Two big Eskom units back online soon

Eskom expects to synchronise Kusile Unit 6 to the grid by the end of February 2025 and return Medupi Unit 4 to service by the end of the first quarter of 2025 or the end of March.

The offline unit at Kusile Power Station will add around 720MW of generating capacity to the grid. In contrast, the Medupi unit, offline due to an explosion in August 2021, will add a further 800MW.

According to energy expert Chris Yelland, the state-owned power utility is reluctant to declare the end of load-shedding until these large units are returned to service and several other critical processes are completed.

MyBroadband asked Eskom about the possibility of it declaring an official end to load-shedding in the near future.

Although it didn’t answer the question directly, it said the return of Koeberg Unit 2 has helped the system and that it will be further strengthened when the Medupi and Kusile units are returned to service.

“Medupi Unit 4 (720MW) is expected to return in the first quarter of 2025,” it said. “The synchronisation of Kusile Unit 6 (800MW) is targeted for the end of February 2025.”

Eskom said it continues to drive its Generation Operational Recovery Plan, which commenced in March 2024, adding that it enhanced efficiencies resulting in a shift in fleet performance.

It said its Summer Outlook for the period from 1 September 2024 to 31 March 2025 remains in force.

“Based on the improved generation performance, the outlook’s base case scenario indicates that there will be no load-shedding if unplanned outages stay at 13,000MW or below,” said Eskom.

“The average unplanned unavailability for this summer is about 11,500MW, 1500MW lower than the base case assumption for the Summer Outlook shared in August 2024.”

It added that it will share its outlook for winter 2025, when electricity demand is expected to rise significantly, in the next few months.

The state-owned power utility has been without the generation capacity of large units like Koeberg Unit 2, Kusile Unit 6, and Medupi Unit 4 for a long time.

Koeberg Unit 2, which was taken offline for critical life-extension maintenance, including refuelling and the replacement of its steam generators, returned to service on 31 December 2024.

This returned roughly 930MW to the grid on New Year’s Eve.

However, Kusile Unit 6 and Medupi Unit 4 have yet to be completely repaired, and until they return, Eskom remains reluctant to say load-shedding is over.

In mid-October 2024, Yelland said he expected Eskom would be more willing to declare the official end of load-shedding once the following tasks are completed:

• Return to service of Koeberg Unit — Done
• Containment building overpressure/leakage testing on Koeberg Unit 1 in January 2025 — Deadline not specified
• Return to service of Medupi Unit 4 following the hydrogen explosion in August 2021 — Expected: February 2025
• Reinstate the flue gas desulphurisation plant at Kusile Power Station — Expected: end of March 2025

Medupi’s 720MW unit 4 generator suffered massive damage shortly after reaching commercial operation in August 2021.

An investigation into the incident showed that technicians had failed to purge the generator of hydrogen before it was mixed with oxygen, resulting in an explosion.

At the time, Eskom said it anticipated returning the unit to service by August 2024. Former Eskom CEO André de Ruyter said the repair work would cost approximately R2.5 billion.

Kusile Unit 6 has yet to reach commercial operation, despite Eskom’s plan for the entire power station to be completed by 2014.

The power utility synchronised unit 5 to the grid in December 2023 and planned to bring unit 6 online by 2024. However, its finalisation was delayed.