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Risk assessment: ice throw

Ice throw or ice fall from an idling or rotating wind turbine might turn into a serious danger when the site of the wind farm is located close to public roads, housing, power lines etc.

In many cases a risk assessment of ice throw or ice fall is required for the approval of a wind farm. “Ice throw” in this context describes pieces of ice falling off a running wind turbine. Special sensor systems might be installed to stop the turbine in the event of icing. In these cases “ice fall” needs to be assessed which describes pieces of ice falling off a wind turbine which is idling or standing still.

The risk assessment of damage to property or persons has to account for the probability as well as for the amount of damage. Therefore the probability of damage due to ice throw or ice fall in the vicinity of the wind turbine will be determined first.

 

Probability distribution of the impact of ice fragment in the vicinity of a wind turbine neglecting the terrain orography
Probability distribution of the impact of ice fragment in the vicinity of a wind turbine neglecting the terrain orography

 

Based on climatological data and calculated trajectories of several million ice fragments of differing size and density the probability of impact of ice fragments in the surrounding area of the wind turbine is determined. In addition to the wind conditions at the site the orography of the terrain may have a large impact on the results. At hilly and mountainous sites the trajectory length of the ice fragments may e.g. be significantly increased in downhill directions.

 

Probability distribution of the impact of ice fragment in the vicinity of a wind turbine respecting the terrain orography
Probability distribution of the impact of ice fragment in the vicinity of a wind turbine respecting the terrain orography

 

The amount of damage will be specifically determined. for your project. Typically the risk of damage to persons is the main focus of this part of the assessment.

We will be happy to support you with our long term experience in the course of your planning process.