Wind farms, birds, and the precautionary approach

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The world’s largest offshore wind farm is not going to be expanded, at least for now. Covering 100 square kilometres, the London Array is not exactly small, but you might argue it is beautiful. (Its vast scale can be seen in satellite photos.) However the potential threat to a bird, the red throated diver, has resulted in expansion plans being held back. We are to await “certainty” about the impacts of the expansion on the red throated diver. Now, as someone who works in mathematical ecology, I am somewhat aware of how difficult it is to get certainty on this. And anyone who has read government rulings on these things will know a large element of subjective judgement enters the business. How many birds can a wind farm kill each year for it to threaten the population? Science can only really give a rough quantitative answer. It can also only provide a rough estimate of how many birds the wind farm will kill. Uncertainty reigns. However government rulings will require something more concrete, while lobbyists (often invoking the precautionary principle) will demand a much lower “bird kill” threshold.

The decision to go ahead with this thing is therefore not based on anything particularly rigorous, and is rather dependent on how much value you would put on a red throated diver. Here we get to the problem of the precautionary approach to things. If we do not build this wind farm we will have to build something else. Is there evidence that alternative is preferable? Making offshore wind farms more expensive in order to protect the occasional bird will do something rather obvious: make them more expensive, and perhaps increase carbon emissions. Which is worse? A little more carbon dioxide in the atmosphere or a few dead birds.

And wind farms are damned well expensive already. Do we need to make them more expensive? Greater environmental restrictions on offshore wind farms may result in more nuclear power plants being built. Is nuclear power better for birds? The evidence for or against this proposition has never been put together, as far as I know.

A very simple calculation. The power density of the London Array is about 2.5 watts per square metre, while British electricity consumption is a bit over 40 GW on average. If Britain wants to get all of its electricity from offshore wind then, using the London Array as a base case, we will need to cover about 20,000 square kilometres of sea in wind farms, or to put that in the typical British unit: an area the size of Wales. This is shown in the map below. And if we want to decarbonise the economy we will likely have to at least double, maybe triple electricity production. Can we really build offshore wind on this scale without environmental groups compromising on some of their principles? Are we really able to find enough “right places”  as defined by the Royal Society for the Protection of Birds? And will we abandon the precautionary approach for something more suited to the day?

Map created by the author using ggmap

4 thoughts on “Wind farms, birds, and the precautionary approach

    Samuel Leuenberger said:
    February 20, 2014 at 9:40 am

    I don’t understand, surely given the average death rate in the windfarm and a good understanding of the population one can come up with a proper mathematical model to show if this threaten the species or not ?Then take objective decisions based on that (of course if the impact is just in the error margin… we’re back to subjective choices)

    Regarding nuclear energy compared to wind it seems obvious that it is safer for birds. Sure I never saw any factual research on this topic, but on what ground ? I mean I can’t even figure out how a nuclear plant would threaten birds aside the possible use of nesting location where the plant buildings are made, but then again this is a ridiculously small surface.
    One possible angle of attack may be the modification of temperature in streams of water for plants not build on the coast, potentially disrupting the food chain and impacting aquatic birds ? But then there are a lot of regulations for such plants already to mitigate any impact on the stream fauna…


      Robert Wilson said:
      February 20, 2014 at 10:56 am


      It’s not particularly easy to work out how many birds are killed by a wind farm in the middle of the sea. Can birds adapt to the wind farm? Such things are poorly understood, which means these decisions have to have a large subjective element.

      I should have made the comparison with nuclear more broad. There is, to my knowledge, no decent comparative analysis of the ecological impact of nuclear plants and wind farms on wildlife. Most of the people express a view that aligns precisely with their view of wind farms and nuclear power plants. Research however is needed to get beyond such armchair ecology.


    johnrussell40 said:
    February 23, 2014 at 1:17 pm

    Perhaps it would help to carry out research to find out how we can make birds avoid the danger of wind turbines?


      Robert Wilson said:
      February 23, 2014 at 1:28 pm

      Some of the people doing research on this think that most birds just avoid them anyway, and that the problem is vastly exaggerated.

      People are doing research though in how to make birds avoid turbines, though I haven’t really been keeping track of how it is going.


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