Das Projekt "Vereisung von Windturbinen" wird vom Umweltbundesamt gefördert und von Deutsches Windenergie-Institut durchgeführt. The main objective of the research program co-funded by the European Commission is the analysis of wind turbine operation under icing conditions within Europe. The increasing application of wind turbines in mountainous regions and In Northern Europe raised the questions which have been partly answered by the project's results: - Which weather conditions cause icing and at which sites do they occur? - Which types of ice accretion can influence wind turbine operation? -What are the influences on aerodynamics, loads, control system, energy output etc.? In order to catalogue ice endangered sites a questionnaire, which is available in English, German and Finnish language, has been distributed to concerned operators and manufacturers. Results from the inquiry have been evaluated in terms of occurrence of icing, types of ice and ice formation, as weil as locations around the turbines where thrown off ice fragments were found. A map of Europe is presented, including the reported icing events from several countries covering from a few days to some weeks of operation under icing conditions. The inquiry also proved the assumptions for ice loads developed within the project to be conservative. Influences of icing on wind turbine loads are discussed and recommendations given with respect to interested parties such as manufacturers, certifioation bodies and operators. This research program investigates most of the possible influences of wind turbine operation under icing conditions such as: - Ice loads. - Public safety (better knowledge of ice debris trajectories). - Prediction of energy loss. - Exploitation of ice endangered sites for wind energy application. Recommendations are given for manufacturers, certification bodies and operators concemed. The results and summary of the present knowledge was discussed during the BOREAS II conference and seminar and has been published as a 371 pages proceedings.
Das Projekt "Richtlinien fuer die Pruefung, Abnahme und Ueberwachung von Windkraftanlagen; Messung an Windkraftanlagen" wird vom Umweltbundesamt gefördert und von Germanischer Lloyd, Hauptverwaltung Hamburg durchgeführt. Bau und Betrieb von Windkraftanlagen beduerfen der Genehmigung durch die zustaendige Bauaufsichtsbehoerde des jeweiligen Bundeslandes. Massgebend fuer die Erteilung bzw. Verweigerung von Baugenehmigungen sind im wesentlichen planungsrechtliche sowie sicherheitstechnische Aspekte, die durch gesetzliche Bestimmungen geregelt sind. Das Land Schleswig-Holstein hat eine entsprechende Richtlinie veroeffentlicht. Die Formulierung der Lastannahmen ist derzeit zurueckgestellt worden, da gesicherte Erkenntnisse nicht in ausreichendem Masse vorliegen. Die im Rahmen dieses Vorhabens gewonnenen Messergebnisse sollen daher in die Richtlinien einfliessen. Die Messungen sollen in Kaiser-Wilhelm-Koog an Anlagen erfolgen, die von Eigentuemern zur Verfuegung gestellt werden. Der Umfang der Messungen ist gemaess den Richtlinien der Internationalen Energie Agentur fuer diesen Problemkreis vorgesehen. Neben der Erfassung von momentanen Belastungen soll das Hauptaugenmerk auf Betriebsfestigkeit und Ermuedungsbeanspruchung gelegt werden, da auf diesem Gebiet noch grosse Unsicherheiten bestehen. Dies gilt sowohl fuer die Lasten als auch fuer die zum Einsatz kommenden Werkstoffe wie z.B. Aluminium und GFK. Dies kann nur durch Ueberwachung der Beanspruchung der Anlage ueber laengere Zeit erfolgen.
Das Projekt "Experimentelle Verifizierung von Lastannahmen kleiner Windkraftanlagen im Inselbetrieb" wird vom Umweltbundesamt gefördert und von Deutsches Windenergie-Institut durchgeführt. The project aims at the improvement of the quality and safety standards of small standalone wind turbines. A draft international standard for small wind turbines has been prepared by IEC. The aim of the project is to validate the rules by measurements. The proposed design rules for small wind turbines in the IEC draft allow to calculate the mechanical stresses in the main components of the wind turbine (blades, shaft, support, structure), caused by extreme and fatigue loading. Within the present project, measurements are carried out on three small commercial wind turbines of different design. The machines are located on different test stations in Europe: an WENUS Inventus 6 machine at DEWI test station in Geemany, a Proven WT 2200 machine at the test station of NEL in Scotland and an LMW 1003 machine at the test Station of CRES in Greece. Mechanical loads are measured in blades, shaft and tower, together with other quantities necessary for the evaluation (wind data, electrical power, etc.). The measured loads will be compared with the values calculated for the specific designs according to the simple method of the draft IEC standard. From the comparison, conclusions will be drawn for a refinement of the international standard and towards the Essential Requirements of the applicable European Council Directives.