Wind
Wind Energy – how it works
Wind energy, currently the cheapest renewable energy source, involves the generation of electricity from the naturally occurring power of the wind.
Wind turbines capture wind energy within the area swept by 
their blades, proportional to the wind speed cubed, up to the designed maximum blade speed. The blades in turn drive an electrical generator to produce power for export to the grid.
Sites where there is strong, consistent wind, such as Southern Australia, are the most appropriate locations for wind farms. An excellent wind site is generally considered to provide average wind speeds greater than 8 metres per second at ground level.
Greenhouse gas savings
In 2008 estimated wind energy generation saved Australia 3,530,744 tonnes of carbon dioxide. That is equivalent to:
• the removal of 784,610 cars from our roads or
• planting 5.26 million trees.
As an additional environmental benefit, no water is needed for wind farm operation.
In Australia
Australia has some of the world’s best wind resources. The total operating wind capacity at the end of 2008 was 1306 megawatts - a 37 percent rise on 2007. This equated to a generation of approximately 3,500 gigawatt hours of electricity annually. In 2009 a number of new wind farms have been commissioned and the total operating capacity now stands at 1476 megawatts - generating over 4,200 gigawatt hours of electricity annually.
Currently there are 47 operating wind farms in Australia, with a total of 834 operating turbines. South Australia has the largest installed capacity around 50 per cent of the nation’s total capacity.
Potential
There are currently almost 6,000 megawatts (MW) of large-scale wind farm energy projects proposed around the country, many of them having already received planning permission.
Global view
The use of wind power continues to grow around the world. Global installed capacity at the end of 2008 was almost 121 gigawatts producing approximately 260 terrawatt hours of electricity annually.
In 2008, more than 27 gigawatts of new wind capacity was installed around the world with a value of around $US48 billion - a 28 percent increase on 2007.
The top four wind energy nations for 2008 were:
• United States - 25,170 MW
• Germany - 23,903 MW
• Spain - 16,754 MW
• China - 12,210 MW
Current Issues
In 2007 the Government committed to ensuring that 20 percent of Australia's electricity supply would come from renewable energy sources by 2020 by establishing the expanded national Renewable Energy Target (RET) scheme. Draft legislation on the design of the expanded RET was released in December 2008 and the final legislation was passed in August 2009.
The development of national wind farm guidelines will assist in wind farm planning and approval process and help address some of the barriers to wind farm development.
