Lakes, a different scene for the offshore wind industry

Nowadays, principal areas for wind farms are at mainland and sea, increasing offshore projects. These locations have their own advantages and disadvantages, in terms of profitability, technical challenges and environmental impacts.

But there are other locations where this kind of technology is suitable for the exploitation of the  wind resource. In this post, we want to introduce an emplacement where there have been developed some projects and researches but is still in its beginnings.

These locations are big lakes. Although in our planet the area of big lakes is very small compared to mainland or seas, they have some advantages regarding both of them which generate special interest.

Compared to mainland locations, lakes have similar advantages as sea, either near shore or offshore. They are:

  • Higher speed winds due to obstacles absence.
  • “Cleaner” winds (less turbulences), which means better behaviour against fatigue failure, and better quality of generated energy.
  • Less visual impact to population.
  • Far away from settlements. Noise, glare and reflection problems are decreased.
  • Not too far to consumers, due it is usual to find big cities around lakes, energy transports could be directly and without go through very big distances.

Compared to offshore and near shore at sea lakes have next advantages:

  • Less chemical inconvenient from the media against wind mill, due to water at lakes is not salty, corrosion is so much lower, which means more life time of components, less maintenance and less costs of protection products and materials.
  • Lower loads suffered by the wind mills due ties and waves.
  • Smaller depths for implementation. It decreases problems of foundations at lake bed. 

Shared and own disadvantages:

About lake life, vibrations and noise produced by the wind turbine could affect to migratory bird flyways and aquatic life. There have been developed researches about the impact of the wind mills in birds, bats and aquatic life and it has been proved that the caused damage is not critical, very harmful either.

Actually, noise and vibrations inside the water have important consequences in aquatic life. Trying to mitigate these circumstances, there are some investigations that are currently being developed in order to oxygenate lake`s bed, pumping air inside it (very interesting in “dead zones” with low density of vegetation), it could increase vegetation meaningfully and could have an influence of 3000m around the wind mill.

Although visual impact is lower than mainland wind farms, they change the landscape of the location; this affects to population of surrounding settlements and also could harm tourism. There have been done some studies for different offshore distances, 4.8, 9.6 or 16 kilometres (3, 6, 10 miles), and they have concluded that visual impact is low for 10 or more kilometres away from the shore, and, therefore, the population could assume it.

Lakes with very cold climatology could suffer the same problem as offshore sea wind mills in northern seas where ice appear in the base of the tower. There have been designed some conical shapes (which do not increase so much costs) of the tower basis which avoid the ice generation.

Nowadays there are some wind farms developed in lakes, as the wind farm in Vänern lake (Sweden), and there are a lot of projects starting to born in the USA Grate Lakes, which concerns to Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin, and also in Canada regions of Ontario and Quebec.

SOLUTE INGENIEROS has already developed some researches by its own and has performed some projects in the structural and foundations offshore technologies. Since its experience estimates favorable conditions from an structural point of view for this kind of sites.