A Council for Scientific and Industrial Research (CSIR) analysis paints a bleak picture of Eskom power plants’ reliability and the potential impact on load-shedding.
CSIR researchers Warrick Pierce and Bianca Ferreira showed how power plant breakdowns and Eskom’s energy availability factor (EAF) worsened.
Although the utility’s planned and unplanned outages were relatively similar in 2017 and 2018, breakdowns have increased substantially since then.
They noted that there is now a distinct separation in the statistical distribution of breakdowns and planned maintenance.
Stated differently, breakdowns have become larger without decreasing in frequency.
This is concerning as unplanned outages are a significant contributor to load-shedding in the country.
Eskom’s average weekly EAF was 78.7% in 2017 and only dropped to around 68% at its lowest point that year.
Comparatively, the average weekly EAF in 2021 was 61.8%, and it dropped as low as 53.3%.
The CSIR’s data shows that the average weekly EAF has decreased steadily, with figures of 71.8%, 66.9%, and 65.0% reported for 2018, 2019, and 2020, respectively.
However, despite the decreased EAF, increased load-shedding, and the uptick in unplanned outages, Eskom generated more electricity in 2021 than in 2020.
In May 2022, Eskom revealed its load-shedding outlook for the rest of the year, revealing that it could have to implement load-shedding for 81% — or 295 days — of the year.
The power utility highlighted three possible scenarios for load-shedding between April 2022 and 2023. These included its Base Case, Base Case + 1,500MW, and Base Case + 3,000MW (the worst-case scenario).
The worst-case scenario would see Stage 4 or greater power cuts implemented for 104 days in summer and 191 days over winter.
The Base Case is the most optimistic and would see load-shedding active for 16 days of the year. However, the country had already surpassed the Base Case scenario when Eskom revealed the data.
The scenario showed that Stage 1 would be the highest level implemented.
The country experienced Stage 4 load-shedding in April 2022, meaning that Eskom’s middle-ground (Base Case + 1,500MW) has also been surpassed.
This year, Eskom has been extensively using its open-cycle gas turbine (OCGT) power plants to meet peak demands.
By the end of March 2021, the diesel costs to run its OCGTs had amounted to R6.9 billion, and with the global oil price rising steadily, its continued use of OCGTs could worsen its financial situation further.