The Front Cover

One of today’s hot topics in energy policy and its economics is the reduction of uncertainties in wind resource assessment and forecasting. The article on page 7 provides details of the state of the art for wind tunnel modelling for atmospheric flow over topography. The  image on the cover shows Laser–Doppler anemometry used for non-intrusive flow measurements. Two beams are made to intersect at their waists (focal points). Hazer particles pass through the fringes. Doppler equivalent frequency-shift of the scattered light is measured and the velocity of the fluid can be calculated.

Publisher's Note

Features

 Wind Tunnel Simulation
By Graciana Petersen, Bernd Leitl and Michael Schatzmann, EWTL Environmental Wind Tunnel Laboratory, Germany

Wind Speed in Wind Farms
By Peter Fogh Odgaard, kk-electronic a/s, Denmark

Where Agility is Key

By Niels LaWhite, Chief Scientist, Second Wind, USA

Avoiding Catastrophic Failure in Wind Turbine Blades
 By Dr Hessam Ghasemnejad, School of Aerospace and Aircraft Engineering, Kingston University London, UK

STX Windpower Introduces a New Direct Drive Wind Turbine
By M. Huizer and N. te Welscher, STX Windpower B.V., The Netherlands

WWEA Page

WWEA Page September 2011