Wind Energy | Wind Energy in Cold Climates

In a cold climate such as Canada’s, icing represents one of the biggest challenges to the operation of wind turbines. Based on actual measurements, icing can occur up to 20% of the time between the months of November and April. Wind turbines must therefore be able to sustain at least limited icing without incurring damage that would prevent normal operation.
Accumulation of ice on the blades results in a power output reduction, and an increase in the rotor loads, which may require stopping the turbine for safety reasons. However, it is advisable that power production be maintained in situations of moderate icing so as to:

• minimize downtime periods and increase the benefits from the more favorable winter winds; and
• keep the rotor turning and thereby limiting the ice growth to the leading edge part of the blade that is likely fitted with some ice protection equipment.

With this knowledge in mind, researchers at CanmetENERGY have been involved in supporting several ice mitigation and cold climate projects for wind energy over the past several years.
Old Crow, Yukon
Early in the fall of 2002, CanmetENERGY supported Yukon Energy Corporation (YEC) to install a meteorological station including an ice detector on a mountain near Old Crow, Yukon. The ice detector was part of an autonomous station that included anemometers and data loggers. The icing severity at Old Crow was confirmed by the observations recorded at the station. Icing was so intense that the instruments became inoperable. NRCan and the wind resource assessment community benefits from this this project that confirmed the need for robust instruments and redundancy at locations where atmospheric icing is severe.

St. Leon, Southern Manitoba
CanmetENERGY has also been involved in another project in collaboration with the University of Manitoba where experiments were performed in a state-of–the-art academic wind tunnel with icing capabilities. One of the objectives of this project was to simulate the icing conditions found near St. Leon in Southern Manitoba where there is a large wind farm. Experiments in the tunnel helped to provide an understanding of the fundamentals of ice formation and to create estimates on how the turbines production is affected by the presence of ice. The work also focused on optimizing ice mitigation techniques and allowed for progress towards developing new innovative design solutions for wind turbine applications in cold climates.

Eastern Canada
A third project done in collaboration with CanmetENERGY researchers involved the acquisition of scientific material to study and document the climatic conditions of an area favorable for the operation of wind turbines. This area is located at an elevation of approximately 610 m in a mountainous domain of Eastern Canada. Instrumentation was attached to two towers in order to characterize the local environment in terms of wind speeds, wind direction, atmospheric pressure, humidity, duration of icing events and precipitation. The scientific information collected will help explain the failure of turbines that had been designed for the European climates and will instead help design turbines that are more adapted to North American’s more severe climatic conditions.