By Rich Bowden Sep 9, 2006, 16:23 GMT
Currently the world's fastest growing renewable power source, wind energy is the transformation of the wind's kinetic force into mechanical power through a turbine. The mechanical power can be used for such tasks as grinding grain or pumping water or converted into electricity through a generator for use by homes and businesses.
"[Though] only about five countries in the world produce nearly three quarters of all the wind power, with the growth rate that we are seeing [wind power] is the fastest growing energy source in the world," according to Joseph Florence of the Earth Policy Institute in Washington. "A decade ago, wind energy stood at 5,000 megawatts so that 60,000 megawatts of installed capacity that we have today represents a twelve-fold increase over the last ten years," said Florence in a Radio NZ interview.
Wind farms are essentially a large-scale grouping of turbines which can vary in number from one or two to hundreds of turbines and generate power from as low as 50 kilowatts to several hundred megawatts. The largest wind farm in the U.S at present is the Stateline Wind Energy Centre, situated along the Oregon/Washington border. The Centre, with around 450 turbines, has a generating capacity of 300MW or enough electricity to power around 72,000 homes.
Wind energy has played an important part in humankind's history with the first known windmill dating back to 2000 B.C to ancient Babylon. First used in Europe in the twelfth century to mill grain, by 1840, England had around 10,000 windmills scattered across the country. Though ultimately superseded by more cost effective machinery during the Industrial Revolution, the windmill is still regarded as an important part of the world's cultural landscape.
In countries such as Australia, the use of wind energy on rural properties was common until the introduction of grid electricity in the 1950's. Considered by many an iconic symbol of Australian rural life, many wind driven water pumps are still in use in rural parts of the country.
The traditional "farm windmill" of the American West first appeared towards the end of the 19th century with the export of windmills becoming a major enterprise according to the Iowa Energy Centre website.
"Until the diesel engine came along, many transcontinental rail routes in the U.S. depended on large multi-vane windmills to pump water for steam locomotives," said the Centre.
"In the 1930s and 1940s, hundreds of thousands of electricity producing wind turbines were built in the U.S…. These wind turbines typically provided electricity to farms beyond the reach of power lines and were used to charge storage batteries, operate radio receivers and power a light bulb or two. By the early 1950s, however, the extension of the central power grid to nearly every American household, via the Rural Electrification Administration, eliminated the market for these machines."
Modern interest in wind energy had its origins following the OPEC oil embargo of 1973 when research in alternative energy grew in response to rising oil prices. However it wasn't until the turn of the century, with mounting evidence supporting scientific opinion that tied global warming to CO2 emissions caused by fossil fuels, that large-scale wind farming was seriously contemplated.
Accounting for 23% of the total electricity needs in Denmark, 4.3% in Germany and around 8% in Spain, Europe is currently the largest producer of wind powered electricity production with 72% of all power generated globally. However with countries such as India and China becoming aware that their developing economies need to be driven by more than fossil fuels, many wind energy companies are looking to these countries as the future growth market for wind power.
Josh Bradshaw, spokesman for the Australian wind energy company Roaring Forties spoke to the Australian ABC of the potential of the Chinese market.
"They want to install 30,000 megawatts of wind over there, which is almost as much as Australia's entire capacity," he said.
With the cost of use to the consumer falling steadily, and its mitigating effect on climate change, wind energy's future as an energy source seems to be assured. Currently the most rapidly growing renewable energy in the world, wind energy proponents believe wind energy to be capable of increasing further its percentage of the world's energy needs as countries look to utilize more environmentally friendly fuels.
"Wind has come of age," said Lester Brown, president of the Washington-based Earth Policy Institute. "And wind can now go toe-to-toe with any of the fossil fuels in competing for markets."
"I think if we want to make wind the centrepiece of a new energy economy, including powering cars and generating electricity, I think it has the potential to totally dominate the U.S. energy economy," he said.
According to a July 2006 report by the Australian Conservation Foundation, the world must reduce greenhouse emissions by 60% in order to avoid dangerous climate change and a transition to wind energy away from CO2 polluting fossil fuel sources such as coal and oil is seen by wind energy supporters as a crucial first step in beginning this process.
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