It was really good news to read today that the first unit of the Ingula pumped storage power station has been commissioned! The extra 330 MW is a most welcome addition.
But I am troubled by the slow spread-out commissioning for the remaining five units at Medupi. If the economy really does start to grow as we so desperately need we will be left short again and lack of generating capacity will again throttle growth. Why is the commissioning of the remaining units at Medupi so slow? Is there any excuse for this shocking tardiness?
Another concern is that we are fooling ourselves with the touted 7031 MW increase in generating capacity since 2005. Much of this “increase” is attributable to renewables, which add very little to base load capacity to meet peak power demands. Worse still we have to provide real baseload capacity to replace their capacity since the renewables cannot be relied upon. In the case of solar PV, which accounts for more than half of the renewables, it can be relied on for one thing only: it will always drop to zero during the biggest peak demand period of every day since the sun will have set! Wind too can only be relied on for about 30% of its capacity (although this too is doubtful). It’s a bit like Rommel relying on the numerically large Italian army to hold a key section of his battle line. (Being a great general, he never did.)
In effect, all that the renewables do is replace part of the coal consumption during less important times of the day. While this is a “nice to have”, it is a very expensive luxury. The cost of renewables is way higher than the mere marginal cost of the coal that is saved. Our current ability to avoid load shedding is primarily attributable to bringing in 800 MW of solid additional base load capacity with the commissioning of the first unit of Medupi power station and bringing other older base load generating stations back into service. Helped along by the lamentable state of our economy. The contribution of the renewables was conspicuous by its absence, with 800 MW from Medupi worth about 5333 MW of renewables, which is a bit like 85% of the army running away in the face of the enemy.
It must also be appreciated that the primary purpose of pumped storage schemes like Ingula is to generate power over and above the actual primary generating capacity that is available. In effect it is a type of battery (but much more efficient and much bigger than other batteries) used to store excess power produced during low demand periods so that it can be released during peak periods when otherwise we would not have had sufficient generating capacity. This saves the cost of building extra primary generating units only to have them stand idle for most of the time until the peak arrives: typically in the dead of winter. So thanks guys for bringing Ingula on line at last.
The big hidden cost of renewables lies in their parasitic nature. By cutting into the coal-fired and other forms of base load generation during the day they force base load stations to stand idle until the peak demand periods arrive, thereby artificially pushing up their unit cost while at the same time reducing the unit cost of the renewables that are allowed to run flat out, while they can.
This is self-deceiving economic madness. Correct evaluation of the costs should include the renewables fair share of the capital and operation and maintenance cost of the base generation stations. Moreover, it must also include a fair share of the cost of hydraulic batteries like the Ingula, Drakensburg and Palmiet pumped storage schemes, plus the ensuing transmission losses. Failure to take this into account is an exercise in intellectual suicide.
Aside from gerrymandering the power generation costs, this economic lie also exposes us to relying on something that is not really there when we need it, i.e. 85% or more of the renewables generating capacity. The cost of load shedding when this occurs is very much greater than the distorted unit cost of the power generation itself.
So could Eskom please give us some really useful information on the base load generating capacity that is actually available to us to meet peak power demands? Please also factor that into the true cost of renewables.
In defence of the much maligned diesel generators which have the most expensive unit cost of all of our modes of power generation, they still render a valuable service that renewables cannot match, i.e. they provide power during exceptional peak demand periods. The current economic problems have nothing to do with their primary function. The problem arises from their abuse to fill in for the lack of primary base load generating capacity. But even in this abnormal application the cost of not supplying the electricity would have been much higher.
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