Author: Alicia Webb
Once you've decided a wind farm is right for your community, the next step is to identify potential locations. There's a lot of useful information online, so you can start researching as soon as you're ready. Essentially, what you're looking for is a site that's high up, clear, not too close to houses, and not too far from an electrical grid connection point.
This article describes the high-level identification process for general regions. For information on investigating these areas in more detail, visit our next article Investigating potential wind farm sites.
Defining a boundary
The first thing to consider is your 'boundary of investigation', which will vary depending on your community's needs. If it's important that your wind farm is near a town at the centre of your community, you could decide to investigate within a circle around town, with for example a 20 km radius. The area you decide to consider should take into account things like topography and grid access, which we discuss in more detail below. It's better to start wider and narrow your field of investigation later than the other way around.
If proximity to a town is not an issue, you should consider other boundary constraints, like the driving distance from your community, or the borders of your council shire or even your state.
Gathering relevant information
Maps
To get started, you'll need a good map. Google Earth is a really useful online tool, and free to download. You can use it to 'fly over' your area to see hills and valleys, towns, and how heavily vegetated an area is.
For even better detail, map shops sell paper maps to a scale of 1:25,000. At this early stage it's best to get a map that covers your entire area of consideration. Later on, when you start going into more detail, you can buy higher resolution maps.
Your map needs to include:
- height contour lines
- roads and tracks
- state and national park regions
- electrical grid information
- towns and other populated areas.
Wind speed and direction information
Two of the most widely used sources for wind information are the National Renewable Energy Atlas, and the Bureau of Meteorology's weather stations across Australia.
Australian Renewable Energy map
AREMI is funded by the Australian Renewable Energy Agency and developed by Data61 in partnership with Geoscience Australia and the Clean Energy Council. The AREMI website provides access to renewable energy and general information which has been provided by various third party data custodians.
Bureau of Meteorology
The Bureau of Meteorology collects wind speed and direction data at 30 minute intervals, at various locations across the country. At this early stage, the main thing to consider is wind direction roses. These show the frequency distribution of the wind direction. Some sites are highly directional. For example, a coastal site may experience onshore or offshore winds 90% of the time. Meanwhile, inland sites may have an even amount of wind from all directions.
Knowing the direction of the wind is important because it can help you identify useful landscape features like ridges. The bureau has a full explanation of wind roses on its website.
You can also find some national wind rose maps and some site specific wind rose data.
Electrical grid information
There are two important issues to consider when it comes to grid connection:
- the distance between your wind farm and the electrical grid
- the capacity for the electrical grid to accept and transport your energy
At this very early stage, you'll just be looking at the distance to the grid. The closer your potential site is to a grid connection point, the cheaper it will be to connect to. A community-scale wind farm is more likely to connect to a lower voltage line, like 22kV. These lower voltage lines are called 'distribution lines' whereas high voltage lines on tall towers are called 'transmission lines'. It's just worth trying to highlight areas within a few kms of the distribution lines.
Distribution lines are operated by electrical distribution companies who generally control a specific region. It's worth finding out which company manages distribution in your area. If you're unsure where local distribution lines are or what voltage a line is you might be able to call the distributor and chat about your area.
Pulling the information together
Once you have a map, an idea of where the windiest areas might be, and where the electrical grid is, it's time to start focusing on particular areas of interest. Here are some of the main things to look for:
- Areas closest to the electricity grid.
- Higher ground (hills and ridges).
- Clear land (for example, farming land rather than forest areas).
- Areas that aren't too populated.
- Areas that look suitable on the renewable energy atlas.
Google Earth has a particularly useful option you can use to analyse elevation. Go to 'settings' or 'preferences' and select the '3D view' tab. Change the 'elevation exaggeration' setting to three, the maximum setting. Now if you tilt Google Earth you'll see the hills and ridges three times higher than they really are. Google Earth can also help you see which areas are clear and which are forested.
Once you've highlighted a few potential sites, you can start to consider each one in more detail. .