Ilona Bastigkeit Research Associate Fraunhofer Institute for Wind Energy and Energy System Technology IWES
Am Seedeich 45 27570 Bremerhaven
Germany
ilona.bastigkeit@iwes.fraunhofer.de www.windenergie.iwes.fraunhofer.de
High Altitude LiDAR Measurements of the Wind Conditions
for Airborne Wind Energy Systems
Ilona Bastigkeit, Markus Sommerfeld, Peter Rohde, Claudia Rudolph Fraunhofer IWES
Airborne wind energy (AWE) systems are flying in heights between 100 m and 1000 m. Thus, for a resource assess-ment as well as for power curve estimation the wind con-ditions over these heights have to be considered. Be-sides, new methods for both have to be developed on ba-sis of these analyses.
During extensive measurement campaigns within the OnKites II project (‘Studies of the potential of flight wind turbines, Phase II’, funded by the German Federal Ministry for Economic Affairs and Energy, BMWi) high-resolution wind data up to 1100 m height were collected at differ-ent locations onshore and nearshore [1]. Within measure-ment campaigns near Pritzwalk and Emden (Germany), the scanning LiDAR system Galion G4000 of the company Sgurr Energy was used. The scanning LiDAR system mea-sured the wind speed at 40 measurement heights during six months at each site which allows a better estimation of the wind resources at these heights. The results of the analyses of the data will be shown.
The analyses of the LiDAR data show a strong depen-dence of the vertical wind profile on different stratifica-tion condistratifica-tions of the atmospheric boundary layer. Thus, the shear of wind speed plays an important role for AWE systems. Up to an altitude of around 400 m the highest gradients in wind speed can be found. For an estima-tion of wind resources the distribuestima-tion of wind speed is used by calculating the Weibull distribution. The Weibull parameters have been analyzed at all 40 measurement heights. Besides, an investigation of downtimes of AWE systems because of very low as well as too high wind speeds at both locations has been done.
References:
[1] Bundesministerium für Wirtschaft und Energie (BMWi): Forschungsjahrbuch Energie 2015. http://www.forschungsjahrbuch-energie.de/downloads/forschungsjahrbuch-2015.pdf
