The risk of load-shedding in 2022 is likely to be high as Eskom’s maintenance plans could see a big chunk of its generating capacity out of action.
Unit 2 at Koeberg nuclear power station will be shut for 155 days from January for the replacement of steam generators to extend the life of the power station by another 20 years. During the last quarter of next year, unit 1 will also be put on outage for 155 days for similar modifications and scheduled maintenance. Each unit of Koeberg generates 928MW.
“Koeberg will therefore operate for about 10 months at half capacity, having switched off 920MW of capacity. Coupled with the loss of Medupi unit 4 and Kendal unit 1, this means Eskom will operate with reduced output of some 2,300MW for next year, in addition to the high breakdowns we have experienced, increasing the risk of load-shedding,” Eskom CEO André de Ruyter said during a presentation to release Eskom’s interim results to end-September.
Also, modifications to Kusile will mean the unit’s capacity will be lost for six months.
Eskom has an installed generation capacity of about 46,000MW though only about 30,000MW is usually available.
De Ruyter said Koeberg’s generation is reliable so having its units out of service would place additional risks on the system. The reliability and availability of the coal-fired plants would have to be enhanced to compensate for this.
The results for the generation division during the six months to end-September were disappointing due to high levels of unplanned losses, with the electricity availability factor declining to what De Ruyter said was “a very poor” 65.27% and contributing to 21 days of load-shedding, which removed 427GW from the system. The energy availability factor in the previous interim period was 67.8%. The below-target plant availability resulted in the high use of open-cycle gas turbines, which cost R4.5bn over the six months, an increase from the R2.6bn previously.
The decline in the division’s performance was worsened by the explosion of the Medupi unit 4 generator in August. The unit will return to production in 18 months. There was also a fire in the transformer of the Kendal unit 1 power station in September. It will return to service next week. These two incidents accounted for a loss of 1,360MW from the national electricity grid.
De Ruyter noted that boiler modifications have been completed on all six Medupi units as well as Kusile unit 1. Similar work is in progress at Kusile unit 2 and will soon be rolled out to unit 3.
“To perform these modifications each of these units have had to be switched off for a period of at least 75 days, meaning Eskom has had to cope for 450 days in the case of Medupi without a whole unit that would ordinarily contribute some 500MW to the national grid. The modifications being applied at Kusile will similarly cost the country at least a whole unit’s capacity for half a year,” said De Ruyter.
He noted that the new build is progressing well, with Medupi unit 1 achieving commercial operation on July 31, adding installed capacity of 794MW. This marked the completion of the construction and commissioning activities on the 4,764MW Medupi project.
De Ruyter said the design defects of Medupi’s boilers have largely been addressed and they are now performing at design specifications. Good progress has also been made on Kusile unit 4, which is on course for commercial operation by the target date of June 2022 and will add about 700MW to the grid.
Eskom made a profit in the first six months of 2021 — traditionally the better half — but expects to sink back into an after-tax loss in the year to end-March. It made an interim net after-tax profit of R9.2bn on revenue of R135bn compared with a R216m profit at the end of September 2020 but projects a net after-tax loss of R9.1bn on revenue of R246bn for the full financial year. In the year to end-March 2021 Eskom made a net loss of R18.9bn.
Net interest-bearing debt was reduced with government assistance of R31.7bn to R360.3bn from the R420.6bn at the end of September 2020. The finance cost of R16.6bn remains unsustainable and is expected to erode profit by year end. Municipalities’ debt to Eskom grew by R5.6bn to R40.9bn, and if fully repaid it would offset more than 10% of the power utility’s total debt.
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