A key phase in the planning process of a wind farm is measuring and analysing the wind speeds and wind directions at a proposed site. This data is used at various stages of the project, from determining what type and size of wind turbine would be most efficient, to deciding whether the site is viable in the long term. Wind Prospect is not linked with a specific wind turbine manufacturer, which enables us to model the turbine best suited to extract maximum energy from the wind at that site.
We generally install wind monitoring equipment onsite for a minimum period of 12 months. This measured data is then compared to long term wind data acquired from sources such as Bureau of Meteorology Automatic Weather Stations and satellite data in order to predict over a longer term period.
Wind monitoring equipment generally consists of one or more wind monitoring masts betwenn 60-120 metres high, with wind speed measuring equipment (anemometers) and wind direction measuring equipment located at various heights on the mast. It is not uncommon to have six or seven anemometers at different heights on a mast. These sensors are all electronic, and automatically transfer data back to the Wind Prospect offices each day, where it is verified to ensure the monitoring equipment is working correctly. The monitoring equipment is powered by a small solar panel unit that is connected to the mast.
At least one wind monitoring mast is usually installed at each site, but often more are used depending on the size of the site. Remote sensing technology is now also commonly used for monitoring the wind. These devices fit on a standard size trailer and can be easily moved around the site to measure the wind speed at various locations. They work by pulsing sound (sodar) or light (Lidar) into the air above them, then capturing the echo and deducing the wind speed at multiple heights. These devices can be as accurate as standard anemometry on wind monitoring masts and can significantly impove the accuracy of wind monitoring at a site.
Once 12 months of wind data has been collected an initial analysis is undertaken using powerful computer modelling techniques. The software takes into account the contours and characteristics of the surrounding land, including any obstacles such as buildings, forests, and turbulence from the turbines themselves. From this analysis, a long term wind speed and a monthly average wind speed are forecast for the site. This data informs selection of an appropriate turbine for use at the wind farm.