Our table showing a typical wind speed for Britain of 7.6 m/s and for Germany of 6.2 m/s was included to give an idea of relative wind speeds. These estimates were not used in our calculation of energy yields, which were all from actual data from operators in Germany and Britain. There is a considerable spread about the mean, thus with fixed payments in Germany, the profitability of some installations will be higher than others.
Many of the German installations comprise a few machines only and by implication are more costly. But while this may be true at a specific site, the data show no clear differences in wind farm prices and single machine prices. There is, though, a trend towards higher prices for higher wind speed sites (in both countries) and, as we wrote, the higher costs in Germany could be due to the need for piling into the silt in coastal regions. In addition, the German installations often use taller (more costly) towers, but this does not account for all the difference between installed costs. One key factor may be the lengthy planning procedures in Germany which can lead to machines being ordered long before they are required.
The wind speed differences undoubtedly account for a substantial proportion of the difference in energy generation costs but planning and certification procedures are also contributory factors.