On 5 May 2025, Eskom announced its latest power system update and Winter 2025 outlook, confirming that its power system is in a further improved and more reliable position than it has been in recent years.
For Winter 2025, if unplanned outages remain below 13 GW load shedding is not expected. If outages increase to 15 GW, load shedding would be limited to a maximum of 21 days of the winter period’s153 days at Stage 2 – an improvement over the prior winter’s worst-case prediction of Stage 5 loadshedding.
The improved winter outlook is due to a decrease of 3.1 GW in unplanned outages compared to the previous year. As a result, the forecast range has been lowered to 13 to 15 GW, from 14 to 17 GW in Winter 2024. Last winter, the country did not experience load shedding, with unplanned outages averaging 12.3 GW – significantly below the Winter 2024 base-case projection of 14 GW.
At the media briefing, Dan Marokane, Eskom Group Chief Executive said: “The prediction for this year’s Winter Outlook is built on an improvement in operational performance and overall efficiency. During the past financial year for Eskom (FY 2025), load shedding was lower than in the previous two years. In FY 2025 we delivered power 96% of the time; in the previous year the figure was just 9.9%. Our diesel open cycle gas turbines were used about 50% less in FY2025 compared to the two previous financial years, enabling a saving of around R16 billion (on diesel costs).
“Against this progress, we have also encountered some setbacks in operational excellence, as evidenced by the recent load shedding implemented between January and April 2025. The respective incidents have been investigated and analysed, and a targeted plan has been put in place to reinforce operational discipline and accelerate recovery initiatives to address the root causes related to the recent load shedding events,” Marokane said.
Power system recovery
Several key performance indicators informed the Winter Outlook.
- Unplanned outages decreased by 3.1 GW year-on-year, enhancing available generation capacity. Between May 2023 (18 GW) and April 2025 (13.5 GW), there was a significant 4.5 GW reduction, reflecting improved plant performance. The summer average of 12.5 GW in unplanned outages proved better than the forecast base case of 13 GW, despite some units being reclassified from planned to unplanned outages due to time overruns in scheduled maintenance.
- Planned maintenance for FY25 reached 12.8%, up from 12% in the previous year, marking a 0.8% increase. Between September and March, maintenance activity averaged 14.5%, compared to 14.07% during the same period the previous year and 11.8% in FY23, reflecting an increase of 2.7% compared to FY23. This forward-looking approach has contributed to Eskom’s enhanced preparedness for winter and to ensuring compliance with environmental and regulatory requirements.
- Plant availability improved to 61% in FY2024/25, up from 54.6% the previous year, a ~ 6.5% year-on-year improvement. Eskom anticipates a notable increase in the Energy Availability Factor (EAF) as it completes the outstanding actions in its recovery plan.
- Diesel consumption dropped by some 50%, resulting in cost savings of around R16.51 billion year-on-year – reflecting reduced reliance on emergency generation.
- Sales volumes grew by about 3.6% year-on-year, driven by improved generation capacity, higher exports and reduced reliance on diesel.
- Kusile Units 2 and 3 have been successfully reconnected to the main stacks and are now operating with the flue gas desulphurisation (FGD) system, as they are designed to do. Unit 1 is currently undergoing a scheduled outage and is expected to return to service in June, also connected to the main stack. This follows authorisation from the Department of Forestry, Fisheries and the Environment (DFFE), which had previously permitted the temporary operation of the three units without the FGD system – under strict environmental conditions – until 31 March 2025, following the 2022 structural failure of the west stack.
- A total of 3.470 GW wind capacity was made available through curtailment in the Eastern and Western Cape.
- On the distribution front, in line with its goal to modernise the power system, Eskom has installed 880 000 smart meters to date. Among other benefits, this technology allows for effective demand control through load limiting and enables eligible customers to return surplus clean energy to the grid, helping to reduce strain on the system during peak times.
- Continued investment in securing generation capacity will see the addition of 2 500 MW of energy supply through scheduled projects.
- Koeberg Unit 2 was successfully returned to service in December 2024, following the completion of the Long-Term Operation project and delivering more than 900 MW to the system.
- Kusile Unit 6 was synchronised to the grid on 23 March 2025, contributing 800 MW intermittently; it is scheduled to reach commercial operation by September 2025.
- The return of Medupi Unit 4 is progressing well and is anticipated to return 800 MW to service by the end of May 2025.
Bheki Nxumalo, Eskom Group Executive for Generation, said at the briefing: “In FY2025, Eskom produced more energy than in the previous two years and we continue to make bold decisions with the future in mind – to build a stronger, more reliable power system for the country. We have continued to maintain high levels of planned maintenance as part of our efforts to improve fleet reliability in preparation for the high winter demand, and to meet environmental licensing conditions and regulatory requirements.
“We have evolved our Generation Recovery Plan to ensure our data-led analysis into the delays in returning units from outages on time, which has caused our fleet to be constrained and not able to accommodate a sudden loss of units, receives intense management focus. We are using our high challenge, high support culture to assist our teams to rectify this situation,” Nxumalo said.
In the bigger picture, Marokane said as Eskom strives to ensure energy security it is focusing on evolving its business to position it for the energy transition and increasing competition.
This entails a number of key initiatives which include: implementing around 5.90 GW of clean energy projects by 2030, the formal legal separation of its Distribution and Generation divisions, enhancing Distribution and Generation products and services, and exploring strategic partnerships for funding and execution.
Additionally, proactive interventions continue to be implemented to improve the governance and control environment to achieve a high-performance ethical culture.
Eskom expressed its gratitude to the government and other key stakeholders, including the National Energy Crisis Committee (NECOM), for their support in enabling the notable improvements in the power system. Marokane also commended all Eskom employees for their diligent execution of the Generation Recovery Plan and their dedication to the turnaround of Eskom.
For more information visit: www.eskom.co.za
