Offshore Wind Power Meteorology.- Wave Loads on Wind-Power Plants in Deep and Shallow Water.- Time Domain Comparison of Simulated and Measured Wind Turbine Loads Using Constrained Wind Fields.- Mean Wind and Turbulence in the Atmospheric Boundary Layer Above the Surface Layer.- Wind Speed Profiles above the North Sea.- Fundamental Aspects of Fluid Flow over Complex Terrain for Wind Energy Applications.- Models for Computer Simulation of Wind Flow over Sparsely Forested Regions.- Power Performance via Nacelle Anemometry on Complex Terrain.- Pollutant Dispersion in Flow Around Bluff-Bodies Arrangement.- On the Atmospheric Flow Modelling over Complex Relief.- Comparison of Logarithmic Wind Profiles and Power Law Wind Profiles and their Applicability for Offshore Wind Profiles.- Turbulence Modelling and Numerical Flow Simulation of Turbulent Flows.- Gusts in Intermittent Wind Turbulence and the Dynamics of their Recurrent Times.- Report on the Research Project OWID - Offshore Wind Design Parameter.- Simulation of Turbulence, Gusts and Wakes for Load Calculations.- Short Time Prediction of Wind Speeds from Local Measurements.- Wind Extremes and Scales: Multifractal Insights and Empirical Evidence.- Boundary-Layer Influence on Extreme Events in Stratified Flows over Orography.- The Statistical Distribution of Turbulence Driven Velocity Extremes in the Atmospheric Boundary Layer - Cartwright/Longuest-Higgins Revised.- Superposition Model for Atmospheric Turbulence.- Extreme Events Under Low-Frequency Wind Speed Variability and Wind Energy Generation.- Stochastic Small-Scale Modelling of Turbulent Wind Time Series.- Quantitative Estimation of Drift and Diffusion Functions from Time Series Data.- Scaling Turbulent Atmospheric Stratification: A Turbulence/Wave Wind Model.-Wind Farm Power Fluctuations.- Network Perspective of Wind-Power Production.- Phenomenological Response Theory to Predict Power Output.- Turbulence Correction for Power Curves.- Online Modeling of Wind Farm Power for Performance Surveillance and Optimization.- Uncertainty of Wind Energy Estimation.- Characterisation of the Power Curve for Wind Turbines by Stochastic Modelling.- Handling Systems Driven by Different Noise Sources: Implications for Power Curve Estimations.- Experimental Researches of Characteristics of Windrotor Models with Vertical Axis of Rotation.- Methodical Failure Detection in Grid Connected Wind Parks.- Modelling of the Transition Locations on a 30% thick Airfoil with Surface Roughness.- Helicopter Aerodynamics with Emphasis Placed on Dynamic Stall.- Determination of Angle of Attack (AOA) for Rotating Blades.- Unsteady Characteristics of Flow Around an Airfoil at High Angles of Attack and Low Reynolds Numbers.- Aerodynamic Multi-Criteria Shape Optimization of VAWT Blade Profile by Viscous Approach.- Rotation and Turbulence Effects on a HAWT Blade Airfoil Aerodynamics.- 3D Numerical Simulation and Evaluation of the Air Flow Through Wind Turbine Rotors with Focus on the Hub Area.- Performance of the Risø-B1 Airfoil Family for Wind Turbines.- Aerodynamic Behaviour of a New Type of Slow-Running VAWT.- Numerical Simulation of Dynamic Stall using Spectral/hp Method.- Modeling of the Far Wake behind a Wind Turbine.- Stability of the Tip Vortices in the Far Wake behind a Wind Turbine.- Modelling Turbulence Intensities Inside Wind Farms.- Numerical Computations of Wind Turbine Wakes.- Modelling Wind Turbine Wakes with a Porosity Concept.- Prediction of Wind Turbine Noise Generation and Propagation based on an Acoustic Analogy.- Comparing WAsP and Fluentfor Highly Complex Terrain Wind Prediction.- Fatigue Assessment of Truss Joints Based on Local Approaches.- Advances in Offshore Wind Technology.- Benefits of Fatigue Assessment with Local Concepts.- Extension of Life Time of Welded Fatigue Loaded Structures.- Damage Detection on Structures of Offshore Wind Turbines using Multiparameter Eigenvalues.- Influence of the Type and Size of Wind Turbines on Anti-Icing Thermal Power Requirements for Blades.- High-cycle Fatigue of "Ultra-High Performance Concrete" and "Grouted Joints" for Offshore Wind Energy Turbines.- A Modular Concept for Integrated Modeling of Offshore WEC Applied to Wave-Structure Coupling.- Solutions of Details Regarding Fatigue and the Use of High-Strength Steels for Towers of Offshore Wind Energy Converters.- On the Influence of Low-Level Jets on Energy Production and Loading of Wind Turbines.- Reliability of Wind Turbines.
1 Offshore Wind Power Meteorology (p. 1-2)
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 aims to provide this knowledge. This paper describes its scope and argues why it is needed 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. 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 speci.c meteorological knowledge is essential are wind turbine design, resource assessment, wind power forecasting, etc. Wind power meteorology has therefore established itself as an important topic in applied meteorology (Petersen et al., 1998). For wind power utilization on land, substantial knowledge and experience has been gained in the last decades, based on the detailed meteorological and climatological knowledge available. Offshore, the meteorological knowledge is less developed since there has been little need to know the wind at heights of wind turbines over coastal waters and any measurements at offshore locations are di.cult and extremely expensive.
The aim of this paper is to describe the scope of offshore wind power meteorology and to argue why this topic should be given more attention both from the meteorological point of view and from the wind power application point of view. The paper is structured in three main sections: First some particular problems of offshore measurements are discussed in Sect. 1.2. This is followed by a section giving examples for meteorological effects specific for offshore conditions. Their importance for wind power application is shown in Sect. 1.4, followed by the conclusion.
1.2 Offshore Wind Measurements
In recent years, measurements with the aim to determine the wind conditions for offshore wind power utilization have been erected at a number of locations (Barthelmie et al., 2004). Offshore wind measurements are a challenging task, not only since an offshore foundation and support structure for the mast are needed, but also because of the challenges to provide an autonomous power supply and data transfer, the difficulties of maintenance and repair in an offshore environment, etc. These difficulties lead to high costs of offshore measurements and often lower data availability compared to locations on land. Additionally, the flow distortion of the self supporting mast usually requires a correction of the measured wind speeds for wind profile measurements (Lange, 2004).
Two measurements, from which results are shown in this paper, are the Rødsand field measurement in the Danish Balitc Sea and the FINO 1 measurement in the German Bight.
