Gust description for wind energy purposes

Allan Morales

Carl von Ossietzky University of Oldenburg, Institute of Physics, Oldenburg, Germany

The gusts are related to the unsolved problem of turbulence and small scale intermittency, which leads to heavy tailed statistics and therefore gives high probability of large fluctuations. These fluctuations can lead to unexpected and numerous extreme events. All this has implications for the wind profile of the boundary layer and influences the wind turbines in form of mechanical loads and fluctuation in the power production. Our approach in order to achieve a good characterizations of such fluctuations is the usage of the probability density functions (which strongly differ from a Gaussian distribution) of wind speed increments where the intermittent behavior is somehow described by a parameter \lambda based on a description due to Boettcher (itself based on Castaing's description of laboratory turbulence). Finally we also show some work related with the implications of thermal stratification on the wind profile.