Wind Energy is defined as, energy contained in the force of the winds
blowing across the earth’s surface. When attached, wind energy can be converted
into mechanical energy for performing work such as pumping water, grinding
grain, and milling lumber. By connecting a spinning rotor to an electric
generator, modern wind turbines convert wind energy into electrical energy
(Windpower,2003).
Wind is created when air that has been warmed over sun-heated land
rises, leaving a vacuum in the space it once occupied. Cooler surrounding
air then rushes in to fill the vacuum. This movement of rushing air is
what we know as wind.
History
Egyptians may have been the first to capture wind energy when they sailed
boats up the Nile River beginning around the 4th century BC. For centuries
afterward, wind-powered sailing boats sailed the world's seas and oceans,
serving as the major form of profitable transport. Wind energy has been
controlled on land since the first windmill was developed by the ancient
Persians in the 7th century AD. Windmills have since been used to mill
grain, pump water, saw timber, and provide other forms of mechanical energy
(Britannica,2003).
Modern wind energy systems consist of three basic components: a tower
on which the wind turbine is mounted, a rotor that is turned by the wind,
and the nacelle, which houses the equipment, including the generator, that
converts the mechanical energy in the spinning rotor into electricity.
The tower supporting the rotor and generator must be strong. Rotor blades
need to be light and strong in order to be efficient and to withstand prolonged
use in high winds(Windpower,2003).
Development of Wind Turbines
During the 1930s, interest in powering electric lighting and appliances
on homesteads across the Great Plains led to the development of small,
battery-charging wind turbines. These wind chargers were early indicators
of the small two- and three-bladed wind turbines used today to provide
electricity for secluded residences, and to provide electricity to villages
in developing countries.
The modern wind turbine is the result of design and material advances
made during the 1980s and 1990s, which have enabled wind turbines to become
increasingly efficient (Britanica,2003). Today, wind turbines the same
size as the traditional European windmill can generate 250 to 300 kilowatts
of power!
Wind Turbines
Today and The Future
Many countries began exploring alternative sources of energy during
the oil shortages of the 1970s. As improvements in wind energy technology
have evolved, the modern wind energy industry has emerged. Increasingly,
modern wind turbines produce electric power as efficiently as other power
generation technologies. One of the major obstacles for developing wind
energy is finding suitable ground and wind conditions.
With the growing worldwide demand for electric power and the rising
concern about global warming, many experts believe that the use of wind
energy will continue to increase. As wind power becomes an increasingly
cost-effective source of electricity, the market for wind power should
continue to expand(Bown,1998).