Why has Britain suddenly been plunged into an energy crisis, with spot prices for electricity rising to over £400 per MWh, ten times what they were this time last year?
The spike in global gas prices caused by economic recovery from Covid has been commented on often enough, as has the failure of Britain to maintain sufficient gas storage reserves – we have closed a large gas storage facility as other countries have been building up theirs’.
So, too, we have learned of the failure of many smaller energy companies to hedge the prices of their energy, thus putting them at risk of spikes in wholesale prices.
But there is one aspect to this crisis that has received rather too little comment: low wind speeds, which have reduced output from wind farms.
While the current lull is chiefly a vagary of the weather, global wind speeds have been trending downwards for several decades, threatening to undermine an energy strategy that is over-dependent on wind power.
According to the sixth assessment report of the Intergovernmental Panel on Climate Change, global mean land wind speed (excluding Australia) showed a fall of 0.063 meters per second per decade between 1979 and 2018.
Global wind speeds have been trending downwards for several decades
We hear little about this observed trend. Is this because it runs contrary to the alarmist claim that we face a future of ever-stronger storms?
In fact, the observational data shows not only a slight fall in mean wind speeds but also a reduction in the strength of storms right up to 60 degrees north – the latitude on which lie the Shetlands.
Given there are relatively few human settlements north of this latitude it suggests that most places are facing a lower risk from damaging winds.
But low wind speeds are certainly a threat to the wind power industry. Danish wind energy specialist Orsted recently issued a profit warning partly as a result of lower-than-expected wind speeds.
That wind energy has the problem of being intermittent has of course been known about since the beginning of the wind industry; it is obvious.
But a generalized fall in yield from wind farms threatens to disrupt any energy policy that is over-dependent on wind.
No one seems to be sure why global wind speeds over land are falling – whether as a result of changing atmospheric circulation, increasing urban development, or whatever – but research at Germany’s Max Planck Institute has concluded that existing wind turbines themselves could play a serious role in lessening the wind power available to be extracted by future wind farms.
The theoretical study found that a turbine in an area covered with wind farms could be expected to generate only 20 percent of the energy that an isolated turbine would produce.
That is a seriously large reduction which raises the question: just how many wind farms can a country like Britain absorb before the turbines are all stealing power from each other, and are we doomed to suffer repeated energy crises thanks to our overreliance on the wind?
Read more at Spectator UK
Better yet, wind farms slow the wind and thus alter the climate of the land they occupy. It would be nice to be able to use that land for a second purpose, but the slower wind means hotter soil and more water loss to evaporation—the land becomes more arid.
So sucking energy out of the wind reduces wind speeds? Who would have ever thought of that! And a large wind farm has a lot of turbines sucking energy out of the wind.
You’ve only got to look at the picture at the top of this piece to realise how stupid the designers of windfarm layouts are: if the wind happens to be blowing directly along a straight line of turbines only the leading one will get the full force. Wouldn’t a quasi-random distribution be a bit better? But even then there would be a general masking effect.
That would make sense to have them set randomly so as to get as much of the wind energy extracted as possible. But with the ever-changing wind direction I would think that there is no best layout but one that takes into account which direction the wind is most likely to blow. Like here along the Front Range of Colorado the winds frequently come from the west/southwest except when it’s not!
… the answer, my friend, is blowin’ in the wind, the answer is blowin’ in the wind …
When the globe is cooling there’s less wind.
Yes, cooling climate means more viscous air, just as a cooling Gulf Stream slows down as the water becomes more viscous. There be a vicious feedback. With cooling, less energy is delivered to Europe by the Gulf Stream and Europe is colder and, with a warmer stream, Europe gets hotter as the stream is hotter as well as faster, being less viscous.