Wind Energy - Clean energy for our environment and economy

People have been harnessing the energy of the wind for centuries. The old farms in Holland and other parts of the world have used windmills to pump water or grind grain. Today the 'windmill', in the form of a turbine, is being used to harness the wind to generate electricity. Technology development has taken the principles of the windmill to effectively harness wind energy through the use of turbines. Wind turbines, just like windmills, are mounted on a tower to capture the most energy. At heights of around 30 metres they can take advantage of faster and less turbulent wind than at lower levels. The energy of the wind is captured by propeller-like blades. When the air moves over the blade, a pocket of low pressure air forms on the downwind side of the blade. This low pressure air pocket pulls the blade toward it causing the rotor to turn (lift). The force of this pull is actually stronger than the wind's force against the front of the blade (drag). The combination of lift and drag causes the rotor to turn like a propeller, and this in turn spins a generator to make electricity.

Wind turbines are used as stand-alone applications or they are connected to a utility power grid or even combined with a photovoltaic system. The number of wind turbines is determined by the output required and the weather conditions at the specific location.

When a large number of turbines are required they are often referred to as a 'Wind Farm'. This term refers to any group of adjacent wind turbine generators that are connected electrically. The 'farm' includes associated infrastructure such as internal roads, underground cabling for electrical cabling. Each wind turbine acts independently, generating from the available wind resource. The electricity generated flows through common cabling into the grid.

Wind farms are the world's fastest growing electrical generation source. Every wind farm development is different and site specific. The generating capacity ranges from a few megawatts to hundreds of megawatts. In the USA, wind energy accounts for less the one percent of the electricity generated, but installed capacity has been expanding at an average annual rate of more than 20 percent.

In Australia, wind energy costs around twice as much as energy from coal generation, but the cost of wind power and other renewable energy is falling. This cost comparison is done without taking into account the environmental costs of fossil fuel based energy.

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Did you know?

  1. The UK is the windiest country in Europe, so much so that we could power our country several times over using this free fuel.
  2. A modern wind turbine is designed to run continuously for over 20 years, or for 120,000 hours. By comparison, the design life time of a car engine is 20 times less at only 4,000 to 6,000 hours.
  3. Wind turbines are a remarkably robust technology, designed to be operated remotely, needing only 40 hours maintenance time per year. There are wind turbines installed and generating electricity in the desert, the Arctic and even in the North Sea.
  4. A typical turbine in the UK will generate over 4.7 million units of electricity each year, that ?s enough to make 170 million cups of tea a year, to run a computer for 1620 years, or to meet the electricity demands of more than 1,000 homes each year.
  5. The blades on a modern wind turbine sweep 48 tons of air every second, that ?s the same weight as 10 elephants or 5 double decker buses.
  6. Every unit of electricity from a wind turbine displaces one from conventional power stations: wind turbines in the UK currently prevent the emission of one and three-quarter millions tonnes of carbon dioxide each year.
  7. The impetus for modern wind turbines came with the oil crisis of the mid-70s and the technology advanced so rapidly that wind energy is listed as one of the top ten inventions of the 1980 ?s.
  8. In the last 20 years, the power production of wind turbines has increased by a factor of 100, while the costs of generating electricity from the wind has fallen by 80%.
  9. Wind is the fastest growing energy source worldwide, and has been for over a decade with an annual growth rate of 30%.
  10. The global wind industry has an estimated annual turnover of £5.5 billion, 84% of which is based in Europe.

Source: The British Wind Energy Association