Wind energy is the process of using the motion of the wind to generate electricity.

Wind energy is generated through turbines. Wind spins the turbine's blades-like the blades of a propeller-which rotates an internal shaft. The rotating shaft then turns gears that power a generator; the electricity generated can then be pumped into a utility grid. Turbines are mounted at least 100 feet off the ground, where the wind is smoother than at ground level. Wind power is a form of renewable energy, also called alternative energy because it represents an alternative to our current system, in which most of our energy needs are fulfilled by non-renewable fossil fuels (coal, oil, and natural gas).

Humans have harnessed the power of the wind for centuries. As early as 200 B.C., people used windmills to produce food and pump water. Ever since then, windmills have been used, with fluctuating degrees of popularity, to produce power all over the world. In the 1970s, when oil prices spiked, so did interest in wind power as a viable form of electricity production. Since then, research and technological innovations have brought down the cost of wind energy-mostly produced today through wind farms, groups of turbines that function as power plants.

Wind energy is clean, inexpensive, and inexhaustible. It is also highly dependent on location: turbines need a site where the wind is constant. This is likely to be the case in more remote areas, which can make it difficult to plug into utility grids to deliver the energy to cities. The same factor can make wind power a cost-effective alternative source of energy for rural areas.

Some early wind farms were poorly sited in bird migration paths, leading to the deaths of thousands of birds and giving wind power a bad reputation. But better turbine design and more considered placement of wind farms has greatly reduced bird deaths. What's more, many environmentalists now point out, the impacts of global warming--if we continue releasing greenhouse gases into the atmosphere--will kill far more birds than wind turbines ever would.

The aesthetics of wind farms has also inspired occasional opposition. A proposal to locate a farm in the ocean off of Cape Cod has divided environmentalists, with some (such as Robert F. Kennedy, Jr.) arguing that the offshore turbines would mar the view and pose problems for local fishermen and recreational, and others accusing them of "not-in-my-backyard" style hypocrisy. The future of the project is still up in the air.

Experts believe that wind could ultimately provide a fifth of the U.S.'s electricity needs. There are enough installed wind farms currently to power 2.5 million "average American homes."

Additional Resources

Department of Energy's Wind and Hydropower Technologies Program

National Renewable Energy Laboratory

Wind Powering America

American Wind Energy Association

Books

Energy Revolution: Policies for a Sustainable Future by Howard Geller

The End of Oil: On the Edge of a Perilous New World by Paul Roberts

Renewable Energy Policy by Paul Komor

Wind Energy Basics by Paul Gipe 

Residential Wind Power with Mick Sagrillo