Eskom’s maintenance backlog has grown over the past year, with a quarter of planned projects for the 2021/22 year deferred to next year due to cash flow problems. 

The delayed maintenance comes on top of historical backlogs - some of which date back to 2013 - and which continue to weigh down plant reliability. Eskom has recorded its worst energy availability factor ever, with only 63% of the plant available, on average, at any one time. 

This resulted in a record number of nearly 1 200 hours of load-shedding over the financial year so far. It also resulted in higher usage of expensive, diesel-fired gas turbines - already coming in at a cost eight times higher than budgeted.

One of Eskom CEO Andre de Ruyter’s key strategies to restore Eskom's plant, when he took over two years ago, was to implement "reliability maintenance", in terms of which plants would be maintained strictly in line with the original equipment manufacturers' specifications. 

Eskom executives provided their quarterly state of the system on Thursday. load-shedding remained a risk, said Eskom, particularly as the two units of Koeberg – Eskom’s most reliable power plant – would be on long-term outage. This will take 920MW out of the system for more than 300 days. 

Head of generation Phillip Dukashe said that the biggest problem constraining the maintenance programme was Eskom’s cash flow. The chief financial officer has been unable to release funds timeously due to cash constraints. 

The uncertainty around cash for maintenance also led to inefficient maintenance planning, as units have been taken out for long-term maintenance, putting them out of action, long before the cash was available. 

Out of 84 planned maintenance outages for this year 28 of them have been deferred to 2022/23.

“The plant is unforgiving and it will take itself out and fail.”

Dukashe outlined the impact of long-term maintenance back logs on plant performance. For example, a maintenance plan dating back to 2013, to refurbish control and instrumentation at 11 power stations, is in most cases yet to commence. High load losses were also due to: the failure to refurbish cooling towers; repair of boiler tube leaks where there is a backlog of 28% projects; and shutdowns to emissions levels, caused by inefficient plants. 

Despite the failing energy availability factor, Eskom plans to run its coal plants above the benchmark in the coming financial year, it emerged in the company’s tariff increase application last week.

Dukashe acknowledged that this would lead to greater wear and tear on the plant. 

De Ruyter said that funds had "now begun to flow" from Eskom’s coffers for maintenance and it was his intention to implement "reliability maintenance" rigorously. Eskom would not compromise on planned maintenance, when unplanned outages were high, he said.

"We are absolutely firm in our resolve to restore the long-term sustainability of the system."

Dukashe also noted an ongoing skills drain from the generation division, which he said, was losing 37 people a month to resignations and retirements out of its 12 000 staff. The rate was far higher than previous years, he said.

"As you know the best people leave first. I’m worried about the loss of experience of skilled individuals which will make our plant recovery more difficult," he said.