Researchers at the Fraunhofer Institute for Applied Polymer Research (IAP), working with the BBF Group, have developed a lightweight rotor for small wind turbines designed to operate efficiently in areas with low wind speeds. The first prototypes have now been delivered for testing.
The new turbines begin generating power at wind speeds as low as 2.7 metres per second, compared with about 4 metres per second for similar systems. Wind tunnel tests show that the rotor can reach up to 450 revolutions per minute, producing 2,500 watts at 10 metres per second and achieving an efficiency of 53 percent – close to the physical limit of 59 percent.
The rotor blades are made from hollow fibre composite shells, reducing overall weight by up to 35 percent compared to traditional foam-core designs. The components are produced using automated fibre placement and 3D-printed moulds, improving quality and precision. The laminate structure allows the blades to flex under strong winds, preventing overload without complex control systems.
Five prototypes have been installed at different locations by BBF Group to assess performance under varying conditions. Future research will focus on developing recyclable monomaterial designs to further improve sustainability.
