Establishing wind speed at a site is a critical part of any wind farm development. Typically, a staged approach is used, to manage risk and cost.
Initially, site prospecting can be conducted using satellite based ‘wind atlases’, and consideration of any nearby bureau of meteorology wind data, and local terrain features (ridges are especially good). However, this only gives a very rough estimate.
To go further, it is necessary to measure wind speed at turbine ‘hub’ height, on site. Traditionally, this has meant installing a wind monitoring mast, which is a costly and somewhat invasive approach, particularly when many sites will not proceed past this point.
Sodar (and another similar technology called lidar) offer a credible alternative here, which can enable development of an initial hub height site record.
Should the initial wind monitoring show the site has promise, more data needs to be collected to satisfy investors (and many other technical studies need to be completed as well). This next stage will typically involve more equipment, such as masts or lidar, including complementary use of sodar.
Even after a project is ready for construction, wind monitoring continues to have a function. After commissioning of turbines, wind monitoring allows verification of their performance to specifications (do they produce the right power for the wind speed), and then assists with ongoing asset management.