Wind Power

   Wind energy has historically been used directly to propel sailing ships or converted into mechanical energy for pumping water or grinding grain, but the principal application of wind power today is the generation of electricity. Although wind produces only about 1.5% of worldwide electricity use, it is growing rapidly, having doubled in the three years between 2005 and 2008. Individuals may purchase these systems of home wind power to reduce or eliminate their dependence on grid electricity for economic or other reasons, or to reduce their carbon footprint.
Wind Power

Smart Energy

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   Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines and homemade windmills. Large scale wind farms are typically connected to the local electric power transmission network, with smaller turbines being used to provide electricity to isolated locations. Utility companies increasingly buy back surplus electricity produced by small domestic turbines. Wind energy as a power source is favoured by many environmentalists as an alternative to fossil fuels, as it is plentiful, renewable, widely distributed, clean, and produces lower greenhouse gas emissions.
Electric Wind Turbine
Parts of an Electric Windmill
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   The design of a wind turbine is based on the principle of lifting force, the same one that is created by the different speed circulation of air on each side of the wings of a plain, but in this case, the blades of the turbines.

   The wind moves past the blades of the wind turbine causing lift to the blades allowing for the blades to spin like a large pinwheel (station 1). The three blades are attached to a hub (station 2) that is connected to a turning shaft. From there it can be changed into AC current or stored on battery banks. The shaft goes through a gear transmission box ( station 6 ) where the turning speed is increased. Note that the gear connected to the mean shaft is bigger than the one connected to the Generator. The high speed shaft turns a generator that makes electricity. If the wind gets too high, the turbine could be damaged, so a brake ( station 4 ) will keep the blades from turning too fast. Which now a days the entire system is electronically controlled to safeguard the components from over speeding.
   On average, wind speeds usually must be above 20 km/h (12.4 mph) for a windmill turbine to work efficiently. The average production of a turbine is between 40 and 400 kilowatts of electricity. If a home needs about 3 kw, it means that one turbine could supply more than 100 homes.


   As in any construction project, a blueprint is required for the job to be successful. The proper materials along with following a proven guideline is essential for building an efficient and durable wind generator. Windmills for home use are an excellent way to begin reducing your energy costs and utilizing a free source of clean, renewable energy. Plans on how to build wind turbine can be found in the products tab of this website.
   As interest in wind power generation increases, more homeowners are looking into building a homemade windmill to produce electricity for their homes. Building a windmill power generator is really a simple task anyone with average mechanical ability can accomplish. No special tools or equipment is needed, and all the materials for construction are readily available.
   Building a simple homemade windmill generator you can produce enough energy to power your entire house, so instead of paying thousands on a commercial windmill turbine you can spend a little amount of time to create your own windmill generator. After all, once your homemade windmill power generator is built it doesn't require any more maintenance and can produce enough energy for many years to come. To get an idea of how much energy you can harness from the wind it would first be wise to determine the average wind speeds in your particular geographic location. Thanks to a company called 3TIER you can do just that. By using their program called FirstLook you can view the average wind speeds in your exact location and determine the windmill type, size, and location to provide the best efficiency. The data used by FirstLook was taken from many years of analysis and is still being perfected today to provide you with the best and most accurate results.
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How Wind Turbines Work
How A Basic Electric HAWT Works:
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http://www.3tier.com/firstlook/
The Different Types of Windmills:
   
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   There are two main types of windmills out on the market today as shown in the figure on the left. The better known windmill is the Horizontal Axes Wind Turbine (HAWT) (left) and the Vertical Axes Wind Turbine (VAWT) (right). The HAWT is the most common because it is slightly more efficient than the VAWT, thus producing more power for a given wind speed. A horizontal axis turbine's swept area always faces the wind. But with a VAWT, the swept area is a cylinder perpendicular to air flow. As such, part of the “swept area” is working, while part is simply being blown around, not at an optimal angle to generate lift. However, the VAWT has its advantages being that it can handle turbulent winds much better therefore well suited for urban or residential locations. In addition, because the VAWT can take the wind at any direction and the gearbox is close to the ground where as
the HAWT has to be mounted high in the air and be able to rotate so it's always facing into the wind by using its tail vane the VAWT are usually much cheaper and economical to build.
Build Your Own Windmill:
Details of VAWT Designs:
There are actually two different VAWT designs that each have their pros and cons based on particular applications. One’s called a Savonius rotor, which essentially, uses drag forces and cannot exceed a Tip Speed Ratio (TSR) of 1 or in other words, cannot rotate faster than the speed of the wind turning it. It’s similar to an anemometer as shown in the picture below and they are very common because they’re very crude, very low-tech, and can operate in low wind speeds. However, in more detail, a Savonius rotor operates in the 5 to 10 percent efficiency range. People have been able to tweak the efficiency rate — ideally, they might be as high as 15 percent.
Then there’s the Darrieus model — the type that resembles an egg beater and can be placed close to the ground. Essentially, you have the same type of blades as the HAWT but there are two or three vertically oriented blades revolving around a vertical shaft (shown in picture above). The Darrieus models use an airfoil design proving a much more efficient turbine than the Savonius rotor due to a TSR much greater than 1. A wind turbine airfoil works in the same way as an airplane wing. An airfoil has a flat side and a curved or cambered side. The result of air passing over the two sides is a force known as “lift.” The lift will continue as long as there is forward motion over the airfoil (wind) to generate the required lift, simply meaning that the Darrieus rotor has a hard time starting from rest at low wind speeds. A model of this application can be seen in the figure on the left.
Savonius Rotor
Anemometer
Darrieus Rotor
Wind power generation has an expansive future according to experts. Renewable wind energy technology has been the fastest growing source of electricity generation in the world in the 1990s. However, the majority of this growth has been in Europe, where government policies and high conventional energy costs favor the use of wind energy. The U.S. Department of Energy recently announced the Wind Powering America initiative with goals to power at least 5% of the nation's electricity with wind by 2020, increase the number of states with more than 20 megawatts of wind to 16 states by 2005 and 24 states by 2010, and increase federal use of wind energy to 5% by 2010.
As one of Mother Nature’s gifts, the wind is available and plentiful and won’t deplete our world’s natural resources. Wind power produces no pollution that can contaminate the environment, since no chemical processes take place, like in the burning of fossil fuels, in wind power generation there are no harmful by-products left over. According to the U.S. Census, more than 17 million homes in America are located on land that is appropriate for a small wind system. Could your home be one? See how this technology works and decide whether you are ready to make the transition.