Kriel Power Station has six 500MW units for a total installed capacity of 3 000MW with a turbine maximum continuous rating of 36.90%. Picture: supplied
Eskom continued to utilise the summer break over the past week, along with the lower demand from industry, to increase its planned maintenance activities and further improve the reliability of its generation fleet for the winter period, which starts on April 1, 2025.
The utility, which reached 289 consecutive days without load-shedding on Friday, stated Friday that its maintenance averaged at approximately 8,000 MW last week. Its year-to-date diesel savings of R16.28 billion was about 63.4% less than the R25.67bn spent during the same period last year, due to the ongoing improvements in generation performance.
Over the past seven days, average unplanned outages stood at 14 155 MW, reflecting a slight improvement compared to the 14 611 MW recorded in the same period last year—a reduction of 456 MW. This was mainly due to delays in returning some units undergoing planned maintenance to service, combined with the loss of generating units as a result of boiler tube leaks. As of today, unplanned outages are at 14 077 MW, which is 1 077 MW higher than the summer 2024 base case.
To meet demand under these circumstance, the Open-Cycle Gas Turbine (OCGT) load factor was increased, although it has since decreased. An additional 4 150 MW of generation capacity was expected to return to service by this evening.
Last August, Eskom shared its summer outlook for the period from September 1, 2024 to March 31, 2025, predicting a likely scenario of a load-shedding-free summer due to structural generation improvements.
“This outlook remains unchanged. Our year-to-date unplanned outages average is 11 982 MW, which is 1 018 MW less than our 2024/5 summer base case of 13 000 MW,” the utility said in a statement.
Eskom’s Energy Availability Factor (EAF) improved slightly from an average of 54.65% to 56.97% over the past week, with Koeberg, Medupi, and all peaking stations achieving an average EAF of 70% and above. Two other power stations recorded EAFs above 60%.
The Unplanned Capacity Loss Factor (UCLF) was at 25.09% for the year to January 9, 2025, improving from 32.86% in the corresponding period last year. Ongoing planned maintenance at 5.787 MW was aligned with the summer maintenance strategy to further improve the reliability of the stations in preparation for winter 2025 and beyond.
The year-to-date EAF is at 61.99%, a significant improvement of 7% compared to the same period last year. The use of peaking stations, including pumped storage and OCGTs, remains key in managing electricity demand during peak times, particularly between 5 PM and 10 PM.
Between 1 April 2024 and 9 January 2025, Eskom spent about R9.39bn on OCGTs, generating 1,527.02 GWh, significantly lower than the R25.67bn spent during the same period last year, which produced 4,094.48 GWh.
Eskom said it continued to face network overloading issues in certain local areas due to illegal connections, vandalism, meter tampering, unauthorised network operations, theft of network equipment, and purchasing electricity from unlicensed vendors.
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