Wind turbines in offshore wind farms near Borssele and Egmond aan Zee were turned off for four hours last Saturday to allow migrating birds to leave the area safely, energy minister Rob Jetten has confirmed. 

It is the first time anywhere in the world that wind turbines have been halted to allow birds safe passage, Jetten said. “We want to keep the impact of wind farms on nature as small as possible and this is one measure to do this,” he said. 

Experts estimate that the turbine blades kill some 50,000 birds every year as offshore wind farms proliferate on their migratory routes.

Wind farm owners will use predictions showing when large numbers of birds are about to move to decide when to turn off their turbines. These are based on forecasts by bird migration experts and a model devised by a PdD student at the University of Amsterdam using weather data and bird radar systems. 

“In spring and in autumn, millions of birds move over the North Sea some nights,” said Tim van Oijen from bird protection group Vogelbescherming Nederland.

“It is crucial that North Sea wind farm development is done in a responsible way. Turning off the turbines during migration will help achieve that.”

The turbines are not completely halted, but their revolution is reduced to a maximum of two per minute.

Last Saturday’s stoppage is part of a series of trials taking place this spring to assess if turbines can be halted without damage to the network. The system will be officially enforced from the autumn.