Eskom said the power system is constrained but resilient.
Loadshedding will not be necessary if unplanned outages stay below 13,000 Megawatts (MW).
If outages rise to 15,000MW, loadshedding would be limited to a maximum of 21 days out of 153 days and restricted to Stage 2.
Daphne Mokwena, Spokesperson of Eskom, said unplanned outages from 23 to 29 May 2025, were at 13, 871 MW, representing an increase of 883MW compared to the same period last year.
“Fluctuations in unplanned outages are mainly driven by outage slips, which occur when a unit initially scheduled for planned maintenance is reclassified as unplanned due to exceeding the scheduled maintenance timeframe” said Mokwena.
As of Friday, unplanned outages amounted to 13,327MW, while the available generation capacity is at 29,913MW (excluding the 720 MW capacity generated by Kusile Unit6).
Kusile Unit 1, which was out out of service since the end of March 2025, was returned to the system on Friday. The unit’s flue gas desulphurisation (FGD) system and permanent stack were repaired.
This unit is expected to contribute about 800 Megawatts (MW) to the system.
Another 2, 930MW of generation capacity is expected to be returned to service ahead of Monday’s (2 June 2025) peak, to further stabilise the grid.
The Unplanned Capacity Loss Factor (UCLF), which measures the capacity lost due to unplanned outages, is at 28.60% for the financial year to date (1 April to 29 May 2025).
Planned maintenance for the period ending (23 to 29 May 2025), is at about 4,883MW, which is slightly above the winter maintenance levels observed in previous years.
The Open-Cycle Gas Turbine (OCGT) load factor increased to 12.70% this week, compared to 7.65% in the previous week (16 to 22 May 2025).
Diesel usage is expected to decline further as more units return from long-term repairs and maintenance activities are reduced, increasing available generation capacity.
Picture: Fr Kevin Kilgore