Analysing wind farm efficiency on complex terrains

The Science of Making Torque from Wind 2014

Castellani, Francesco^1 ; Astolfi, Davide^1 ; Terzi, Ludovico^1 ; Hansen, Kurt Schaldemose^1 ; Rodrigo, Javier Sanz^1

University of Perugia-Department of Engineering, Via G. Duranti, 93-06125 Perugia, Italy^1

关键词: Atmospheric stability;    Complex terrains;    Hilly terrains;    Monin-Obukhov length;    Performance assessment;    Terrain complexity;    Wake interactions;    Wind directions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/524/1/012142/pdf
DOI  :  10.1088/1742-6596/524/1/012142

来源: IOP

【 摘 要 】

Actual performances of onshore wind farms are deeply affected both by wake interactions and terrain complexity: therefore monitoring how the efficiency varies with the wind direction is a crucial task. Polar efficiency plot is therefore a useful tool for monitoring wind farm performances. The approach deserves careful discussion for onshore wind farms, where orography and layout commonly affect performance assessment. The present work deals with three modern wind farms, owned by Sorgenia Green, located on hilly terrains with slopes from gentle to rough. Further, onshore wind farm of Nprrekffir Enge has been analysed as a reference case: its layout is similar to offshore wind farms and the efficiency is mainly driven by wakes. It is shown and justified that terrain complexity imposes a novel and more consistent way for defining polar efficiency. Dependency of efficiency on wind direction, farm layout and orography is analysed and discussed. Effects of atmospheric stability have been also investigated through MERRA reanalysis data from NASA satellites. Monin-Obukhov Length has been used to discriminate climate regimes.