e-POSTER: Best Practices for Quantifying, Interpreting, and Utilizing Atmospheric Stability Measurements
22 May 19
11:30 AM
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11:55 AM
Tracks:
Poster Presentations, Resource Assessment
Atmospheric stability is an important metric in the wind industry because it governs long term site suitability and energy yield estimate of wind turbines. This work will fulfill the needs of both the numerical modeling and WRA communities by analyzing state-of-the-art methods for calculating atmospheric stability. Based on the methods reviewed and analyzed, we will recommend best practices for calculating atmospheric stability using standard wind resource assessment sensors and optimum tower set-up. We will discuss how measured and mesoscale modelled atmospheric stability parameters and mean wind speed profiles should be incorporated into computational fluid dynamics (CFD) simulations to deliver added value for the wind resource assessment. Five different sites have been investigated. Stability metrics have been calculated using physical measurements and different methods (e.g., Sukanta, Svenningsen, Holtslag, Profile method, Eddy-covariance method, and the Richardson method). Where available, ultrasonic data is used to compute the Monin-Obukhov length and its value is compared with values derived using met mast measurements as well as mesoscale models. Thereby, it is possible to conclude which method delivers the best results and the associated uncertainties. A comparison of CFD simulations with neutral and stability-dependent boundary conditions has been made based on measurements and model results and validated against wind speed and turbulence data from met masts.