The International Energy Agency has released a report detailing the steps required to collect high-quality, well-documented remote sensing data for use in wind resource assessments on land.
As wind turbines have become taller, and rotor diameters have steadily increased over the past decades as developers seek to extract more energy from the wind. This trend has led to a need for vertically-resolved wind profiles, with wind speed and wind direction data at multiple heights. Traditionally the wind speed and direction profile was provided by meteorological towers, and if the turbines that were installed were taller than the towers, the tower data were extrapolated vertically. However, extrapolation of data adds uncertainty to the wind resource estimation process.
Ground-based, active remote-sensing of winds is now seen by the wind industry as a useful tool to reduce the uncertainty in wind speeds at hub-height and higher. Two remote sensing technologies have become popular for wind energy applications. These are sodar (or SODAR, short for SOnic Detection and Ranging), and lidar (or LIDAR, short for LIght Detection and Ranging). Although different implementations of the technologies exist, vertical-profiling of wind often involves measurements of wind speed in a cone of the atmosphere, and the calculation of the wind vector at different heights.
To view the entire International Energy Agency report, click here.