wind energy proceedings of the euromech colloquium

Wind Energy Proceedings of the Euromech Colloquium 123 Joachim Peinke, Peter Schaumann Wind Energy Colloquium Proceedings of the Euromech and Stephan Barth (Eds.) With 199 Figures and 14 Tables LibraryofCongressControlNumber: This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broad- casting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of S eptember 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. Springer is a part of Springer Science+Business Media. springer.com imply, even in the absence of a specific statement, that such names are exempt from the relevant pro- tective laws and regulations and therefore free for general use. Printed on acid-free paper 543210 package A E LT X 2006932261 The use of general descriptive names, registered names, trademarks, etc. in this publication does not SPIN 11534280 89/3100/SPi ISBN-13 978-3-540-33865-9 S pringer Berlin Heidelberg New York ISBN-10 3-540-33865-9 Springer Berlin Heidelberg New York © Springer-Verlag Berlin Heidelberg 2007 Institute of Physics 26111 Oldenburg peinke@uni-oldenburg.de University of Hannover Institute for Steel Construction Appelstrasse 9a 30167 Hannover Dr. Stephan Barth ForWind - Center for Wind Energy Research Germany Institute of Physics 26111 Oldenburg Germany stephan.barth@uni-oldenburg.de Prof. Dr Ing. Peter Schaumann Germany Typesetting by the editors and SPi using Springer ForWind - Center for Wind Energy Research Carl-von-O ssietzky University O ldenburg Carl-von-O ssietzky University O ldenburg Cover design: Eric h Kirchner, Heidelberg schaumann@ stahl.uni-hannover.de Prof. Dr. Joachim Peinke ForWind - Center for Wind Energy Research Preface Wind energy is one of the prominent renewable energy sources on earth. During the last decade there has been a tremendous growth, both in size and power of wind energy converters (WECs). The global installed power has increased from 7.5 GW in 1997 to more than 50 GW in 2005 (WWEA – March 2005). At the same time, turbines have grown from kW machines to 5 MW turbines with rotor diameters of more than 100 m. This enormous develop- ment and the more recent use in offshore application made high demands on design, construction and operation of WECs. Thus not only a new major in- dustry has been established but also a new interdisciplinary field of research affecting scientists from engineering, physics and meteorology. In order to tackle the problems and reservations in this interdiscipli- nary community of wind energy scientists, ForWind, the Center for Wind Energy Research of the Universities of Oldenburg and Hanover, arranged the EUROMECH Colloquium 464b – Wind Energy, which was held from October 4, 7, 2005, at the Carl von Ossietzky University of Oldenburg, Germany. The central aim of this colloquium was to bring together the up to then separate communities of wind energy scientists and those who do fundamental research in mechanics. Wind energy is a challenging task in mechanics and many of future progress will find relevant applications in wind energy conversion. More than 100 experts coming from 16 countries from all over the world attended the meeting, confirming the need and the concept of this colloquium. The 46 oral and 28 poster presentations were grouped in the following topics: – Wind climate and wind field – Gusts, extreme events and turbulence – Power production and fluctuations – Rotor aerodynamics – Wake effects – Materials, fatigue and structural health monitoring Phenomenological approaches mainly based on experimental and empirical data as well as advanced fundamental mathematical scientific approaches have VI Preface been presented, spanning the range from reliability investigations to new CFD codes for turbulence models or Levy statistics of wind fluctuations. During this meeting it became clear, which fundamental scientific tasks will have essential importance for future developments in wind energy: – A better understanding of the marine atmospheric boundary layer, ranging from mean wind profiles to high resolved influences of turbulence. These questions need further measurements as well as genuine simulations and models. A proper and detailed wind field description is indispensable for correct power and load modeling. – CFD simulations for wind profiles and rotor aerodynamics with advanced methods (aeroelastic codes) that include experimental details on the dynamic stall phenomenon as well as near and far field rotor wakes. – A site independent description of wind power production taking into account turbulence induced fluctuations. – Material loads of different components of a WEC and the fatigue recog- nition of which due to the high number of lifecycles of such complex machines. – To establish an advanced numerical hybrid model for a 3D simulation of a WEC, taking into account wind and wave loads as well as all effects of operation in a so-called ‘integrated’ model. Many intensive discussions on these and other topics took place between participants from different disciplines during coffee and lunch breaks and also during the social evening events reception of the city at the “ehema- lige Exerzierhalle” and the conference dinner on the nightly lake of Bad Zwischenahn. The positive feedback for the meeting’s scientific and social aspects encour- aged the scientific committee to decide to have follow-up meetings alternately organized by Duwind, Risø and ForWind. All participants shared the opinion that the scientific interdisciplinary cooperation and international collabora- tion shall be intensified. The organizers want to thank the scientific committee members Martin K¨uhn, Gijs van Kuik, Soeren E. Larsen, Ramgopal Puthli and Daniel Schertzer for helping to organize this conference and establishing this book. Further- more, we are grateful for the financial support of the Federal Ministry of Edu- cation and Research, the City of Oldenburg and the EWE company. Special thanks go to Margret Warns, Elke Seidel, Moses K¨arn, Martin Grosser, Frank B¨ottcher for organizing all technical and administrative concerns. Contents List of Contributors XXI 1 Offshore Wind Power Meteorology Bernhard Lange 1 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Offshore WindMeasurements 2 1.3 Offshore Meteorology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.4 Application to Wind Power Utilization . . . . . . . . . . . . . . . . . . . . . . . 4 1.5 Conclusion 5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Wave Loads on Wind-Power Plants in Deep and Shallow Water Lars Bergdahl, Jenny Trumars and Claes Eskilsson 7 2.1 A Concept of Wave Design in Shallow Areas . . . . . . . . . . . . . . . . . . 7 2.2 Deep-Water Wave Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Wave Transmission into a Shallow Area Using a Phase-Averaging Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.4 Wave Kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.5 Example ofWaveLoads 10 2.6 Wave Transmission into a Shallow Area UsingBoussinesq Models 12 2.7 Conclusions 12 2.8 Acknowledgements 12 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3 Time Domain Comparison of Simulated and Measured Wind Turbine Loads Using Constrained Wind Fields Wim Bierbooms and Dick Veldkamp 15 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2 Constrained Stochastic Simulation of Wind Fields . . . . . . . . . . . . . 15 VIII Contents 3.3 Stochastic Wind Fields which Encompass Measured WindSpeedSeries 16 3.4 Load Calculations Based on Normal and Constrained Wind Field Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.5 Comparison between Measured Loads and Calculated Ones BasedonConstrainedWindFields 19 3.6 Conclusion 20 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4 Mean Wind and Turbulence in the Atmospheric Boundary Layer Above the Surface Layer S.E. Larsen, S.E. Gryning, N.O. Jensen, H.E. Jørgensen and J. Mann 21 4.1 Atmospheric Boundary Layers at Larger Heights . . . . . . . . . . . . . . 21 4.2 DatafromHøvsøre Test Site 22 4.3 Discussion 24 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5 Wind Speed Profiles above the North Sea J. Tambke, J.A.T. Bye, B. Lange and J O. Wolff 27 5.1 Theory of Inertially Coupled Wind Profiles (ICWP) . . . . . . . . . . . 27 5.2 Comparison to Observations at Horns Rev and FINO1 . . . . . . . . . 29 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6 Fundamental Aspects of Fluid Flow over Complex Terrain for Wind Energy Applications Jos´eFern´andez Puga, Manfred Fallen and Fritz Ebert 33 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 6.2 ExperimentalSetup 34 6.3 Results 35 6.4 Conclusions 38 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 7 Models for Computer Simulation of Wind Flow over Sparsely Forested Regions J.C. Lopes da Costa, F.A. Castro and J.M. L.M. Palma 39 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.2 Mathematical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 7.3 Results 40 7.4 Conclusions 42 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 8 Power Performance via Nacelle Anemometry on Complex Terrain Etienne Bibor and Christian Masson 43 8.1 Introduction and Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 8.2 Experimental Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 8.3 ExperimentalAnalysis 43 Contents IX 8.4 Numerical Analysis 44 8.5 Results andAnalysis 44 8.5.1 Comparaison with the Manufacturer . . . . . . . . . . . . . . . . . . 44 8.5.2 Influence on the Wind Turbine Control . . . . . . . . . . . . . . . 44 8.5.3 Influence of the Terrain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 8.5.4 Numerical Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 8.6 Conclusion 46 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 9 Pollutant Dispersion in Flow Around Bluff-Bodies Arrangement El˙zbieta Mory´n-Kucharczyk and Renata Gnatowska 49 9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 9.2 Results ofMeasurements 50 9.3 Conclusions 52 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 10 On the Atmospheric Flow Modelling over Complex Relief Ivo Sl´adek, Karel Kozel and Zbyˇnek Jaˇnour 55 10.1 Mathematical Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 10.1.1 Turbulence Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 10.1.2 Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 10.1.3 Numerical Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 10.2 Definition of the Computational Case . . . . . . . . . . . . . . . . . . . . . . . . 57 10.2.1 Some Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 10.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 11 Comparison of Logarithmic Wind Profiles and Power Law Wind Profiles and their Applicability for Offshore Wind Profiles Stefan Emeis and Matthias T¨urk 61 11.1 Wind Profile Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 11.2 Comparison of Profile Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 11.3 Application to Offshore Wind Profiles . . . . . . . . . . . . . . . . . . . . . . . . 62 11.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 12 Turbulence Modelling and Numerical Flow Simulation of Turbulent Flows Claus Wagner 65 12.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 12.3 Governing Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 12.4 Direct Numerical Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 12.5 Statistical Turbulence Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 X Contents 12.6 Subgrid Scale Turbulence Modelling . . . . . . . . . . . . . . . . . . . . . . . . . 68 12.6.1 Eddy Viscosity Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 12.6.2 Scale Similarity Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 12.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 13 Gusts in Intermittent Wind Turbulence and the Dynamics of their Recurrent Times Fran¸cois G. Schmitt 73 13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 13.2 Scaling and Intermittency of Velocity Fluctuations . . . . . . . . . . . . . 74 13.3 Gusts for Fixed Time Increments and Their Recurrent Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 13.4 The Dynamics of Inverse Times: Times Needed for Fluctuations Larger than a Fixed Velocity Threshold . . . . . . . 78 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 14 Report on the Research Project OWID – Offshore Wind Design Parameter T. Neumann, S. Emeis and C. Illig 81 14.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 14.2 Relevant Standards and Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . 81 14.3 Normal Wind Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 14.4 Normal Turbulence Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 14.5 Extreme Wind Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 14.6 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 14.7 Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 15 Simulation of Turbulence, Gusts and Wakes for Load Calculations Jakob Mann 87 15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 15.2 Simulation over Flat Terrain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 15.3 Constrained Gaussian Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 15.4 Wakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 15.4.1 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 15.4.2 Scanning Laser Doppler Wake Measurements . . . . . . . . . . 90 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 16 Short Time Prediction of Wind Speeds from Local Measurements Holger Kantz, Detlef Holstein, Mario Ragwitz and Nikolay K. Vitanov . 93 16.1 Wind Speed Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 16.2 Prediction of Wind Gusts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Contents XI 17 Wind Extremes and Scales: Multifractal Insights and Empirical Evidence I. Tchiguirinskaia, D. Schertzer, S. Lovejoy and J.M. Veysseire 99 17.1 Atmospheric Dynamics, Cascades and Statistics . . . . . . . . . . . . . . . 99 17.2 Extremes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 17.3 Discussion and Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 18 Boundary-Layer Influence on Extreme Events in Stratified Flows over Orography Karine Leroux and Olivier Eiff 105 18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 18.2 Experimental Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 18.3 Basic Flow Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 18.4 Downstream Slip Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 18.5 Boundary Layer and Wave Field Interaction . . . . . . . . . . . . . . . . . . 108 18.6 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 19 The Statistical Distribution of Turbulence Driven Velocity Extremes in the Atmospheric Boundary Layer – Cartwright/Longuet-Higgins Revised G.C. Larsen and K.S. Hansen 111 19.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 19.2 Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 20 Superposition Model for Atmospheric Turbulence S. Barth, F. B¨ottcher and J. Peinke 115 20.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 20.2 Superposition Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 20.3 Conclusions and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 21 Extreme Events Under Low-Frequency Wind Speed Variability and Wind Energy Generation Alin A. Cˆarsteanu and Jorge J. Castro 119 21.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 21.2 Mathematical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 21.3 Results and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 21.4 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 [...]... in the description of the wind shear 1.5 Conclusion With the example of the vertical wind speed profile offshore it was shown that specific meteorological conditions exist at the potential locations of offshore wind farms, i.e over coastal waters in heights of 20 to 200 m Since the interest in the wind conditions at these locations is new, the specific meteorological knowledge still has to be improved The. .. offshore vertical wind speed profiles Wind Energy 4: 99–105 3 Barthelmie RJ, Hansen O, Enevoldsen K, Motta M, Højstrup J, Frandsen S, Pryor S, Larsen S, Sanderhoff P (2004) Ten years of measurements of offshore wind farms – What have we learnt and where are the uncertainties? In: Proceedings of the EWEA Special Topic Conference, Delft, The Netherlands 4 Csanady GT (1974) Equilibrium theory of the planetary... evaluate the magnitude of the effect for wind power applications (Lange et al., 2004a) The effect of this correction on the profile can be seen in Fig 1.4, where different theoretical wind profiles are compared 140 Height [m] 120 100 80 60 Neutral Stable Stable & Inversion IEC design profile 40 20 6 8 10 12 14 Wind speed [m/s] Fig 1.4 Comparison of different theoretical wind speed profiles 1 Offshore Wind Power... the wind The wind is, on the other hand, also the most important constraint for turbine design, as it creates the loads the turbines have to withstand Therefore, accurate knowledge about the wind is needed for planning, design and operation of wind turbines Some tasks where specific meteorological knowledge is essential are wind turbine design, resource assessment, wind power forecasting, etc Wind power... for the efficient development of offshore wind power and which has the potential to produce new meteorological knowledge about the atmospheric flow over the sea References 1 Barthelmie RJ (1999) The effects of atmospheric stability on coastal wind climates Meteorological Applications 6(1): 39–47 2 Barthelmie RJ (2001) Evaluating the impact of wind induced roughness change and tidal range on extrapolation of. .. modified by Monin–Obukhov similarity theory for thermal stability In Fig 1.3 the prediction of Monin–Obukhov theory for the ratio of wind speeds at 50 m Geostrophic wind Wind profile Atmospheric stratification Air temperature Momentum transfer Sea surface roughness Water temperature Fetch Wave field Fig 1.2 Sketch of influences on the wind field over coastal waters Wind speed ratio u(50)/u(30) 1.20 1.15... the influence of the surface on the flow The most obvious one is the roughness of the sea, which is very low, but also changes due to the changing wave field (Lange et al., 2004b) The momentum transfer between North Sea Baltic Sea FINO 1 (100 m) Rødsand (50 m) Fig 1.1 The measurement sites Rødsand in Denmark and FINO 1 in Germany 1 Offshore Wind Power Meteorology 3 wind and water, governed by the sea surface... effects like currents and tides influence the wind speed over water (Barthelmie, 2001) The dedicated meteorological measurements made in connection with planned offshore wind power development helped to improve the knowledge about the wind conditions relevant for offshore wind farm installations One example is the vertical wind speed profile over coastal waters The wind speed profile is commonly described... for the efficient development of offshore wind power 1.1 Introduction Wind power utilization for electricity production has a huge resource and has proven itself to be capable of producing a substantial share of the electricity consumption It is growing rapidly and can be expected to contribute substantially to our energy need in the future (GWEC, 2005) The ‘fuel’ of this electricity production is the wind. .. Engineering University of Hannover Appelstr 9A, 30167 Hannover Germany 1 Offshore Wind Power Meteorology Bernhard Lange Summary Wind farms built at offshore locations are likely to become an important part of the electricity supply of the future For an efficient development of this energy source, in depth knowledge about the wind conditions at such locations is therefore crucial Offshore wind power meteorology . Wind Energy Proceedings of the Euromech Colloquium 123 Joachim Peinke, Peter Schaumann Wind Energy Colloquium Proceedings of the Euromech and Stephan Barth (Eds.) With. ForWind, the Center for Wind Energy Research of the Universities of Oldenburg and Hanover, arranged the EUROMECH Colloquium 464b – Wind Energy, which was held from October 4, 7, 2005, at the. stahl.uni-hannover.de Prof. Dr. Joachim Peinke ForWind - Center for Wind Energy Research Preface Wind energy is one of the prominent renewable energy sources on earth. During the last decade there has been