Eskom has provided a dismal outlook for its anticipated power system performance in the coming 12 months, with its worst-case scenario requiring 326 days of load-shedding.
The power utility delivered the forecast during a recent presentation to Parliament’s Joint Portfolio Committee on Public Enterprises and Mineral Resources.
To estimate the amount of load-shedding Eskom would have to implement in the near future, the utility uses a base case scenario that assumes a certain amount of its grid will be unavailable due to unplanned outages and other losses.
It also includes about 2,200MW of emergency operating reserves like its open-cycle gas turbines (OCGTs) within its generating capability.
In its latest outlook, Eskom assumes it will have 13,000MW of unavailable capacity throughout the year, a change from its previous approach, where it used 12,000MW of outages for the summer months.
Even in this “better” scenario, Eskom expects to implement up to 24 days of stage 1 load-shedding between September 2022 and August 2023.
The more medium-risk assumption adds a further 1,500MW of unpredictable capacity. That sends the outlook to 203 days, with stage 2 being the most frequently required level of load-shedding.
In the worst-case scenario, which assumes a base case plus 3,000MW of at-risk capacity, the utility would have to implement load-shedding on 326 days (89%) of the year.
It is worth noting that Eskom has regularly found itself with unavailable unplanned capacity losses over 15,000MW in recent months.
That would fall in between the medium-risk and worst-case scenarios.
The table below summarises Eskom’s plant performance and load-shedding outlook for September 2022 to August 2023.
In the medium-risk and worst-case scenarios, it is important to note that Eskom would have to burn more diesel to run its OCGTs to keep to the indicated load-shedding stages.
For example, under the worst-case scenario, Eskom said it would have to burn R8.95 billion in diesel in December 2022 to avoid going higher than stage 3 load-shedding.
The utility said history has shown that it was impossible to burn diesel worth more than R2.4 billion per month due to the physical limitations in transporting the fuel.
Therefore, where the plan showed a diesel usage greater than this, South Africans should expect additional stages of load-shedding.
That means under the medium risk case, the stage of load-shedding required would be higher than stage 2 for five out of 12 months.
Under the worst-case scenario, it will be higher than stage 3 throughout the year.
Over 23,000MW of new generation
Fortunately, there is a glimmer of hope that load-shedding’s severity could be substantially relieved over the next two and a half years.
Eskom provided details of 23,294MW of generating capacity expected to come onto the grid during this time.
“Successful implementation of all the initiatives will greatly reduce the risk of load-shedding,” the utility said.
The timeline and amount of capacity expected to be added to the system are as follows:
- February 2023 — 3,514MW
- August 2023 — 2,861MW
- February 2024 — 1,474MW
- August 2024 — 7,389MW
- February 2025 and after — 8,011MW
To bring all this generation online would require plant performance to improve according to Eskom’s generation recovery plan to address load losses, including those at Kusile units already in operation.
It also includes the commissioning of two new Kusile units and the return to service of Medupi Unit 4, which suffered a devastating explosion in 2021.
The vast majority of new capacity will be sourced from “standard offer” independent power producer bid windows, emergency generation procurement, power imports, Eskom’s land leasing initiative, and battery energy storage system scheme.
“Timing of new generation capacity is dependent on the market response and regulatory processes,” Eskom said.
The utility added that demand management interventions would help free up a further 1,450MW of capacity.
The utility provided the chart below to break down which capacity is expected to come online over the next two and a half years. Eskom JET is short for “just energy transition,” which includes its battery storage projects.