Environmental Engineering Reference
In-Depth Information
air from the nearby Atlantic Ocean. This air movement is most powerful in the Gulf of
Mexico, which is why the Caribbean islands, Central America, and the southeastern United
States are regularly hit by hurricanes.
From Windmills to Wind Farms
Wind-propelled boats plied the Nile as early as 5000 BCE. By 200 BCE, simple windmills
in China were pumping water. By the eleventh century CE, wind was used extensively
in the Middle East to mill grains and spices. Around this time, merchants and crusaders
brought windmill technology to Europe, where it was enthusiastically adopted. No region
was more profoundly influenced by early wind power than the Netherlands, where the
windmill was adapted for draining lakes and marshes in the Rhine delta.
Today's windmills, instead of pumping water or milling grain, generate electricity. That
is why engineers, unlike the general public, talk about wind turbines rather than windmills.
Only in developing countries, or as a tourist attraction in places such as Holland, are
windmills used to perform mechanical work.
Someregionsarewindierthanothers.However,thewindiestsitesarenotnecessarily the
best suited to exploiting wind energy. The Caribbean region, for example, though famous
for its hurricanes, is not an ideal location for wind turbines. This is because the winds are
seasonal and too powerful to exploit, at least using the technology available today. Stable
and moderate winds are best suited to wind power. Most modern turbines begin generating
electricity at a wind speed of 3 metres per second, but cannot operate above 25 metres per
second. This is because the tower and turbine may be damaged at the higher wind speeds.
Temperate zones, such as northern Europe, the cone of South America, and New Zealand
are the best locations for wind energy.
Wind Turbines
As a child growing up in Ireland, I made an early acquaintance with the power of wind.
I learned to cycle when I was about six, and from that time onward this became my
main mode of transport. In Ireland, there is no getting away from the wind. It is as
defining a feature of life as the sun in the Sahara or snow in Greenland. Whether I
had the wind at my back or in my face cycling to school meant a difference between
arriving in time or suffering the wrath of Mr. Kelly, the vice principal, who lay in wait
for latecomers. I understood that wind, depending on its direction, may be a hindrance or
a help. Those who have designed windmills - from the earliest mechanical devices to the
latest multi-megawatt turbines - have also had to contend with this characteristic of wind.
