Community Research and Development Information Service - CORDIS

Mapping wind energy in the Baltic Sea

As environmental and planning issues provide barriers to building wind farms on land, it will be necessary to place more wind turbines offshore in the future. However, the cost of current offshore wind farm electricity is somewhat higher than that generated on land, despite the wind speeds at sea being much higher than those found over land. More knowledge about wind patterns offshore is needed, especially in coastal regions as it likely that wind farms would be placed in these areas.

The methodology consisted of a three step zooming procedure. General climate study data were put into four different mesoscale models. These models were thus created and tested for their use in simulating wind behaviour. They generated the input for the WAsP model. The final output from this model at specific sites will give the computed wind resource. As well as determining the relationship between distance from the coast and wind speed, low-level jets were also studied. These are local wind speed maxima in the lower part of the atmospheric boundary and they can be of importance to offshore wind resources. Each of the methods was tested in this process and a database of condensed information was created.

The wind sources in the Baltic Sea and the Gulf of Finland were mapped. The main results are illustrated by colour coded wind resource maps of the Baltic Sea. They show that there is a relatively small variation of energy density across the sea, decreasing towards the north east. From southern Sweden and northern Germany to the eastern part of the Bay of Finland, the energy density decreases by about 30% (700 to 450 W/m{2}). The coastal influence study showed that the wind energy is lower at coastal sites than over the open sea. This is because the rough land surface slows the wind down and also the sea surface is rougher near land than it is far away from the coast. The study highlighted the fact that the coast affects wind energy over much longer distances than was previously thought: 20 km instead of the predicted 5 km. The energy output, in general, decreases by 40% on moving from the coast to the open sea, although this will depend on the local climate and terrain.

The maps provide basic tools to identify feasible sites for wind turbines. Thus, they help to determine the market potential for wind energy. Although indirectly, the results promote increasing the penetration of renewable wind energy in the European electricity generation system.

Reported by

Risø National Laboratory
399 Frederiksborgvej
4000 Roskilde
See on map
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top