The Inadequacy of Wind Power
by: Wade Allison
Note 40, The Global Warming Policy Foundation © Copyright 2023
Translated from the Oxford English by: Michael J Setter
The plan to dramatically cut combustion of fossil fuels was accepted at the 2015 Paris Conference. The desired reaction around the world has been to revere ‘renewables’, the sources of energy delivered intermittently by the power of the Sun. Unfortunately, this power, especially in the form of wind, is attenuated by the huge distance that sunlight must travel to reach the Earth and is extremely weak. That is why, before the advent of the Industrial Revolution, it was unable to provide the energy to sustain even a small global population with an advanced standard of living.
Today, modern technology is deployed to harvest these weak sources of energy. Vast ‘farms’ that overwhelm the natural environment are built, to the detriment of other creatures. Developments are made regardless of the damage wrought. Hydro-electric schemes, enormous turbines and square miles of solar panels are constructed, despite being unreliable and ineffective; even unnecessary. (1)
In particular, the generation of electricity by wind tells a disappointing story. The political enthusiasm and the investor hype are not supported by evidence, even for offshore wind, which can be deployed out of sight of the controversial “my back yard” scenario. What does the evidence actually say?
That the wind fluctuates is common knowledge. But these fluctuations are grossly magnified to an extent that is not immediately obvious – and has nothing to do with the technology of a wind turbine. The energy of the wind is that of the moving air, and, as every student knows, such energy is ½Mv2 , where M is the mass of air and v the speed. The mass of air reaching each square meter of the area swept by the turbine blade in a second is M=ρv, where ρ is the density of air: about 1.2kg per cubic meter. So, the maximum power that the turbine can deliver is ½ρv3 watts per square meter.
If the wind speed is 10 meters per second (about 20 mph) its power is 600 watts per square meter at 100% efficiency. (2) That means to deliver the same power as Hinkley Point C (Hinkley Point C is a two-unit, 3,200 MWe nuclear power station under construction in Somerset, England) by wind would require 5.5 million square meters of turbine swept area – that should be quite unacceptable to those who care about birds and to other environmentalists. But the performance of wind is much worse than that, as a look at the simple formula shows. Because the power carried by the wind depends on the third power of the wind speed, if the wind drops to half speed, the power available drops by a factor of 8. And worse still, if the wind speed doubles, the power delivered goes up 8 times, and as a result the turbine has to be turned off for its own protection. This is not related to the technology of the turbine, which can harvest no more than the power that reaches the area swept by its blades.
The effect of the fluctuations is dramatic. In Figure 1, the blue area shows the total EU and UK wind energy generated each day in 2021. The installed nominal generating capacity was 236GW (the brown dashed line), but the highest output in the year was 103GW (26 March). This is not the headline plot that the industry shows to its investors, the media and politicians, but it comes from their own published annual WindEurope Report. (3)
The wind blows somewhat more steadily offshore than onshore, as every sailor knows. Nevertheless, the unreliability inherent in wind energy persists. Figure 2 shows the wind power generated by all UK offshore windfarms in March 2022, as presented online on the Crown Estate website. (4)
Over some periods, it rose to the nominal installed capacity of 10GW. However, for 8 days at the end of the month it averaged no more than 1.2GW. The green rectangle (added) illustrates that 8.8GW was not available for this time, presumably because the average wind speed halved. That much energy, 1600GWh, is 1000 times the capacity of the world’s largest grid storage battery (1.6GWh at Moss Landings, California). Battery technology has its own problems. It can provide for laptops and other portable applications, even car batteries at up to 75 kWh, but larger batteries have problems with safety (5), and mineral shortages. (6) Batteries 20 million times larger are never going to be available and storage batteries will never make good the failure of offshore wind farms, even for a week. And furthermore, the wind can drop for longer periods than that.
However, the bluster of windfarm politics, as pursued by the UK Government, ignores evidence, it seems. The industry is keen to promote onshore wind also. However there the fluctuations are greater than offshore and the political deterrence from “My Back Yard” is stronger. Consequently, the Government has promoted offshore projects. On 6 October 2020, Boris Johnson announced that ‘wind farms could power every home by 2030’.
He continued to harangue the public in Churchillian tone ‘Your kettle, your washing machine, your cooker, your heating, your plug-in electric vehicle – the whole lot of them will get their juice cleanly and without guilt from the breezes that blow around these islands.’ He was describing Government policy to expand existing offshore wind power from the existing capacity of 10.4GW by an additional 40GW, in addition to the already installed onshore capacity of 13.6GW.
The significant word in the announcement was ‘could’. Evidently, offshore wind might provide such lighting in the UK – sometimes. But Great Britain needs reliable energy all the time. British consumers should follow the example of Alice who, in negotiating terms with the White Queen, insisted on clarification of the day on which jam should be delivered. (7) Evidently, they should not look to wind power for reliable energy, but elsewhere. (1)
With general energy shortages, the war in Europe, high prices and the likelihood of failures in electricity supply, many popular scientific presumptions underlying energy policy should be questioned. Wind power fails on every count.
Notes:
1 https://www.mdpi.com/2673-4362/3/3/13
2 Coincidentally, this is about the same power per sqm as the solar flux on the illuminated globe. However, the share of this received at the latitude of the UK is reduced, especially in winter and at night, of course, when most energy is needed.
4 On its website, Crown Estate publishes a plot showing the running output over the previous 30 days. https://www.thecrownestate.co.uk/en-gb/what-we-do/asset-map/.
6 https://www2.bgs.ac.uk/mineralsuk/statistics/rawMaterialsForALowCarbonFuture.
7 https://en.wikipedia.org/wiki/Jam_tomorrow
About the author: Wade Allison is Emeritus Professor of Physics at the University of Oxford, and a Fellow of Keble College. In addition to teaching mathematics and physics at Oxford and researching at CERN, he is also deeply involved in medical physics and the biological effects of radiation, on which he has published three books: Fundamental Physics for Probing and Imaging (OUP, 2006), Radiation and Reason (2009) and Nuclear is for Life (2015).
BigMouth Note: Mr. Allison is an advocate of nuclear energy. It is my opinion that we will see better overall solutions to our civilizational power requirements become available in the near future, especially from fusion and the interim use of Thorium powered small scale generators. Large scale nuclear fission power plants need not be constructed. There is certainly sufficient fossil fuel available in the interim if its distribution and political interference are addressed rightly.