Science Centres: Energy

Rapid assessment of potential wind energy sites

New Zealand’s variable terrain and climate mean it’s almost always necessary to combine existing data with specific measurements at a potential wind farm site.

In addition to conventional meteorological instruments, NIWA has built a transportable Doppler Acoustic Sounder unit, known as a SODAR (‘sonic detection and ranging’). The SODAR produces high-resolution vertical profiles of wind speed and direction. It can be set to take measurements at 20 levels anywhere between 20 m and up to 1500 m above the ground.

The unit is mounted on a trailer, can be set up quickly at almost any remote location, and operates unattended. It’s easy to shift, so it can be used to assess different positions within a proposed site. Without SODAR, people would typically use equipment mounted on a fixed mast up to the proposed height of the turbines, and this can be 70 metres. SODAR does not usually eliminate the need for some mast-mounted measurements, but the mast can be

The unit also calculates information useful for air quality studies, such as the height of the mixing layer.