Wind farm technology goes sonic

The pressing need for viable alternative energy sources that do more than just supplement coal fired power-stations is driving advances in the development of wind energy. One major hurdle in establishing successful wind farms is the difficulty in attaining accurate site evaluation data and it is this problem that the Triton Sonic Wind Profiler seeks to address. Designed to measure wind-speed at heights of up to 200m without the need for erecting costly and less effective masts, the wind profiler utilizes a technique known as Sodar (sound detection and ranging) that measures sound waves echoes in the atmosphere in a similar way to Sonar detection used by submarines underwater.

In evaluating a suitable site to erect a windfarm measurements need to be taken over a period of at least a year. This is traditionally achieved through use of a meteorological mast or met mast – a tower equipped with anemometers and other weather instruments. The limitations of these masts include a height restriction of 60m (any tower above this height requires aircraft warning lights) which makes assessment of a site for a turbine 75-80m high less than ideal along with their high visibility, which raises public concerns before the site has been properly evaluated.

Relying on precise measurements of frequency and time delay from sound pulses that are bounced back to the transmission unit by wind turbulence, Sodar technology addresses these concerns by providing a virtually invisible tool which measures the wind speed and direction at various heights up to 200 meters. The Triton system also overcomes some of the problems associated with existing Sodar technology by remaining effective even in poor weather and delivering easy to interpret wind data without an on-site presence.

Triton also boasts innovations such as a hexagonal transducer array and a tri-lobed acoustic enclosure that increase accuracy by improving signal-to-noise ratios and beam focus, rugged construction making the unit effective in all weather conditions and the ability to correct measurements when used on uneven ground.

Despite the key significance of this and other new wind measurement technologies such as the laser based LiDAR unit featured last week on Gizmag.com in the arena of wind farm evaluation, Second Wind see applications for the technology beyond this in areas including the detection of wind shear at airports.