Open AccessEvaluating the impact of wind induced roughness change and tidal range on extrapolation of offshore vertical wind speed profiles
Author(s) -
Barthelmie R. J.
Publication year - 2001
Publication title -
wind energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.743
H-Index - 92
eISSN - 1099-1824
pISSN - 1095-4244
DOI - 10.1002/we.45
Subject(s) - extrapolation , roughness length , wind speed , offshore wind power , range (aeronautics) , wind profile power law , surface roughness , meteorology , log wind profile , environmental science , wind gradient , submarine pipeline , turbine , surface finish , wind power , atmospheric sciences , geology , geography , physics , engineering , geotechnical engineering , mathematics , statistics , aerospace engineering , electrical engineering , quantum mechanics , mechanical engineering
Wind energy resource estimation frequently requires extrapolation of wind speeds from typical measurement heights to turbine hub‐heights. However, this extrapolation is uncertain, and this uncertainty is exacerbated in the offshore environment by the effect of the dynamic surface (i.e. surface roughness and height respond to wind speed or vary over time). This paper examines the impact of roughness variations and small tidal ranges on mean predicted wind speeds in near‐neutral conditions. Roughness variations offshore are in the range 0.002 and 0.00002 m. This range of roughnesses gives a difference in predicted wind speed extrapolated from 10 to 50 m of less than 8%. For a more typical range of 0.0005 tp 0.00005 m, the difference will be smaller (∼3%). With a tidal range of 4 m the difference in mean wind speed extrapolated from 10 to 50 m height is about 1%. Copyright © 2001 John Wiley & Sons, Ltd.