Just over 60 years ago, on March 26, 1949, the Fraunhofer-Gesellschaft was founded in the large conference hall of the Bavarian Ministry of the Economy. At the time, the idea was to develop new structures for research after the war’s destruction, and to spur reconstruction of the economy. Today, the globally-respected institute analyses current macro trends and identifies fields of research that will play a particularly important role in the future in meeting challenges such as climate change, dwindling resources and preventive healthcare. Wind energy is firmly on the agenda. PES presents an exclusive Fraunhofer research paper.
There’s a fair wind blowing for wind energy: Europeans invested 13 billion euros in new turbines in 2007. Tens of thousands of wind turbines are already in operation, and more are being planned. To keep them working reliably, interdisciplinary teams are developing new technologies for construction, quality assurance and maintenance.
For the turbines to actually produce the theoretically calculated outputs, they must be in perfect technical condition. Even small material defects can have devastating consequences. The inspection of the components, above all, the 70-meter long rotor blades, is a science in itself. Fraunhofer engineers in Bremerhaven specialise in the oversized material and reliability tests. In a building that is 85 meters long and 25 meters high, Dr. Arno von Wingerde und his colleagues can test rotor blades: the blade to be examined is securely screwed into a concrete block firmly anchored to the ground and then tensed with wires. In order to understand exactly how the rotor blade distorts under a load, scientists from the Fraunhofer Institute for Information and Data Processing IITB have developed their own measurement system and installed it in Bremerhaven. Markings are placed on the rotor blade that is to be checked and in the building; a camera registers these markings during the trial. Software evaluates the images, determines the exact position of the marked points in the area, and calculates where the rotor blade has bent or distorted, and by how much. “This information is important, because it allows us to draw conclusions about material loads and possible damage causes,” Dr. Martin Ruckhäberle from IITB explains.