Wind turbines too close to one another also create their own wind shear.

Posted Category: News

See this article for a summary of accidents and fatalities 

Very important new  research results from Germany – now also published (August 2015) in a top level scientific journal about limits due to turbulence in wind”parks” that considerably limits the energy production from the wt’s due to turbulence between the single wt’s.

Note the far reaching consequences for local wt planning and efficiency.

This text  is the (MJ Google) translation of the Der Speigel interpretation of the attached paper which is published by The National Academy of Science in the USA.  Wind turbines too close to one another also create their own wind shear. As do trees ,houses ,small hills and even full near ripe fields of corn.

How turbulent winds abuse wind turbine drivetrains compliments the Jena -Max Planck paper. Heidenreich and Herr are 2 Americans and they have done some technical research for the US Department of Energy. Study the piece about the Wind Over Power Ratio as it is now possible to identify wind turbines that are more likely to breakup. All you need is the rated power speed and the cutout speed. The rated power speed is the wind speed at which the wind turbine reaches plated output. Divide the Cut out speed by the rated power speed and cube the answer. If the result is greater than 4.6 the stresses on the wind turbine are such that there is a hight likelihood that it will collapse. Most of these large multi megawatt greater than 101 meter hub diameter to  which this applies to, should be 9. This is excessive and is likely to break up the wind turbine.

On wind farm layout you might look up the Johns Hopkins Catholic University Of Louvain Better turbine spacing for large wind farms on wind farm layout.
The industry continually increases its understanding of the role that sheer winds and turbulence play in
wind-power generation. Shear winds are a condition mainly caused by the typography of the surrounding countryside, locations near mountain ridges, or the nearness of buildings, highway overpasses, and other landmarks. A shear wind causes this portion of incoming wind to flow vertically up the turbines face, in addition to the normal wind going through the blade sweep. The blades can be loaded non-linearly, sending varying loads going through the drivetrain. Shear winds are most often experienced by turbines on ridge tops and those located near the front edge of a plateau. Winds striking the face of these mountains deflect vertically, resulting in shearing winds.

They need to return to the drawing board for these large wind turbines or else they will all collapse in 5 to 7 years.

Here the link to the Danish article and the investigation

It might be useful to start using the Machinery Directive to get a Market Surveillance on these specific wind turbines.

A Summary of Wind Turbine Accident data to 30 September 2015

Comments are closed.