Dairy farmer Yann Joly, in the Somme department of northern France, is claiming damages from CSO Energy, operator of the 48MW Nouvion-St Riquier wind farm.
Joly recorded that milk production fell from 10,000 litres a year to 7,000 litres after the first turbines were installed in 2011 and then to 5,000 litres after the project was extended in 2013.
The closest turbines – Enercon E70 2MW machines – are 1.8km away.
After numerous tests by vets and agricultural experts yielded no results, Joly concluded that the turbines were to blame. He called in geo-biologist Arthur Revel, who supported his theory.
While acknowledging that geo-biology is not recognised by the scientific community, Revel believes the cows were suffering from "profound stress" caused by the vibrations from the turbines passing through the subsoil.
In the first case of its kind in France, Joly has now taken the operator to court, calling for the turbines to be removed and claiming €356,900 in compensation.