope finance minister Tito Mboweni will be able to clarify funding when he gives his budget speech on February 20. Eskom is in a sinkhole of debt – the astronomical sum of R419bn – and it is obvious that Mboweni, like Ramaphosa, does not possess a magic wand.
Therefore, any changes are likely to be incremental rather than radical.
It is clear that money meant for maintenance and good corporate governance at Eskom has not been well spent.
The impact of this on our economy may be felt for some time. But a decisive recovery plan must be implemented immediately...