Wind power
Anyone who has struggled to stay upright in a strong gale is aware of the intrinsic power of the wind. Indeed wind energy has been harnessed by people for centuries.
The windmills with cloth sails used in many European countries are a good example, as are the multi-bladed windmills commonly seen on farms and in rural areas of Australia. The power of the wind is also used to propel sailing ships, cool homes on balmy summer evenings, and fly kites.
Recent research and development into harnessing the wind means that we can now generate electricity using wind energy.
Machines that generate electricity from the wind work in much the same way as the more familiar European windmills of old. These machines are called wind turbines.
What is a wind turbine and how does it work?
Diagram of a wind turbine
A wind turbine comprises a tower, topped by an enclosure called a nacelle, and the rotor, which is the propeller-like structure connected to the nacelle. The nacelle houses an electrical generator, power control equipment and other mechanical equipment, which is connected to the rotor.
The rotor blades are made from light composite materials such as fibreglass. They are well researched and shaped to maximise the energy harnessed. The wind strikes these blades, and due to their shape, the wind causes the rotor to spin. When the wind is strong enough, the rotational energy in the rotor is converted to electrical energy within the generator.
Towers are commonly made of steel tubes, although some earlier models used steel lattices. The height of the tower varies from turbine to turbine, and is determined by the length of the blades, size of the generator, and the need to access the smoother winds available further from the ground. Wind turbines in Australia are commonly between 50 and 80 metres tall.
How much energy is there in the wind?
Diagram showing the inside of the nacelle
Wind turbines can generate significant amounts of electricity. Wind electrical power is generally proportional to the speed of the wind cubed. This means that if the wind speed doubles, the power generated is increased eightfold.
Apart from the actual wind speed at a site, the length of the blades on the rotor also determine the amount of power produced. The longer the blade, the more wind it can harness.
Wind turbines that are capable of generating 1 MW of electrical energy are now relatively common.
Wind energy in NSW
NSW has an excellent wind resource. Background wind speeds in NSW are comparable to northern Europe, where a large portion of international wind generation is currently installed.
NSW has an estimated potential for over 3000 MW of wind energy. Currently, 150 MW has been installed or is under construction.
The NSW Wind Atlas poster provides a snapshot of the state's wind resource. Many of the good sites in NSW are due to the hills and ridges of the Great Dividing Range interacting with the calmer background winds that blow from west to east across the vast NSW inland.
Contact Customer Programs on 1300 136 888 or download the Wind Atlas Poster (PDF 5MB).
In addition to a good wind resource, NSW has an extensive electricity transmission network, providing easy access for new wind farms to the national electricity grid.
Wind farms in NSW
Blayney Wind Farm, in the Central Tablelands of NSW, has 15 wind turbines, each with a capacity of 660 kW. It was commissioned in October 2000, and will produce enough electricity annually to power 3500 homes.
Wind farm
Crookwell Wind Farm was the first grid-connected wind farm in Australia when installed by Pacific Power in 1998. It consists of eight 600 kW turbines giving a total capacity of 4.8 MW. Now owned by Eraring Energy, the wind farm supplies electricity to Country Energy's GreenPower customers.
Hampton Wind Park is a two hour drive from Sydney, past the Blue Mountains. Power from two 660 kW wind turbines enhances the quality of supply in the surrounding rural electrical grid. This wind farm supplies electricity to Integral Energy's GreenPower customers.
Kooragang Island's single 600 kW wind turbine has been operated by EnergyAustralia since its installation in 1997. It provides GreenPower for Energy Australia's Pure Energy customers.
NSW Wind Energy Handbook
The NSW Wind Energy Handbook provides a comprehensive kit of information on all aspects of wind energy development in NSW. It has material for all participants in commercial wind energy development, including decision makers, developers, investors, landholders and the local and wider community. The Handbook does not specifically cover small-scale wind energy technology.
The Handbook can be downloaded here (950 kB PDF). Please note that the handbook was published in 2002, and some information is no longer valid. In particular, the reader is advised to seek updated information regarding 'The wind energy market' (Section 3) and 'Planning issues for wind farms in NSW' (Section 5).