The study investigates possible coherence of flying insect losses recently discovered in Germany and
insect impingement on the rotor blades of wind turbines.
Evidence from literature confirms that migrating insects select fast air streams above the turbulent
surface layer of the atmosphere for the purpose of efficient displacement to breeding grounds. Wind
farm developers select sites with strong winds and install high towers with rotors just above the
surface layer in order to optimize the energy output of their wind turbines. As a result of this
coincidence, large numbers of flying insects can be expected in wind farms.
Model calculation of the amount of insect biomass that traverses wind rotors during operation
provides a first estimate of the order of magnitude of 24,000 tons of insects crossing the German
wind park throughout the summer season. Based on conservative model assumptions, five percent of
the insects flying through a rotor could be actually damaged. The related loss of 1,200 tons per year
since more than fifteen years could be relevant for population stability.
Species flying at critical rotor heights between 20 and 220 meters above ground level in addition to
those already found within this study should urgently be identified by DNA meta-barcoding of the
deposits that are regularly found on rotor blades. In addition to that, wind farms should be enabled
to recognize approaching insect swarms and to react accordingly for their protection and