With our ballistic ice throw model SWIM we calculate the location-specific probability for ice throw in the radius of every wind turbine in your wind park. The model calculates the trajectories of several million ice pieces based on a time series of wind speed and wind direction.
The wind turbine is always kept directly facing the wind and the rotational speed is adjusted according to the current wind speed. Location and turbine specific characteristics such as the vertical wind profile, the air density, the hub height or the rotor blade diameter are taken into account.
Assisted by the calculated probability for ice throw and the maximum distance, it can be determined whether a road, a hiking trail or a cross-country trail is in danger. We distinguish between the icefall of a stationary turbine and ice throw of a producing turbine - such as a turbine in a spin operation.
In combination with the probability of a person or an object near the wind turbine, the risk of being hit by a piece of ice is determined and placed in a relationship to socially accepted risks.
Meteotest has already produced ice throw reports for wind parks in Switzerland, Germany and Austria. The methodology is state-of-the-art and is accepted by the authorities.
The base data, the methodology and the results are presented clearly and comprehensibly in the ice throw reports. In addition, the customer receives the results in the form of KMZ files for viewing and further processing, for example, in Google Earth.
From 2005 to 2009 Meteotest conducted a unique ice throw field study at an altitude of 2330 m asl in the Swiss Alps. After each icing event an inspection of the site took place and the pieces of ice found were individually recorded. From 2011 to 2016 Meteotest conducted a further field study at the sites of St. Brais and Mont Crosin in the Swiss Jura Mountains.
Thanks to these studies Meteotest has been able to acquire valuable real-world experience in ice throw and how to implement it in the model.