Abstract : 2G.7
Wind profile and turbulence on a mountain in Laterns

Richard Werner, Caroline Draxl
salzachwind Gmbh

The area of Laterns indicates a high value of wind energy potential in the land register of Austria's federal state Vorarlberg. Thus measurements will be accomplished over a period of 12 months to verify this calculated and promising value.

A measurement mast was erected on the NOB, a mountain situated in the second line of the mountains on the northern part of the Alps, in 1785 m asl. Measurements have been accomplished with anemometers in 10 m and 30 m in 10 minute intervals, also the wind direction in 30 m is recorded. The power law indicates a wind speed ratio of 1,31 between 30 and 10 m above ground for neutral conditions. As a first result, using data from Oct. 2006 to Dez. 2006 an analysis of this ratio has been done in 8 wind sectors with more than 10 000 data.

The data are important for the detection of a wind profile and to calculate wind speeds between 40 and 100 m above ground. Windspeed in the lower level shows an evident influence of the orography. Detailed analyses have been done with wind speeds higher than 9 m/s. The probability in 8 wind sectors shows this influence when northern winds are existing.

Fluctuations of turbulence are indicated as the variation coefficient in 10 minutes intervals; the median of this coefficient is near 0.17; its regression is described over different time series up to 2 hours. Analyses show that in the two measuring heights the turbulence is different, thus detailed turbulence analyses for each wind sector will be given.