The newly appointed Eskom head of generation will have to hit the ground running as the embattled power utility braces itself for a tough winter when the national grid is expected to come under severe pressure, leading to even higher levels of load-shedding and curtailment.
Eskom last week appointed long-time staffer Bheki Nxumalo as its new group executive for generation. Nxumalo, returning to a role he had held from July 2019 to August 2020, will start his job with breakdowns of more than 17,000MW of generating capacity.
The entity is scrambling to keep the lights on, with the dreaded stage 6 making a comeback last week after several breakdowns at Eskom’s power stations put the grid under strain.
Tough winter
A senior manager in the generation department, who wished to not be named as he is not authorised to speak to the media, told Business Day the winter season is going to be tough and the priority remains to keep the grid stable.
“The grid will remain stable but the amount of load-shedding or curtailment in order to keep the system stable would need to increase if demand increases. More load-shedding doesn’t mean a less stable grid. As the load increases and generation is not there, the system operator will always strive for balance,” he said.
“The way in which our system operates is world-class. Some countries have come to Eskom to ask how we manage the system. We are actually teaching some European countries how to manage a system with large deficits because it is done so efficiently by the system operator.”
The Sunday Times reported at the weekend that the country was silently slapped with stage 8 power cuts this week and the situation may get worse as winter approaches. The Eskom official, however, denied this and said the power cuts emanate from both load-shedding and load curtailment.
‘Biggest fear’
“Each of the different metros do different sizes of curtailment and they get requested to do it. Load-shedding and load curtailment is a responsible way to manage the security of the grid because the measures ensure the grid is balanced. Losing the grid is the biggest fear,” he said.
He added that load-shedding is the rotation of blackouts where various areas are taken off grid, determined by the system operator, and that load curtailment is when the utility asks large energy users to reduce their power usage.
The loss of units 1, 2 and 3 at Kusile, coupled with unit 1 at Koeberg, which is currently on long-term outage for maintenance, prompted Eskom to implement stage 6 load-shedding on Friday before reducing it to stage 5.
However, Saturday load-shedding went to stage 6 from stage 5 after the tripping of unit 2 at Koeberg power station — meaning it produced no power as unit 1 is offline for maintenance. The two units each have a capacity of 920MW.
Koeberg has been plagued by a series of maintenance and safety issues that have raised questions about its long-term viability. The country’s only nuclear power station comes to the end of its life in the second half of next year. Eskom has applied to the National Nuclear Regulator for a 20-year extension to the plant’s lifespan.
The utility said on Sunday it was returning Koeberg unit 2 to service, which will add much-needed support to the grid.
The cause of the trip was due to “problems with the feedwater pumps on the secondary unit”. The reactor has been critical, and reactor power is being increased to enable turbine commissioning, the utility said. “The unit is expected to safely synchronise to the grid before morning peak tomorrow [Monday], once all required activities are completed,” Eskom said.
“Breakdowns are currently 17,481MW of generating capacity while the generating capacity out of service for planned service is 5,657MW. Over the past 24 hours a generation unit each at Duvha and Medupi power stations were returned to service. In the same period, two generating units at Kriel, as well as one at Koeberg power station, were taken offline.”
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