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The goal of the Swiss project "Alpine Test Site Gütsch" is to expand the knowledge base on atmospheric icing specifically in the Alps. The project includes an inter-comparison of ice detectors, the performance monitoring of a wind turbine and recommendations for the estimation of icing conditions at sites not equipped with ice detectors. The ice de...
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... Guetsch, another approach was developed: a commer- cially available Mobotix web cam was installed on the nacelle of the wind turbine ( fig. 5) and the passing blade is signaled by the use of video motion detection [10]. An image of the blade is recorded every 30 minutes and automatically sent to the project's ftp server. For the interested readers, the regularly updated images can be seen on the project's website [1]. All images are filtered manually on ice accretion. In ...
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Wind turbines generate electricity by removing kinetic energy from the atmosphere. We show that the limited replenishment of kinetic energy from aloft limits wind power generation rates at scales sufficiently large that horizontal fluxes of kinetic energy can be ignored. We evaluate these factors with regional atmospheric model simulat...
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... These safety distances have the purpose to protect local residents from impairment through noise and shading effects. Impacts from ice falling will be excluded from further discussion, since the impact range of slung ice pieces can be estimated by the 1.5-fold length of the tower height plus rotor diameter, and, therefore, is in any case smaller than the distances for noise protection or shading [26,27]. According to that, the ice falling range for the biggest wind power plants with a height of 200 m is limited with 400 m. ...
The political agenda on wind power usage intends its further expansion in a large scale. As most energy sources, wind power can have negative impacts on humans and environment; this expansion can be accompanied by land use conflicts with land uses sensitive to disturbance. During operation, disturbances from noise, shadow, or ice throw can occur. Due to the dimensions of modern wind power systems, wind power farming can pose a threat to birds and bats (collision and avoidance) and may also lead to a change of landscape sceneries, which can cause conflicts with residents, nature conservation, or tourism interests. Therefore, the control of wind power expansions by spatial planning plays a key role for the mitigation of negative impacts as well as for its public acceptance. Spatial planning offers instruments to resolve potential conflicts with affected stakeholders. On a regional level, the determination of priority and exclusion areas for the use of wind power based on functional criteria represents the most essential planning measure.
... Dans ce qui suit, les différents modèles sont abordés selon les paramètres météorologiques utilisés. Des modèles qui utifisent l'humidité relative, la hauteur des nuages, la nébulosité et la Cattin et al. (2007), dans le cadre d'une recherche sur la détecfion du givrage atmosphérique pour l'exploitation d'énergie éolienne, ont ufilisé le modèle de température et d'humidité relative en combinaison avec un troisième paramètre, la radiation solaire. Sur le site à l'étude, le type de givrage atmosphérique le plus fréquent est le givrage en nuage. ...
... The most reliable instrument to detect icing conditions is the ice detector. Unfortunately, a comprehensive inter-comparison of commercially available ice detectors on the Guetsch site clearly showed that there is currently no instrument available which reliably and automatically measures ice accretion [10,11]. However, two promising instruments could be identified (Fig. 4): ...
Summary Icing is an important issue when operating wind turbines in high altitude or arctic areas as it can cause significant production losses and represent a safety risk. The Swiss research project "Alpine Test Site Gütsch" which is em- bedded in the European "COST Action 727: measuring and forecasting atmospheric icing on structures", aims to extend the knowledge on icing on structures in the Swiss Alps. The ratio between meteorological and instrumental icing becomes important when the implementation of a blade heating is considered. Therefore, several additional measurement parameters were evaluated for their suitability to deliver this information. The study revealed, that in-cloud icing conditions can be detected fairly well by use of air temperature, relative humidity and the sky temperature, which is derived from incoming long wave radiation. It further showed that there is currently no ice detector on the market which is able to reliably measure icing. The monitoring of the Enercon E-40 wind turbine showed, that the ice detection via power curve seems to work con- siderably well except for light icing and during periods with low wind speed. However, this method gives no infor- mation if blades are still iced after heating cycle. This makes the automatic restart a safety risk. In many cases, not all the ice could be melted during one heating cycle, especially at the leading edge of the blades. The heat transfer to the leading edge therefore should be optimized. An extensive field study on ice throw revealed that ice throw is a safety risk especially during or right after a blade heating cycle and in the area under the blades
... Coincidentally, a fully equipped test station of the Swiss meteorological network SwissMetNet was installed about 200 m away from the wind turbine in 2003 (Fig. 1). The immediate proximity of the two facilities operating under icing conditions led to the launch of the research project "Alpine Test Site Gütsch: meteorological measurements and wind turbine performance analysis" [2, 3, 4] which is embedded in the European "COST Action 727: measuring and forecasting atmospheric icing on structures" [5, 6]. ...
Icing is an important issue when operating wind turbines in high altitudes or arctic areas as it can cause significant production losses and represent a safety risk. In 2004, a 600 kW Enercon E-40 wind turbine with integrated blade heating was installed on Guetsch mountain, Switzerland, at 2'300 m asl. Coincidentally, a fully equipped test station of the Swiss meteorological network SwissMetNet is situated about 200 m from the wind turbine. The immediate proximity of the two facilities operating under icing conditions led to the launch of the national research project "Alpine Test Site Gütsch" which is embedded in the European "COST Action 727: measuring and forecasting atmospheric icing on structures". When planning wind turbines in icing environment, it is crucial to know about the ratio between meteorological and instrumental icing, the latter being the cause of the first. The relation be-comes especially important when the integration of a blade heating system for the wind turbine is considered. On Guetsch, a new approach to estimate the conditions for in-cloud icing was tested. The method, based on measurements of relative humidity, temperature and incoming long wave radiation, together with a correction of the relative humidity values at temperatures below 0°C led to a considerable improvement of the detection of in-cloud icing on Guetsch.
