In modern wind farms, made of traditional horizontal axis wind turbines, generators have impressively increased in dimension in order to benefit from the stronger winds of higher altitudes. As a result, generators must be spaced far apart from each other to avoid aerodynamic interferences and efficiency reduction.

Taking inspiration from schooling fish, Prof. Dabiri from the California Institute of Technology (Caltech) has found a way to increase wind farm efficiency whilst at the same time reducing aesthetic and environmental impacts.

The array adopted by groups of fish swimming together in order to reduce turbulence and interferences to a minimum was applied to a set of vertical axis wind turbines, which are only 10 meters high and can be placed much closer to each other. The innovative aspect of this scheme was to arrange the turbines in pairs and having the two adjacent elements counter-rotating.

An experimental field was established to apply this theory and tests demonstrated that this array creates a wind funnel so that after passing through 5 rows of generators the wind strength is still 95% of that received by the first row, thus maximizing the power produced.

A wind farm of this closely-packed design could therefore produce 20 to 30 watts per square metre of land, around 10 times more than current wind farms, whilst also being less obtrusive for the landscape.

For further information please check Clatech website.