Environmental Engineering Reference
In-Depth Information
or nuclear plant. The main cost of geothermal energy is the initial cost
of drilling the wells. Geothermal energy could be an ultimate answer to
the world's growing energy needs.
Energy from the Wind: Hold On to Your Hat
The idea of harnessing energy from the wind goes back to the earliest
recorded history. Along with the waterwheel, windmills are the oldest
tools to capture and use nature's power for human purposes. Today's
wind turbines can harness enough energy from the wind to supply thou-
sands or even millions of homes with electricity, and in many European
countries wind power is an essential and growing part of the energy
supply. More than eighty nations now tap the wind to produce com-
mercial electricity. The wind generates more than 1.5 percent of the
world's electricity, up from 0.1 percent in 1997.
In the United States, wind supplies 1 percent of our electricity needs,
powering the equivalent of 4.5 million homes. Capacity increased by 60
percent in 2009 to 35,000 megawatts. Wind power is growing rapidly,
with Texas leading the way, 9,708 megawatts. It accounted for 42
percent of new capacity additions in the United States in 2008, second
only to natural gas for the fourth year in a row.
The United States now leads the rest of the world in cumulative capac-
ity and electricity generation. Because of the extensive fl at Midcontinent
area, we are well supplied with strong winds (fi gure 7.4). In such a fl at
area, over 90 percent of the land area may be favorably exposed to the
wind, in contrast to areas of rugged topography where only the ridge
crests may be suitably exposed. Iowa, second only to Texas in wind
power capacity, surged past California in 2008. Fourteen percent of
Iowa's electricity now comes from wind power. Kansas is also rapidly
increasing its wind-generating capacity. Wind in the Midcontinent may
turn out to be a more valuable commodity than crops in some areas.
Wind power is now less expensive than natural gas and is tied with
geothermal power as the least expensive form of alternative, renewable,
and nonpolluting energy supplied by nature. It is the fastest-growing
renewable energy source on the planet.
Energy Potential
Based on data from 2400 locations, researchers at Stanford University
believe that there is ample wind in the United States to supply all the
country's electricity.
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This may be overly optimistic but it suggests that
