By Lehlohonolo Lehana.
Eskom has presented its load shedding outlook for the 2022/23 summer period, with the power utility warning that its system is likely to remain constrained for the near future.
Presenting the system update on Tuesday (15 November), Eskom noted that its system plan works on a maximum of 13,000MW of generation being offline due to unplanned breakdowns.
This plan is updated weekly based on current generation trends and lays out the predicted number of days of load shedding for 18 months forward.
However, the plan comes with some significant caveats.
Firstly, the plan is tight, Eskom said, and any significant outages or slips have a knock-on impact on the whole model. Secondly, the plan does not factor in industrial action or employee protests – such as the illegal strike that happened earlier in the year that pushed the country to stage 6 load shedding.
The power utility also noted that there is a variance of around 4,000MW in unplanned outages, making it difficult to plan ahead. “There’s always a cone of uncertainty,” it said.
In the overall picture of South Africa’s energy system capacity, it is evident that the country simply does not have enough capacity to meet demand.
Ideally, Eskom said, demand should never exceed available capacity, but the current outlook shows that stability is heavily reliant on the continued use of open-cycle gas turbines (OCGT) to keep the lights on.
In the group’s baseline scenario, with 13,000MW of power out due to failures, South Africa would experience seven days of load shedding at stage 1. However, Eskom warned that this isn’t entirely realistic as this would require R7.3 billion worth of diesel to keep the OCGTs burning.
Not only is this level of fuel spend completely unaffordable, but it is also not logistically or physically possible for the group to transport and use that much diesel. Eskom previously indicated that it can only use R2.4 billion worth of diesel a month.
Even if it were able to spend the money to simply burn more diesel – which it stressed it cannot do due to a lack of funds – the logistics around moving diesel around make it an impossible solution.
So wherever the plan indicates OCGT costs over this physical limit, higher stages of load shedding are inevitable, Eskom said. This includes its base case (best-case) scenario.
Under the base case, it anticipates almost no load shedding as long as unplanned breakdowns remain below 13,000MW.
If breakdowns exceed 13,000MW and remain below 14,500MW, persistent load shedding will continue, at least at stage 2. Higher stages here are inevitable, however, due to the diesel limitations mentioned above.
If breakdowns exceed 14,500MW and move in excess of 16,000MW, high levels of load shedding will be in place almost permanently, as there are no months where the diesel costs are within the limits.
Eskom chief operating officer Jan Oberholzer said that the current round of load shedding would be downgraded to just stage 2 on Tuesday, following an escalation to stage 3 on Monday.
“Due to the vulnerability and unpredictability of the power system, coupled with the major capital projects, maintenance and major repairs to be executed starting during the next few months, the risk of continued load shedding remains quite high, “Oberholzer said.