Wind Turbines

Introduction:

Wind turbines capture the energy of wind and transform it into kinetic energy that is then converted to electricity. Turbines are available in a range of sizes and designs and can either be free-standing, mounted on a building or integrated into a building structure (Pennycook, 2008).

System types:

There are basically two sorts of wind turbines: horizontal-axis design and vertical-axis design. Horizontal-axis wind turbines are the most common type used and can have various sizes. This type of turbine has a horizontal rotor shaft and generator usually located at the top of a tower. The propeller-type blades are used to capture wind thus are oriented into the wind, for instance for small turbines a wind vane is used, or if it is a larger turbines a wind sensors will be used in conjunction with servomotors. A turbine system include the following: a rotor, or blades, which convert the wind’s energy into rotational shaft energy; a nacelle containing a drive train, usually including a gearbox ( some wind turbines can even work without the gearbox), a tower which is meant to support the rotor and the drive train. There is electronic equipment such as controls, electrical cables, ground support equipment, and inter-connection equipment (Pennycook, 2008).

Fig 1: The following image shows the some components of a horizontal wind turbine.

Source: (Alexander, 2008)

Usually, vertical-axis turbines are known to have a rotor shaft oriented vertically. This eludes the necessity for a tower and the generator is located at ground level. It also has the advantage to have no need for a yaw mechanism in order to turn the rotor into wind. The principle disadvantages of vertical-axis turbines are that the efficiencies are lowe...

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...enerates 1 to 5KW (kilowatts) of energy. However if the development is outside a covered or off-grid area where it will depend only to wind turbine for power, that will increase the needs intensely (Cooper, 2010).

In sizing wind turbine for a dwelling, first of all you determine how much energy you need to supply for your home. There is another option which is to use an energy calculator; there is one that is on the website: www.thesolarguide.com . This demonstrates how you obtain the total kilowatt hours you need. According to the American Wind Energy Association, homes use approximately 9,400 kilowatt-hours (KWh) of electricity per year (about 780Kwh per month). To make a substantial contribution in order to meet the demand depending on the average wind speed in the area, a wind turbine rated in the range of 5 to 15 kilowatts would be needed (Cooper, 2010).