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Papers by Bernhard Lange
The two years I was living in Denmark and working at Risø have a save place in my memory for bein... more The two years I was living in Denmark and working at Risø have a save place in my memory for being two of the most intense years of my life both personally and professionally. This was largely due to the open atmosphere combined with a truly professional work attitude of ...
... Role of wind power forecasts in grid integration Bernhard Lange, Arne Wessel, Jan Dobschinski... more ... Role of wind power forecasts in grid integration Bernhard Lange, Arne Wessel, Jan Dobschinski, Kurt Rohrig Windenergiesysteme ... Bernhard Lange, Kasseler Symposium Energie-Systemtechnik 2009 32 Thank you for your attention! Bernhard Lange blange@iset.uni-kassel.de ...
To achieve precise wind resource assessments, to calculate loads and wakes as well as for reliabl... more To achieve precise wind resource assessments, to calculate loads and wakes as well as for reliable short-term wind power forecasts, the vertical wind profile above the sea has to be modelled with high accuracy for tip heights up to 160m. For these purposes, it is crucial to consider the special meteorological characteristics of the marine atmospheric boundary layer. Continuing our work in the EU-project ANEMOS [1], we analysed marine wind speed profiles that were measured at the two met masts Horns Rev (62m high) and FINO1 (103m) in the North Sea. We found pronounced effects of thermal stratification and of the influence of the land-sea transition. In many situations, the wind shear is significantly higher than expected with standard approaches in mesoscale models. Nevertheless, the numerical analysis of the marine wind field above the North Sea from the German Weather Service seems to provide a good assessment of wind speeds at 103m height. For an improved simulation of the vertical wind speed profiles, we developed a new analytic model of marine wind velocity profiles. In particular, the flux of momentum through the Ekman layers of the atmosphere and the sea is described by a common wave boundary layer. The good agreement between our theoretical profiles and observations at Horns Rev and FINO1 support the basic assumption of our model that the atmospheric Ekman layer begins at 10 to 30m height above the sea surface.
Journal of Physics: Conference Series, 2014
ABSTRACT As the rapid wind power build-out continues, a large number of new wind farms will come ... more ABSTRACT As the rapid wind power build-out continues, a large number of new wind farms will come online but forecasters and forecasting algorithms have little experience with them. This is a problem for statistical short term forecasts, which must be trained on a long record of historical power production ? exactly what is missing for a new farm. Focus of the study was to analyse development of the offshore wind power forecast (WPF) quality from beginning of operation up to one year of operational experience. This paper represents a case study using data of the first German offshore wind farm "alpha ventus" and first German commercial offshore wind farm "Baltic1". The work was carried out with measured data from meteorological measurement mast FINO1, measured power from wind farms and numerical weather prediction (NWP) from the German Weather Service (DWD). This study facilitates to decide the length of needed time series and selection of forecast method to get a reliable WPF on a weekly time axis. Weekly development of WPF quality for day-ahead WPF via different models is presented. The models are physical model; physical model extended with a statistical correction (MOS) and artificial neural network (ANN) as a pure statistical model. Selforganizing map (SOM) is investigated for a better understanding of uncertainties of forecast error.
Der Anteil der Stromerzeugung aus Windenergie hat in Deutschland in den letzten Jahren stetig zug... more Der Anteil der Stromerzeugung aus Windenergie hat in Deutschland in den letzten Jahren stetig zugenommen. Inzwischen gibt es zu Zeiten mit hoher Einspeisung und schwachem Verbrauch ganze Netzregionen, die vollständig aus Windenergie gedeckt werden. Durch den geplanten Ausbau der Offshore-Windenergie wird die Bedeutung der Windenergie für die Stromversorgung weiter zunehmen. Sie wird dauerhaft einen wichtigen Beitrag zu einer klimaschonenden und sicheren Energieversorgung leisten. Bei zunehmendem Anteil an der gesamten Stromerzeugung führt die Integration dieser Technologien zu neuen Herausforderungen an das Stromversorgungssystem.
The two years I was living in Denmark and working at Risø have a save place in my memory for bein... more The two years I was living in Denmark and working at Risø have a save place in my memory for being two of the most intense years of my life both personally and professionally. This was largely due to the open atmosphere combined with a truly professional work attitude of ...
... Role of wind power forecasts in grid integration Bernhard Lange, Arne Wessel, Jan Dobschinski... more ... Role of wind power forecasts in grid integration Bernhard Lange, Arne Wessel, Jan Dobschinski, Kurt Rohrig Windenergiesysteme ... Bernhard Lange, Kasseler Symposium Energie-Systemtechnik 2009 32 Thank you for your attention! Bernhard Lange blange@iset.uni-kassel.de ...
To achieve precise wind resource assessments, to calculate loads and wakes as well as for reliabl... more To achieve precise wind resource assessments, to calculate loads and wakes as well as for reliable short-term wind power forecasts, the vertical wind profile above the sea has to be modelled with high accuracy for tip heights up to 160m. For these purposes, it is crucial to consider the special meteorological characteristics of the marine atmospheric boundary layer. Continuing our work in the EU-project ANEMOS [1], we analysed marine wind speed profiles that were measured at the two met masts Horns Rev (62m high) and FINO1 (103m) in the North Sea. We found pronounced effects of thermal stratification and of the influence of the land-sea transition. In many situations, the wind shear is significantly higher than expected with standard approaches in mesoscale models. Nevertheless, the numerical analysis of the marine wind field above the North Sea from the German Weather Service seems to provide a good assessment of wind speeds at 103m height. For an improved simulation of the vertical wind speed profiles, we developed a new analytic model of marine wind velocity profiles. In particular, the flux of momentum through the Ekman layers of the atmosphere and the sea is described by a common wave boundary layer. The good agreement between our theoretical profiles and observations at Horns Rev and FINO1 support the basic assumption of our model that the atmospheric Ekman layer begins at 10 to 30m height above the sea surface.
Journal of Physics: Conference Series, 2014
ABSTRACT As the rapid wind power build-out continues, a large number of new wind farms will come ... more ABSTRACT As the rapid wind power build-out continues, a large number of new wind farms will come online but forecasters and forecasting algorithms have little experience with them. This is a problem for statistical short term forecasts, which must be trained on a long record of historical power production ? exactly what is missing for a new farm. Focus of the study was to analyse development of the offshore wind power forecast (WPF) quality from beginning of operation up to one year of operational experience. This paper represents a case study using data of the first German offshore wind farm "alpha ventus" and first German commercial offshore wind farm "Baltic1". The work was carried out with measured data from meteorological measurement mast FINO1, measured power from wind farms and numerical weather prediction (NWP) from the German Weather Service (DWD). This study facilitates to decide the length of needed time series and selection of forecast method to get a reliable WPF on a weekly time axis. Weekly development of WPF quality for day-ahead WPF via different models is presented. The models are physical model; physical model extended with a statistical correction (MOS) and artificial neural network (ANN) as a pure statistical model. Selforganizing map (SOM) is investigated for a better understanding of uncertainties of forecast error.
Der Anteil der Stromerzeugung aus Windenergie hat in Deutschland in den letzten Jahren stetig zug... more Der Anteil der Stromerzeugung aus Windenergie hat in Deutschland in den letzten Jahren stetig zugenommen. Inzwischen gibt es zu Zeiten mit hoher Einspeisung und schwachem Verbrauch ganze Netzregionen, die vollständig aus Windenergie gedeckt werden. Durch den geplanten Ausbau der Offshore-Windenergie wird die Bedeutung der Windenergie für die Stromversorgung weiter zunehmen. Sie wird dauerhaft einen wichtigen Beitrag zu einer klimaschonenden und sicheren Energieversorgung leisten. Bei zunehmendem Anteil an der gesamten Stromerzeugung führt die Integration dieser Technologien zu neuen Herausforderungen an das Stromversorgungssystem.