Satellite information for wind energy applications

M. Nielsen, Poul Astrup, Charlotte Bay Hasager, R.J. Barthelmie, S.C. Pryor

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    Abstract

    An introduction to satellite information relevant for wind energy applications is given. It includes digital elevation model (DEM) data based on satellite observations. The Shuttle Radar Topography Mission (SRTM) is useful for regional scale wind resourcestudies. Comparison results from complex terrain in Spain and flat terrain in Denmark are found to be acceptable for both sites. Also land cover type information can be retrieved from satellite observations. Land cover type maps have to be combined withroughness data from field observation or literature values. Land cover type maps constitute an aid to map larger regions within shorter time. Field site observations of obstacles and hedges are still necessary. The raster-based map information from DEMand land cover maps can be converted for use in WASP. For offshore locations it is possible to estimate the wind resources based on ocean surface wind data from several types of satellite observations. The RWT software allows an optimal calculation ofSAR wind resource statistics. A tab-file with SAR-based observed wind climate (OWC) data can be obtained for 10 m above sea level and used in WASP. RWT uses a footprint averaging technique to obtain data as similar as possible to mast observations.Maximum-likelihood fitting is used to calculate the Weibull A and k parameters from the constrained data set. Satellite SAR wind maps cover the coastal zone from 3 km and offshore with very detailed information of 400 m by 400 m grid resolution. Spatialtrends in mean wind, energy density, Weibull A and k and uncertainty values are provided for the area of interest. Satellite scatterometer wind observations have a spatial resolution of 25 km by 25 km. These data typically represent a site furtheroffshore, and the tab-file statistics should be used in WASP combined with topography and roughness information to assess the coastal wind power potential. Scatterometer wind data are observed ~ twice per day, whereas SAR only are obtained 3 to 8 timesmonthly. The relatively low number of samples and the absolute uncertainty within the maps, ~ 1.3 ms-1, offer wind resource statistics useful only in pre-feasibility studies or in combination with classical offshore observations.
    Original languageEnglish
    Number of pages57
    ISBN (Print)87-550-3374
    Publication statusPublished - 2004
    SeriesDenmark. Forskningscenter Risoe. Risoe-R
    Number1479(EN)
    ISSN0106-2840

    Keywords

    • Risø-R-1479
    • Risø-R-1479(EN)

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