Wind Power Generators

Here you get outlined information on Wind Power Generators which are also widely known as Wind Turbines. Their differences with Wind Mills. How they work and how they can be installed according to your needs and space.

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Aruba’s Wind Park at Vader Piet

How they work
Wind Powe Generators make use of the renewable wind energy source, for the production of electricity. They are rotary devices that extract energy from the wind. Wind Turbines use blades to catch the wind. The wind forces the blades of the propeller to rotate a shaft. This shaft in turn drives an electric generator which then generates electricity.

Wind Power Generators are also called home wind turbines, home wind generators, wind power units, wind energy converters or aerogenerators, when they are to produce electricity for the home. It is called wind mill power or simple windmill if the extracted wind energy is used for mechanical purposes like pumping water, grinding stones, cutting lumber to name some.

Wind Power Generators can be mounted on roofs or on masts depending on it’s size. Usually a 2kW or lower can be mounted on a roof.
Mast mounted wind power generators need more land space and you have to take in consideration that there are no obstacles to hinder the flow of wind to the generators.
To consider a wind power unit your area must have an average wind speed of more than 5m/s (equivalent to 11.2 mph).

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Windturbine Oranjestad Aruba
Electric Generators, how they produce electricity
One way to produce electricity is to move an electric wire across a magnetic field or moving the magnetic field crossing the wire. You’ll get a small voltage between the ends of the wire. By moving in opposite direction you’ll generate again a voltage but this time the polarity is also opposite to the first one. If there is no movement between wire and magnetic field there is also no voltage generation in the wire.

To generate a substantial voltage output we wound a wire to form an electric coil. There are other factors to consider to determine the amount of electricity that will be generated. The speed of the movement between coil and magnetic field. The number of loops on the coil. The physical distance between the coil and the magnet. The intensity or strength of the magnetic field. All electric generators work on this principle.

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Windturbine Hooiberg Aruba
(click on picture for the Story)
Applications
All wind power generators, big or small, have an electric generator. A wind generator is considered small if its capacity is from 20Watt to 100kW. They are mostly used for stand-alone buildings. Smaller than 1kWatt systems are also called Micro wind systems and are mostly used for charging batteries, to run water-pumps, to supply for camping facilities, caravans and sailboats.

The consumption of the average home in U.S. is about 900kWh a month. The fastest growing market is the grid-connected, residential models 1 to 10kW.Small domestic wind systems normally require permission from your local authority. If you are not familiar with electrical installation or electricity, you better acquire an electrician who is known with the electrical codes in your country. Remember safety comes first when you deal with electricity and when installing a mast.

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Windturbine Shete Aruba
Systems

Like solar panels home wind power generators can be grid tied (connected to the grid) or can be used as stand-alone or off grid (disconnected from the utility grid). With a grid tied system, any surplus electricity generated, can be sold back to the utility company so reducing your electricity bill. On a stand-alone or off-grid system the surplus energy can be stored in batteries for the times there will be lesser or no wind.

Wind power generators can also be installed in conjunction with solar panels and a back-up Diesel DC-Generator to produce the necessary power for your needs. Such a configuration is called a hybrid system. It is the most efficient and economical arrangement for a renewable energy system. The two supplies will complement each other.

At night the wind blows and when the sun is up the wind becomes lesser. The Diesel Genenerator function as back-up to charge the batteries in times of extreme little production from both the sun and the wind. The sun’s energy is at its maximum in summer months, while the wind’s energy is down. And the opposite takes place in the winter months.

We distinguish between two types of wind power generators.
The Horizontal Axis and the Vertical Axis.

The Horizontal Axis or HAWT

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Graphic www1.eere.energy.gov
 

The horizontal axis wind turbine has the rotor shaft and the generator shaft in a horizontal position and pointing into the wind. The rotor and the generator are both on top of the tower or mast. It has a yaw drive assembly that allows the turbine to face directly into the wind.

Small turbines use a wind vane to point into the wind. Large turbines use wind sensor in combination with servo motor to do the job. When pointed into the wind, the wind power turns the wind-blades and with it the rotor. In small turbines the rotor shaft is directly connected to the generator while in large turbines it is connected through a gearbox to speed up to rotation of the electrical generator.

HAWTs come in two types the upwind and the downwind machines. The upwind type is the traditional every day version where the blades are at the wind side. The downwind type receives the wind in the back of the blades. It needs no additional mechanism to keep it in line with the wind. But it is vulnerable to fatigue failures due to cyclical turbulence behind the mast.

The Vertical Axis or VAWT

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Vertical axis wind turbines have their main axis perpendicular to the ground. The generators and gearboxes can be mounted close the ground. VAWT perform well in both rural and urban surroundings.
They perform better than horizontal axis in places where there are a lot of turbulences. They are not affected by wind directions, the wind may blow from any direction. No yaw mechanism is needed.

They can be mounted on top of the roof. They are simple to install and easy to maintain. Their operation is quiet.
At low speed winds traditional horizontal axis wind turbines are more efficient. But at high wind speeds, VAWTs can be 7 to 8 times more efficient than horizontal axis.
They can withstand much higher wind speeds to about 140mph and still producing power. And they have a nice appearance.

For additional information on wind energy
please go to Wind Power Facts

We include here some links to important sites for the consumer.
For Research and Development go to
Energy Efficiency & Renewable Energy. (EERE)

Publications on Research and Development go to
National Renewable Energy Laboratory. (NREL)

The most important factor to determine whether a wind project is feasible for you is the level of wind resource available at your site.
Find out at a government office if there are any laws to comply with. If there are any incentives you can benefit from or that can lower the price of your purchase.

Check with the utility company for any applicable rules.
Make your home energy efficient to reduce the size of your turbine.
Then make an energy budget.
If you need help, get a consultant to help you size your system based on your electricity needs and the wind specifications in your area.
Your manufacturer can also help you with this sizing and wind specs.
If you cannot yourself, look for a small wind installer in your area or a construction company who can do the work.
May be you’ll need an electrician for the electrical work or check if the construction company has his own electrician.

Enjoy the work well done and best of all…
Enjoy the clean energy of the wind turbine,
that one day will be your free energy.