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A quarter in, how do things really look at Eskom?

Worryingly, planned maintenance is running at lower than obvious levels.

March might not have seen a repeat of February’s 14 days of load shedding (yes, half the month!), but just because we haven’t had rolling blackouts, doesn’t mean things are all fine at the power utility.

For one, we had the sudden suspension of CEO Tshediso Matona and three senior executives on March 12. Oh, and Chairperson Zola Tsotsi “stepped down” on March 31 (let’s not even start with his three hare-brained schemes to add generation in the short term, as revealed by City Press on Sunday).

So, load shedding on only three days in March. But, dig into the data, and the generation capacity situation looks worrying. Eskom confirmed the use of its contractual right to “interrupted load supply”, effectively where it cuts supply to BHP Billiton’s Hillside aluminium smelter in Richards Bay.

It also “reduced down” demand on March 9, 10, 11, 21, 22, 23, 24, 25 and 26 – that’s nine days. This is load curtailment. Basically, load shedding for its large industrial users. When demand is reduced, Eskom refers to “primary energy constraints” in its system status bulletins. This means, for one or more reasons, it cannot run its open cycle gas turbines which are capable of producing 2072MW at peak. Without speculating wildly, the only obvious reasons why it wouldn’t run the diesel turbines would be because it lacks the budget or lacks the diesel.

Forecast peak demand vs actual peak demand

 Screen Shot 2015-04-12 at 8.02.39 PM  

The gap between generating capacity (supply) and demand – or Eskom’s reserve margin – is as thin as ever. For last month, it ran at an average of 5.35%, however there are three big ‘buts’: the open cycle gas turbines were run for all but those nine days of the month, demand was artificially forced lower on those days, and the average is skewed by weekends. Strip out Saturdays and Sundays (where it tends to mostly run a decent surplus of capacity), and the number drops to 4.04%.

If Eskom’s been performing the equivalent of a high-wire walk over the past six months, March 12 was trapezing on the edge of a samurai sword. According to the utility, demand on that Thursday was 31643MW, with supply of 31627MW. That’s a shortfall of 16MW. This happened once previously this year, on February 23 where there was a 20MW shortfall (on that day, it exercised its right to interrupt load supply). On both occasions, it skated through. Perhaps we’ve come closer to the abyss than we think…


Forecast demand 1

Forecast demand 2

Actual demand

Forecast capacity 1

Forecast capacity 2

Actual capacity


Feb 23








Mar 12









Screen Shot 2015-04-12 at 8.02.15 PM

But this is the war room managing chaos day by day. Of major concern is the fact that Eskom simply cannot keep up with its maintenance backlog. That planned maintenance number hasn’t moved significantly all year: it’s largely been suck in the 3500MW – 5500MW range, mostly hovering around 4500MW. That tells one picture.

Again, dig deeper and the numbers are terrifying.

Screen Shot 2015-04-12 at 8.02.39 PM

On the one hand, the unplanned outages number looks significantly better due to the return of 1800MW of supply after “emergency repairs” at Majuba (there’s still 1110MW out of action at that plant, since the silo collapse in November). It’s worth mentioning that these repairs are temporary and rely on mobile coal feeders to keep the hungry power station fed. Add back the 1800MW to the unplanned outages figure, and they’re as high as the crisis in late January/early February where a quarter of the country’s generating capacity was offline unexpectedly.

But, the planned maintenance figure is the real problem. Remember, there’s 900MW from Koeberg offline until the end of May. That’s another six weeks from now. Take that number off Eskom’s published planned maintenance figures and it’s clear that it’s struggling to do 4000MW of maintenance at any one point in time, never mind the 6000MW it should be.

The 900MW from Koeberg is not going to solve the ‘winter problem’ by itself. There’s a race against a change in seasons to get the 794MW of “full potential” from Medupi Unit 6 into the grid. At the start of March, then-chief executive Tshediso Matona said this would happen “within the next three months”. (Chances of this happening given that every single other deadline has been missed?)

Get the ramp up of Medupi Unit 6 right, and get some of that planned maintenance done (properly!), and we’ll be alright for winter. Don’t, and watch the unplanned outages and general unpredictability rocket upwards because Eskom simply hasn’t had the headroom to get plant fixed. The vicious circle it’s been battling against all summer will continue.

Tick tock.

* Hilton Tarrant works at immedia.

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Why hasn’t government proceeded with the idea of “energy ships”? They are available and I gather they can be hooked up to the grid fairly quickly.

I guess because of cost. The unit cost of the electricity generated by the “energy ships” is probably very similar to the cost of the gas turbines used by Eskom (same type of generators). It is several times of the price charged by Eskom and without drastic increase in the price of electricity Eskom could not pay for it.

So Hilton why can Eskom not keep up with planned maintenance? Saying that they cannot is something that by now all but the clinically insane know is true. Please give a deeper an analysis. Just quoting stats is historically interesting bit that’s all.

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