State-owned electricity producer Eskom warned on Wednesday that there was 11 000 MW of capacity currently “at risk” over and above the more than 13 600 MW out owing to full or partial load losses and the 5 300 MW unavailable owing to planned maintenance.

Speaking after the utility again extended load-shedding, which was implemented at extremely short notice on April 11, by a further two days, generation executive Phillip Dukashe said that the number of units at risk of breakdowns was disturbingly high.

“That obviously causes us to be uncomfortable, really uncomfortable, because those units can then trip at any stage,” he said, adding that Eskom was aiming to use the upcoming Easter weekend to work through as many of the units as possible to try and reduce the risk of trips.

While leave had not been uniformly cancelled for the long weekend, plans were in place to ensure that both Eskom employees and contractors were available to perform urgent maintenance.

The forecast of a possible resumption of rainy conditions next week was adding to Dukashe’s discomfort, particularly given that the persistent recent rains had contributed to the most recent bout of load-shedding.

Eskom would not be load-shedding those parts of flood-stricken KwaZulu-Natal where power had been restored, however.

CEO André de Ruyter reiterated that the unreliability of the coal fleet was the result of more than a decade of under-maintenance, which arose largely as a result of a failure to build the new capacity in time and was intensified by serious delays to the building of Medupi and Kusile.

He noted that planned maintenance currently stood at about 11.2% for the first time in many years, but said new capacity was required to provide Eskom with the “headroom” it needed to conduct even higher levels of maintenance on the coal fleet.

“If you look at the minimum requirements for maintenance that should have been done on an annual basis, it's closer to 13%.

“And to be safe, according to global benchmarks, we should actually have taken out 18% on planned maintenance,” De Ruyter said.

Likening the backlog to taking on debt, De Ruyter added: “The loans that we took from the future by deferring maintenance and not doing maintenance … are now falling due and they are proving very expensive for us to address.”

He added that the “ultimate answer” lay in adding new capacity as soon as possible.

Eskom would officially release its winter system outlook on May 11, but had already warned that load-shedding was likely during the period.

The utility’s scenario planning for winter includes a range of between 12 000 MW and 15 000 MW for unplanned plant unavailability.

Under the worst-case scenario, there could be as many as 100 days of load-shedding this winter.

Dukashe also confirmed that Eskom intended to continue with planned maintenance of between 4 000 MW and 5 000 MW throughout winter.