The power in the wind increases with the cube of the wind speed. Hence, the resource available at a specific location depends strongly on the annual mean wind speed. The European Wind indicates on a large scale those regions with similar annual mean wind speed. However, the annual mean wind speed at a specific location depends strongly on the local topography and may vary considerably from the regional mean.
It should also be noted that the annual mean wind speed increases with the height above ground of the measurement; for example, the difference in annual mean wind speed between a height of 40 m and 60 m is approximately 10%. Hence, the resource at a specific site depends strongly on the locality and the size of wind turbines to be installed. Nevertheless, general trends hold, with the annual mean wind speed increasing to the north and to the west.
With an annual mean wind speed of roughly 7 m/s for England and Wales and 8 m/s for Scotland, the UK clearly has a very rich resource compared to other European countries. To emphasize this fact, it is sometimes claimed that the UK has 40 % of the European wind resource. Of course, this claim is highly subjective, being dependent on the details of the resource estimation and the definition of Europe used, and should be interpreted merely as indicative of the comparative richness of the UK resource.
Not all of the wind power resource can be realized however. Wind farms must be sited in open country avoiding sites of scientific interest and sufficiently far from inhabited buildings and roads. Unfortunately, much of the exploitable resource is located to the north and west, far from the main population centres. To fully exploit this resource would require the transmission of large amounts of electrical power over long distances from the points of generation to the points of consumption. The national grid is currently not well placed to accommodate this transmission because of such restrictions as the capacity of the inter-connector between Scotland and England.
Again, the wind power annual mean wind speed increases to the north and west, with the UK well resourced. The resource that can be exploited must be in shallow water and away from major shipping lanes. Even with these restrictions, there is a large exploitable resource off the north west, south east and south west coasts of England. These have the advantage of not being far away from the large centres of population, and so may be particularly valuable. In particular, there is a considerable offshore resource round the southern part of England. For example, the annual mean wind speed at a height of 50 m on the sea coast round England is 7–8.5m/s and 10 km offshore at a height of 100m is 8.5–10m/s. Sites with these wind speed attributes would be sufficiently well resourced for exploitation.
In comparison to the UK’s annual electricity demand of roughly 350 TWhours/year, it would be technically feasible, but not practical, to generate 1,000 TWhours/year of electricity from wind. Instead, the accessible and economic resource is approximately 150 TWhours/year. Onshore wind power could contribute in the region of 50 Twhours/year and offshore wind power could contribute in the medium term 100 Twhours/year.
From the above discussion, it is clear that the UK wind power resource is particularly strong in comparison to other European countries. However, the UK record in exploiting that resource is relatively poor. The very rapid growth in wind power capacity installed in the EU is stood at 35GW, constituting 70% of the world total.
The USA accounts for much of the non-European capacity. The contributions to the total EU installed capacity by the leading countries, Germany, Spain, and Denmark, are 16,629MW, 8,263MW, and 3,117MW, respectively, followed by Italy, the Netherlands, and the UK, with 1,125MW, 1,078MW, and 888MW. Although it is increasing rapidly, the UK installed capacity is rather modest in comparison to Germany, Spain, and Denmark, especially when the extent of the resource is taken into account