Wind Energy
A wind turbine converts the kinetic energy in wind into electrical energy. Each wind
turbine produces 1.5 megawatts of electricity. In reality, wind energy is a converted
form of solar energy. The sun's radiation heats different parts of the earth at different
rates-most notably during the day and night, but also when different surfaces (for
example, water and land) absorb or reflect at different rates. This in turn causes
portions of the atmosphere to warm differently. Hot air rises, reducing the atmospheric
pressure at the earth's surface, and cooler air is drawn in to replace it. The result is
wind.
Air has mass and when it is in motion it contains the energy of that motion("kinetic
energy"). Some portion of that energy can converted into other forms mechanical
force or electricity that we can use to perform work.
We have been harnessing the wind's energy for hundreds of years. From old Holland
to farms in the United States, windmills have been used for pumping water or grinding
grain. Today, the windmill's modern equivalent—a wind turbine—can use the wind's
energy to generate electricity.
Wind turbines, like windmills, are mounted on a tower to capture the most energy. At
100 feet (30 meters) or more aboveground, they can take advantage of the faster
and less turbulent wind. Turbines catch the wind's energy with their propeller-like
blades. Usually, two or three blades are mounted on a shaft to form a rotor.
A blade acts much like an airplane wing. When the wind blows, a pocket of low-
pressure air forms on the downwind side of the blade. The low-pressure air pocket
then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of
the lift is actually much stronger than the wind's force against the front side of the
blade, which is called drag. The combination of lift and drag causes the rotor to spin
like a propeller, and the turning shaft spins a generator to make electricity.
Wind turbines can be used as stand-alone applications, or they can be connected to
a utility power grid or even combined with a photovoltaic (solar cell) system. For utility-
scale sources of wind energy, a large number of wind turbines are usually built close
together to form a wind plant. Several electricity providers today use wind plants to
supply power to their customers.
Stand-alone wind turbines are typically used for water pumping or communications.
However, homeowners, farmers, and ranchers in windy areas can also use wind
turbines as a way to cut their electric bills.
Small wind systems also have potential as distributed energy resources. Distributed
energy resources refer to a variety of small, modular power-generating technologies
that can be combined to improve the operation of the electricity delivery system.
Wind energy is now recognized as one of the least expensive methods for generating
electricity and it can be employed relatively quickly. Cost-wise, wind energy is
competitive with natural gas and coal. Further, the fact that wind energy utilizes a
"free" fuel source means that it is immune to the price fluctuations now common to
fossil fuels. Timing-wise, it can take 18-36 months from the time a coal or gas plant is
permitted until it is completed, whereas a large-scale wind plant can be constructed in
a period of 4-8 months.
The expansion of wind energy brings with it another significant benefit. Rural
communities, where wind projects are almost always located, receive substantial
economic boosts from wind energy projects. Wind projects provide construction
employment and long-term skilled operating jobs, extra income for farmers, local
property tax revenue, preservation of existing habitat and conservation of land and
resources. It is exactly these rural benefits that have led to support from farm
bureaus, rural economic development commissions, state legislatures, ranching
interests, and Native American tribes throughout North America.
A wind turbine converts the kinetic energy in wind into electrical energy. Each wind
turbine produces 1.5 megawatts of electricity. In reality, wind energy is a converted
form of solar energy. The sun's radiation heats different parts of the earth at different
rates-most notably during the day and night, but also when different surfaces (for
example, water and land) absorb or reflect at different rates. This in turn causes
portions of the atmosphere to warm differently. Hot air rises, reducing the atmospheric
pressure at the earth's surface, and cooler air is drawn in to replace it. The result is
wind.
Air has mass and when it is in motion it contains the energy of that motion("kinetic
energy"). Some portion of that energy can converted into other forms mechanical
force or electricity that we can use to perform work.
We have been harnessing the wind's energy for hundreds of years. From old Holland
to farms in the United States, windmills have been used for pumping water or grinding
grain. Today, the windmill's modern equivalent—a wind turbine—can use the wind's
energy to generate electricity.
Wind turbines, like windmills, are mounted on a tower to capture the most energy. At
100 feet (30 meters) or more aboveground, they can take advantage of the faster
and less turbulent wind. Turbines catch the wind's energy with their propeller-like
blades. Usually, two or three blades are mounted on a shaft to form a rotor.
A blade acts much like an airplane wing. When the wind blows, a pocket of low-
pressure air forms on the downwind side of the blade. The low-pressure air pocket
then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of
the lift is actually much stronger than the wind's force against the front side of the
blade, which is called drag. The combination of lift and drag causes the rotor to spin
like a propeller, and the turning shaft spins a generator to make electricity.
Wind turbines can be used as stand-alone applications, or they can be connected to
a utility power grid or even combined with a photovoltaic (solar cell) system. For utility-
scale sources of wind energy, a large number of wind turbines are usually built close
together to form a wind plant. Several electricity providers today use wind plants to
supply power to their customers.
Stand-alone wind turbines are typically used for water pumping or communications.
However, homeowners, farmers, and ranchers in windy areas can also use wind
turbines as a way to cut their electric bills.
Small wind systems also have potential as distributed energy resources. Distributed
energy resources refer to a variety of small, modular power-generating technologies
that can be combined to improve the operation of the electricity delivery system.
Wind energy is now recognized as one of the least expensive methods for generating
electricity and it can be employed relatively quickly. Cost-wise, wind energy is
competitive with natural gas and coal. Further, the fact that wind energy utilizes a
"free" fuel source means that it is immune to the price fluctuations now common to
fossil fuels. Timing-wise, it can take 18-36 months from the time a coal or gas plant is
permitted until it is completed, whereas a large-scale wind plant can be constructed in
a period of 4-8 months.
The expansion of wind energy brings with it another significant benefit. Rural
communities, where wind projects are almost always located, receive substantial
economic boosts from wind energy projects. Wind projects provide construction
employment and long-term skilled operating jobs, extra income for farmers, local
property tax revenue, preservation of existing habitat and conservation of land and
resources. It is exactly these rural benefits that have led to support from farm
bureaus, rural economic development commissions, state legislatures, ranching
interests, and Native American tribes throughout North America.
| CLICK THUMBNAIL ABOVE diagram above shows some of the pieces and parts inside a wind turbine: |
| Copyright 2007 Great American Energy |
