Prospecting the world for wind
How we use our unique technology to find the best places around the world for wind power.
A location that is effective for large scale wind turbines needs to satisfy four wide-ranging criteria. The site needs to:
- be windy
- be located close to major electricity lines
- have community and landowner support
- satisfy environmental and planning considerations
Let's concentrate first on finding windy locations.
The best sites for wind turbines have annual average wind speeds of 6-10 meters a second (the precise speed depending on the economics of the particular wind farm). So where in the world, or in a particular country, do these wind conditions occur?
To find the best locations we at Windlab use a software called Windscape. Originally developed by Australian scientific organization CSIRO and then extensively developed in-house by us, the software uses as its starting point inputs from weather data collected around the world.
This data, measured at 6 hourly intervals by balloons and other meteorological techniques, includes wind speed, wind direction, temperature and humidity. Importantly, the measurements are taken not just at ground level - instead the data is collected as the balloons ascend through the atmosphere to a height of up to 20km. This metrological data is then used to construct a picture of the weather conditions for the whole world on a 1 x 1 degree grid of latitude and longitude. From this long-term data we can ascertain the average wind speeds of locations around the world.
The next step is to apply sophisticated computer modeling to improve the resolution of the information. Through successive steps that take into account the natural forces that dominate at different scales, a picture of wind speeds and directions can be developed at resolutions of 27 x 27 kilometers, 9 x 9 kilometers and 3 x 3 kilometers.
A different computer model, developed entirely by Windlab, is then applied. This results in wind speed data being available at an incredible resolution of 100 x 100 meters - all without leaving the office!
Building a picture
So what does this computer modeling actually look like?
This image, generated by Windscape, shows annual average wind speeds for the whole of Australia. Red indicates highest wind speeds, yellow medium wind speeds and blue low wind speeds.
A cursory glance indicates that high wind speeds occur on the southern and western coastlines, while a closer examination shows high wind speeds in other areas - for example, some parts of inland south-eastern Victoria. But the state of Victoria is over 200,000 square kilometers in area - and to successfully site wind turbines, we need to know where to locate individual turbines to within 50 or 100 meters!
This image shows two different wind mapping resolutions. Within the state of Victoria the resolution has been improved to 100 x 100 meters, while north over the border in New South Wales the resolution is 3 kilometers. The higher resolution mapping provides sufficient detail that specific sites of wind power potential can now start being identified.
In this image we've now zoomed into an area in the west of the state. At this resolution even the actual shape of the land can be seen - the wind speed is higher on hilltops and ridges and lower in valleys. If you look closely, you can even see the pattern of rivers represented by the lower wind speeds found in the river valleys! In the middle of this image is an area of wind power potential - Oaklands Hill.
So what does the Oaklands Hill area look like when we zoom right in? Now we can see not only the areas of high wind speeds, but as shown by the lightest pink color, where within those areas are the best potential sites for wind turbines.
So far all that we've examined are computer models of wind speeds - but what does this landscape actually look like? For example, is the area dotted with quarries, is it heavily vegetated or is there a town of people right in the middle of our proposed wind turbine site? This aerial photo, of the same area covered by the Windscape image above, shows that the landscape is actually one of extensive farming.
The next step is to overlay a contour map on the Windscape image. This shows that the highest wind speeds occur on the top of hills. That's good - the modeling makes sense! From this you might think that all that was needed was a contour map - just look for high hills and find plenty of wind. But remember that the average wind speed is higher across this whole area than many other parts of the state and that the modeling shows where within the area the highest speeds are experienced.
But who owns the land? This map superimposes the areas owned by different people on the modeled wind speeds and the topography. These are the people with whom Windlab will negotiate financial agreements for the siting of wind turbines on their land.
There are other important factors that need to be taken into account. These factors might be environmental, planning, cultural or relate to the heritage of the area. In this case a microwave communication system is located in the area - the paths of the microwave beams are highlighted. If the wind turbines are not to impact on telecommunications, they need to be sited outside of these beams.
Finally the provisional siting of the individual wind turbines can be carried out. On this map the turbines are shown as yellow dots, red lines show roads, green lines show power connection cables and the squares are buildings. Following on-site monitoring of actual wind speeds, completion of environmental impact studies and consultation with local communities and landholders, it's likely that these turbine locations will be changed a little. In fact, normally the turbine locations go through several iterations.
And the outcome of all this work? The AUD$175 M Oaklands Hill wind farm, 5km south of Glenthompson in the Southern Grampians of Victoria, is now an operating wind farm owned by AGL Energy. It consists of 32 turbines having a combined output of 67MW - sufficient for 35,000 average households. It was commissioned in 2011.
By using sophisticated software, developed in-house, together with advanced mapping and remote sensing technologies, Windlab can find the best locations for wind turbines almost anywhere in the world. Without even setting foot on the land they can even plan the location of individual turbines!
And that's simply extraordinary.