The simple answer is that we have an energy rather than a capacity shortage, arising from a deleterious mix of planned, but more crucially, unplanned maintenance and maintenance slippages. This combination means that something like 20% of our generation capacity is currently out of service.
Engineering News Online has confirmed that there is something like 3 000 MW of capacity out for planned maintenance, and a whopping 5 000 MW down for unplanned maintenance. This is resulting in a daily shortfall of between 2 500 MW and 3 000 MW below average and peak demand.
In other words, of the 42 000 MW of nominal capacity and what appears to be an actual capacity of around 37 000 MW in the Eskom system, between 8 000 MW and 9 000 MW is currently unavailable. That means that the utility is only producing around 29 000 MW against a demand of between 31 000 MW and 33 000 MW. The result is ongoing load shedding.
It also means that Eskom is far from operating at its previously stated generation aspiration of ‘90-7-3’, or 90% plant availability, 7% planned outages, and 3% unplanned. In fact, had it been operating at such levels there would have been no need for load shedding at all.
For this reason, a lot of urgent attention is currently being given to the issue of unplanned cuts, given that the ‘planned’ maintenance peak of around 5 000 MW actually took place before Christmas and the load-shedding crisis being faced in January is, thus, being massively deepened by the unplanned or extended maintenance.
The unplanned events range from a turbine fire at Matla, through to load losses associated with wet coal, coal shortages, poor quality coal and poor mill performance across just about every power station from Arnot to Tutuka.
“What we are experiencing at the moment, therefore, is a an energy shortage rather than a capacity shortage,” demand-side management GM Andrew Etzinger told Engineering News Online, adding that the capacity could be recovered, but that to ensure it is brought back on a sustainable basis some “breathing space” was required.