I see I am the last to post. Oh well. Anyway, here is some information about wind energy and its applications. I shall refrain from repeating what Cynthia has posted.
What is Wind Energy
Wind energy converts kinetic energy that is present in the wind into more useful forms of energy such as mechanical energy or electricity. Wind energy is a pollution-free, infinitely sustainable form of energy. It doesn’t use fuel; it doesn’t produce greenhouse gasses, and it doesn’t produce toxic or radioactive waste.
Windmills that were used to grind grain are an example of early uses of wind energy. Modern uses of wind energy include generation of electricity and pumping water. Current wind energy machines are called “wind turbine generators“, “wind pumps”, or more generally, “wind turbines“.
The history of wind energy
Humans have used wind energy for thousands of years. Ancient Persians used wind energy to pump water before the birth of Christ. The world was explored by wind-driven ships long before engines were invented. As recently as the 1920s, over a million wind turbines pumped water and provided electricity to farms in North America. As said above, windmills used to grind grain is also an example of early uses of wind energy, and perhaps one that is closer to our time.
The current interest in wind energy was started by the need to develop clean, sustainable energy systems that can be relied on for the long-term future. Modern aerodynamics and engineering have improved wind turbines. They now provide reliable, cost-effective, pollution-free energy for individual, community, and national applications.
The nature of wind energy
Wind energy is the kinetic energy that is present in moving air. The amount of potential energy depends mainly on wind speed, but is also affected slightly by the density of the air, which is determined by the air temperature, barometric pressure, and altitude.
For any wind turbine, the power and energy output increases dramatically as the wind speed increases. Therefore, the most cost-effective wind turbines are located in the windiest areas. Wind speed is affected by the local terrain and increases with height above the ground, so wind turbines are usually mounted on tall towers.
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The information is gotten from the homepage of The Canadian Renewable Energy Network (CanREN), created through the efforts of Natural Resources Canada (NRCan) and its stakeholders. Its purpose is to increase the understanding of renewable energy to accelerate the development and commercialization of renewable energy technologies.
CanREN promotes what NRCan and its partners are doing to advance the role of renewable energy in Canadian society. It offers general information on renewable energy sources, highlights the technologies and applications being developed to harness these sources, and presents Canadians with the knowledge and support they need to make renewable energy part of their everyday lives.
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There. I shall post up to here today. Credits to http://www.canren.gc.ca/ for the wonderful information. 
Posted by: Jenny
Who winded up the last one to post on: 2 April 2008
voices of the winds