Wind turbine blades, its seems, currently break more frequently, and less predictably, than anyone is comfortable with (certain windfarms are now collecting piles of broken blades for which there is no repair/recycling process).
According to a back of the envelope calculation, based on typical geometry, if a fragment of the tip of a blade comes off it can travel up to 2 turbine diameters in one direction and up to 15 diameters (2 football pitch lengths) in the opposite direction.
This represents a potential threat to anything which lies to one side of a turbine (ie particularly to the left of a counterclockwise blade when viewed from the front).
Today’s invention is a way to lay out a wind farm so that any boundaries are no closer to the machines than two diameters (+safety margin), even when variations in wind direction are accounted for. It also requires that the 12 o’clock direction of blade rotation is always away from the local border.
Although this may increase the damage to more central turbines, it lessens the possibility that vehicles, people or buildings on the periphery will suffer costly impacts.
See also http://www.fastcompany.com/1551751/what-fish-can-teach-us-about-wind?1266744130