Beware of Dunkelflautes

Peter Smith25 May, 2023 4 Min Read
What happens when the sun don't shine and the wind don't blow?

A couple of right-thinking blokes, Douglas Pollock and Bill Ponton, have gone to some lengths to show the limitations of wind power using arithmetic and algebra. Though, to be fair, Ponton’s exercise is also founded on empiricism using the experience of wind power in the U.K. Personally, I find my arithmetic and algebra easy to understand but other people’s extremely difficult and extremely tedious. Unless I’ve slept particularly well the night before, I am prone to nodding off. A point which is not made entirely idly, as I will explain.

Pollock's analysis, which I covered here in The Pipeline, purports to demonstrate that wind turbines cannot deliver a greater percentage of the power required by a grid than is their ratio of average output to plated capacity. Thus, if turbines on average produce 30 percent of their plated capacity (a good approximation to experience) then they will only be able to provide 30 percent of electricity required by the grid. Clearly this is wrong and takes no account of overbuilding. Nevertheless, it does point to the need for expensive overbuilding. And considerable overbuilding to get the percentage up. Over to Ponton.

Ponton’s analysis (“The Cost of Increasing Wind Power Capacity: A Reality Check”) is far more sophisticated than is Pollock’s. He models the successive doubling of wind power capacity in the U.K.; finding that the incremental increase in electricity generated progressively falls. And towards a limit of providing at most 53 percent of the grid’s needs. It also gets very costly to get anywhere near that, as he shows.

Out of gas.

Are the analyses of Pollock and Ponton useful? Yes and no. Yes, they underscore the limitations of wind power. On the other hand, assumptions plague them both. Pollock abstracts from the possibility of overbuilding turbines. Ponton assumes that gas peaking must operate for a minimum period of time, thus reducing the power outflow from wind. Why he makes this crucial modelling assumption he simply doesn’t make clear. Which brings me to the general question of clarity.

Both analyses are hard to grasp. Hence my reference to induced slumber. They are opaque. Opaqueness is a real problem when you’re competing against a regime that deals in misdirection. Misdirection is its forte.

Claims that renewable energy is the cheapest source of power, might shame Tokyo Rose or Lord Haw-Haw. How about announcements of the installation of a similar megawatt-hour battery as the coal power station being closed down. One lasts an hour; the other operates continuously. They are not nearly the same. But they’re made to sound the same. Grid scale battery storage is perhaps the biggest con since Charles Ponzi entrapped gullible investors. And then there’s the electrification of everything and net-zero. Bigger illusions than anything Harry Houdini could have ever devised.

You can’t compete with this labyrinth of deceit by putting up opaque models. You’ll be ignored and brushed aside by the climate cultists. And you will confuse and confound the populace. It must be kept simple, stupid. My forte.

One simple approach covered here and elsewhere by my friend Rafe Champion, consists of three interrelated self-evidently true propositions. The first is that a modern economy needs an adequate level of continuous power. The second is that wind and solar provide only intermittent power. The third follows from the first two. Storage is required to bridge gaps when wind and solar are providing insufficient and, at times, little or no power at all. Pumped-hydro storage is hard to find and extremely costly to build. Batteries simply can’t bridge gaps beyond a short time.

There’s debate about their frequency and extent, but dunkelflautes most certainly happen and most everywhere. No wind to speak of and dark skies. Take the state of New South Wales (NSW) where I live. According to the Australian Energy Regulator, it consumed 67.5 terawatt hours of power in 2021-22. That comes down to 7,700 megawatts per hour.

The biggest battery in the southern hemisphere is the so-called “big battery” in the Australian state of Victoria. It cost A$160 million and has a capacity of 450 MW hours of storage. Let us suppose a dunkelflaute brownout of a mere 8 hours in NSW. Needed is 8 times 7,700 MWh to provide sufficient power. This equals 53,900 MWh. Or, 120 big batteries at a cost of around A$19 billion. It’s a joke of course.

In theory, it should work...

To go back to the three propositions. They are simple and straightforward and unchallengeable. The man and woman in the street can understand them. Nothing about them is contentious. They are even accepted by those wedded to renewable energy.

Of course there is debate about the potential mitigation of shifting power from one place where its windy to another where it’s not, and about the likelihood of extensive and long-lasting wind droughts. Nevertheless, no one can dismiss the possibility of widespread dunkelflautes occurring. That’s why the Australian government, for example, is sinking billions into a forlorn effort to build the pumped-hydro project Snow 2.0; and is torn asunder by a coincident hatred of “polluting” natural gas while acknowledging its essential role in firming renewable energy. Cognitive dissonance in full display, courtesy of dunkelflautes.

Let’s not be convoluted or algebraic. Let’s be simple. We need power every minute of every day. The sun and wind can’t deliver that. Sometimes they deliver nothing at all. How are we going to bridge the gap? And, how impossibly much will it cost? Aye, there's the rub, as usual.

After a career in economics, banking and payment-systems management, Peter Smith now blogs on the topics of the day. He writes for Quadrant, Australia’s leading conservative online site and magazine. He has written Bad Economics, of which, he notes, there is much.


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3 comments on “Beware of Dunkelflautes

  1. Batteries plug the gap because wind/solar are intermittent and cannot give continuous grid supply, but doesn’t the same problem arise for recharging the batteries? Since wind/solar are not despatchable, they cannot be redirected to recharge batteries as required. And if they do have output won’t this be going into the grid rather than into batteries?

  2. Peter Smith is fortunate to be an Australian because we happen to have world-leading wind-watchers, or at least leaders in watching the performance of the fleet of windmills across the country. These are Paul Miskelly and Anton Lang. They have demonstrated that there are wind droughts (defined as the turbines running at 10% or less of their capacity) across the whole of South Eastern Australia for periods up to three days.
    That is the end of the story so far as the green energy transition is concerned and clearly the decision to allow intermittent energy to corrupt the grid is the biggest policy blunder ever in peacetime.
    The official policy is to keep building capacity, as though having a bigger petrol tank helps when it is empty.
    Wind and solar can DISPLACE coal and gas but they can't REPLACE them.

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