Eskom’s weekly energy availability factor (EAF) hit a new low of 48.6% at the end of 2022 – the first year that it dropped by 50%.

This was revealed in the Council for Scientific and Industrial Research’s (CSIR’s) annual statistics on power generation in South Africa for 2022.

The energy availability factor shows the ratio of the energy that the available capacity could have produced during this period.

In Eskom’s case, it shows the percentage of generation capacity that produced electricity when needed.

If all power stations run at full capacity, the EAF will be 100%. However, breakdowns and planned maintenance reduce the availability of power stations.

Because of increased breakdowns at Eskom’s power stations, its EAF declined from 78.7% in 2017 to 58.1% in 2022. The lower EAF is the reason South Africa has higher levels of load-shedding.

The CSIR said it is largely due to the increase of unplanned outages – detailed by the unplanned capacity loss factor – experienced by Eskom.

Eskom’s weekly EAF dropped below 50% for the first time in December 2022, resulting in the highest load-shedding month ever.

It means that less than half of Eskom’s power stations and generation units worked as expected that week.

2022 was also the year that most load-shedding has not been Stage 2, having been overtaken by Stage 4.

Stage 6 load shedding has far surpassed that experienced in 2019, the only other year with Stage 6.

The chart below shows the declining EAF trend between 2017 and 2022.