Titel: Remote wind speed sensing for site assessment and normal year correction – The use of sodar technology, with special focus on forest conditions
Författare: Daniel Gustafsson
Utgivare: Kungliga Tekniska Högskolan
Årtal: 2008
Ämnesord: Vindmätning, vindkraft i skogsmiljö
Sökord/keyword: anemometer, AQ500 sodar, forest
Examensarbete (Pdf)
Sammanfattning/Abstract: This thesis aims to give the wind power industry better tools to approach the uncertainties of the wind climate, by describing the wind characteristics in forests, remote wind speed sensing technologies, and normal year correction methods.
This thesis includes a wind analysis of a forest site in the southern part of Sweden, which indicates significantly lower wind speed than the MIUU model, high turbulence and pronounced wind shear. It also contain a comparison of the measurements from 4 December 2007 until 29 June 2008 by an AQ500 sodar from AQ System and a 97 m met mast instrumented with cup anemometers and wind vanes. Finally, the thesis includes an assessment of different methods and sources of data for normal year correction based on the wind index approach.
The sodar and mast analysis concludes that the measurements of the AQ500 are trustworthy. The difference in mean wind speed compared to cup anemometer is in the magnitude of 0.1 m/s and the turbulence readings show good conformity for wind speeds up to 12 m/s.
The normal year correction analysis concludes that depending on the lengths of the period of the measurements, different sources are best used. The Danish production index is best used for the eleven month of available data for this thesis, but for longer measurement campaigns NCAR data could successfully reduce the uncertainties.
Due to confidentiality reasons some of the content of the internal report for Vattenfall has been left out of the public report. This is primarily information about the site of the measurements (referred to as Site A), but also some of the conclusions and a proposed measurement strategy.