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Wind
Energy
 Wind
energy is defined
as the “power generated by harnessing the wind, usually
by windmills”16. In scientific terms, wind
energy is the "force" of winds blowing across the earth’s
surface21.
Wind energy is usually associated with wind
turbines/windmills, but there are other similar concepts
out there, check out Floating
Air Turbines and
Underwater Power.
Wind is caused by uneven heating on the earth’s surface. The
equator region receives more heat than say, Antarctica.
That heat tries to move from hotter to colder regions. Wind
energy was first harvested centuries ago, when early
windmills were used to power millstones, pumps, and
forges.
Wind farms have been, and are being constructed in upland
areas of the British Isles, such as Wales and the Lake
District, but they have been objected to because of
visual and noise pollution. To solve this problem,
engineers have suggested offshore locations, where wind
speeds are higher and the impact of visual pollution is
dramatically reduced16.
When harnessed, wind energy
can be converted into mechanical energy for performing
work such as pumping water, grinding grain, and milling
lumber21. The amount of kinetic energy within
Earth's atmosphere is equal to about 10,000 trillion
kilowatt-hours.
The picture below shows how much wind energy is currently
harvested by the entire world and a future prediction.
Image Source:
WWEA
An efficient windmill can
produce approximately 175 watts per square meter of propeller-blade
area at a height of 25m3. In 2006, a total of
73,904 MW was generated, so if each windmill has 2 sq.
meters of area, that equals to over 200,000 wind turbines
working throughout the globe.
Wind Energy Presentation by U.S. Department of Energy -
Consumer Guide to Renewable Energy |
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