Eskom Maintains Grid Stability Amid Cold Snap, Targets 2 450MW Boost

by Kelebogile Matlou

On Friday, 27 June 2025, Eskom announced that its power system remains stable, successfully managing rising electricity demand as South Africa experiences a cold snap. Through the strategic use of emergency reserves, Eskom has managed to meet critical morning and evening peak demands despite occasional system constraints.

As part of its Generation Recovery Plan, Eskom aims to restore 2 450MW of generation capacity before the evening peak on Monday, 30 June 2025, in an effort to strengthen overall grid reliability. Between 20 and 26 June, the utility reported that planned maintenance averaged 3 789MW, indicating a reduction in scheduled outages. Meanwhile, the Energy Availability Factor (EAF) fluctuated between 60% and 64%, with the month-to-date average at 60.61%.

However, Eskom continues to face challenges. The Unplanned Capability Loss Factor (UCLF) has risen to 29.36% for the current financial year, compared to 27.25% in the previous year. One major factor is the delayed return of Medupi Unit 4, a unit with 800MW capacity, which is still offline. As of now, total unplanned outages amount to 15 137MW, reducing available generation to 30 703MW.

This total does not include Kusile Unit 6, which has supplied 720MW to the national grid since 23 March 2025, despite not being fully operational. Together, these efforts helped Eskom meet the Friday night peak demand of 28 810MW. Recent data shows the load factor for open-cycle gas turbines (OCGTs) dropped to 11.37%, slightly down from the previous week but higher than 6.21% at the same time in 2024. Diesel use is expected to decline as more generating units return from long-term repairs.

According to Eskom, the Winter Outlook report released on 5 May 2025 remains valid. The utility says load shedding can be avoided if unplanned outages are kept below 13 000MW. If they rise to 15 000MW, Stage 2 load shedding may be needed for up to 21 days over the 153-day winter period.

From 20 to 26 June, unplanned outages averaged 14 696MW which is 2 815MW higher than the same week in 2024 and 1 696MW above Eskom’s baseline target of 13 000MW. This is mainly due to the ongoing delay with Medupi Unit 4, initially expected to return to service by 30 May 2025. Planned maintenance for the financial year to date has averaged 5 481MW, making up 11.67% of Eskom’s total capacity. Despite this, the year-to-date EAF stands at 58.47%, slightly lower than 61.19% last year, mostly due to a 2.1% increase in unplanned outages.

Financially, Eskom has spent about R4.76 billion on OCGT fuel, generating 810.24GWh—a significant increase from 442.65GWh last year, but still within the annual budget. As South Africans rely heavily on electricity during winter, Eskom urged the public to avoid illegal connections and electricity theft, warning that these activities overload transformers and damage infrastructure.

Eskom encouraged consumers to buy electricity only from accredited vendors and to report illegal activity via Crime Line. For better energy efficiency, the utility recommends using tools like the Eskom Residential Calculator to track and reduce electricity use. Eskom will provide the next update on Friday, 4 July 2025, or sooner if significant changes occur.