Environmental Engineering Reference
In-Depth Information
TABLE 2.1
U.S. Energy Consumption by Source (2013)
Energy Consumption
(quadrillion Btu)
Energy Source
Renewable total
9.291
Biomass (biofuels, waste, wood, and wood-derived)
4.607
Geothermal energy
0.221
Hydroelectric conventional
2.561
Solar thermal/PV energy
0.307
Wind energy
1.595
Source:
EIA,
Monthly Energy Review
, Energy Information Administration,
Washington, DC, 2014 (
http://www.eia.gov/totalenergy/data/monthly/
pdf/mer.pdf).
Today, several hundred thousand windmills are in operation around the world,
many of which are used for pumping water. The use of wind energy as a pollution-
free means of generating electricity on a significant scale is attracting the most
interest in the subject today. As a matter of fact, due to current and pending short-
ages and high costs of fossil fuels to generate electricity, as well as the green move-
ment toward the use of cleaner fuels, wind energy is the world's fastest growing
energy source and could power industry, businesses, and homes with clean, renew-
able electricity for many years to come. In the United States, wind-based electric-
ity generating capacity has increased markedly since the 1970s. Today, though,
it still represents only a small fraction of total electric capacity and consumption
(see Table 2.1), despite the advent of $4/gal gasoline, increases in the cost of elec-
tricity, high heating and cooling costs, and worldwide political unrest or uncer-
tainty in oil-supplying countries. Traveling the wind corridors of the United States
(primarily Arizona, New Mexico, Texas, Missouri, and north through the Great
Plains to the Pembina Escarpment and Turtle Mountains of North Dakota) gives
some indication of the considerable activity and seemingly exponential increase in
wind energy development and wind turbine installations; these machines are being
installed to produce and provide electricity to the grid.
DID YOU KNOW?
We can classify wind energy as a form of solar energy. Winds are caused by
uneven heating of the atmosphere by the sun, irregularities of the Earth's sur-
face, and the rotation of the Earth. As a result, winds are strongly influenced
and modified by local terrain, bodies of water, weather patterns, vegetative
cover, and other factors. The wind flow, or motion of energy when harvested
by wind turbines, can be used to generate electricity.
