THE Minerals Council has warned that load shedding remains a strong possibility for the winter months as energy supply was constrained, with Energy Availability Factor (EAF) at 57.5%.

This is according to an electricity update for February to March 2025 released by the Council last week.

André Lourens, economist from the council, said that from 7–10 March, a sudden loss of 2,700MW in generation capacity - including Koeberg Unit 2,930MW and two Kusile units - led to increased reliance on Open Cycle Gas Turbines (OCGTs) to meet demand.

“The narrow margin between dispatchable generation and electricity demand underscored these challenges. Average demand for the month stood at 22,509MW, while dispatchable generation averaged 22,357MW, necessitating a total of 55 hours of load shedding during March,” Lourens said.

“As these reserves were depleted, loadshedding became necessary to restore emergency reserves. Later, on 19 March, additional loadshedding was implemented following the failure of five generating units, two of which were from the Cahora Bassa hydroelectric system in Mozambique. Breakdowns were frequent and without warning in March.”

Lourens added that when tracking the historical EAF over recent years, 2025 is trending downward after a promising start to the year.

“In 2025, the EAF appears to be aligning with the lower levels seen in the first few months of 2024 and remains well below the pre-Covid highs of 2019. However, on a month-to-month basis, production edged up by 0.5% compared to January 2024. The Stats SA data aligns with data from Eskom showing that February was a particularly challenging month for Eskom, as it recorded the largest gap between minimum and maximum EAF levels since 2022 - highlighting the system’s fragility.”

Lourens said that South Africa’s electricity system remains under severe strain - evident in indicators such as the idle EAF.

Energy expert Professor Wikus van Niekerk who is the dean of engineering at Stellenbosch University, said that he agreed the EAF was not looking positive and the council assessment is on the right track.

“We need, however, more feedback from Eskom on how they are doing getting Kusile units 2 and 3 and Medupi 4 back online. If that is going well and they all are back by the month of May, then we may be okay.”

Energy expert Ruse Moleshe, managing director of RUBK, an energy and infrastructure consulting and advisory firm, said that there was always a risk of load shedding in a tight supply and demand situation like Eskom has, without sufficient reserve capacity.

“During the winter period, demand for electricity increases due to a higher need for heating and other services. However, the return of significant capacity from planned maintenance is likely to mitigate that risk.”

Eskom recently said load shedding remained suspended; however, the power system was constrained due to ongoing increased planned maintenance and high electricity demand driven by overcast weather conditions nationwide.

“The high level of planned maintenance aims to enhance fleet reliability for peak winter demand while also ensuring compliance with environmental and regulatory requirements. Currently, 7 034MW of the generation capacity is under planned maintenance,” Eskom said.

“The Unplanned Capacity Loss Factor (UCLF), or unplanned outages, for the financial year-to-date (1 to 3 April 2025), stands at 28.67%, improving from 31.92% in the same period last year.”

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