Energy Meteorology: ENDOW

Evaluation of heat and momentum flux in the marine atmospheric boundary layer for offshore wind energy utilisation

Overview

In this project the fluxes and profiles of heat and momentum in the marine atmospheric boundary layer are characterised with measurements performed in the German North Sea in cooperation with the FINO-Project.
In the FINO project of the German government, run by Germanischer Lloyd Wind Energie, research platforms are installed in the German part of the North and Baltic Sea to gain information needed for the utilisation of offshore wind energy in Germany. As part of this project, the German Wind Energy Institute performs measurements of the meteorological conditions over the sea with a 100 m high measurement mast 45 km north of the island Borkum in the German North Sea. Aim of these measurement is to gaim data needed for the characterisation of the wind conditions for the planning of wind farms.
The program of the meteorological measurement is extended in this project by utilising high resolution ultrasonic anemometers with a sampling rate of 50 Hz. Three anemometers at different heights are available, of which one has been funded in this project. They are used to measure vertical heat and moisture fluxes for scientific research, which are than used together with the available profile data to evaluate the applicability of commonly used meteorological models (Monin-Obukhov theory and flux-profile relations).
In previous investigations with data from the field measurement Rødsand in the Baltic Sea important deviations of these models from the measurements were found. A first analysis of data from the FINO measurement station was performed in this project. It suggest that there is less influence of thermal effects over the North Sea compared to the Baltic.
With this research we want to contribute to a general scientific understanding of the flow characteristics of the coastal marine boundary layer - knowledge which will be essential for the successfull utilisation of offshore wind energy as part of the German energy supply of the future.

Sketch of FINO measurement platform
© Germanischer Lloyd

Co-operations and Funding

The measurements for this project are performed by the German Wind Energy Institute (DEWI).

Partial funding has been provided by the 'Deutsche Bundesstiftung Umwelt'

Final Report

Lange, B., S. Tautz: Bestimmung von Wärme- und Impulsfluss in der marinen atmosphärischen Grenzschicht für die Offshore-Windenergienutzung (BAGO). ForWind Bericht 2004-02, ForWind, University of Oldenburg, Oldenburg, 2004
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Publications

Tautz, S., B. Lange, D. Heinemann: Correction of the heat and momentum flux measurements with the ultrasonic anemometers at the FINO I offshore meteorological mast for flow distortion and mounting effects. Proceedings of the German Wind Energy Conference DEWEK 2004, Wilhelmshaven, Germany, 2004, published on CD
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Lange, B.: Comparison of wind conditions of offshore wind farm sites in the Baltic and North Sea. Proceedings of the German Wind Energy Conference DEWEK 2004, Wilhelmshaven, Germany, 2004, published on CD
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Tautz, S.: Thermal Effects in the Atmospheric Boundary Layer above the North Sea, Diplomarbeit, Universität Oldenburg, ForWind Report 2004-01, 2004

Tautz, S., B. Lange, D. Heinemann: On the importance of flow distortion correction of ultrasonic anemometers for flux measurements in the marine surface layer. EGU 1st General Assembly, Nice, France, 25.-30.4.2004. Geophys. Res. Abstr. (2004) vol. 6, published on CD
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Contact

Dipl.-Phys. Jens Tambke
ForWind - Centre for Wind Energy Research
Institute of Physics - University of Oldenburg
D-26111 Oldenburg, Germany

Tel: +49 (0)441 - 3611 6736
Fax: +49 (0)441 - 3611 6739
e-mail: jens.tambke@forwind.de