Since falling ice fragments can pose a security risk for the surroundings of the wind turbine, the authorities request measures to reduce the risk from icefall to an acceptable level.
It is established in Austria to shut down wind turbines over the entire persistence of icing. However, falling ice fragments during defrosting of the plant still represent a potential security risk.
Location-specific information on the number and intensity of local glaciation events are required for the modelling of resulting hazard areas and to estimate the energy production loss. So far most models are based on simplified assessments that do not meet the international state of the art.
Moreover, there are even in an international context hardly any experiences about resulting ice formations on rotor blades as well as details of the falling pieces of ice (such as their size distribution, possible flight trajectories and resulting distances). These risk-related aspects led subsequently to recurrent discussions about the usefulness and effectiveness of measures and policies.
In order to address the mentioned problems, the following objectives were expressed for the present project proposal:
- Modelling and provision of an “Icing Map” in a spatial resolution of 3x3km for entire Austria (accumulations of ice on a 3cm standard cylinder, in accordance with ISO 12494).
- Evaluation of (1), based on long term wind turbine operating data and providing a regional icing climatology for wind turbines with information about an average number, duration and intensity of icing events.
- Monitoring of icing events at wind turbines using an innovative imaging method to generate a data base in terms of number, size, distance and possible flight trajectories of falling ice fragments
- Define resulting hazard areas due icefall for all regions in Austria by modelling the respective landing locations of ice pieces around wind turbines and exposed structures.
- Development of scientifically verified policies and measures for possible further reduction of risk through ice-fall, together with lawyers and experts
Project –> End of June 2019