Eskom's additional 800MW from Kusile Unit 6 tipped to bolster SA's energy supply

Energy experts on Monday welcomed Eskom announcing the addition 800MW to the grid from Kusile Unit 6, saying this marked a crucial step toward dealing with load shedding, which was surprisingly implemented at Stage 2 last week. 

Experts were also of the view that Kusile Unit 6 meant the completion of one of the country's largest infrastructure projects and a key milestone in Eskom’s strategic objective of adding 2 500MW of new capacity to the grid by the end of this month.

Kusile Power Station will contribute a total of 4 800MW to the national grid once all units are fully operational, making it South Africa’s largest infrastructure project.

“Its sister project, Medupi, will see its Unit 4 return 800MW by the end of April 2025 from an extended outage following a generator stator failure and the completion of the project. Both South Africa’s new build power station projects will then be essentially completed once Kusile Unit 6 is in commercial operation,” said the power utility. 

Eskom group executive for generation, Bheki Nxumalo, said Eskom was at a critical point returning megawatts to the grid.

“This milestone is a testament to the unwavering dedication and resilience of Eskom’s employees and contractors. Their commitment has driven us forward despite numerous challenges.

“As we celebrate this progress, our focus is now on ensuring that Unit 6 achieves commercial operation in the second half of 2025, further strengthening South Africa’s energy security.”

Prof Vally Padayachee, power and energy expert and former Eskom executive manager, said this was certainly a positive development for South Africa's energy landscape.

“This increase in generation capacity is a most welcome addition, especially in the context of our ongoing challenges with load shedding,” he said.

“While this additional capacity may help to temporarily alleviate some of the pressure on the grid and reduce the frequency and severity of load shedding, it is important to recognize that Eskom's generation system remains in a vulnerable state (although some would argue it's in a precarious state given the most recent four bouts of load shedding in a month).”

Padayachee added that Eskom had noted the overall generation capacity was still at risk, and the utility has not yet fully overcome its operational challenges.

“With an Energy Availability Factor (EAF) hovering around 60%, the system is not yet operating at optimal levels. For sustainable relief from load shedding, we ideally need the EAF to improve to between 70% and 75%,” he said.

“This improvement is crucial to ensure that we have sufficient reserve capacity or headroom – typically estimated at around a sustainable 10% to 15% (preferably 20%) to accommodate unexpected outages or demand surges.”

Padayachee said that while the addition of 800MW from Kusile Unit 6 was a significant step forward and should contribute to mitigating load shedding risks in the short term, it was essential for Eskom to continue addressing its generation challenges comprehensively.

Ruse Moleshe said that this was important for South Africa because it will strengthen the security of supply and energy availability.

“The recent challenges of load shedding indicate that South Africa needs to have more availability to mitigate that risk in the event that something goes wrong with any of the plants in the overall electricity system,” Moleshe said.

“This is also an opportune moment as the country faces a winter period where the electricity demand will increase relative to the summer period.”

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