Matthew Wadham-Gagnon, project lead at Canada’s TechnoCentre éolien: "In the next few years we anticipate a competitive offering of proven and effective de-icing systems. Anti-icing coatings, while promising in laboratories, have yet, to our...

By Susan Kraemer

Q: What are the technological challenges of cold climates?

A: Wind energy in cold climates faces two types of challenges: temperatures below normal operation standards, for example, under -20° Celsius, and icing. Most, if not all of the installed wind energy capacity in Canada is subject to some degree of icing.

Today’s wind turbines are very well adapted for operation in low temperatures, generally being capable of production to -30 oC and designed to survive -40 oC.

Active de-icing technologies, such as hot air or electro-thermal systems, are available from different OEMs and performance validations are ongoing.

In the next few years we anticipate a competitive offering of proven and effective de-icing systems. Anti-icing coatings, while promising in laboratories, have yet, to our knowledge, proven to work on full scale wind turbines.

Q: How are ice throw risks currently addressed in Canada?

The risk of ice throw is taken into account both by developers, in the pre-project impact assessment study, and the operators in their operational procedures.

For instance, setback distances from roads, trails and infrastructures based on empirical formulas such as the Seiffert formula, or in some cases, ballistic studies, are established in the wind farm layout.

In some cases, maintenance work can be delayed if safe access to the turbines is threatened by the risk of ice shedding or throw. Some wind farm operators will also proceed to preventive curtailment in the presence of particular meteorological conditions.

At the moment, the industry recognises that the risk associated with ice throw needs to be managed, and a rather conservative approach is usually taken.

Safe positioning of turbines with respect to public roads or areas and safe operation and maintenance procedures contribute to mitigating the risk of ice throw in Canada. Continued research and development around ice throw will mostly lead to optimising turbine positioning as well as O&M procedures.

What is TechnoCentre éolien doing to quantify ice throw risk?

Our organisation has performed, in collaboration with Senvion, a measurement campaign during the past two winters that helped improve our understanding of the dispersion of ice pieces around wind turbines and their characteristics; size, direction & distance from the turbine.

We have also collaborated with RES to validate and improve a theoretical ice throw model that they have developed based on physics, statistics and turbine characteristics.

Our measurement campaign combined with ice throw modelling shows that the empirical Seiffert formula is conservative and that ballistic modelling, when the appropriate parameters are used, can lead to a much better understanding of ice throw patterns and thereby improve health and safety precautions relative to ice throw in wind farms.