Alarm bells as Eskom power station reliability drops
Energy sector analyst and EE Business Intelligence managing director Chris Yelland has raised the alarm about Eskom’s rapidly declining energy availability factor (EAF).
EAF measures the proportion of Eskom’s power-generating fleet available to dispatch power relative to its installed capacity.
“We need to keep a close watch on the declining EAF trend and the increasing unplanned outage (breakdown) trend in 2026,” Yelland said.
While EAF remained above 2025 levels, it dropped below 2021 levels at the start of April and continued to decline to below 2022 levels by the end of the month.
The declining EAF, on its own, is not cause for concern, as Eskom’s planned capacity loss factor (PCLF) was relatively high. This represents the proportion of the fleet offline for scheduled maintenance.
However, breakdowns have also increased rapidly since March. Although Eskom’s unplanned capacity loss factor (UCLF) trend line remained below that of 2023, 2024, and 2025, the rapid rise was a concern.
Eskom said in its weekly power system update that its EAF for the financial year to date (since 1 April) stood at 60.29%.
This was an improvement from the 56.48% EAF over the same period last year, despite increased planned maintenance averaging 7,356MW since the start of the current financial year.
“This performance reflects sustained progress under Eskom’s turnaround strategy and represents a 5.27% improvement compared to the corresponding period two years ago,” Eskom stated.
“Between 1 and 7 May 2026, average unplanned outages declined to 11,593MW, a reduction of 964MW compared to the 12,556MW recorded over the same period last year, contributing to a less constrained power grid.”
Over the same period, the UCLF was 24.18%, down from 26.42% recorded during the same period last year, contributing to available capacity.
During the same period, Eskom’s PCLF, which reflects the proportion of the fleet offline for scheduled maintenance, averaged 13.66%.
“While this is lower than the 14.66% in the previous financial year, it is aligned with Eskom’s efforts to ensure environmental compliance, improve reliability, and support long‑term sustainability.”
In addition, 980MW is currently in cold reserve due to excess capacity. Therefore, there was no imminent danger of load-shedding.
Eskom EAF, breakdowns, and maintenance charts
The system is stable — Eskom
Eskom said its system remained stable despite its evening peak reaching nearly 2,000MW above anticipated levels.
This was driven by seasonal conditions, including a sharp rise in evening consumption as temperatures dropped.
“This has been achieved alongside the natural tapering of solar generation at sunset, demonstrating enhanced operational resilience and improved capacity utilisation across the fleet,” it said.
Eskom also stated that its performance was supported by continued progress in reliability, as well as disciplined maintenance execution and cost optimisation.
“This performance reflects the sustained impact of the Generation Recovery Plan and reinforces Eskom’s Winter Outlook projection of no loadshedding,” it said.
For the financial year to date, diesel expenditure was at R469.24 million, significantly lower than the R2.436 billion incurred in the same period last year, reflecting an 80.74% reduction year-on-year.
“This continued reduction demonstrates both the cost savings and the operational improvements achieved through Eskom’s ongoing turnaround efforts,” the state-owned power utility said.
“Overall, this positive trend highlights the growing stability and efficiency of the power system.”
Eskom said it strategically used diesel during the past week at peak demand times to meet higher-than-expected demand and maintain the required reserves in line with the South African Grid Code.
“To further ensure a stable electricity supply, Eskom will bring 2,889MW of generation capacity online ahead of the evening peak on Monday, 11 May 2026,” it said.
MyBroadband contacted Eskom for comment regarding Yelland’s remarks, but did not receive a response by publication.
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