power can be harnessed to be a non-polluting, never-ending source of energy to
meet electric power needs around
the world. Wind power
is a form of renewable energy – energy that is replenished daily by the sun. Wind power is created when a portion of the earth is heated by
solar radiation; the heated air raises creating a vacuum while cooler
air rushes into the low pressure areas to create wind power.
turbines come in a variety of sizes, depending upon the use of the
electricity. The large, utilityscale
turbine may have blades
over 132 feet long (40 meters), meaning the diameter of the rotor is
over 264 feet (80 meters) – nearly the length of a football field. The
turbines might be mounted on towers 264 feet tall (one blade would extend
about half way down the tower), produce 1.8 megawatts of power (1.8 MW
or 1800 kilowatts, 1800 kW), supply enough electricity for
600 homes and cost over a million and
a half dollars!
designed to supply part of the electricity used by a home or business, and
farms are much smaller and
less costly. A residential- or farm-sized turbine may have a rotor
up to 50 feet in diameter
and be mounted on a metal lattice tower up to 120 feet (35 meters) tall.
These turbines may cost from as little as a few thousand dollars for very
small units up to perhaps $40,000-$80,000.
Very small turbines may
be designed to charge batteries and supply electricity to homes that are
not connected to the utility
system. In these systems, the batteries store the electricity until it is
needed. Small agricultural systems may not need any storage devices
because the generated power is consumed immediately.
Wind Power Notes:
The wind is slowed
dramatically by friction as it brushes the ground and vegetation, it
may not feel very windy at ground level. Yet the power in the wind may
be five times greater at the height of a 40-story building (the height
of the blade tip on a large, modern wind turbine) than the breeze on
the wind is accelerated by major land forms, so that entire areas of the
country may be very windy while other areas are relatively calm. Since
our country’s founders tended to build our cities and towns where the
wind doesn’t blow strongly, the vast majority of people don’t live
in high-wind areas.