Understanding Wind Power Technology: Theory, Deployment and Optimisation

3Wind Resources, Site Assessment and Ecology

Hermann van Radecke

3.1 Introduction

This chapter deals with production and environmental aspects of wind energy. How the wind resource is determined using current methods and reanalysis data will be discussed first. This is followed by a simple calculation of the annual energy production of a wind turbine. It is shown how, in a wind farm, the opposite-side weakening is calculated. Then the emissions of the wind turbines are described and noise and shadow emissions will be discussed in detail. Two programs with which wind farms are planned are mentioned. The technical guidelines of the FGW and the IEC 61400 that prescribe the measuring procedures and other processes in connection with wind turbines are mentioned. The environmental influences are regulated by means of the Federal Emission Law (BImSchG), and the approval procedure based on it is sketched out. Exercises and their solutions are given.

3.2 Wind Resources

Wind resources, their calculations and the resulting energy production are presented in the following.

3.2.1 Global Wind Systems and Ground Roughness

The main direction of the wind in Europe is southwest by west. This is a result of the global wind system. The sun and the slant of the Earth’s surface relative to the sun, described with the cosine of the geographical width plus the declination of the sun, drive the system by means of differential warming. At the Equator it is warm, the air density is low, the air rises, and a low-pressure ...