Delegates are invited to meet and discuss with the poster presenters during the poster presentation sessions between 10:30-11:30 and 16:00-17:00 on Thursday, 19 November 2015.
Lead Session Chair:
Stephan Barth, ForWind - Center for Wind Energy Research, Germany
Ulla Heikkilä (1) F Rene Cattin (1) Silke Dierer (1) Rebecca Gugerli (1) Markus MÃ¼ller (1) Sara Koller (1)
(1) Meteotest, Bern, Switzerland
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Performance of Enercon wind turbines under icing conditions in Europe
Atmospheric icing has a significant impact on the development and the operation of wind parks. It causes production losses and represents a safety risk for passers-by and service personnel. Still, there is an emerging market for wind energy projects in cold climate. Furthermore, sinking electricity prices increase the pressure on existing projects to maximise the production in order to stay profitable. In this context, the performance and the efficiency of a de-icing system is a central aspect for a successful wind park.
During winter 2012/13 and 2013/14, ENERCON wind turbines, equipped with a rotor blade heating, were monitored in order to evaluate their performance under icing conditions. The wind parks were located in Switzerland, Czech Republic, Germany and Sweden. The wind turbines were equipped with one camera pointing at nacelle and two cameras pointing at the blades. Furthermore, the operational data of the wind turbines was examined.
In a first step, the icing conditions at the sites were analysed. Based on a classification of camera images, the IEA ice class of each site was identified. Furthermore, the periods of meteorological icing were subdivided in three classes of icing intensity and the instrumental icing in five classes of ice loads. This allowed for a more detailed interpretation and comparison of the different icing climates at the test sites. Finally, the typical wind conditions (wind speed and wind direction) during icing events were studied.
Main body of abstract
In a second step, the performance of the blade heating was examined in general with regard to the icing conditions and in selected case studies. The rotor blade heating of the different wind turbines was operated in various operational modes within the same wind park. This allowed for a detailed comparison of the performance of different heating strategies during icing events and a quantification of the overall icing losses with regard to the site-specific icing climate.
The analysis showed that the ENERCON rotor blade heating significantly increases the energy production under icing conditions. The performance of the rotor blade heating system strongly depends on ice load and icing intensity. The performance is good for light to moderate ice load and intensity classes but decreases for events with high ice loads and severe icing intensity. These situations are not very frequent, but still impact the total energy yield loss.
These results also show that the local icing conditions (ice loads and icing intensities) need to be known in detail in order to estimate related energy yield losses in a proper way.