A recent map illustrates that for 2011, wind speeds were 5-10% above normal in northern Europe and up to 10% below normal in southern Europe.
The data, collected by renewable energy assessment and forecasting company 3TIER, shows departures from long-term mean wind speed with above normal areas in red and below normal areas in blue and provides an indication of how wind projects should have performed relative to their long-term production average based on their location. This type of analysis enables financiers and operators to perform portfolio analysis across regions and quickly view the effects of weather anomalies on both existing and proposed investments.
In 2011 wind speeds across Europe varied considerably from region to region. In the UK, Scandinavia, and around the Baltic Sea wind speeds trended roughly 5-10% above normal. Meanwhile southern Europe experienced wind speeds up to 10% below normal except for a few isolated areas along the Mediterranean coast. The 2011 annual map is based on total variance from average for the full year and does not depict the significant wind speed variability that occurred from month to month and quarter to quarter. This is shown in the 2011 quarterly maps, which illustrate departures from average ranging from -20% to +20%.
2011 began with substantially below normal wind speeds across a majority of Europe due to a high-pressure ridge known as a Greenland High. This structure was hovering over the western Atlantic Ocean late in 2010 and began to shift eastward toward the northern Atlantic in early 2011. This created a blocking effect above the UK, causing severe deformation to the storm track as well as warm temperatures and substantially low wind speeds in the UK, France, and Germany in the second half of the first quarter.
In the second quarter, this ridge started to break down resulting in numerous storms and anomalously high wind speeds over a broad swath of northern Europe. During this period, below normal wind speeds were primarily constrained to Spain, France, northern Italy, and areas of Ukraine and Russia. The third quarter featured milder anomalies, though an area from the UK to the Baltic Sea remained above normal. Finally, the fourth quarter enhanced this pattern, with substantial positive deviations across northern Europe, and negative deviations highlighted in Spain and a broad land area between the Adriatic and Black Seas.
The wind performance maps were created by comparing hourly data for 2011 with hourly wind conditions averaged over the period 1981-2010 from 3TIER’s continually updated European meteorological dataset. When comparing 2011 with over 30 years of hourly wind speed data, the most similar year to 2011 in its anomaly pattern is perhaps 1990. That year, however, saw much more dramatic departures from normal than this past year. Final wind speed values for the 2011 analysis were computed using a numerical weather prediction (NWP) model run at a 15 km resolution and adjusted using available observations. The underlying datasets for 3TIER’s wind performance maps provide clients with operational intelligence for every location within a region and are available in nearly all regions worldwide.