Sodar Wind Monitoring Project

 

Sodar deployment project summary

 

New England Wind has received a grant of $43,000 from the New South Wales government, Office of Environment and Heritage (OEH), to hire a ‘sodar’ wind monitoring device. A sodar is a trailer mounted device that uses sound, reflected off the atmosphere, to measure wind speed and direction at varying heights, up to about 200 m (which covers the height of all conceivable wind turbines). It is a modern, reliable method of wind monitoring, which provides reasonable accuracy and has gained acceptance for use in pre-feasibility site assessments.

The sodar equipment is owned by Embark and will be leased for 12 months by the New England Wind project.

Fulcrum 3D and Epuron who are the manufacturers of the sodar equipment, have provided in-kind support for this project and have delivered and set up the equipment at the first testing site.

 New England Wind will use the sodar as part of its process of technical site investigation and pre-feasibility assessment. Previously, New England Wind had originally been investigating the Woodville East site, however, this site is no longer under consideration due to the cost of grid connection. As such, New England Wind is looking at a number of new site options. The major limitation on progressing any of these sites is a lack of wind speed data. The sodar should provide the necessary information to address this limitation, at least to the level of being able to screen out sites that are clearly not feasible. Sites that are not screened out will still require subsequent investigation and more wind monitoring before they could be considered viable.

 

The objective of the grant project is to obtain site specific wind resource data, so as to quantify the likely energy generation, and reduce uncertainty in the feasibility assessments for prospective sites. It is expected that this will enable decisions to be made about the potential for each site, and will galvanise future actions and provide opportunities for seed funding for full technical feasibility of the most viable site.

 

Technically, success of the project will be measured by recovery of wind resource data, including wind speed, shear, and turbulence at hub height (80-100m), with a high recovery rate (>90%), over twelve months (total) at up to 4 sites. Technical success will also include delivery of appropriate data analysis (including correlation with long term records) and summary information, necessary to revise site viability and business case assessment, with reduced uncertainty.

 

Measures of the project's success in terms of education and information for the community will include showing the general public what wind data looks like and how it is used to judge whether a site will work (and how to tell if a site really is windy!). This will include assisting Z-NET to evaluate wind options for Uralla. Further, the project will establish a public test case for the use of sodar in wind monitoring, which can be communicated to other community wind farm groups.

 

Some more information on wind monitoring

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.