Eskom expects a load shedding-free 2025/26 summer after its strongest winter performance in years. However, ongoing delays in returning Koeberg Unit 1 to service are raising concerns about grid reliability in the coming months.
This was outlined during Eskom’s summer outlook briefing on September 5 when the utility highlighted improved generation performance and the risks posed by Koeberg’s extended outage.
Koeberg Unit 1 has been offline for major life-extension work and maintenance. Eskom initially expected the unit to return in July, later moving the target to the end of August. Officials now say the reactor is ready for fuel reloading but they await final approval from the National Nuclear Regulator before commissioning can begin. Eskom is aiming to start the process before the end of September.
“Now we need Koeberg in summer,” said Dan Marokane, Eskom’s Group Chief Executive. Transmission: “Historically, Koeberg has been critical in winter peak demand, but the grid is shifting. With growing solar generation, we see high daytime supply followed by a steep evening drop – the so-called ‘duck curve’. Koeberg’s steady, constant output is essential to close that evening gap.”
He stressed that the 1 000 MW unit is a critical, carbon-free resource, providing reliable baseload power. Delays in its return place additional pressure on the grid and increase the risk of load shedding, particularly during periods of evening peak demand.
Eskom’s summer outlook at a glance:
- 97% supply performance this past winter with only 26 hours of load shedding
- No load shedding forecast for summer 2025/26 compared to 13 days last summer and 176 days in summer 2023/24
- 4 000 MW additional capacity added since last summer through plant returns and new builds
- Energy availability factor up to 61,1% year to date (up 6% over two years)
- Diesel spend halved, saving R16 billion year-on-year
- Return of Koeberg Unit 1 expected to add 930 MW of reliable baseload
