Fraunhofer Used Drones to Protect Wind Turbines from Ice

Fraunhofer has recently developed a technique for applying coatings to wind turbines quickly and efficiently.

A team from Fraunhofer managed to protect the rotor blades from ice using drones. The new technique has been developed by experts from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM and the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in the project TURBO – ‘Temporary Coating by means of Drones.’

This is useful for protecting wind turbines from moisture and cold, as ice formation on the rotor blades can cause rotational imbalance and consequently increased wear. In addition, given that the turbines must remain idle for several days, this would also lead to huge losses for operators due to the pause in electricity production.

The use of drones for ice prevention has to satisfy several conditions:

• Respect for the environment;
• Coating materials must demonstrate good adhesion and sufficient durability to remain on the rotors for weeks and protect them from ice;
• The spraying system used must be precise and light;
• Drones must have a high payload and allow very precise control.

The Fraunhofer IPA team has produced the equipment for applying the coating. It consists of a pump that presses the fluid urea/wax mixture at high pressure into a long, thin lance, at the tip of which there is a nozzle with a diameter of 0.3 millimetres. This airless pump system is capable of producing droplets with a diameter of 100 micrometres and, even at a wind speed of 35 Km/h, these droplets can be sprayed precisely onto the edges of the rotor blades, where they then solidify.

“Our dec-ades of experience in modelling coating processes really helped us out. We were able to draw on this expertise. However, we had to adapt the process parameters to the complex geometry of the wind turbines,” has stated Oliver Tiedje, Project Manager at Fraunhofer IPA.