Alternative
energy index
For more information, view the most frequently
asked questions about wind power
Wind Power
Humanity has been using the wind to do work for thousands of years. The
kinetic energy of the wind can be changed into other forms of energy, either
mechanical energy or electrical energy. When wind fills a sail, its kinetic
energy is being used to push a sailboat through the water. Farmers have been
using wind energy for many years to pump water from wells using windmills like
the one shown on the right. Wind is also used to turn large grinding stones to
mill or grind wheat or corn, just like a water wheel is turned by water power.
The wind is also used by a wind turbine to make electricity.
According to the on-line Illustrated
History of Wind Power Development, the first use of a large windmill to
generate electricity was a system built in Cleveland, Ohio, in 1888 by Charles
F. Brush. The Brush machine had multiple-blades more than 50 feet in diameter.
Over the last 100 years, wind turbines have advanced dramatically through
newer technology and better understanding of the dynamics of the wind
resource. But in order to generate electricity, you still need relatively
constant wind speeds in any given location.
A wind turbine is very similar to a child's pinwheel or the propeller of an
airplane. The blade of a turbine is tilted an angle. The movement of the air
is channeled creating low and high pressures on the blade that force it to
move. The blade is connected to a shaft which in turn is connected to an
electrical generator. The mechanical energy of the turning blades is changed
into electricity.
Wind speeds typically must be sustained and at least 10 miles per hour to
turn larger turbines fast enough to generate electricity. The turbines usually
produce about 50 to 300 kilowatts of electricity each. A kilowatt is 1,000
watts (kilo means 1,000). You can light ten 100 watt light bulbs with 1,000
watts. So, a 300 kilowatt (300,000 watts) wind turbine could light up 3,000
light bulbs that use 100 watts.
Wind power for your home
Small wind turbines (usually producing lesss than 10
kilowatts of electricity) can be used to generate electricity for a home or
small business. A kilowatt is equal to 1,000 watts -- the amount of
electricity that can illuminate ten 100-watt light bulbs.
Local ordinances, zoning and building codes should first be
investigated before considering buying a small wind turbine.
The smaller turbines today are fairly efficient, producing
electricity in winds as low as 7 to 10 mph. They are also fairly quiet. The wind
system usually generates power at the same voltage that your home uses, so the
turbine can be wired directly to the home or business' electrical system like an
appliance.
When the wind is blowing, the turbine provides power for the
home. When it is not blowing, the utility company provides the power. Sometimes
both sources provide power for the home. If your home is using less electricity
than what the wind turbine is making, your electrical meter may actually
"turn backwards." This is called "net metering."
A typical 10 kilowatt home wind turbine system will cost
$25,000 - $35,000 to install. Depending on the amount of wind available, it will
produce between 10,000 to 18,000 kilowatt/hours (kWh) per year. Such a turbine
has a blade diameter of about 20-25 feet and needs to sit on a tower about 100
feet tall. Homes sitting on a one acre parcel could probably accommodate such a
turbine, depending on local zoning restrictions.
