Commissioning of a new ice-free anemometer: 2011 Field tests at WEICan

The main objective of this article is to present the results gathered during the commissioning of a new ice-free cup anemometer developed at Université Laval. These tests took place at the Wind Energy Institute of Canada (WEICan) between January 2011 and April 2011, whereby icing events occurred and through the observations in this paper will show the need for ice-free anemometers in the wind industry in cold climates. Unbiased wind measurements cannot be obtained without ice-free anemometers. At such sites, the use of unheated wind speed sensors during the resource assessment phase leads to higher uncertainty of the wind speed. The use of properly heated anemometers can reduce wind speed measurement uncertainty, thus reducing financial uncertainty. A crude estimation of the financial losses based on the number of icing hours and the number of installed MW is also proposed. Caution should be exerted when choosing and installing ice-free instruments. Under specific conditions, improperly heated anemometers can lead to less accurate wind measurements than unheated anemometers. Wind turbines safe operation could be jeopardized with the use of improperly heated anemometers.

► Ice-free anemometers are needed for wind energy applications in cold climate. ► Uncertainty related to wind speed measurements leads to financial losses and safety issues. ► Under glaze icing conditions, wind vane signal can be used to indentify icing event. ► Improperly heated instruments can yield measurements less accurate than unheated ones. ► At WEICan, financial losses due to icing can be crudely estimated to 45$ per installed MW per hour of icing.