SA will have enough generation capacity for the next five years, even if its economy grows by 2.6% over the period, a new report by power utility Eskom says.
But this is based on the proviso that Eskom keeps the energy availability factor (EAF) of its power stations at an average of 63%, the report by the utility’s system operator (SO) said.
In the week ended October 27 the EAF reached almost 64%, but the average for the year to date is just below 60%.
Should it decline towards 50%, the country could once again face load-shedding, according to the medium-term system adequacy outlook.
“Understanding the impact that these additional renewables have on the grid stability will enable the system operator to put measures in place that ensures the system remains resilient and stable,” it said.
Eskom is required by energy regulator Nersa to publish the outlook by October 30 every year to give guidance to policymakers about the need for additional generation capacity.
Improved outlook
The latest version showed an improved outlook compared with 2023, which showed an inadequate supply in all scenarios.
The latest outlook considered a moderate growth scenario in the demand for electricity, based on an average GDP growth rate of 2.2% over the period. This will result in an annual increase in demand of 1.1% and a high demand scenario, based on average growth of 2.6% and 1.6% growth in electricity demand annually over the period.
The outlook also considered reserve requirements, the loss of 5,300MW of generation capacity by 2029 due to the shutdown of two open-cycle gas turbines in 2026 and units at five coal-fired power stations in 2029. On the other hand, the last two units at Kusile will be in operation by next year, as will Medupi’s unit four that was out of service for a long time after a generator explosion.
The system operator took into account 2,183MW of Eskom battery storage and renewable generation that will come into commercial operation during the period as well as 6,431MW of existing and 6,797MW of planned renewable capacity from the government’s renewable energy independent power producer procurement (REIPPP) programme.
It included REIPPP battery storage from the first three bid windows and 3,000MW of gas generation from an independent power producer (IPP). The preferred bidder for the first phase of this project is expected to be announced in March next year.
From the private sector 8,681MW of renewable generation capacity from projects at an advanced stage of development was factored in, as well as rooftop solar that is not registered with Nersa of 1,612MW-4,500MW.
Lastly, 2,387MW of non-Eskom licensed capacity, 1,005MW from privately owned open cycle gas turbines Dedisa and Avon, and the 1,150MW imported from Cahora Bassa in Mozambique were added to get a full picture of the supply of electricity in 2025-29.
Based on all this data and the absence of load-shedding in the past months due to Eskom’s improved plant performance, the operator confirmed that Eskom’s plant availability is the most important lever to ensure adequacy.
“The Eskom operational generation recovery initiatives aimed at improving EAF to levels above 70%, will further enable the economic growth for the country,” the study said.
A new challenge, should all the planned generation projects be competed successfully, is excess energy on the system, it states. “However, this scenario is predominantly dependent on projects that are still in the feasibility stages and this introduces high uncertainty pertaining to its full materialisation.”
Among the study’s recommendations is that the impact of the sharp increase in renewable generation should be studied and understood, “as intermittency and variability of these technologies introduce supply and demand balancing challenges on the system.
As the penetration levels of these technologies increase, the complexities associated with supply and demand balancing also increase.
“Understanding the impact that these additional renewables have on the system will enable the system operator to put measures in place that ensures the system remains resilient and stable.”
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