More compact and quieter

A breath of fresh air for vertical axis wind turbines

Sébastien Le Fouest with his motorized and sensor-equipped miniature wind turbine with a vertical axis of rotation.

(Bild: Alain Herzog / EPFL)

New wind turbines could produce electricity more quietly than conventional systems. Instead of rotating horizontally, the rotor blades of the wind turbines optimized by Swiss researchers rotate vertically around a central axis like a spinning top. As they also require less space and are less dangerous for birds, such vertical wind turbines could compete with traditional models in the long term.

Vertical wind turbines have been around for some time. Until now, however, their development has faced a physical challenge, as the Swiss National Science Foundation (SNSF) announced on Wednesday. As their axis of rotation is perpendicular to the wind, the angle between the wind and the rotor blades is constantly changing. As soon as the wind reaches a certain speed, a so-called dynamic stall occurs, which leads to air turbulence and turbulence.

In a study published in the journal "Nature Communications", a research team from the Swiss Federal Institute of Technology in Lausanne (EPFL) led by Karen Mulleners has now demonstrated a solution to this problem: they installed a device that allows the rotors to change their inclination.

"Captain" on board
"A ship needs a crew to adjust the sails in order to stay on course," explained Sébastien Le Fouest, first author of the study, in the press release. "If you equip the rotor blades of wind turbines with small motors, you effectively provide them with a captain so that they too can adapt to the conditions."

The researchers have built a miniature turbine with a single rotor blade. They equipped it with sensors to measure the energy generated in the flow channel. This allowed them to determine how much the rotor blades should adapt.

Efficiency tripled
The researchers tripled the efficiency of their vertical wind turbine in the laboratory. "Our data shows that it is very likely that the service life and efficiency of traditional wind turbines could be matched or even exceeded," says Le Fouest.

This is now to be investigated in further research projects. A collaboration with a Swiss company has already been initiated to test the results on an industrial prototype, according to the SNSF.