Posters

Abstract

While the cup anemometers stand firm as the reference of wind measurement, the multiplication of wind measurement instruments and the diversification of the environment in which they are installed become the new norm. These come with new challenges and uncertainties regarding their reliability to measure the wind as accurately as the cup. Turbulence measurement is known to be biased when measured by a LiDAR or a cup being impacted by wakes. On their own, cup anemometers have also their challenges. In dust or seaside conditions, they tend to become gripped, impacting their wind data on several scales. To find out if a wind data is reliable, no matter the device that measured or its environment, several methods are being tried to bring a solution. Among them, the spectral analysis stands out for its versatility and its theoretical background. While the spectral analysis is an already well know domain, its interest in wind resource assessment grows has regrown recently to tackle several topics: extreme wind speed, forecasting, data scaling,… It can also be used for data validation. The Kolmogorov 5/3 law is a well-known constant trend that characterises the decrease in both scale and energy of turbulence eddies. Applying the spectral analysis to a measurement is a way to check if the devices recorded the phenomenon at the correct magnitude. If the device sees a larger slope, something is gripping it. And reversely, if the slope is smaller than -5/3, then something non-expected is adding kinetic energy to the wind. This study aimed at listing the possible cases of devices spectrum and environmental signatures visible by the spectral analysis. Then, for some cases, a proposition of correction, directly on the spectrum is done and its impact on usual wind resource assessment studies is assessed. The results showed a controlled change in the results while having corrected the imperfection noted in the spectrum. A more automated approach is being developed to widen its use among the wind resources assessment community.