The likes of the BBC and the Guardian are always keen to tell us when wind farms have generated a lot of electricity in the UK. A couple of headlines from the BBC over recent years give the general picture. From 6^th January 2023 – Wind generated a record amount of electricity in 2022; and from 7^th January 2025 – Record year for wind power in 2024. The same thing can be found in the Guardian. 3^rd January 2023 – UK sets new record for wind power generation; 21^st December 2023 – Wind turbines generate more than half of UK’s electricity due to Storm Pia ; and 6^th September 2024 – Wind and solar farms power Great Britain’s grid to greenest ever summer. There are loads more in similar vein, but that’s enough to make the point. The associated point is that they seem rather less keen to talk about the other side of the coin – dunkelflautes, usually in winter when demand for electricity is at its highest, when life is cold, dark and miserable.

And so I was rather surprised to see a Guardian article that does talk about the problem with dunkelflautes. Needless to say the emphasis is on the success of wind power, rather than on its repeated failures, as is evident from the headline, written on Wednesday 22^nd January 2025, following several dunkelflaute days, but in anticipation of a fierce storm due to rush in from the Atlantic. According to the Guardian, this would send wind turbines spinning madly, generate loads of electricity and send prices plummeting: “‘Weather bomb’ expected to cause fall in UK wholesale energy prices – Gusts of up to 80mph may bring disruption but also a surge in cheap wind power after days of near-zero output”. From the Guardian’s point of view this is a great headline, because it kills two birds with one stone. It tells us that wind power is returning to save us, and it gets in a quick upping the ante phrase about the “climate crisis” (sic), an opportunity to repeat a phrase that is much beloved of the Guardian – “weather bomb”.

Having got in my usual disapproving comments about the Guardian, I give them credit for reporting fairly and openly about the problems experienced by the National Grid. It admits that renewable energy output fell to near zero this week; that windfarms have produced the lowest level of electricity since September 2023 (despite, I would add, there being rather more of them operational now than there were 16 months ago); and then it gives us these three very damning paragraphs:

Britain’s wind power output fell to just above zero on Wednesday, which, combined with the cold, dark weather, caused the market price for electricity to climb to almost £250 per megawatt-hour at auction, or almost seven times the average price before the pandemic.

The sudden drop-off in renewable energy due to dull windless winter weather, known as dunkelflaute in German, has also forced the system operator to pay gas power stations more than £500/MWh to run on Wednesday evening when household demand is expected to reach its peak.

The weather conditions – the third dunkelflaute of the winter so far – left Britain’s electricity grid reliant on gas-fired power stations. They accounted for more than 70% of power generation at points on Wednesday.

But that was where reporting reality ended. It went on to say that these sorts of issues are why we need more long-duration energy storage, and gave us the usual dubious claims that all this will save us money in the long-run. For instance, we are told that that battery storage will need to grow fivefold by 2030 (I would suggest that is another impossible task, to go along with the impossible targets set by Mr Miliband for various forms of renewable energy by 2030) to between 11 and 15GW; and that if we reach 20GW it could (weasel word) save the electricity system £24Bn by 2050 (that’s less than £1Bn p.a. between now and then, a fraction of the costs all this stuff is adding to the running of the energy system). The acknowledgement that long-duration energy storage is what’s needed is interesting – stuff like pumped hydro (more despoliation of our wild places, especially in poor Scotland) because batteries and interconnectors don’t come up to snuff:

Akshay Kaul, a director at Ofgem, the energy industry regulator, said: “We’ve seen this winter that when you have a period of still, cold, cloudy weather [that] batteries on their own, and [power] interconnectors on their own, are not sufficient.”

The final piece of the propaganda picture is a repeat of the peculiarly persistent myth by the renewables industry that renewables are cheap – they’re not when whole system costs are taken into account and artificial carbon costs are stripped out.

This week’s data
All of which is a long-winded introduction to the fact that we at Cliscep have been keeping track of the pathetic performance of renewables this week, and the consequent implications for costs with gas generators and interconnector operators being able to take advantage of the Grid’s desperation for sources of electricity at almost any cost. Of course, if gas generators were allowed simply to supply electricity on a steady basis, instead of giving priority to renewables, and having to ramp up and down on demand, these costs would be avoided. This is what various Clisceppers have recorded this week:

Electricity generation at 8.53am on 19^th January: Gas 62.6%, solar 0.1%, wind 12.7%.

Electricity generation at 5.14pm on 19^th January: Gas 61.3%, solar 0%, wind 7.9%. Price: £141.97/MWh.

Electricity generation at 8:00 am 20^th January (a cold Monday morning): Gas 71%, nuclear 9%, biomass 8%, wind 8%, solar 0% and (note this) interconnectors 1%. Price: £218.41/MWh

Electricity generation at 8.04pm on 20^th January: Gas 62.3%, solar 0%, wind 9.4%. Price: £157.14/MWh.

Electricity generation at 7:30 am on 21^st January(a cold Tuesday morning): Gas 70%, nuclear 10%, biomass 8%, wind 14%, solar 0% and interconnectors -5%. Price: £133.72/MWh

Electricity generation at 9.08pm on 21^st January: Gas 63.5%, solar 0%, wind 7%, interconnectors 9%. Price: £154.77/MWh.

Electricity generation at 7:00 am on 22^nd January: Gas 74%, nuclear 11%, biomass 9%, wind 1%, solar 0% and interconnectors 4%. Price: £128.53/MWh

Electricity generation at 10.35am on 22^nd January: Gas 65.6%, solar 1.8%, wind 0.7%, interconnectors 11.4%, nuclear 9.3%.

Electricity generation at 4.02pm on 22^nd January: Gas 60.6%, solar 1.1%, wind 1.4%, interconnectors 13.1%. Price: £191.46/MWh.

Electricity generation at 5.23pm on 22^nd January: Gas 60.2%, solar 0%, wind 2.1%, interconnectors 13.3%. Price: £272.58/MWh.

I should also, in all fairness, report that on Thursday 23^rd January, as Storm Éowyn approached and wind speeds started to pick up, wind farms performed rather better (though their performance was a long way from spectacular). For instance, at 8.10pm, gas was down to 33.5% while wind was generating 38.6%, nuclear 9.7% and we were still relying on the interconnectors for 10.8%. And the price was still high, at £117.54 per MWh.

Storm Éowyn

The Guardian article mentioned above was very optimistic that this week’s profound dunkelflaute would come to an end in dramatic fashion, once stormy conditions arrived, saying “it will also lead to tumbling wholesale electricity prices by causing cheap wind power to surge 40-fold in 48 hours.” It also claimed:

However, electricity prices for Thursday and Friday have fallen by more than half, to £107/MWh and £84/MWh respectively at auction, as wind power is forecast to surge from 0.4GW to 16GW by Friday morning.

How did that work out in practice? I confess to not having had time to monitor the prices all day on Thursday, but when I did look prices were still high (as mentioned above) at £10.54 per MWh higher than claimed by the Guardian.

On Thursday afternoon, somewhat ironically, the Telegraph reported “Thousands of turbines to switch off for Storm Eowyn because winds are too strong – Millions will be paid to operators in compensation for missed output”. This is what it said:

Thousands of wind turbines are to be switched off during Storm Éowyn because the power generated by its 100mph gusts would overwhelm the UK’s electricity grid.

The extreme weather will generate an unusably large amount of energy when Éowyn hits wind farms in Scotland and the North Sea on Friday, forcing operators to disconnect their machines.

The idle turbines are none the less expected to deliver millions of pounds of profits for wind farm operators, who will be able to claim so-called constraint payments for disconnecting them…

…Renewable UK, which represents the wind industry, as well as major operators including Equinor and Scottish Power, did not respond to requests for comment.

Storm Éowyn is likely to result in some wind farms being switched off for safety reasons, too. This is because turbines are designed to work best within normal wind ranges.

Extreme winds and increased rotation speeds risk damaging turbine blades, bearings and other components.

So much for the reports in anticipation of the Storm. How have things worked out in practice? Well, at 8am on 24^th January, wind was certainly performing better than at any time this week, generating 45.8% of our electricity needs, while gas had to ramp right down from its earlier highs, to just 24%. Nuclear was up to 10.6% and we were still relying on the interconnectors for a net 11.5% (it would have been 13.5%, but – as is so often the case – we were exporting 2% to Ireland). As for price, at £113.09 per MWh, our electricity was still very expensive, and almost £30 per MWh higher than the figure suggested in advance by the Guardian. That figure, of course, doesn’t take into account increased constraints payments, which come out of a different pot (but which we, the consumers and taxpayers, still pay).

Interestingly, according to the iamkate website wind’s output seems to have peaked at 3.30am, when demand was probably close to its lowest, and then declined through the small hours towards breakfast time when demand increased. Very useful!

The apparent decline in wind through the morning does seem to be borne out by the statistics. By 8.20am, wind’s contribution had declined to 43%, i.e. down by 2.8% in 20 minutes. The interconnectors were up to a net 12.6%, and the price was still stuck at £113.09 per MWh.

By 8.55am, wind was down to 41.2% (solar was chipping in a massive 1%), gas was on 25.6%, the interconnectors were supplying a net 12.5%, and the price was on its way back up, at that time to £115.93 per MWh.

At 9.20am wind was generating 40.8%, solar was up to 1.8%, the interconnectors were still supplying a net 12.5%, and the price was still £115.93 per MWh.

The decline continued steadily but surely. By 9.40am, wind was down to 40.2% and the price was up to £118.22 per MWh. And 15 minutes later wind was down below 40%, at 38.9%. The price was £117.86 per MWh. By 10am, wind had slipped slightly again, to 38.8%.

I could carry on eyeballing the figures for the rest of the day, but I think the above is sufficient to make the point. Given how windy it is here right now, I assume (although I don’t know) that wind’s declining contribution to the grid is due to it being too windy rather than because wind is declining through the day. It seems as though electricity generated by wind is a bit like the porridge in Goldilocks and the the Three Bears. Whereas the porridge was either too hot or too cold, with the wind sometimes there’s not enough, sometimes there’s too much – it has to be just right to do the job.

In due course we may discover the extent to which wind turbines have been turned off for safety reasons and the extent it was to avoid overloading the grid. Along with that, we may learn what today’s constraints payments will add up to. One thing is clear, too much wind is the other side of the dunkelflaute coin. The idea that the UK should make itself completely reliant on this (and other renewable) sources of electricity is very unwise, as is making us dependent on electricty for most of our daily activities – driving in cars, heating our homes, cooking our food. Yet again, we learn that thousand of homes are without electricity due to the storm – 71,500 in Ireland, according to the Guardian and many more in Cumbria and Lancashire, according to our local media, with power not expected to be restored in some cases before 6pm tomorrow. No doubt Scotland, too, will be badly affected the day is over.

The Guardian’s claim that the storm would bring cheap electricity in its wake appears to have been unduly optimistic. In fact, everything about the campaign for net zero and renewable energy seems to be massively over-optimistic, and potentially very damaging in so many ways.