What are the current uses of wind technology?

Changing World of Energy

For over a century, our world has been powered primarily by carbon fuels. In recent years, concern about global warming and the harmful effects of fuel emissions has created new demand for cleaner and sustainable energy sources, like wind. In many areas around the globe, the energy market is also being driven by a dual new dynamic: deregulation and privatization. As more and more consumers choose who produces their power, the market for renewable resources is forecast to expand at an even greater pace.
Today, more than 39,000 megawatts of wind energy are installed throughout the world, and forecasts for wind power continue to be favorable with more than 83,000 cumulative megawatts predicted worldwide by 2007. With a cost of energy of approximately 3.5 to 4 cents per kilowatt hour and declining, wind is a low-cost renewable energy source that is less expensive than coal, oil, nuclear and most natural gas-fired generation, and is becoming attractive to utilities and electric cooperatives.
http://www.gepower.com/businesses/ge_wind_energy/en/about_wind_ener.htm[MP17]
  • Wind turbines have become a mature state-of-the-art technology during the last decade, and wind farms are operating actively all across Europe.
  • Since 1998 world-wide production of wind power has increased at a rate of up to 40% per year, creating jobs for over 70000 people and providing electricity for 35 million people.
  • In 2001, 70% of wind installation were in Europe and at the moment European companies produce over 80% of the wind turbines.
Although wind is intrinsically intermittent, it is still possible to meet at least 10 to 15% of a country’s needs. More could be achieved, but that would require extra storage systems, which at the moment would not be a commercially advantageous step to take. ("Research - Energy - - Wind." EUROPA - European Commission - Homepage. N.p., n.d. Web. 3 Nov. 2009. <http://ec.europa.eu/research/energy/nn/nn_rt/nn_rt_wind/article_1101_en.htm>.) [DLus8]

The use of wind turbines can be a great way to provide a source of clean and renewable energy for your home or business. There are a number of small wind energy devices that you can use to generate power, and most of these are very cost effective in providing a substantial level of electricity.

Many people in the U.K are investing in wind energy technologies in addition or as an alternative to solar power. Wind energy is also a key ingredient for the United Kingdoms future energy growth, and the plan to reduce carbon emissions. [MBoz8]

Offshore wind energy is a promising application of wind power, particularly in countries with high population density, and difficulties in finding suitable sites on land. Construction costs are higher at sea, but energy production is also higher.(http://www.talentfactory.dk/en/pictures/offshore.htm)[FKha1]

Following the energy crunches of the ‘70s, a renewed interest in wind began to develop. Spurred on by government incentives (now largely extinct), wind farms began to sprout. California leads the world for installed capacity - 44%. During 1994 California produced 3.2 billion kWh from wind power.
In the Altamont Pass, near San Francisco, the use of wind power on farmland increased the value of that land from $400 per acre to $2000 per acre, while only reducing the available grazing land by 5% (Scientific American, Sept. 1990). This energy costs $0.075/kWh, though in some areas, due to greater wind power, the price is $0.05/kWh.

By rejecting nuclear power, Denmark has made the greatest commitment to wind power of any nation. Second only to California, Denmark has 540 MW of installed capacity and produced 1.1 billion kWh during 1994. Six of the top ten wind turbine manufactureres (including #1) are Danish companies.



A wide range of generating capacities allow wind turbines to fill a wide range of applications and sites. Individual producers, generating electricity for their own home needs may use a turbine as small as 10kW (this would power one hundred 100 Watt light bulbs at peak power). Larger utility based wind farms may use turbines from 50kW all the way up to 2 MW (1 MW = 1000 kW). The typical sizes for modern utility applications are between 200 and 300 kW.
Wind power can be tapped in a variety of places. To see some pictures of actual wind turbines in action click to see a typical “row farm”. Wind can also be tapped on water, or as mentioned above, on farms.(http://www.geology.wisc.edu/geo411/hasselman.html) [CBer7]

Efficiency of Wind Turbines
Are wind turbines competent tools of harnessing energy? As with all machines and energy conversion tools, there is some loss of energy in the windmills and it does not convert all the wind energy to electrical energy. This is due to friction and loss of energy due to heat. Thus, a wind turbine can convert a maximum of about 59% of the wind energy to electrical energy. This was determined by a German physicist named Albert Betz, way back in 1919, and is known as Betz's law. Could this percentage of energy transforming efficiency be enough for completely fulfilling our energy requirements? Though it does seem like an insufficient percentage of energy production, wind turbines can give decent energy returns. Some of the factors that can affect the efficiency of a wind turbine are:
  • Wind Speed: Wind turbines are usually designed to run at a specific wind speed and any variation in wind velocity can lower their efficiency.
  • Temperature Changes: Extreme change in temperature can affect the running of a wind turbine. Although this issue is being addressed with improved designs nowadays, alterations in temperature does still cause changes in energy conversion efficiency in wind mills.
  • Loss of Energy: As in any machine there is a loss of energy, due to friction and resistance. Though work is being done to improve turbine designs to reduce and limit this energy loss, fact is that it still does persist. Even the best designs in wind turbines can help harness only up to 70-80% kinetic energy.
http://www.buzzle.com/articles/wind-turbines-cost.html
http://www.buzzle.com/articles/renewable-energy-solar-power-wind-turbines.html
wind turbinehttp://www.alternative-energy-news.info/technology/wind-power/wind-turbines/
Horse Hollow Wind Energy Centerhttp://www.metaefficient.com/renewable-power/the-largest-wind-farm-in-the-world-horse-hollow.html
Horse Hollow Wind Energy Center
http://www.geology.wisc.edu/geo411/hasselman.html

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Charles F. Brush (1849-1929) (http://windwithmiller.windpower.org/res/brush.jpg) [BWar1]
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The Giant Brush Windmill in Cleveland, Ohio (https://www.procon.org/files/alternativeenergy/windmill.jpg) [BWar1]
During the winter of 1887-88 Brush built what is today believed to be the first automatically operating wind turbine for electricity generation (http://windwithmiller.windpower.org/en/pictures/brush.htm) [BWar1]


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(http://renaissanceronin.files.wordpress.com/2008/11/wind_turbines_farm.jpg)
[BWar1]

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(http://www.canadiangeographic.ca/atlas/Images/Glossary/Wind_energy.jpg)
[BWar1]


See full size image
See full size image
http://climateofourfuture.org/colossal-magnetic-levitation-wind-turbines-proposed/ [SSha1]

  • 1 Maglev wind turbine. It powers 750 thousand homes. 1 maglev wind turbine requires less than 100 acres.
    It’s a ambitious vision of a magnetically levitated wind turbine that can generate one gigawatt of energy (enough to power 500,000 homes). This is the device proposed by a new Arizona-based company, MagLev Wind Turbine Technologies. The company claims that it can deliver clean power for less than cent per kilowatt hour using this wind turbine. http://climateofourfuture.org/colossal-magnetic-levitation-wind-turbines-proposed/ [SSha1]



The most economical application of wind electric turbines is in groups of large machines (660 kW and up), called "wind power plants" or "wind farms." For example, a 107-MW wind farm near the community of Lake Benton, Minn., consists of turbines sited far apart on farmland along windy Buffalo Ridge. The wind farm generates electricity while agricultural use continues undisturbed.
Wind plants can range in size from a few megawatts to hundreds of megawatts in capacity. Wind power plants are "modular," which means they consist of small individual modules (the turbines) and can easily be made larger or smaller as needed. Turbines can be added as electricity demand grows. Today, a 50-MW wind farm can be completed in 18 months to two years. Most of that time is needed for measuring the wind and obtaining construction permits—the wind farm itself can be built in less than six months.
(http://www.awea.org/faq/wwt_basics.html) [Bwar1]

What is wind energy?

Wind energy is a form of solar energy. About 1% to 2% of the energy coming from the sun is converted into wind energy. Generation of air currents is a direct effect of the combination of two phenomena: circulation of hot air and Earth rotation. Hot air is lighter than cold air, and will rise into the sky until it reaches approximately 10-km (6 miles) altitude and then spread to the North and the South. The equator represents a low-pressure area. At the Poles, there will be high pressure due to the cooling of the air.

  • Since Earth is rotating, any movement on the Northern Hemisphere is diverted to the right, (In the Southern Hemisphere it is bent to the left). This apparent bending force is known as the Coriolis force. Riverbeds are dug deeper on one side than the other is. (Which side depends on which hemisphere we are in). The combination of these two factors gives rise to the more complex movement of air, known as wind.

  • This so-called geostrophic wind, a stable air stream from West to East is, however, disturbed by the turbulent phenomenon which we call weather. Clouds formed by the cooling of moist air cast shadow on the ground, thus leading to differences of the surface temperature, which in turn give rise to air movements with fairly chaotic patterns. The roughness of the Earth’s surface increases the turbulence of these air movements and reduces the wind speed.


Drawing of the rotor and blades of a wind turbine, courtesy of ESN
Drawing of the rotor and blades of a wind turbine, courtesy of ESN

[DLus8]

Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetation. (http://www1.eere.energy.gov/windandhydro/wind_how.html)[FWal7]

The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical
power or electricity. Wind turbines convert the kinetic energy of the wind into mechanical power. This mechanical
power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this

mechanical power into electricity to power homes, businesses, schools, and the like. (http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf) [MBoz8]

The main work of wind turbines is to utilize the energy of wind and convert it into electricity; stronger wind is considered good for electricity production. But the speed of wind should not be too strong because it makes turbines spin too fast and in this process it commits suicide! Why is it so? Because turbine blades get ripped off by stronger winds – excessive heat damages the alternator. Turbine tower too can't remain unaffected by the strong wind. To prevent all this damage a mechanical breaking system furling is generally used. This method prevents wind turbine from spinning too quickly by turning the blades away from the direction of the wind. Furling can be manual or automatic with same goal i.e. turning the turbine blade edges into the wind when the wind is dangerously strong and stormy. (http://www.alternative-energy-news.info/technology/wind-power/wind-turbines/) [MBoz8]

Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetative cover. This wind flow, or motion energy, when "harvested" by modern wind turbines, can be used to generate electricity. http://windeis.anl.gov/guide/basics/index.cfm [AFah1]

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.(http://www.awea.org/faq/wwt_basics.html)[Fkha1]

How Wind Turbines Work

Wind turbines use energy from the wind in order to generate electricity. They do this with their blades, which capture the wind and turn. When there is no wind, the blades will remain at a 45-degree angle so that the turbine can draw maximum energy from gentle winds. Turbines begin to produce energy when wind speeds reach about four meters per second. The blade gradually rotates towards an angle of 0 degrees with the broad surface facing the wind. When the wind strikes the blade, it creates positive pressure on the front of it and negative pressure behind it. In other words, the wind pushes against the front edge and creates a suction effect behind the blade, which makes the rotor turn. At maximum rotational speed, the blade tips reach a speed of 250 km an hour.
http://www.vestas.com/en/modern-energy/experience-the-wind/how-do-wind-turbines-work.aspx[MP17]
Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetation. Humans use this wind flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity.
The terms wind energy or wind power describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.
So how do wind turbines make electricity? Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Take a look inside a wind turbine to see the various parts. View the wind turbine animation to see how a wind turbine works.
This aerial view of a wind power plant shows how a group of wind turbines can make electricity for the utility grid. The electricity is sent through transmission and distribution lines to homes, businesses, schools, and so on.http://www1.eere.energy.gov/windandhydro/wind_ad.html Wind Turbine Power
Windturbine.jpeg
(Image retrieved from: http://www.urbansprout.co.za/node?page=3)
"Research - Energy - - Wind." EUROPA - European Commission - Homepage. N.p., n.d. Web. 3 Nov. 2009. <http://ec.europa.eu/research/energy/nn/nn_rt/nn_rt_wind/article_1101_en.htm>.
[DLus8]

Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.(http://www1.eere.energy.gov/windandhydro/wind_how.html)[FWal7]
Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to make electricity.
The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity The electricity is sent through transmission and distribution lines to a substation, then on to homes, business and schools.
High-tech turbines equal low environmental impact. That’s why wind power is gaining public approval and generating increased awareness.
It is also becoming economically competitive with more conventional power sources – a fact that’s greatly improving its prospects as a viable energy source. (http://images.google.com/imgres?imgurl=http://www.galileoscientific.com/wind_energy.jpg&imgrefurl=http://www.galileoscientific.com/how-a-wind-turbine-works.htm&usg=__VVhi6E7Z_RBNW_4zI3ijC5703jI=&h=476&w=500&sz=54&hl=en&start=4&um=1&tbnid=XBW-jO1MyPHGJM:&tbnh=124&tbnw=130&prev=/images%3Fq%3Dhow%2Bdo%2Bwind%2Bturbines%2Bwork%26hl%3Den%26rlz%3D1T4DKUS_enUS306US238%26sa%3DX%26um%3D1) [MBoz8]

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(http://www.86wind.com/en/UploadFile/20086713729496.jpg) [MBoz8]

Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies
an electric current. Most large modern wind turbines are horizontal-axis turbines, like the traditional farm windmills
used for pumping water. Wind turbines are often grouped together into a single wind power plant, also known as a
wind farm, and generate bulk electrical power. Electricity from these turbines is fed into a utility grid and

distributed to customers just as it is with conventional power plants. (http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf) [MBoz8]
Wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to create electricity.
Wind turbines are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more above ground, they can take advantage of faster and less turbulent wind.
Wind turbines can be used to produce electricity for a single home or building, or they can be connected to an electricity grid (shown here) for more widespread electricity distribution. (http://www1.eere.energy.gov/windandhydro/wind_animation.html) [MBoz8]
wind_turbines_Darrieus_windmill.jpg
30 m Darrieus wind turbine in the Magdalen Islands


30 m Darrieus wind turbine in the Magdalen Islands

Darrieus wind turbine
"Eggbeater" turbines. They have good efficiency, but produce large torque ripple and cyclic stress on the tower, which contributes to poor reliability. Also, they generally require some external power source, or an additional Savonius rotor, to start turning, because the starting torque is very low. The torque ripple is reduced by using 3 or more blades which results in a higher solidity for the rotor. Solidity is measured by blade area over the rotor area. Newer Darrieus type turbines are not held up by guy wires but have an external superstructure connected to the top bearing.

http://www.solarnavigator.net/wind_turbines.htm[MP17]


The ability to generate electricity is measured in watts. Watts are very small units, so the terms kilowatt (kW, 1,000 watts), megawatt (MW, 1 million watts), and gigawatt (pronounced "jig-a-watt," GW, 1 billion watts) are most commonly used to describe the capacity of generating units like wind turbines or other power plants.(http://www.awea.org/faq/wwt_basics.html)[FKha1]

Most manufacturers of utility-scale turbines offer machines in the 700-kW to 2.5-MW range. Ten 700-kW units would make a 7-MW wind plant, while 10 2.5-MW machines would make a 25-MW facility. In the future, machines of larger size will be available, although they will probably be installed offshore, where larger transportation and construction equipment can be used. Units up to 5 MW in capacity are now under development.(http://www.awea.org/faq/wwt_basics.html)[FKha1]

The most economical application of wind electric turbines is in groups of large machines (660 kW and up), called "wind power plants" or "wind farms." For example, a 107-MW wind farm near the community of Lake Benton, Minn., consists of turbines sited far apart on farmland along windy Buffalo Ridge. The wind farm generates electricity while agricultural use continues undisturbed.(http://www.awea.org/faq/wwt_basics.html)[FKha1]

Wind plants can range in size from a few megawatts to hundreds of megawatts in capacity. Wind power plants are "modular," which means they consist of small individual modules (the turbines) and can easily be made larger or smaller as needed. Turbines can be added as electricity demand grows. Today, a 50-MW wind farm can be completed in 18 months to two years. Most of that time is needed for measuring the wind and obtaining construction permits—the wind farm itself can be built in less than six months(http://www.awea.org/faq/wwt_basics.html)[FKha1]

It's important to understand that wind is actually a form of solar energy - so by saying that a wind turbine harnesses solar power isn't totally incorrect. Wind is a phenomenon that occurs caused by the uneven heating of the Earth's surface in combination with the spinning of the planet on its axis.(http://www.greenlivingtips.com/articles/65/1/How-wind-turbines-work.html) [fkha1]

There are two basic types of wind generators including the horizontal axis wind turbine and the vertical axis wind turbine. Understandably one turns on a horizontal axis (or axel) and the other one upon a vertical axis (or axel).
Each type of wind turbine works in similar fashion. Basically, the wind blows past the wind generator blades or rotors causing a low pressure system on the trailing edge of the blades similar to a wing of an airplane. Utility scale wind turbine blades may need a wind speed of 10 mph or more to start turning while residential wind turbines may start rotating at speeds of 7 mph or less.(http://www.windturbinesnow.com/how-wind-turbines-work.htm) [Fkha1]

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wind turbines make use of renewable energy source to produce electricity without the emission of greenhouse gases. One can install smaller wind turbines at home to supply power for air conditioner (AC) or inverter. In recent times, wind turbines are gaining popularity to combat global warming and carbon dioxide production in the atmosphere, yet providing energy to meet our lavish lifestyles. (http://www.buzzle.com/articles/how-do-wind-turbines-work.html)[FKha1]

Decades ago if you drove by a field and happened to see a windmill spinning in the wind, chances are the blades were made of wood. With new inventions and better technology today, wood is still used as material for turbine blades. The design is different however. And a lighter wood material is used, in order to carve the blade and faster speed rotation.(http://www.buzzle.com/articles/windmill-blades-and-from-what-they-are-made.html)[FKha1]

When we see a wind turbine, the most significant component is the tower that holds the blades. The efficiency of wind turbines to some extent depends on the height of the tower. In other words, the tower height should be such that the blades can make use of the available wind energy to maximum amount. Following are the machinery of wind turbines:
  • Blades or rotor (either two or three)
  • Brake (to stop turbine rotation in emergencies)
  • Anemometer (for measuring wind speed)
  • Controller (regulates the turbine)
  • Gear box (to start the machine)
  • Generator (for producing electricity)
  • High-speed and low-speed shaft (to drive generator)
  • Nacelle (houses the turbine and is placed on top of the tower)
  • Pitch (for controlling the direction of blades)
  • Tower (houses the rotor)
  • Wind direction (upwind turbine)
  • Yaw drive (required for upwind turbine and is used to regulate rotor direction)
  • Yaw motor (powers the yaw drive)
  • Wind vane (to measure wind direction)
http://www.buzzle.com/articles/how-do-wind-turbines-work.html
http://www.buzzle.com/articles/windmill-blades-and-from-what-they-are-made.html
http://www.awea.org/faq/wwt_basics.html
http://www.awea.org/faq/wwt_basics.html
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liftdrag
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http://www.alternative-energy-news.info/technology/wind-power/wind-turbines/

Wind Turbine
Wind Turbine
One of the key performance differences in wind turbine designs is caused by the driving mechanism of the rotor. A wind turbine rotor can either be turned around by the aerodynamic drag of rotor blades or by the aerodynamic lift of rotor blades. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

The output of any wind turbine depends, to a large extent, on four main factors: prevailing wind speed at the rotor axis height or hub height, rotor swept area, overall system reliability, and total power conversion efficiency from wind to electricity. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

Savonius style configuration. The major benefit of the Savonius rotor is that it is self-starting and starts in low winds. This allows our users to wring as much out of their wind conditions as is possible for a given wind swept area.
[http://pacwind.remnet.com/page5.html] [SDiv7]
Power output in formulaexternal image 1-1332-small-wind-turbines-driving-performance.jpgP = wind turbine power performance fed into the grid (watts)

CP = aerodynamic efficiency of conversion of wind power into mechanical power, often called the power coefficient

Πme = conversion efficiency of mechanical power in the rotor axis into mechanical power in the generator axis. Encompasses all combined losses in the bearings, gearbox, and so on

Πel = conversion efficiency of mechanical power into electric power fed into the grid, encompassing all combined losses in the generator, frequency converter, transformer, switches etc

p = air density in kg/m3 (~1.25 kg/m3 depending on environmental conditions)

v = wind speed some three rotor diameters upwind from the rotor plane in m/s

A = rotor swept area in m2]http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

Mechanical losses in a wind turbine are mainly due to friction in components such as bearings and gearbox components. With many micro wind turbines, the rotor drives the generator directly in a so-called direct drive or gearless system. In other wind systems a gearbox or a belt drive is applied in the drive train to step-up the relatively slow rotor speed to a much faster generator speed. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

The majority of micro wind turbines operate with a predefined cut-in speed; certain makes and types also operate with a predefined cut-out wind speed. The difference between cut-in and cut-out wind speeds is the operational range. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

Traditionally wind turbines applied in an open field are horizontal-axis designs fitted with an upwind rotor. The rotor thereby faces the wind when turning in front of the tower and these installations typically feature two, three or four aerodynamically shaped rotor blades when based on the lift principle. Many microturbine designs are, for cost reasons, fitted with fixed angle blades and operate on the stall principle. Others have pitch-variable rotor blades, a mechanically or electrically operated control and safety system aimed at limiting output beyond the nominal wind speed. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

Some state-of-the-art micro wind turbines, such as the 2.5 kW WES5 Tulipo, are also equipped with an active yaw system that redirects the rotor to the prevailing wind direction and comprises a wind direction sensor, yaw motor(s), and sometimes a yaw brake. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

In the operational output range, wind power generated increases with wind speed cubed. In other words, at a wind speed of 5 m/s, the power output is proportional with 5 cubed (53) = 125, whereas at a wind speed of 6 m/s, the power output is proportional to 63 or 216. This shows that an increase of wind speed of only 20% gives rise to a power increase of 73%. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

Wind power in the built environment
The site for a proposed urban wind turbine should be selected carefully, and the installation choice is crucial. Once the turbine has been selected, the prevailing wind speed at hub height is the only variable left in their physical relationship and is therefore a key-determining factor for an expected energy yield.
Building roofs towering well above surrounding buildings have, in general, good prospects for offering economic wind speeds and, as a rule of thumb, wind speed generally increases with height. But, close to the roof the situation is more complex. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

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Small wind turbines mounted on a building [http://www.renewableenergyworld.com/assets/images/story/2008/8/7/1332-small-wind-turbines-driving-performance.jpg] [SDiv7]
http://www.renewableenergyworld.com/assets/images/story/2008/8/7/1332-small-wind-turbines-driving-performance.jpg
http://www.renewableenergyworld.com/assets/images/story/2008/8/7/1332-small-wind-turbines-driving-performance.jpg




[http://pacwind.remnet.com/Savonius.gif] [SDiv7]

http://pacwind.remnet.com/Savonius.gif
http://pacwind.remnet.com/Savonius.gif

Wind Turbines are often made up of a few basic components: a rotor (the part that actually rotates in the wind), an electrical generator, a speed-control system, and a tower. Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current. Most large modern wind turbines are horizontal-axis turbines, like the traditional farm windmills used for pumping water. Wind turbines are often grouped together into a single wind power plant, also known as a wind farm, and generate bulk electrical power. Electricity from these turbines is fed into a utility grid and distributed to customers just as it is with conventional power plants. [DBea1] http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf

History of wind turbines:

The history of wind power as it relates to windmills and wind turbines started around 200 B. C. in Persia (Iran). The first windmills were vertical axis wind turbines that were used for pumping water and grinding wheat and other grains.http://www.windturbinesnow.com/history-wind-power.htm [AFah1]

Over 8 million mechanical windmills have been installed in the US since the 1860's and some of these units have been in operation for more than a hundred years. (http://www.altestore.com/howto/Wind-Power/Small-Wind-Turbines-Primer/a28/) [OPar7]

In the late 1970's and early 1980's intense interest was once again focused on wind energy as a possible solution to the energy crisis. As homeowners and farmers looked to various electricity producing renewable energy alternatives, small wind turbines emerged as the most cost effective technology capable of reducing their utility bills. (http://www.altestore.com/howto/Wind-Power/Small-Wind-Turbines-Primer/a28/) [OPar7]

Small wind turbines were installed in all fifty States. None of the small wind turbine companies, however, were owned by large companies committed to long term market development, so when the federal tax credits expired in late 1985, and oil prices dropped to $10 a barrel two months later, most of the small wind turbine industry once again disappeared. (http://www.altestore.com/howto/Wind-Power/Small-Wind-Turbines-Primer/a28/) [OPar7]


  1. Wind energy propelled boats along the Nile River as early as 5000 B.C. By 200 B.C., simple windmills in China were pumping water, while vertical-axis windmills with woven reed sails were grinding grain in Persia and the Middle East. http://www1.eere.energy.gov/windandhydro/wind_history.html [ECon8]
  2. The popularity of using the energy in the wind has always fluctuated with the price of fossil fuels. When fuel prices fell after World War II, interest in wind turbines waned. But when the price of oil skyrocketed in the 1970s, so did worldwide interest in wind turbine generators. http://www1.eere.energy.gov/windandhydro/wind_history.html [ECon8]
  3. 980 – New Hampshire, US

  1. 1991 – Vindeby, Denmark
    The first offshore windfarm is created in Vindeby, in the southern part of Denmark. The windfarm consists of 11 450kW turbines.

  • The first windmills were developed to automate the tasks of grain-grinding and water-pumping and the earliest-known design is the vertical axis system developed in Persia about 500-900 A.D. The first use was apparently water pumping, but the exact method of water transport is not known because no drawings or designs -- only verbal accounts -- are available. The first known documented design is also of a Persian windmill, this one with vertical sails made of bundles of reeds or wood which were attached to the central vertical shaft by horizontal struts (see Figure 1a). A 19th Century American approximation of this panemone device is shown at the left (Figure 1b). http://www.telosnet.com/wind/early.html [SSha1]
FIGURE 1B:
external image panemone.jpghttp://www.telosnet.com/wind/early.html [SSha1]
Figure 1b. A 19th-century American knock-off of the Persian panemone that probably made a wonderful clothes dryer.

Grain grinding was the first documented wind mill application and was very straightforward. The grinding stone was affixed to the same vertical shaft. The mill machinery was commonly enclosed in a building, which also featured a wall or shield to block the incoming wind from slowing the side of the drag-type rotor that advanced toward the wind. http://www.telosnet.com/wind/early.html [SSha1]
Vertical-axis windmills were also used in China, which is often claimed as their birthplace. While the belief that the windmill was invented in China more than 2000 years ago is widespread and may be accurate, the earliest actual documentation of a Chinese windmill was in 1219 A.D. by the Chinese statesman Yehlu Chhu-Tshai. Here also, the primary applications were apparently grain grinding and water pumping. http://www.telosnet.com/wind/early.html [SSha1]




  • The history of wind power as it relates to windmills and wind turbines started around 200 B. C. in Persia (Iran). The first windmills were vertical axis wind turbines that were used for pumping water and grinding wheat and other grains.China has also laid claims to having invented windmills around 2,000 years ago, but the first documented claims appear in the 1200's. Around 250 A.D. the Romans introduced windmills into their culture and in the 700's so did Afghanistan. The Afghanistan windmills were also of the vertical axis style and cloth sails or reed matting was developed to catch the air. These windmills were used to grind corn and sugarcane plus draw water. http://www.windturbinesnow.com/history-wind-power.htm [SSha1]

  • The first windmill in the world built for electrical production was in 1887 in Scotland built by Professor James Blyth. A year later in 1888 in the U. S. Charles Brush of Cleveland, Ohio built a large wind turbine used to generate electricity. http://www.windturbinesnow.com/history-wind-power.htm [SSha1]
  • Also, in 1931 the Darrieus wind turbine was developed as a vertical axis turbine used to generate electricity. By the 1930's farms across the U. S. were using small wind turbines to generate electricity for farmhouses, irrigation and other reasons since the electrical grid was slow in reaching many locations.
In 1941 another large scale wind turbine was developed in Castleton, Vermont. Oil shortages in the 1970s saw a resurgence in interest in wind energy and in the 1980s California started offering incentives for wind development. http://www.windturbinesnow.com/history-wind-power.htm [SSha1]


external image BrushCharlesF2%255B1%255D.jpg CharlesF. Brush http://windpowerisfree.com/ [SSha1]






  1. The first wind turbines were used in Persia for the grinding up of grain (http://www.free-press-release.com/news-brief-history-of-wind-turbines-1252572139.html) [BWar1]
  2. Windmills were first used to produce electricity around 1888. Charles Brush from Cleveland Ohio created these turbines (http:www.free-press-release.com/news-brief-history-of-wind-turbines-1252572139.html) [BWar1]
  3. By the 1930's wind mills could be found on farms in the U.S to produce electricity(http://www.free-press-release.com/news-brief-history-of-wind-turbines-1252572139.html) [BWar1]

1.What was once largely stall-regulated, constant speed machines in the 50-500 kW range in the 1980s has evolved in the late 90s to modern variable pitch, variable speed turbines with power electronics in the 750 kW to 2+ MW range. (http://www.sandia.gov/wind/2006reliability/tuesday/09-benbell.pdf) [FWal7]
2.The first windmills were developed to automate the tasks of grain-grinding and water-pumping and the earliest-known design is the vertical axis system developed in Persia about 500-900 A.D(.http://www.telosnet.com/wind/early.html)[FWal7]
3.The first use was apparently water pumping, but the exact method of water transport is not known.( http://www.telosnet.com/wind/early.html)[FWal7]

external image moz-screenshot-9.pngexternal image moz-screenshot-10.pngpanemone.jpg A 19th-century American Windmill (http://www.telosnet.com/wind/early.html)[FWal7]

In the late 1970's and early 1980's intense interest was once again focused on wind energy as a possible solution to the energy crisis. As homeowners and farmers looked to various electricity producing renewable energy alternatives, small wind turbines emerged as the most cost effective technology capable of reducing their utility bills. (http://www.alternative-energy-resources.net/wind-turbine-history.html) [MBoz8]



In July 1887, a Scottish academic, Professor James Blyth, undertook wind power experiments that culminated in a UK patent in 1891.[[#cite_note-Price-5|[6]]] In the United States, Charles F. Brush produced electricity using a wind powered machine, starting in the winter of 1887-1888, which powered his home and laboratory until about 1900. In the 1890s, the Danish scientist and inventor Poul la Cour constructed wind turbines to generate electricity, which was then used to produce hydrogen.[[#cite_note-Price-5|[6]]] These were the first of what was to become the modern form of wind turbine. (http://en.wikipedia.org/wiki/Wind_power#History) [SSha1]


The cost per kilowatt hour (kWh) of electricity dropped by about 50 per cent with the appearance of this generation of wind turbines. The wind industry became much more professionalised, and the parallel development of the European Wind Atlas Method by Risoe National Laboratory was extremely important in lowering kWh costs. (http://www.talentfactory.dk/en/pictures/windrush.htm)[FKha1]

Having started series manufacturing of wind turbines about 5 years earlier, Danish manufacturers had much more of a track record than companies from other countries.(http://www.talentfactory.dk/en/pictures/windrush.htm([FKha1]

The prototype of the NEG Micon 2 MW turbine (1024 x 768 pixels, 132K JPEG) was commissioned in August 1999. It has a 72 m (236 ft.) rotor diameter. In this case (Hagesholm, Denmark) it is mounted on a 68 m tower.(http://www.talentfactory.dk/en/pictures/multimeg.htm)[FKha1]




The power of wind was first used in Persia as early as 200B.C. such as the windwheel of Heron of Alexandria was marked as one of the first machines powered by wind. Sistan and Iran followed suit, building more practical windmills in the 7th century, these windmills were used to grind corn and draw up water, and were used in the gristmilling and sugarcane industries.By the 14th century, Dutch windmills were in use to drain areas of the Rhine River delta. In Denmark by 1900 there were about 2500 windmills for mechanical loads such as pumps and mills, producing an estimated combined peak power of about 30 MW. The first known electricity generating windmill operated was a battery charging machine installed in 1887 by James Blyth in Scotland. During the first World War wind turbines were mostly used for water drawing.(en.wikipedia.org/wiki/Wind_turbine)[CBer7]

Wind power has been harnessed by mankind for thousands of years. Wind filled the sails of explorers and fueled trade throughout the world. The Dutch used wind to claim land from the ocean, and early European settlers in the American West used wind to pump water for farms. During the first half of the 20th century wind was used to provide electricity for many rural areas before the expansion of the electrical grid offered a cheaper and more reliable form of power. http://www.geology.wisc.edu/geo411/hasselman.html [NSan8]


http://www.greenstudentu.com/encyclopedia/energy/wind [AFah1]
Old Wind Machine,Wind power,Windmills, Electricity
Old Wind Machine,Wind power,Windmills, Electricity

By the 1930s windmills were widely used to generate electricity on farms in the United States where distribution systems had not yet been installed. Used to replenish battery storage banks, these machines typically had generating capacities of a few hundred watts to several kilowatts. [http://www.altfuelsnow.com/wind/wind-energy-history.shtml] [SDiv7]

external image moz-screenshot-3.pngexternal image moz-screenshot-4.png




A wind turbine from the 1930's [http://www.altfuelsnow.com/wind/wind-energy-history.shtml] [SDiv7]

As the 21st century dawned the commercial wind power industry began expanding at a robust growth rate of about 30% per year, stimulated by the broader availability of wind resources, and falling production costs attributable to advancing technology and wind farm management. The steady run-up in oil prices after 2003 led to increasing fears that peak oil was imminent, further increasing interest in commercial wind power. [http://www.altfuelsnow.com/wind/wind-energy-history.shtml] [SDiv7]

Small on-site turbines have a long history. Now the arrival of small, domestic-scale wind turbines on the shelves of hardware stores has been welcomed by many but criticized by others as 'vanity' development, rather than a serious commitment to low-carbon generation. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

reliable micro-electricity generating wind turbines up to about 20 kW have been in use since the 1920s or 1930s. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

Reliability of wind turbines:

1.Global wind electricity-generating capacity increased by 24 percent in 2005 to 59.1 gigawatts. This represents a twelve-fold increase from a decade ago, when world wind-generating capacity stood at less than 5 GW. * (http://www.sandia.gov/wind/2006reliability/tuesday/09-benbell.pdf) [FWal7]
2. Turbines are being sited in extreme hot, cold and corrosive climates that require special design and O&M attention; and now offshore applications make system reliability even more critical as access for maintenance is limited. (http://www.sandia.gov/wind/2006reliability/tuesday/09-benbell.pdf) [FWal7]

3. Offshore turbines have technical needs not required of onshore turbines due to the more demanding climatic environmental exposure offshore.(http://social.windenergyupdate.com/news/depth-identifying-wind-turbine-reliability-issues)[FWal7]
4. direct drive wind turbines do not necessarily have better reliability than geared drive turbines but do have better potential to improve their reliability with time. Wind turbine generators and converters are both achieving reliabilities considerably below that of other industries but the reliability of these subassemblies is improving with time.(http://social.windenergyupdate.com/news/depth-identifying-wind-turbine-reliability-issues)[FWal7]
5.Wind turbines direct and indirect drive converters exhibit higher failure frequencies throughout their operation than converters in other industries. Direct drive wind turbines are not necessarily more reliable than geared wind turbines. .(http://social.windenergyupdate.com/news/depth-identifying-wind-turbine-reliability-issues)[FWal7]


With drag-driven wind turbines, the rotor blades are pushed around by the wind and move in the same direction. Such turbines typically combine a low aerodynamic efficiency or small CP number (<11%) with a high materials input requirement and, consequently, are usually rather expensive to manufacture when set against their comparatively limited power output. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

in turbines operating according to the lift principle, each rotor blade is turned by aerodynamic lift force, identical to the force that keeps an aircraft airborne. Rotor blades that operate based on this driving mechanism feature an airfoil shape, like the wings of an aircraft. Lift-driven rotor concepts combine a high CP of up to the theoretical maximum of 59.3%, called the Betz limit, with a much more favourable materials input. [http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]

The differences between both rotor concepts are striking: lift-driven wind turbines combine a high CP with a low material use, while a drag-driven wind turbine links a low CP to high material use. It is therefore difficult to design a micro drag-driven wind turbine that is economical in terms of costs of energy in €/kWh/20 years.[http://www.renewableenergyworld.com/rea/news/article/2008/08/small-wind-turbines-driving-performance-52701] [SDiv7]





The reliability of wind turbines is considered to be fairly low, due to increasing maitenence costs and the poor quality of the gear boxes that help turn the blades on turbine. This also causes power companies to shy away from funding and providing wind power to towns and cities where the wind power is available. The technology that helps the turbines run is also considered primitive at best, due it being considered fairly new technology. ( http://prod.sandia.gov/techlib/access-control.cgi/2006/061100.pdf ) [CBer7]


Repairs on a wind turbine can become fairly expensive. In the instance a blade or larger part of the turbine is damaged, the power company would have to have the parts shipped in, the supplies to put the part onto the turbine, and the labor. In many instances a crane is required to finish and or start the repairs, a crane tends to cost from $50,000 to $70,000 a day. ( http://prod.sandia.gov/techlib/access-control.cgi/2006/061100.pdf ) [CBer7]

Equipment reliability directly affects the LRC in that the LRC figure is only as accurate as the
component life estimates. Wind turbines are commonly designed so that the major component

design lives are equal to the turbine’s design life. (http://prod.sandia.gov/techlib/access-control.cgi/2006/061100.pdf) [MBoz8]

The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. Wind turbines being manufactured now have power ratings ranging from 250 watts to 5 megawatts (MW). http://www.awea.org/faq/wwt_basics.html [AFah1]

Wind speed is a crucial element in projecting turbine performance, and a site's wind speed is measured through wind resource assessment prior to a wind system's construction. Generally, an annual average wind speed greater than four meters per second (m/s) (9 mph) is required for small wind electric turbines (less wind is required for water-pumping operations). Utility-scale wind power plants require minimum average wind speeds of 6 m/s (13 mph). http://www.awea.org/faq/wwt_basics.html [AFah1]

Availability factor (or just "availability") is a measurement of the reliability of a wind turbine or other power plant. It refers to the percentage of time that a plant is ready to generate (that is, not out of service for maintenance or repairs). Modern wind turbines have an availability of more than 98%--higher than most other types of power plant. After more than two decades of constant engineering refinement, today's wind machines are highly reliable. http://www.awea.org/faq/wwt_basics.html [AFah1]

Can We Rely on Wind Power?
Yes. Wind power is currently supplying 48 billion kilowatt-hours (kWh) of electricity annually in the U.S., powering the equivalent of over 4.5 million homes. Wind power is an important part of electric utility generation portfolios. Yet some question whether wind power, being a variable resource (meaning it generates electricity when the wind is blowing, not on demand) can be relied upon as part of a system that provides reliable electricity to consumers without interruption. Based on a growing body of analytical and operational experience, the answer is a resounding "yes."
According to many utilities and reliability authorities, wind power can readily be accommodated into electric system operations reliably and economically.
http://www.renewableenergyworld.com/rea//news/article/2008/03/clearing-the-air-wind-power-and-reliability-51767 [NSan8]

Is Wind Less "Reliable" than Conventional Generation?
No. Conventional resources occasionally shut down with no notice, and these "forced outages" require operating reserves. For example, a power system that has 1,000-megawatt nuclear or coal plants will typically keep 1,000 megawatts of other generation available, to be ready to quickly supply electricity if a plant unexpectedly shuts down. The power system can still be operated perfectly reliably in this fashion. Thus, "reliability" is not specific to any single generation facility, rather it is measured on a system-wide basis.
As noted by Jon Brekke, Vice President of Member Services for Great River Energy, a utility that operates in Minnesota and Wisconsin: "Wind energy is a valuable part of our diverse and growing energy portfolio. When partnered with other traditional generation resources, wind energy is an effective way to provide reliable, clean and affordable power to our member cooperatives.
Geographic diversity of wind energy helps even out the variability of wind energy in the regional market. In addition, wind farms are typically made up of many individual turbines, which reduce the impact of outages. For instance, there are 67 1.5-MW turbines at our Trimont Wind Farm, so if one is down for maintenance only 1.5% of the total wind farm's generating capacity is lost."
Changes in wind energy output are not instantaneous, as are conventional generator failures. Because of the geographic diversity inherent with large numbers of wind turbine installations, it typically takes over an hour for even a rapid change in wind speeds to shut down a large amount of wind generation. This is a significant benefit when compared with the instantaneous tripping of conventional units. In addition, wind forecasting tools that warn system operators of pending major wind output variations are becoming widely used and better integrated into system operations.
http://www.renewableenergyworld.com/rea//news/article/2008/03/clearing-the-air-wind-power-and-reliability-51767 [NSan8]


No, in fact wind energy is more reliable than the conventional generation. It is more reliable because as long is the sun is around there will always be wind energy. Basically we have 4 billion more years of the suns energy. That number surpasses our amount of natural generation by about 10 times. [DBea1]

How are wind turbines used?:

Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetation. Humans use this wind flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity. (http://www1.eere.energy.gov/windandhydro/wind_how.htmlhttp:www1.eere.energy.gov/windandhydro/wind_how.html) [OPar7]

a wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Take a look inside a wind turbine to see the various parts. View the wind turbine animation to see how a wind turbine works. (http://www1.eere.energy.gov/windandhydro/wind_how.html) [OPar7]

Wind turbines are used to generate electricity from the kinetic power of the wind. Historical they were more frequently used as a mechanical device to turn machinery. There are two main kinds of wind generators, those with a vertical axis, and those with a horizontal axis. Wind turbines can be used to generate large amounts of electricity in wind farms both onshore and offshore. (http://www.alternative-energy-news.info/technology/wind-power/wind-turbines/) [MBoz8]

A wind turbine is a rotating machine which converts the kinetic energy of wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is instead converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator.(http://en.wikipedia.org/wiki/Wind_turbine){CBer7}

Table 1 Estimated cost of electricity generation from fossil fuel and renewable sources Energy source Estimated cost ($/MWh) Wind 60 – 80 Fossil fuel Coal Natural gas combined cycle 31 – 40 37 – 44 Renewables Solar Tidal Geothermal Biomass Bagasse Small hydroelectric Large hydroelectric 400 – 800 80 – 150 40 – 130 50 – 75 30 – 100 40 – 70 10 – 81(https://www.tai.org.au/file.php?file=discussion_papers/DP91.pdf)[CBer7]


In Europe, Denmark receives over 20% of its electricity from wind power, and in 2007 Germany received 7% of its electricity from wind power. Both Spain and Portugal had periods in 2007 when wind power provided over 20% of their electricity. In the U.S., Minnesota and Iowa both get close to 5% of their electricity from wind power. These examples provide real-world experiences with high penetrations of wind power, as a valuable part of a utility generation mix that supplies reliable electrical service to consumers without interruption.
http://www.renewableenergyworld.com/rea//news/article/2008/03/clearing-the-air-wind-power-and-reliability-51767 [NSan8]


Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity. In return the electricity can be used to power homes, businesses, or factories. [DBea1] http://www1.eere.energy.gov/windandhydro/wind_how.html


Benefits of using wind turbines:

1. The wind is free and with modern technology it can be captured efficiently.
2. Once the wind turbine is built the energy it produces does not cause green house gases or other pollutants.
3. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used. This is especially the case in agricultural areas as farming can still continue.
4. Many people find wind farms an interesting feature of the landscape.
5. Remote areas that are not connected to the electricity power grid can use wind turbines to produce their own supply.
6. Wind turbines have a role to play in both the developed and third world.
7. Wind turbines are available in a range of sizes which means a vast range of people and businesses can use them. Single households to small towns and villages can make good use of range of wind turbines available today. [OPar7]

  1. Many wind farms have sprung up in the Midwest in recent years, generating power for utilities. Farmers benefit by receiving land lease payments from wind energy project developers. http://www1.eere.energy.gov/windandhydro/wind_ad.html[ECon8]
  2. A cumulative total of 7,600 million tons of CO2 would be avoided by 2030, and more than 15,000 million tons of CO2 would be avoided by 2050. http://www1.eere.energy.gov/windandhydro/wind_ad.html[ECon8]
  3. Wind energy is a domestic source of energy, produced in the United States. The nation's wind supply is abundant. http://www1.eere.energy.gov/windandhydro/wind_ad.html[ECon8]
  4. According to the American Wind Energy Association, if we increase our nation's wind energy capacity to 20% by 2030 http://www1.eere.energy.gov/windandhydro/wind_ad.html [ECon8]

1. The production of wind energy creates no air pollution and, if the turbines are sited properly, has minimal environmental impact.
2. Wind Energy is economically competitive
3. Wind energy is a valuable crop of the future for farmers and ranchers
4. Unlike most other electricity generation sources, wind turbines do not consume water
5. Wind energy is indigenous, homegrown energy source that contributes to national security
6. Wind energy is inexhaustible and infinitely renewable
7. Because wind energy's "fuel" is free, it reduces the risk associated with volatile fossil fuel prices
8. Wind energy is the fuel of today and tomorrow.
http://www.nrel.gov/docs/fy05osti/37602.pdf [DBea1]


No matter how extensively wind is developed in the future, bird deaths from wind energy are unlikely to ever reach as high as 1% of those from other human-related sources such as hunters, house cats, buildings, and autos. (http://www.awea.org/faq/wwt_environment.html#Bird and bat kills and other effects.) [BWar1]



The common loon and other aquatic wildlife are at risk from high concentrations of the toxic heavy metal mercury, emitted largely from coal power plants, according to the National Wildlife Federation. (http://www.awea.org/pubs/factsheets/wildlife.pdf) [BWar1]



Power plants account for 70% of SO2 and 33% of NOx emitted in the U.S. These pollutants not only cause respiratory ailments in humans—and probably also in wildlife—but also acidify rain, snow, and fog. (http://www.awea.org/pubs/factsheets/wildlife.pdf) [BWar1]






Advantages of horizontal wind turbines

1.Blades are to the side of the turbine's center of gravity, helping stability. http://www.solarnavigator.net/wind_turbines.htm[MP17]
2.Ability to wing warp, which gives the turbine blades the best angle of attack. Allowing the angle of attack to be remotely adjusted gives greater control, so the turbine collects the maximum amount of wind energy for the time of day and season. http://www.solarnavigator.net/wind_turbines.htm[MP17]
3.Ability to pitch the rotor blades in a storm, to minimize damage. http://www.solarnavigator.net/wind_turbines.htm[MP17]
4.Tall tower allows access to stronger wind in sites with wind shear. In some wind shear sites, every ten meters up, the wind speed can increase by 20% and the power output by 34%. http://www.solarnavigator.net/wind_turbines.htm[MP17]
5.Tall tower allows placement on uneven land or in offshore locations.
6.Can be sited in forests above the treeline. http://www.solarnavigator.net/wind_turbines.htm[MP17]
7.Most are self-starting. Can be cheaper because of higher production volume, larger sizes and, in general higher capacity factors and efficiencies.
http://www.solarnavigator.net/wind_turbines.htm[MP17]

One of the greatest advantages of Wind Energy is that it is ample. Secondly, wind energy is renewable. Some other advantages of Wind Energy are that it is widely distributed, cheap, and also reducing toxic gas emissions. Wind Energy is also advantageous over traditional methods of creating energy, in the sense that it is getting cheaper and cheaper to produce wind energy. Wind Energy may soon be the cheapest way to produce energy on a large scale.

The cost of producing wind energy has come down by at least eighty percent since the eighties. Along with economy, Wind Energy is also said to diminish the greenhouse effect.

Also, wind energy generates no pollution. Wind Energy is also a more permanent type of energy. The wind will exist till the time the sun exists, which is roughly another four billion years. Theoretically, if all the wind power available to humankind is harnessed, there can be ten times of energy we use, readily available. http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html [MP17]


  1. Wind energy is ample [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html
  2. Wind energy is renewable [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html
  3. Some other advantages of Wind Energy are that it is widely distributed, cheap, and also reducing toxic gas emissions [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html
  4. Wind energy is getting cheaper, and cheaper to produce. The cost of creating wind energy has come down almost 80 percent since the 80's. [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html
  5. Wind energy creates no pollution.[DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html
  6. If wind power is correctly harnessed, we will have 10 times the amount of energy available than we do now. [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html
  7. Wind energy is readily available around the globe. [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html

energy forms over conventional sources of generation. Wind energy is a free, renewable resource, so no matter
how much is used today, there will still be the same supply in the future. Wind energy is also a source of clean,
non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse
gases. According to the U.S. Department of Energy, in 1990, California's wind power plants offset the emission of
more than 2.5 billion pounds of carbon dioxide and 15 million pounds of other pollutants that would have
otherwise been produced. It would take a forest of 90 million to 175 million trees to provide the same air quality.
(
http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf) [MBoz8]
1. Wind energy is nothing new. It's a well-known method of using kinetic energy (wind) to produce mechanical energy and has been around for thousands of years since the Persians and later Romans were using windmills to draw water and grind grain.
2. Wind energy is a renewable resource meaning that the Earth will continue to provide this and it's up to people to use it and harness it to best advantage.
3. Wind energy is cheap and is largely dependent upon the manufacturing, distribution and building of turbines for the initial costs. The U. S. DOE estimates wind energy can be produced for as low as 4 to 6 cents per kilowatt hour.
4. Wind energy replaces electricity from coal-fired power plants and thus reduces greenhouse gases that produce global warming.
5. Wind energy is available worldwide and though some countries may be "windier" than others, the product is not like oil that has to be transported on tankers to the far regions of the earth.
6. Wind farms on average have a smaller footprint than coal-fired power plants and even though some people don't like the appearance to wind turbines, they object more to having a coal-fired power plant in their backyards.
7. Wind turbines can also share space with other interests such as the farming of crops or cattle.
8. Wind energy is available in many remote locations where the electrical grid doesn't reach. Farms, mountain areas and third world nations can take advantage of wind energy.
9. Wind energy is creating jobs that are far outpacing other sectors of the economy.
10. Wind energy doesn't have to be used solely on a commercial scale as residential wind turbines are now gaining ground in many communities. (
http://www.windturbinesnow.com/advantages-disadvantages-wind-energy.htm) [MBoz8]

According to the U.S. Dept. of Energy, clean wind power costs $55.60 per MWH (megawatt hour). Meanwhile coal energy costs $53.10 per MWH; nuclear power $59.30 per MWH; natural gas $52.50 per MWH. At the moment, wind power is more expensive than fossil fuels, but those costs are dropping as wind turbines are starting to be produced in mass numbers, making them less expensive.
http://www.ehow.com/facts_4741237_advantages-disadvantages-wind-turbines.html[MP17]

1. Wind energy can help fight Global Warming. Wind turbines produce no air emissions or greenhouse gases.
Wind power is a clean, renewable form of energy, which during operation produces no carbon dioxide. While some emissions of these gases will take place during the design, manufacture, transport and erection of wind turbines, enough electricity is generated from a wind farm within a few months to totally compensate for these emissions. When wind farms are dismantled (usually after 20-25 years of operation) they leave no legacy of pollution for future generation. (
http://www.awea.org/faq/wwt_environment.html#Will) [SSha1]

Wind turbines are a low-cost alternative to many other forms of energy, such as fossil fuels, solar panels or nuclear technology. Residential properties can purchase a small wind turbine for $6,000 to $22,000, installed. These turbines produce from 5 to 15 kilowatts per hour. According to the American Wind Energy Association, the average home saves 50 to 90 percent off its electric bill each month. Even more, many people who build wind turbines can sell excess electricity to the power company every month.
Large industrial wind turbines are an even better value. In 2007, the cost for a commercial-scale wind turbine was roughly $3.5 million installed, according to the Windustry Organization. These turbines produce 2 megawatts of electricity per hour, enough to power 1,400 homes for a year. (
http://www.ehow.com/about_4779281_advantages-using-wind-energy.html) [MBoz8]
  • Wind energy is friendly to the surrounding environment, as no fossil fuels are burnt to generate electricity from wind energy.
  • Wind turbines take up less space than the average power station. Windmills only have to occupy a few square meters for the base, this allows the land around the turbine to be used for many purposes, for example agriculture.
  • Newer technologies are making the extraction of wind energy much more efficient. The wind is free, and we are able to cash in on this free source of energy.
  • Wind turbines are a great resource to generate energy in remote locations, such as mountain communities and remote countryside. Wind turbines can be a range of different sizes in order to support varying population levels.
  • Another advantage of wind energy is that when combined with solar electricity, this energy source is great for developed and developing countries to provide a steady, reliable supply of electricity.
http://www.clean-energy-ideas.com/articles/advantages_and_disadvantages_of_wind_energy.html [AFah1]

First, it is generally the most economical source of renewable energy, competitive with and sometimes cheaper than electricity from fossil fuels and nuclear power. Good sites can produce wind power at eight to ten cents per kilowatt-hour (kWh) – even less when the federal tax credit is factored in. (By comparison, the cost of electricity from a new natural gas plant in California is ten to eleven cents per kWh.) Wind power is expected to become even more cost-effective as the industry develops larger turbines and the price of fossil fuels continues to rise, as it surely will in the long-term.
Second, we have enormous potential for wind power in this region. For example, the 97.5 megawatt (MW) wind farm recently approved near Lompoc could supply 285 gigawatt hours (GWh) a year -- about a tenth of our county’s current demand for electricity. In Santa Barbara County, wind power potential is much, much greater. Professor Dan Kammen -- chairman of UC Berkeley’s Energy Resources Group – and his graduate students, in a study performed for CEC, found potential for nearly 3,800 GWh of wind at onshore sites in the county. When adding the potential from offshore sites and small wind turbines, Kammen calculated a potential of 290,000 GWh. In other words, wind power in our region could theoretically produce over 100 times our current demand for electricity. http://www.cecsb.org/index.php?option=com_content&task=view&id=61&Itemid=100&gclid=CN2nq-3Vhp8CFdA65QodnV5BRQ [NSan8]

Certain renewable energy technologies—such as large-scale wind power—are already economically competitive with traditional sources of energy, such as fossil fuels. Even when the cost of power produced by renewables is more than average utility rates, many companies can still save money by using renewables to institute “peak shaving.” In peak shaving, companies produce renewable energy during periods of peak power use, when utilities often charge higher rates. In addition, government incentives can significantly reduce the actual cost of renewable systems. These incentives include federal, state, and local tax credits; tax deductions; accelerated depreciation; loans; production incentives; rebates; and grants. Specific benefits for companies deploying renewable energy on-site can include:

  • Reducing energy costs or creating a hedge against possible future energy price increases.
  • Improving energy reliability at a company’s location (depending on system configuration).
  • Helping companies to be environmentally responsible and enhance their reputation through a reduction in greenhouse gas (GHG) emissions or a visible commitment to renewable energy http://www.wri.org/publication/harnessing-natures-power?gclid=CMfO247Xhp8CFVFM5Qoddh8Lng [NSan8]
Wind energy has numerous benefits as a power source, including price stability, lack of greenhouse gas emissions, and lack of dependence on imported fuels. As wind increases its penetration into the U.S. power market, it is imperative to minimize costs and maximize reliability, so that it can fully compete with traditional power sources. The primary recurring cost of energy in wind turbines is maintenance. Studies have shown that a few subsystems tend to account for most unscheduled maintenance costs, and for in-service failures and downtime. These subsystems include the gearboxes and the generator. Although technologies to monitor both of these systems already exist in a rudimentary form, these technologies require a large array of costly sensors and data acquisition hardware. This project will develop a low-cost, robust health monitoring system applicable to a wide range of commercial wind turbines. The approach involves the utilization of industry-standard vibration signal processing and condition indicators, which have been developed for aerospace applications. Phase I focused on demonstrating the underlying diagnostic algorithms. Phase II will develop several complete prototypes and demonstrate them on operating wind turbines.


Commercial Applications and Other Benefits as described by the awardee: A low-cost, high-payback health monitoring system would have a significant positive impact on wind turbine operations and maintenance costs. In turn, the net cost of energy for wind power would decrease, providing a good ROI for wind farm operators. Moreover, the reduced cost of energy and increased reliability would accelerate the adoption of this clean energy source. Today’s 16,818 MW of wind power are keeping 28 million tons of carbon dioxide, the leading greenhouse gas associated with global warming, out of the air every year. Wind energy also helps revitalize rural and agricultural-based communities, and decreases our dependence on imported fuels. http://www.sc.doe.gov/sbir/awards_abstracts/sbirsttr/cycle25/phase2/012.htm [NSan8]



  • The wind is an inexhaustible energy source and nature provides it for free.
  • Wind energy is a technologically mature, economically competitive and environment friendly energy choice.
  • It protects the Earth, as every kilowatt hour produced by the wind replaces a kilowatt hour produced by conventional generating plants, which pollutes the atmosphere with greenhouse gases.
  • It does not burden the local environment with dangerous gas emissions, such as carbon monoxide, sulfur dioxide, cancer causing microscopic particles, etc. as conventional electricity generating plants do.
  • It enhances energy independence and security which is especially important for Greece and Europe in general.
  • It contributes to the decentralization of the energy system, reducing energy transmission losses.
So, wind energy has many positive aspects


Modern wind turbines are very quiet machines in relation to their power and through their manufacturers’ continuing improvements keep getting quieter. The problem of noise is corrected either at the source or during the course of operation. Mechanical noise has been minimized at the design stage (side toothed gear wheels), or by acoustic insulation on the inside of the turbine housing. Also, mechanical noise can be corrected during operation by acoustic insulation curtains and anti vibration support footings. Aerodynamic noise can be corrected by careful design of the blades by the manufacturers who make minimization of this type of noise a top priority.

The level of audible noise from a wind turbine, built to modern specifications, at a distance of 200 metres, is lower than the background noise level of a small town in the countryside and of course is not a nuisance. Given the requirement under Greek law that wind turbines be installed at a minimum distance of 500 metres from residential areas, the level is even lower and corresponds to that of a quiet living room. In addition, at the wind speeds in which wind turbines operate, the natural noise (noise of the wind in trees and bushes) covers any noise emanating from them.

Keeping the foregoing in mind along with the sites where wind farms are usually built in Greece for optimization of output, we can state with certainty that wind farms do not cause:

  • An increase in the existing noise level outside their boundaries and even less in residential areas.
  • Exposure of people to a high level of noise.
http://www.cres.gr/kape/publications/papers/dimosieyseis/CRESTRANSWINDENVIRONMENT.doc [NSan8]

ADVANTAGE TO WIND ENERGY
-With the price of natural gas, oil, and other fuels soaring, wind energy is becoming more of a bargain than ever. A recent landmark study of wind integration into the New York State electric power system, looking at a 10% addition of wind generation (3,300 MW of wind in a 34,000-MW system), projected a reduction in payments by electricity customers of $305 million in one year. (http://www.awea.org/faq/wwt_costs.html#How much does wind energy cost) [BWar1]
-Wind energy is one of the most popular energy technologies. Opinion surveys regularly show that just over eight out of 10 people (80%) are in favor of wind energy, and less than one in ten (around 5%) is against it. The rest are undecided. (http://www.awea.org/faq/wwt_environment.html#Will wind energy hurt tourism in my area) [BWar1]

OFF SHORE WIND TURBINES
(
http://www.mywindpowersystem.com/wp-content/uploads/2009/07/alternative-energy-windfarm.jpg) [BWar1]


Disadvantages of using wind turbines:

However, there are some disadvantages for wind energy, which may put a dampener in its popularity. Though the costs of creating wind energy is going down, even today a large number of turbines have to be built to generate a proper amount of wind energy. Though wind power is non-polluting, the turbines may create a lot of noise, which indirectly contributes to noise pollution. Wind can never be predicted.Even the most advanced machinery may come out a cropper while predicting weather and wind conditions. Since wind energy will require knowledge of the weather and wind conditions on long term basis, it may be a bit impractical. Therefore, in areas where a large amount of wind energy is needed, one cannot depend completely on wind.http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html[MP17]

drawback of wind power is that not every location is suitable for a wind turbine. Only select locations have sufficient wind blowing regularly enough to make erecting the turbines worthwhile.Wind turbines are not popular with some of the residents of scenic areas, especially those that rely on tourism. They are considered by these people and some others to be a blight on the [[@#|landscape]], and they have a point: windmills are obtrusive and unsightly. Some also say they are noisy, but this is really only the case if (as with airports) you live next to one. Numerous public opinion surveys have consistently shown that the public prefers wind and other renewable.
http://www.ehow.com/facts_4741237_advantages-disadvantages-wind-turbines.html[MP17]





1. The strength of the wind is not constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity all the time. There will be times when they produce no electricity at all.
2. Many people feel that the countryside should be left untouched, without these large structures being built. The landscape should left in its natural form for everyone to enjoy.
3. Wind turbines are noisy. Each one can generate the same level of noise as a family car travelling at 70 mph.
4. Many people see large wind turbines as unsightly structures and not pleasant or interesting to look at. They disfigure the countryside and are generally ugly.
5. When wind turbines are being manufactured some pollution is produced. Therefore wind power does produce some pollution.
6. Large wind farms are needed to provide entire communities with enough electricity. For example, the largest single turbine available today can only provide enough electricity for 475 homes, when running at full capacity. How many would be needed for a town of 100 000 people? [OPar7]


Disadvantages of vertical wind turbines

1.Most VAWTs produce energy at only 50% of the efficiency of HAWTs in large part because of the additional drag that they have as their blades rotate into the wind. This can be overcome by using structures to funnel more and align the wind into the rotor (e.g. "stators" on early Windstar turbines) or the "vortex" effect of placing straight bladed VAWTs closely together (e.g. Patent # 6784566).
http://www.solarnavigator.net/wind_turbines.htm[MP17]
2.There may be a height limitation to how tall a vertical wind turbine can be built and how much sweep area it can have.
http://www.solarnavigator.net/wind_turbines.htm[MP17]
3.Most VAWTS need to be installed on a relatively flat piece of land and some sites could be too steep for them but are still usable by HAWTs. Most VAWTs have low starting torque.
http://www.solarnavigator.net/wind_turbines.htm[MP17]
4.A VAWT that uses guyed wires to hold it in place puts stress on the bottom bearing as all the weight of the rotor is on the bearing. Guyed wires attached to the top bearing increase downward thrust in wind gusts. Solving this problem requires a superstructure to hold a top bearing in place to eliminate the downward thrusts of gust events in guyed wired models.
http://www.solarnavigator.net/wind_turbines.htm[MP17]


  1. Wind energy cannot be stored (unless batteries are used); and not all winds can be harnessed to meet the timing of electricity demands. http://www1.eere.energy.gov/windandhydro/wind_ad.html [ECon8]
  2. Good wind sites are often located in remote locations, far from cities where the electricity is needed. http://www1.eere.energy.gov/windandhydro/wind_ad.html [ECon8]
  3. Wind resource development may compete with other uses for the land and those alternative uses may be more highly valued than electricity generation. http://www1.eere.energy.gov/windandhydro/wind_ad.html [ECon8]
  4. Depending on how energetic a wind site is, the wind farm may or may not be cost competitive. Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. http://www1.eere.energy.gov/windandhydro/wind_ad.html [ECon8]
  5. Symptoms such as headaches, nausea, sleeplessness and
    depression have all been attributed to low frequency emissions from wind turbines. Medical experts are best placed to conduct more research. Most turbines are placed far away from human habitation so the issue rarely arises at present.
    http://environment.newarchaeology.com/wind_energy.php [ECon8]



The major challenge to using wind as a source of power is that it is intermittent and does not always blow when
electricity is needed. Wind cannot be stored (although wind-generated electricity can be, if batteries are used) and
not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often
located in remote locations far from areas of electric power demand (such as cities). Finally, wind resource
development may compete with other uses for the land, and those alternative uses may be more highly valued

than electricity generation. (http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf) [MBoz8]

1. Wind is an intermittent source of energy and when connected to the electrical grid provides an uneven power supply. Some places such as the Gulf Coast region of the U. S. have too strong of winds during hurricane season that may damage wind turbines.
2. Some people object to the visual site of wind turbines disrupting the local landscape.
3. The wind doesn't blow well at all locations on Earth. Wind maps are needed to identify the optimal locations.
4. The initial cost of a wind turbine can be substantial, though government subsidies, tax breaks and long-term costs may alleviate much of this.
5. Transmission of electricity from remote wind farms can be a major hurdle for utilities since many time turbines are not located around urban centers.
6. The storage of excess energy from wind turbines in the form of batteries, hydrogen or other forms still needs research and development to become commercially viable.
7. Some environmentalists have complained that large utility wind turbines have a detrimental effect to migratory bird flight paths.
8. Depending upon the type of wind turbine, noise pollution may be a factor for those living or working nearby.
9. Even though costs of wind energy have come down dramatically it still has to compete with the ultra low price for fossil fuel power plants.
10. Utility scale wind turbines can interfere with television signals of those living within a mile or two of the installation, which can be frustrating for homeowners. (http://www.windturbinesnow.com/advantages-disadvantages-wind-energy.htm) [MBoz8]


  • The main disadvantage regarding wind power is down to the winds unreliability factor. In many areas, the winds strength is too low to support a wind turbine or wind farm, and this is where the use of solar power or geothermal power could be great alternatives.
  • Wind turbines generally produce allot less electricity than the average fossil fuelled power station, requiring multiple wind turbines to be built in order to make an impact.
  • Wind turbine construction can be very expensive and costly to surrounding wildlife during the build process.
  • The noise pollution from commercial wind turbines is sometimes similar to a small jet engine. This is fine if you live miles away, where you will hardly notice the noise, but what if you live within a few hundred meters of a turbine? This is a major disadvantage.
  • Protests and/or petitions usually confront any proposed wind farm development. People feel the countryside should be left in tact for everyone to enjoy it's beauty. (http://www.clean-energy-ideas.com/articles/advantages_and_disadvantages_of_wind_energy.html) [MBoz8]

The most noticeable impact a wind turbine places upon the environment is noise pollution.
Many people think wind turbines are a great idea, yet a large proportion of these people would oppose a wind farm development close to their home.
This is down to the noise, and many people compare the sound output of a wind turbine to a small jet engine.
The impact of noise pollution has the potential to lower property values within a varying radius of the construction.
Modern technologies are ever increasing the efficiency of wind turbines, yet they fail to decrease the noise output by significant levels.
The noise pollution can greatly depend on the average annual wind speed (i.e. the higher the wind speed, the greater the noise output can be) and the size of the blades.
Noise pollution is said to be one of the biggest disadvantages of a wind turbine. http://www.clean-energy-ideas.com/articles/wind_turbines_impact.html [NSan8]

Another disadvantage regarding a wind turbine and it's impact on the surrounding environment can be expressed with the term "visual impact" or "visual pollution".
Some people believe wind turbines actually look quite nice, yet many people disagree.
You may enjoy the visual impact of turbines, but this does not stop the majority of people seeing turbines as a scare on the landscape. http://www.clean-energy-ideas.com/articles/wind_turbines_impact.html [NSan8]

The third and final most significant impact of a wind turbine on the surrounding environment is mainly argued by wildlife groups.
In some areas of wind farm developments, birds have been found dead around the base of turbines.
The force of the blades high up in the air may not seem powerful to you, yet they are more than capable of harming wildlife.
Also tied in with this matter is the construction of wind turbines. As with many other developments, wind turbines need deep foundations, and this has the potential to destroy underground habitats, and disturb surrounding ones. http://www.clean-energy-ideas.com/articles/wind_turbines_impact.html [NSan8]


  1. Though the costs of creating wind energy is going down, even today a large number of turbines have to be built to generate a proper amount of wind energy.
  2. Though wind power is non-polluting, the turbines may create a lot of noise, which indirectly contributes to noise pollution.
  3. WInd itself is extremely unpredictable. Since wind energy will require knowledge of the weather and wind conditions on long term basis, it may be a bit impractical.
  4. Many potential wind farms, places where wind energy can be produced on a large scale, are far away from places for which wind energy is best suited.
  5. Wind Energy is non-dispatchable. [DBea1] http://www.buzzle.com/articles/advantages-disadvantages-wind-energy.html




Economic costs of using wind turbines:

The costs for a commercial scale wind turbine in 2007 ranged from $1.2 million to $2.6 million, per MW of nameplate capacity installed. http://www.windustry.org/how-much-do-wind-turbines-cost [AFah1]

Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation. If wind generating systems are compared with fossil-fueled systems on a "life-cycle" cost basis (counting fuel and operating expenses for the life of the generator), however, wind costs are much more competitive with other generating technologies because there is no fuel to purchase and minimal operating expenses. http://windeis.anl.gov/guide/basics/index.cfm [AFah1]


Over the last 20 years, the cost of electricity from utility-scale wind systems has dropped by more than 80%. In the early 1980s, when the first utility-scale turbines were installed, wind-generated electricity cost as much as 30 cents per kilowatt-hour. Now, state-of-the-art wind power plants can generate electricity for less than 5 cents/kWh with the Production Tax Credit in many parts of the U.S., a price that is competitive with new coal- or gas-fired power plants. [OPar7]

The most important factors in determining the cost of wind-generated electricity from a wind farm are: (1) the size of the wind farm; (2) the wind speed at the site; and (3) the cost of installing the turbines. Each of these factors can have a major impact. Generally speaking:

  • The larger the wind farm, all other factors being equal, the lower the cost of energy;
  • The higher the wind speed, the lower the cost of energy;
  • The less expensive construction costs are, the lower the cost of energy.
http://www.awea.org/faq/wwt_costs.html#How%20much%20does%20wind%20energy%20cost [AFah1]






Wind energy avoids the external or societal costs associated with conventional resources, namely, the trade


deficit from importing foreign oil and other fuels, the health and environmental costs of pollution, and the cost of


depleted resources. Wind energy is a domestic, reliable resource that provides more jobs per dollar invested than


any other energy technology - more than five times that from coal or nuclear power, according to the U.S.


Department of Energy. In 1994, wind-turbine and component manufacturers contributed directly to the economies


of 44 states, creating thousands of jobs for Americans. (http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf) [OPar7]


Wind energy offers rural landowners a new cash crop. Although leasing arrangements vary widely, royalties are typically around $2,000 per year for a 750-kilowatt wind turbine or 2% to 3% of the project’s gross revenues. Given typical wind turbine spacing requirements, a 250-acre farm could increase annual farm income by $14,000 per year, or more than $55 per acre. In a good year, that same plot of land might yield $90 worth of corn, $40 worth of wheat, and $5 worth of beef. (http://www.nrel.gov/docs/fy04osti/33590.pdf) [MBoz8]

EIA also makes estimates of interconnection costs which are not peculiar to wind but which vary by region from $175 to $457 per kW (in 2001$). Finally, EIA provides estimates for adding transmission capacity to serve “wind farms, which include data for situations requiring transmission in the 0-5 mile range ($8.74 to $15.23 per kW, depending on region), 5-10 mile range ($26.23 to $45.70 per kW), 10-20 mile range ($52.47 to $91.40 per kW) all in 2001$. (http://www.mnforsustain.org/windpower_schleede_costs_of_electricity.htm#A.%20True%20Cost%20of%20Electricity%20from%20Wind) [MBoz8]

Most of the commercial-scale turbines installed today are 2 MW in size and cost roughly $3.5 Million installed. Wind turbines have significant economies of scale. Smaller farm or residential scale turbines cost less overall, but are more expensive per kilowatt of energy producing capacity. Wind turbines under 100 kilowatts cost roughly $3,000 to $5,000 per kilowatt of capacity. That means a 10 kilowatt machine (the size needed to power an average home) might cost $35,000-$50,000. [DBea1] http://www.windustry.org/how-much-do-wind-turbines-cost

What Is the Cost of Wind Integration?
To address wind energy's variability, some incremental generation may be required for system balancing. While this is not a reliability issue, it can add a modest amount to the overall cost of electricity service. The costs of this generation include the costs of keeping the generators available and ready to operate, and the fuel costs of operating them. The exact costs depend on the mix of generation on a given system and various other factors. In a document prepared by the Utility Wind Integration Group in coordination with the trade associations of all three utility sectors (investor-owned, public, and cooperative), the studies and experiences with utility wind integration are summarized as follows:


  • "Wind resources have impacts that can be managed through proper plant interconnection, integration, transmission planning, and system and market operations.
  • System operating cost increases arising from wind variability and uncertainty amounted to only about 10% or less of the wholesale value of the wind energy.
  • A variety of means — such as commercially available wind forecasting — can be employed to reduce these costs.
  • In many cases, customer payments for electricity can be decreased when wind is added to the system, because the operating-cost increases are offset by savings from displacing fossil fuel generation." http://www.renewableenergyworld.com/rea//news/article/2008/03/clearing-the-air-wind-power-and-reliability-51767 [NSan8]




Environmental impact of using wind turbines (Both +/-):


bird.jpg
bird.jpg
This image shows the effects on birds and other flying animals with the addition of windmills to their natural environments. [DBea1] http://greenairradio.com/wp-content/uploads/2008/10/bird.jpg


=

Positive:
Wind is a clean, inexhaustible, indigenous energy resource that can generate enough electricity to power millions of homes and businesses. Wind energy is one of the fastest-growing forms of electricity generation in the world. The United States can currently generate more than 25,000 megawatts (MW) of electricity from the wind, which is enough to power about 7 million average American homes. Industry experts predict that, with proper development, wind energy could provide 20% of this nation's energy needs. http://www.nrel.gov/wind/ [AFah1]


Wind energy system operations do not generate air or water emissions and do not produce hazardous waste. Nor do they deplete natural resources such as coal, oil, or gas,
or cause environmental damage through resource extraction and transportation, or require significant amounts of water during operation. Wind's pollution-free electricity can help
reduce the environmental damage caused by power generation in the U.S. and worldwide. http://www.awea.org/faq/wwt_environment.html



A wind turbine is a device for harnessing the kinetic energy of the wind and converting into mechanical energy by means of a rotor, and then the mechanical energy into electricity by means of a turbine. It is a 100% external image 2_bing.gif, renewable, and independent source of energy. //http://www.ehow.com/facts_4741237_advantages-disadvantages-wind-turbines.html//[MP17]

Wind turbines are used to generate electricity from the kinetic power of the wind. Historical they were more frequently used as a mechanical device to turn machinery. There are two main kinds of wind generators, those with a vertical axis, and those with a horizontal axis. Wind turbines can be used to generate large amounts of electricity in wind farms both onshore and offshore. The articles on this page are about wind turbines. (http://www.alternative-energy-news.info/technology/wind-power/wind-turbines/) [AFah1]


Positive.
1.Wind energy system operations do not generate air or water emissions and do not produce hazardous waste.(http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power)[FWal7)
2.Wind's pollution-free electricity can help reduce the environmental damage caused by power generation in the U.S. and worldwide.(http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power)[FWal7)
3.If wind energy were to provide 20% of the nation's electricity -- a very realistic and achievable goal with the current technology -- it could displace more than a third of the emissions from coal-fired power plants.(http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power)[FWal7)
4.Wind power is a clean, renewable form of energy, which during operation produces no carbon dioxide. While some emissions of these gases will take place during the design, manufacture, transport and erection of wind turbines, enough electricity is generated from a wind farm within a few months to totally compensate for these emissions. When wind farms are dismantled (usually after 20-25 years of operation) they leave no legacy of pollution for future generation.(http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power)[FWal7)
5.Given the scale of the CO2 cuts needed, wind power--as the least expensive, most developed renewable energy technology and the fastest to build--is the best placed renewable technology to deliver carbon emissions reductions on a large scale, quickly(http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power)[FWal7)

Wind energy is a free, renewable resource, so no matter how much is used today, there will still be the same supply in the future. Wind energy is also a source of clean, non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases. http://windeis.anl.gov/guide/basics/index.cfm [AFah1]

The largest wind turbines are designed to be self-contained power plants, outputting electricity directly to the utility grid just like large coal, hydro or nuclear power plants. In some cases, these wind machines are grouped together in ‘wind farms’ with a nearby power substation to handle the electricity pumped out by the machines. Wind power is the single fastest growing energy source worldwide, although it currently comprises a very small portion of global energy supply - 0.051% as of 2003 according to the International Energy Association, but with growth rates of over 50% per year since then. http://www.thesolarguide.com/wind-power/ [AFah1]


  1. Do not cause environmental damage through resource extraction and transportation, or require significant amounts of water during operation.http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power[ECon8]
  2. Wind energy system operations do not generate air or water emissions and do not produce hazardous waste. Nor do they deplete natural resources such as coal, oil, or gas.http://www.awea.org/faq/wwt_environment.html#What%20are%20the%20environmental%20benefits%20of%20wind%20power[ECon8]
  3. In 2000, the Harvard School of Public Health looked at the human health effects from two fossil-fuel-fired power plants in Massachusetts. It estimates that the air pollution from the plants causes:

























-Minimal harmful impacts on birds: In Denmark, the country with the most intensive use of wind energy, wind turbines generate 10% of electricity and are widespread, but have not been found to cause significant harm to wildlife including birds. Power lines pose a much greater threat to birds, according to Danish and U.S. studies. The National Audubon Society recently issued a statement in support of responsibly sited wind project development.

There was a recent discovery that wind power can even affect national security! It seems wind farms cause holes in RADAR coverage as the blades on the turbines confuse the system. Apparently they look like planes. It's so bad that they cause a large RADAR shadow behind them!



  • Wildlife: There have long been arguments that wind turbines affect migratory birds, but more recently it's been discovered that they can make bats' lungs explode!
http://ezinearticles.com/?Advantages-and-Disadvantages-of-Wind-Power&id=1494532
external image Black-Storkjuv-wind-Turb_62.jpg
external image Black-Storkjuv-wind-Turb_62.jpg
http://andalucianguides.blogspot.com/2009/10/avian-traffic-still-heads-south.html [SShafiq1]


Another advantage of wind energy is that when combined with solar electricity, this energy source is great for developed and developing countries to provide a steady, reliable supply of electricity. http://www.clean-energy-ideas.com/articles/advantages_and_disadvantages_of_wind_energy.html [ECon8]
Negative:

  1. Wind turbine construction can be very expensive and costly to surrounding wildlife during the build process.http://www.clean-energy-ideas.com/articles/advantages_and_disadvantages_of_wind_energy.html [ECon8]
  2. Protests and/or petitions usually confront any proposed wind farm development. People feel the countryside should be left in tact for everyone to enjoy it's beauty. http://www.clean-energy-ideas.com/articles/advantages_and_disadvantages_of_wind_energy.html [ECon8]

(http://www.awea.org/faq/wwt_environment.html#Will wind energy hurt tourism in my area) [BWar1]

The most noticeable impact a wind turbine places upon the environment is noise pollution. Many people think wind turbines are a great idea, yet a large proportion of these people would oppose a wind farm development close to their home. This is down to the noise, and many people compare the sound output of a wind turbine to a small jet engine. The impact of noise pollution has the potential to lower property values within a varying radius of the construction. (http://www.clean-energy-ideas.com/articles/wind_turbines_impact.html) [BWar1]


Another disadvantage regarding a wind turbine and it's impact on the surrounding environment can be expressed with the term "visual impact" or "visual pollution".Some people believe wind turbines actually look quite nice, yet many people disagree.You may enjoy the visual impact of turbines, but this does not stop the majority of people seeing turbines as a scare on the landscape. (http://www.clean-energy-ideas.com/articles/wind_turbines_impact.html) [BWar1]

1. Extensive peer reviewed scientific studies by Dr. Nina Pierpont detail the very real hazard to human health if constantly exposed to the infra-sound emanating from arrays of wind turbines.(http://www.wvmcre.org/neg_imapcts/neg_impacts.htm) [SSha1]
2. Destruction of wildlife habitats negatively impacts hunting and other recreational activities
So many acres of forest habitat are destroyed in construction of a modern wind project requiring miles of clearing and grading it could be argued that per kilowatt of energy produced, wind projects are more destructive than conventional plants requiring a much smaller footprint.(http://www.wvmcre.org/neg_imapcts/neg_impacts.htm) [SSha1]


Erosion has also been raised as a concern in the eastern U.S., where wind farms typically must be installed on mountain ridgelines. However, standard engineering practices used by ski areas on the same kind of terrain are adequate to deal with any erosion issues that might be raised by construction of a wind farm and its service road.(http://www.awea.org/faq/wwt_environment.html#Will%20using%20more%20wind%20energy%20reduce%20health%20care%20costs)[BWar1]


=

1. Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, concerns have been raised over thenoiseproduced by the rotor blades, visual impacts, and deaths of birds and bats that fly into the rotors (avian/bat mortality). [DBea1] http://windeis.anl.gov/guide/concern/index.cfm
noise impacts
2. Most of the turbine noise is masked by the sound of the wind itself, and the turbines run only when the wind blows. In recent years, engineers have made design changes to reduce the noise from wind turbines. Early model turbines are generally noisier than most new and larger models. [DBea1] http://windeis.anl.gov/guide/concern/index.cfm
Visual Impacts
3. One strategy being used to partially offset visual impacts is to site fewer turbines in any one location by using multiple locations and by using today's larger and more efficient models of wind turbines. [DBea1] http://windeis.anl.gov/guide/concern/index.cfm
Flying animal mortality
4.
Bird and bat deaths are one of the most controversial biological issues related to wind turbines. The deaths of birds and bats at wind farm sites have raised concerns by fish and wildlife agencies and conservation groups. [DBea1] http://windeis.anl.gov/guide/concern/index.cfm



Is there be any opposition to the use of wind turbines? Why? Do you agree or disagree with those views?:


1. Some say that ice build up will cause harm, but ice build up disrupts the wind turbine due to extra weight. When this extra weight is detected by the wind turbines control system, the wind turbine will shut down. (http://www.awea.org/faq/wwt_environment.html#Why%20is%20there%20sometimes%20opposition%20to%20wind%20energy%20projects) [BWar1] 2. 50,000 americans die each year from air pollution, one third of that pollution is from power plants. In the last 20 years one death was caused by a wind turbine, he was a german skydiver who parachuted off course in to a wind turbine. (http://www.awea.org/faq/wwt_environment.html#Why%20is%20there%20sometimes%20opposition%20to%20wind%20energy%20projects) [BWar1]


Local opposition to proposed wind farms usually arises because some people perceive that the development will spoil the view that they are used to.http://www.awea.org/faq/wwt_environment.html#Why%20is%20there%20sometimes%20opposition%20to%20wind%20energy%20projects [ECon8]

Disadvantages: Highly variable source; relatively low efficiency (30%); unasethetic (visual pollution); disruption of migratory birds (note this is what killed the recently proposed Columbia River Gorge wind turbine project).
http://zebu.uoregon.edu/1999/ph161/l28.html [NSan8]

1.
Why have I heard that "wind turbines kills birds?"
Mainly because there were some well publicised cases of early wind farms in California and Southern Spain where there were genuine collisions between large birds and the turbines. The industry has come a long way since then and wind farms are now far more carefully located.(http://www.yes2wind.com/faqs/aviation-and-radar-equipment/why-have-i-heard-that-%22wind-turbines-kills-birds%22)[FWal7]
The most serious environmental drawbacks to wind machines may be their negative effect on wild bird populations and the visual impact on the landscape. http://tonto.eia.doe.gov/kids/energy.cfm?page=wind_home-basics [AFah1]

The major challenge to using wind as a source of power is that it is intermittent and does not always blow when electricity is needed. Wind cannot be stored (although wind-generated electricity can be stored, if batteries are used), and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities). Finally, wind resource development may compete with other uses for the land, and those alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming. http://windeis.anl.gov/guide/basics/index.cfm [AFah1]


People tend to believe that wind turbines or windmills take away from the natural beauty or take away some of the uniqueness of certain landscapes. I would agree with the fact that the landscape may be effected visually. But I do not agree with the people who say wind energy shouldnt be used just for this sole reason. I would say that the overall well being of the world and lack of resources should outweigh the concern for ruining a landscape. [DBea1] Based on personal opinion and facts from windeis.anl.gov

Would there be any societal impacts to the use of wind turbines?

offshore wind turbines
offshore wind turbines

(http://images.google.com/imgres?imgurl=http://lacoastpost.com/blog/wp-content/uploads/2009/01/wind-turbine.jpg&imgrefurl=http://lacoastpost.com/blog/%3Fp%3D2022&usg=__QOT57nt36YZ6DBTqAEsRd6Jr7tE=&h=366&w=550&sz=44&hl=en&start=1&um=1&tbnid=7ZQyp5rjO8x_HM:&tbnh=89&tbnw=133&prev=/images%3Fq%3DWind%2BTurbines%26hl%3Den%26rlz%3D1T4ADBR_enUS325US325%26sa%3DN%26um%3D1) [BWar1]

Wind energy avoids the external or societal costs associated with conventional resources, namely, the trade
deficit from importing foreign oil and other fuels, the health and environmental costs of pollution, and the cost of
depleted resources. Wind energy is a domestic, reliable resource that provides more jobs per dollar invested than
any other energy technology - more than five times that from coal or nuclear power, according to the U.S.
Department of Energy. In 1994, wind-turbine and component manufacturers contributed directly to the economies

of 44 states, creating thousands of jobs for Americans. (http://windeis.anl.gov/documents/docs/WindFAQ21Jun05.pdf) [MBoz8]
1.
Are wind farms noisy?
In simple terms, No. It is often said that you could stand underneath an operational wind turbine and have a normal conversation without raising your voice. This is perfectly true. The best way of assessing the noise from a wind farm is to visit one for yourself. If this isn’t possible, then there are various videos available on the internet which can help.(http://www.yes2wind.com/faqs/noise/are-wind-farms-noisy)[FWal7]
2.

Do wind farms affect property values?
This isn't a question where a simple "yes" or "no" can be given; albeit that opponents to wind farms will always say "yes". They are wrong to do so! There are many factors which need to be taken into consideration, including: Proximity to the wind farm Market conditions in general Type of housing Location within the UK Differences between the different stages of the applications and construction process Local response. Potential buyers who visit a village festooned with "Say NO to the Wind Farm" or who see a "No wind farm" blimp flying in the sky are going to be made more anxious than in situations where no such visible manifestations of opposition are evident. There is a genuine possibility that the opponents themselves have artificially affected the property market.(http://yes2wind.com/faqs/property-values/do-wind-farms-affect-property-values)[FWal7]

Two main types of studies have been carried out on the impacts of wind farms on property prices: surveys of interested parties (i.e. residents, realtors and surveyors); and transaction-based studies that analyse the actual prices of properties near wind farms. 37 The picture that has emerged from the survey-based studies is not entirely clear. A number of the studies suggest that when wind farm developments are first announced, property prices may decline, probably in response to community concerns about issues like noise and landscape impacts. 38 In contrast, several other survey-based studies indicate that wind farms have no impact on property prices. 39 However, even amongst the survey-based studies that have found that wind farms may negatively affect property prices, the results indicate that the prices are likely to recover after the wind farms start operating as communities learn more about the actual impacts of wind developments. 40 For example, a study by the Royal Institution of Chartered Surveyors in the UK found that 60 per cent of surveyors who were involved in residential property transactions where wind turbines were visible from the property thought that they decreased the value of the property (Khatri 2004). However, 40 per cent believed that wind farms had no impact on property prices and the study found evidence that the ‘discount in property values ... reduces over time as buyers become aware of the specific characteristics of a development’ (Khatri 2004, p. 9). In addition, the results in relation to agricultural land were almost reversed, with 63 per cent of surveyors indicating that they thought the turbines had no impact, 28 per cent thought they had a negative impact and nine per cent thought they had a positive impact. The findings from the Royal Institution of Chartered Surveyors survey are roughly consistent with those from a Scottish study that asked residents near turbines about anticipated and actual problems associated with wind farms (Dudleston 2000). Six per cent of respondents said that they believed property prices would be a problem, but only one per cent said that wind farms had actually caused prices to fall.(https://www.tai.org.au/file.php?file=discussion_papers/DP91.pdf) [CBer7]

(http://blog.mlive.com/news/baycity_impact/2009/06/large_Thumb%20Wind%20Turbines%2006PT.JPG) [BWar1]
(
http://www.nrel.gov/gis/images/map_wind_national_lo-res.jpg) [BWar1]

Wind farm construction presents numerous challenges, but from a tourism viewpoint, it has a direct visual impact on scenic landscapes and an indirect effect on industry due to potential economic losses. Opponents to wind farms believe that constructing large, towering metal structures creates an industrialized landscape in rural and natural areas, which some people consider to be detrimental.

Landscapes are an important tourism resource, so it is unrealistic for tourism stakeholders to offer unequivocal support for wind farms. For this reason, battles to stop wind farm development around tourism attractions continue, while at the same time opinions about wind farms continue to diverge. For example, there is opposition to the recently erected wind turbine on Grouse Mountain in Vancouver and to the proposed wind farm near Mont St. Michel, a UNESCO World Heritage Area in France, even though the turbines would be situated some 15 km from it.(http://tourismintelligence.ca/2009/12/09/do-wind-farms-affect-tourism/)[CBer7]

(www.offshorewindenergy.org/ca-owee/.../Brussels01_Environment.pdf) When the turbines are being built in the sea or along a shoreline, coral reefs can be destroyed. The noise of the turbine running as well as the vibrations will be sent out in all directions, since sound is much louder underwater it may disturb fish and fauna. The vibrations may interrupt how fish and mammals perceive their surroundings, for example a dolphin uses echolocation to find prey and to detect if there is a barrier in front that it may not sea, the vibrations bounce back to the dolphin giving it that information. The vibrations from the turbine would interrupt that information and confuse (possibly disorientate) the dolphin. (this analysis being done by my own personal interpretation and facts) [CBer7]

(www.offshorewindenergy.org/ca-owee/.../Brussels01_Environment.pdf) When wind turbines are built offshore there is the chance of collision with a ship. the sea can be rough, making a boat hard to steer and control. The wind from a storm would give the turbines a lot of power, but because the sea is uncontrollable, a ship can easily be smashed into the turbine. Not only destroying the turbine, but destroying or damaging the boat and the possibility of lost life due the collision as well. [CBer7]

moz-screenshot-6.jpg
moz-screenshot-6.jpg


moz-screenshot-5.jpg
moz-screenshot-5.jpg
Each turbine is rated to produce 3.6 megawatts (MW), assuming the wind is blowing at the correct speed, so this will give a total output from the 54 turbines of 194MW. Each turbine is rated to produce 3.6 megawatts (MW), assuming the wind is blowing at the correct speed, so this will give a total output from the 54 turbines of 194MW. (http://find.galegroup.com/gic/retrieve.do?contentSet=IAC-Documents&sort=Relevance&tabID=T006&searchId=R1&docId=CJ174911213&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%24&inPS=true&searchType=&docId=CJ174911213&docType=IAC) [CKnu7]

Wind turbines capture the kinetic energy of wind with blades shaped much like airplane propellers. These blades are attached to a tower that rises at least 100 feet (30 meters) above the ground. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The best places to build the turbines are North Dakota, Texas, and Kansas, which by themselves could provide all of the electricity needed in the United States, according to a 1991 U.S. Department of Energy wind resource report. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The largest wind farm or large facilities with numerous turbines, operating in the United States is in Stateline, Oregon-Washington: 300 megawatts. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The most common type of windmill in the early twenty-first century was called the vertical-axis wind turbine, which had airplane propeller-type blades mounted at the top of a tall tower. This windmill, called the MOD-2, was designed by NASA. Each MOD-2 was mounted on a 200-foot-tall (61 meters) tower. The blades were up to 150 feet (46 meters) long. The MOD-2 could produce about 2,500 kilowatts of power in a 28-mph (45 kph) wind. Other wind turbine rotors may be larger, but their fundamental design owes much to the design of the MOD-2. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The fuel that powers wind turbines is free, so its price to utility companies does not vary. Wind power does have a number of drawbacks. Wind speed does not remain constant, so the supply of power may not always be the same as demand from consumers. Because many of the best locations for wind turbines are far from urban areas, there are problems with distributing the energy. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind-power electricity can be generated for about four to six cents per kilowatt-hour, making wind power competitive with other forms of generation of electricity. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind power can have harmful effects on the environment. Some environmentalists are concerned about soil erosion, bird safety, and noise pollution. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The most important feature in the operation of wind turbines is lift. To achieve lift, wind turbine designers have borrowed technology from aircraft designers. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]
Wind turbines come in two configurations. One, called a vertical-axis turbine, looks much like an oversized eggbeater. The axis of the turbine is positioned vertically, and the blades are connected to the axis at the top and the bottom. This configuration has one primary advantage: The turbine does not have to be faced into or away from the wind, so it operates no matter which way the wind is blowing, and it does not have to be repositioned to accommodate changes in wind direction. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

A wind turbine has the following components:



The American Wind Energy Association predicted that in 2005 as much as 2,500 megawatts of new wind power capacity could be added in the United States, bringing the total to more than 9,000 megawatts. Worldwide, as of the end of 2003, about 39,000 megawatts of wind power were being generated, producing about 90 billion kilowatt-hours of power, enough for about nine million average American homes. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind energy is safe. Although the risk exists for industrial accidents in the construction of a wind turbine, the same can be said about the construction of any facility. The risk that the public will be harmed by a wind-power facility is nearly zero. With nuclear power the risk of catastrophe is ever present, and with fossil fuel plants, the danger from fire and explosions is high. There has been only one case of a person's being killed by a wind turbine: A skydiver sailed off course and fell into the rotating blades of a turbine. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind turbines can be noisy, and engineers are working on ways to quiet the noise. The best method has been to reduce the thickness of the trailing edges of blades. Noise also has been reduced by placing turbines in an upwind rather than a downwind position. The wind hits the blades first, then the tower, rather than the other way around, eliminating the thumping sound that downwind designs make as the blade passes the wind shadow cast by the tower. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind farms require a fair amount of land, about 24 hectares (60 acres) per megawatt. However, the turbines themselves plus service roads occupy only about 1 hectare (3 acres) of the 24 hectares. Once the turbines have been built, farmers and ranchers can continue to use the land under them for traditional purposes. Land is difficult to find near larger cities. One solution to this problem is to place wind turbines in shallow waters offshore where possible. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The use of wind power benefits the environment, because this form of energy is clean and it does not consume water. It has been estimated that in 2004, existing wind power prevented the release of 10.6 million tons of carbon dioxide, 56,000 tons of sulfur dioxide, and 33,000 tons of nitrogen oxides. It also has been estimated that if only ten percent of wind potential were developed in the ten windiest U.S. states, total carbon dioxide emissions could be cut by one-third. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind power provides jobs. Every megawatt of wind power provides about 4.8 job-years of employment. Wind power also provides exports. It is estimated that by the mid-2010s, 75,000 megawatts of new wind power will be installed worldwide at a cost of $75 billion. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The Darrieus wind turbines have the advantage of working no matter what direction the wind is blowing. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Wind power can have harmful effects on the environment. Some environmentalists are concerned about soil erosion, bird safety, and noise pollution. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

Three factors determine how much energy the wind can transfer to a wind turbine: the density of the air, the area of the rotor, and the speed of the wind. (http://find.galegroup.com/gic/retrieve.do?contentSet=EBKS&sort=Relevance&tabID=T001&searchId=R2&docId=CX3451200http://regfizx.wikispaces.com/Wind+Turbines034&prodId=GIC&currentPosition=1&userGroupName=bhs&resultListType=RESULT_LIST&sgHitCountType=None&qrySerId=Locale(en%2C%2C)%3AFQE%3D(KE%2CNone%2C13)wind+turbines%3AAnd%3ALQE%3D(LU%2CNone%2C29)%22Wind+Turbines|wind+Turbines%22%24&inPS=true&searchType=&docId=CX3451200034&docType=EBKS) [CKnu7]

The way Wind Energy is generated is by the turbine and switchgear are mounted at the top of each tower in a casing called a nacelle, and blades are attached to the turbine. By transferring the wind’s momentum to the rotor blades attached to the turbine itself, it localizes that

||

energy in a single rotating shaft.(http://www.tva.gov/greenpowerswitch/wind_faq.htm)[AKar8]

While Wind turbines were being constructed more largely in the late 1800's, they were becoming more prone to wind damage itself. However, there were some windmills that had a more advanced designs in which the blades could fold up like an umbrella to prevent damage when there were high winds.( From Windmills to Hydrogen Fuel Cells: Discovering Alternative energy Author: Sally Morgan Publisher: Heinemann Library, Chicago, Illinois 2007)[AKar8]



Will the turbines interfere with radio and TV signals?

No. In fact, some turbines can even double as communications towers — for cellular phone transmitters, among other things. You see, the turbine blades are constructed not of metal, but of glass-reinforced epoxy (a material similar to fiberglass), and the turbines are equipped with asynchronous (brushless) generators that don’t create any electrical disturbance within the area. (http://www.tva.gov/greenpowerswitch/wind_faq.htm)[AKar8]

How much electricity is produced?

"The newer turbines expanded the capacity of the Buffalo Mountain site to 29 megawatts of generation, or enough to power about 3,780 homes. They are about 260 feet tall, and the blades are 135 feet long. They have a capacity of 1.8 megawatts each. The three original turbines, with a capacity of 660 kilowatts each, are 213 feet tall, and their blades are 75 feet long. Generally, the higher the tower, the better the access to the wind".(http://www.tva.gov/greenpowerswitch/wind_faq.htm)[AKar8]

"In utility-scale power applications, anywhere from one or two to several hundred turbines are connected to the utility grid, providing electricity when the wind blows."(http://www.blm.gov/wo/st/en/prog/energy/wind_energy.html)[AKara8]

"Winds are created by uneven heating of the atmosphere by the sun, irregularities of the Earth's surface, and the rotation of the Earth. As a result, winds are strongly influenced and modified by local terrain, bodies of water, weather patterns, vegetative cover, and other factors".(http://www.eia.doe.gov/cneaf/solar.renewables/page/wind/wind.html)[AKar8]
Advantages



  • Wind is free, wind farms need no fuel.
  • Produces no waste or greenhouse gases.
  • The land beneath can usually still be used for farming.
  • Wind farms can be tourist attractions.
  • A good method of supplying energy to remote areas.

(http://www.darvill.clara.net/altenerg/wind.htm)[AKar8]
Disadvantages

  • The wind is not always predictable - some days have no wind.
  • Suitable areas for wind farms are often near the coast, where land is expensive.
  • Some people feel that covering the landscape with these towers is unsightly.
  • Can kill birds - migrating flocks tend to like strong winds.
    However, this is rare, and we tend not to build wind farms on migratory routes anyway.
  • Can affect television reception if you live nearby.
  • Can be noisy. Wind generators have a reputation for making a constant, low, "swooshing" noise day and night, which can drive you nuts.
    Having said that, as aerodynamic designs have improved modern wind farms are much quieter. A lot quieter than, say, a fossil fuel power station; and wind farms tend not to be close to residential areas anyway. The small modern wind generators used on boats and caravans make hardly any sound at all.(http://www.darvill.clara.net/altenerg/wind.htm)[AKar8]

Small and Large Wind Systems

"Small wind turbines are quite different from their larger cousins, each playing an important role to meet various energy demands".
"Small scale wind turbines (also know as home or residential wind turbines) can either be connected to the utility grid or stand-alone as an "off-grid" application, normally providing electrical power for home, farm, school, or business applications. Small scale wind machines can have blade length between 3ft-30ft, with a 100ft tower, and can power between 1/4 to 6 average American homes (and even more if they are energy conscious). Small wind turbines require average annual wind speeds of at least according to the American Wind Energy Association, the US is the world leader in small-scale wind energy manufacturing markets". ( http://www.wind.appstate.edu/windturbines/windturbines.php)[AKar8]
"Large scale wind turbines (also know as utility wind turbines) are normally tied directly into the utility grid and are used to provide electrical power for entire communities and municipalities. Each of these large, "utility-scale," wind turbines can have blade lengths up to 150ft and sit on a 200ft tower, and produce enough electricity for 500-600 average homes per year".(http://www.wind.appstate.edu/windturbines/windturbines.php)[AKar8]

external image fanmill.jpg
Figure 5. A steel-bladed water pumping windmill in the American Midwest (late 1800's)
http://www.telosnet.com/wind/early.html
[SSha1]




Types of Wind Machines
"Two types of wind machines are commonly used today":






  • "horizontal, which has blades like airplane propellers; and
  • vertical, which looks like an egg-beater."
"Horizontal-axis wind machines are used the most. They make up 95 percent of all wind machines. A typical horizontal wind machine stands as tall as a 10-story building and has two or three blades that span 60 feet across. The largest wind machines in the world have blades longer than a football field! Wind machines stand tall and wide to capture more wind."
"Vertical-axis wind machines make up just five percent of the wind machines used today. The typical vertical wind machine stands 100 feet tall and 50 feet wide. The most popular vertical wind machine today is the Darrieus wind turbine, named after its inventor, J.G.S. Darrieus, a French engineer."(http://lsa.colorado.edu/summarystreet/texts/wind.ht)[AKar8]


Wind Resources and Energy Production
"Where is the best place to build a wind plant? There are many good sites for wind plants in the United States including California, Alaska, Hawaii, the Great Plains, and mountainous regions. Scientists say there is enough wind in 37 states to produce electricity from the wind. Generally, an average wind speed of 14 mph is needed to convert wind energy into electricity economically. The average wind speed in the United States is 10 mph."( http://lsa.colorado.edu/summarystreet/texts/wind.htm)[AKar8]

Wind Energy Production
"How much energy can we can get from the wind? We will use two terms to describe wind energy production: efficiency and capacity factor".
"Efficiency refers to how much useful energy (electricity, for example) we can get from an energy source. A 100 percent energy efficient machine would change all the energy put into the machine into useful energy. It would not waste any energy. (You should know there is no such thing as a 100 percent energy efficient machine. Some energy is always "lost" or wasted when one form of energy is converted to another. The "lost" energy is usually in the form of heat.)"
"How efficient are wind machines? Wind machines are just as efficient as coal plants. Wind plants convert 30 percent of the wind's kinetic energy into electricity. A coal-fired power plant converts about 30-35 percent of the heat energy in coal into electricity."
"It is the capacity factor of wind plants that puts them a step behind other power plants. Capacity factor refers to the capability of a plant to produce energy. A plant with a 100 percent capacity rating would run all day, every day at full power. There would be no down time for repairs or refueling, an impossible dream for any plant."( http://lsa.colorado.edu/summarystreet/texts/wind.htm)[AKar8]

"With a cost of energy of approximately 3.5 to 4 cents per kilowatt hour and declining, wind is a low-cost renewable energy source that is less expensive than coal, oil, nuclear and most natural gas-fired generation, and is becoming attractive to utilities and electric cooperatives".( http://www.gepower.com/businesses/ge_wind_energy/en/about_wind_ener.htm)[AKar8]

Using wind energy around the world

"Worldwide development of wind energy expanded rapidly starting in the early 1990s. In 1999, over $3.5B was invested in farms that use wind energy. Most of the investment was spent in Europe where conventional electricity costs are higher and where political motivation to reduce greenhouse gas pollution is greater. At the end of April 1999, 10,000 megawatts of wind-generated electricity produced some 22.5 TWh of electricity. That is sufficient electricity for all the industrial, commercial and domestic electrical requirements of about two cities the size of Madrid, Spain – a total of about 8 million people" . (http://www.daviddarling.info/encyclopedia/W/AE_wind_energy.html)[AKar8]

Early in the twentieth century, windmills were commonly used across the Great Plains to pump water and to generate electricity. New ways of using the energy of the wind eventually spread around the world. By the 11th century, people in the Middle East w ere using windmills extensively for food production; returning merchants and crusaders carried this idea back to Europe. The Dutch refined the windmill and adapted it for draining lakes and marshes in the Rhine River Delta. When settlers took this technology to the New World in the late 19th century, they began using windmills to pump water for farms and ranches, and later, to generate electricity for homes and industry.(//http://www.daviddarling.info/encyclopedia/W/AE_wind_energy.html)[AKar8]

The impact of wind farms on landscape and heritage values When poorly sited, wind farms can have an adverse impact on landscape and heritage values. However, if appropriate planning procedures are followed, the risks to landscape and heritage values should be minimal. Also, any concerns about aesthetics should be considered in the context of climate change and broader community attitudes toward renewable energy. (https://www.tai.org.au/file.php?file=discussion_papers/DP91.pdf) [CBer7]



Supply and Transport Issues

"The major challenge to using wind as a source of power is that it is intermittent and does not always blow when electricity is needed. Wind cannot be stored (although wind-generated electricity can be stored, if batteries are used), and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities). Finally, wind resource development may compete with other uses for the land, and those alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming".( http://windeis.anl.gov/guide/basics/index.cfm)[AKar8]

Wind Turbine Size and Power Ratings

"Wind turbines are available in a variety of sizes, and therefore power ratings. The largest machine has blades that span more than the length of a football field, stands 20 building stories high, and produces enough electricity to power 1,400 homes. A small home-sized wind machine has rotors between 8 and 25 feet in diameter and stands upwards of 30 feet and can supply the power needs of an all-electric home or small business. Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts, are used for homes, telecommunications dishes, or water pumping."(http://windeis.anl.gov/guide/basics/index.cfm)[AKar8]


Lustig's reasearch (no particular order) (for images, see links)
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Wind Turbine Diagram." Wind Energy EIS Public Information Center. N.p., n.d. Web. 10 Jan. 2010. <http://windeis.anl.gov/guide/basics/turbine.html>. (dlus8)
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"Wind Energy Photo." Wind Energy EIS Public Information Center. N.p., n.d. Web. 10 Jan. 2010. <http://windeis.anl.gov/guide/photos/photo4.html>. (dlus8)

The British start-up Quietrevolution developed a vertical axis wind turbine which is not only more aesthetic but is also better at gathering wind near and around buildings, which frequently vary in direction. The Helical wind turbine is also quieter because the blade tip speed is lower.


The quietrevolution wind turbines will come in three sizes, the first of which is the QR5 which stands 5m high by 3.1m in diameter. Two other sizes are under development: the QR2.5 (2.5m x 2.5m) and the QR12 (12m x 6m). The turbine will be mounted on a tall mast normally 3m, 6m, 9m or 15m tall. The cost of the turbine varies but is estimated at around 60,000 dollars including installation.
According to quietrevolution the QR5 will generate around 10,000 kWh per year in a site with an average wind of 5.9m/s. This is equivalent to about five low-energy houses’ electricity demand, or the electrical needs of a twenty man office. Unlike other turbines which are usually noisy the unique shape of the quietrevolution turbine allows it to operate in near silent which is ideal for operating close to residential areas. The distinctive helical shape of the turbine is also eye pleasing which is impotent since many communities rejected wind turbines because of their visual impact.
As energy problems increase and the danger of global warming becomes more and more apparent, alternative energy resources gain momentum. Wind, one of the most important alternative energy sources has been used on a small scale for decades. Recently, companies from around the world have been working on creating large scale wind farms. One example is the plan to build three hundred forty-one gigantic turbines near the __Thames Estuary__ off the south-east coast of England, Costing almost $3 billion, and producing up to one gigawatt (GW) of power (approximately 25% of London's domestic use).


Genuth, Iddo. "Quietrevolution Helical Wind Turbine." TFOT - The Future Of Things. The Future Of Things, 31 Jan. 2007. Web. 10 Jan. 2010. <http://thefutureofthings.com/pod/163/quietrevolution-helical-wind-turbine.html>. (dlus8)

That's a problem because wind turbines are expected to operate for 20 years. Early equipment fatigue, especially in turbine gearboxes, threatens to reduce performance and drive up wind power costs just as the industry is poised to capture a greater share of U.S. generating capacity.
Improving their reliability is key to generating a consistently competitive power source – and a healthy return on investment. Both are needed if wind power is to meet 20 percent of the nation's electricity needs by 2030, a scenario a U.S. Department of Energy report issued last year says is possible.

"The end users and the owner-operators say we're only getting five years, or in some cases, three years out of these gearboxes," said NREL principal engineer Sandy Butterfield, who is leading the cooperative study.

Verrengia, Joseph B.. "NREL Gearbox Study Aims to Grease Wind Power's Future." Machinery Lubrication Magazine Home. National Renewable Energy Laboratory, n.d. Web. 10 Jan. 2010. <http://www.machinerylubrication.com/Read/2056/gearbox-grease-wind>. (dlus8)

They ask us to install the wind turbines within already sited structures. Alexandros Washburn, who is the New York’s chief urban designer and a judge for the Next Generation competition, shares his opinion, “The genius of the proposal is that it solved probably the biggest issue of wind production, which is where to locate these very large structures. By incorporating them into transmission towers, which are already located and of the same scale as wind towers, the idea of how it looks on the landscape is very cleverly integrated.”
Another problem that wind farms face is how to transmit the power generated by wind? Wind-it proposal is so simple and practical that we often wonder that why this project has already been not implemented. Wind-it solves the problem of linking energy generation and electricity transmission in the same way–by co-locating them.
By using this new idea, we can pump wind energy right into the grid. We don’t have to create an extensive infrastructure and save the money. Statistics suggest if a third of France’s towers were installed with turbines, they could crank out as much as two nuclear reactors — about 5% of the country’s power needs. This figure might not sound impressive but it will generate a steady stream of clean energy by investing less amount of money.
"Using Existing Infrastructure for Wind Turbines." Alternative Energy. Convera Inc., 26 May 2009. Web. 10 Jan. 2010. <http://energy.converanet.com>. (dlus8)

On and off the grid
As the speed of the wind changes, so too does the electrical output from a wind turbine. For off-grid turbines, supplying power to a home or cabin, batteries are needed to store power and smooth out fluctuations in the power supply. But if a wind turbine or wind farm is part of the power grid, with dozens of power plants and millions of power-consuming appliances, these fluctuations are typically not noticeable. Wisconsin's use of wind power would have to increase over 100 times for these fluctuations to become a problem in the electrical supply.
Capacity factor
The productivity of a wind turbine, or any kind of power plant, is referred to as the capacity factor. The capacity factor is the amount of power produced in a given time period compared to what the generator could produce if it ran at full capacity for that time period. If a generator ran full out all the time, it would have a capacity factor of 100 percent, but no power plant runs all the time. In a good location, a wind turbine may produce on average a third of the maximum power of the generator, or have a 33 percent capacity factor. Typical capacity factors are 20 to 25 percent.
Is it windy enough?
Although the potential for wind power in Wisconsin is not as great as in other states, there are some places windy enough, especially in the eastern part of the state. As the technology improves, less windy areas may become viable. Wisconsin's 35 large wind turbines already in place produce enough power for 7,000 homes. Another 30 turbines are planned, and more could be built over the coming years.
On and off the grid
As the speed of the wind changes, so too does the electrical output from a wind turbine. For off-grid turbines, supplying power to a home or cabin, batteries are needed to store power and smooth out fluctuations in the power supply. But if a wind turbine or wind farm is part of the power grid, with dozens of power plants and millions of power-consuming appliances, these fluctuations are typically not noticeable. Wisconsin's use of wind power would have to increase over 100 times for these fluctuations to become a problem in the electrical supply.
Capacity factor
The productivity of a wind turbine, or any kind of power plant, is referred to as the capacity factor. The capacity factor is the amount of power produced in a given time period compared to what the generator could produce if it ran at full capacity for that time period. If a generator ran full out all the time, it would have a capacity factor of 100 percent, but no power plant runs all the time. In a good location, a wind turbine may produce on average a third of the maximum power of the generator, or have a 33 percent capacity factor. Typical capacity factors are 20 to 25 percent.
Is it windy enough?
Although the potential for wind power in Wisconsin is not as great as in other states, there are some places windy enough, especially in the eastern part of the state. As the technology improves, less windy areas may become viable. Wisconsin's 35 large wind turbines already in place produce enough power for 7,000 homes. Another 30 turbines are planned, and more could be built over the coming years.
Can We Rely on the Wind?
Wind energy is often criticised for being unreliable. Critics claim that wind energy can never replace existing power stations, or remove the need for new power stations to be built, because the wind cannot be relied upon. In technical terms this argument boils down to the question; 'can wind energy be regarded as having a capacity credit?'
Wind energy can be relied upon, even though the wind is not available 100% of the time. Wind turbines generate electricity for 70-85% of the time, but not always at full output. Most wind turbines start generating power at wind speeds of around 3 or 4 m/s (when the output is a few kilowatts), generate maximum ("rated") power at around 15 m/s and shut down to prevent storm damage at 25 m/s or above. The proportion of time that wind turbine is generating between these wind speeds depends on the average wind speed at the site. Most sites where wind turbines are installed in the UK have wind speeds in the range 7.5 - 9 m/s and so generate for 70-85% of the time.
" The Reliability of Windpower ." Energy Center of Wisconsin: Accelerating Energy Efficiency. N.p., n.d. Web. 11 Jan. 2010. <http://www.ecw.org/windpower/web/cat2b.html>. (dlus8)

No energy technology can be relied upon 100% of the time.
The concept of load factor deals with the day to day productivity of electricity generating plant. Different energy technologies have different load factors, no individual power plants is always available to supply electricity. All power stations are unavailable at certain times, whether for routine maintenance or for unexpected reasons.
The load factor of an energy technology is the ratio (expressed as a percentage) of the net amount of electricity generated by a power plant to the net amount which it could have generated if it were operating at its net output capacity.
Wind farms can be treated statistically in exactly the same way as conventional power plant. For any type of power plant it is possible to calculate the probability of it not being able to supply the expected load. As wind is variable, the probability that it will not be available at any particular time is higher. Wind energy has a lower load factor than many other technologies, as shown in the table, but this is compared to the maximum power the turbine can give out, not it's average.


Energy Technology
Load factor
Sewage Gas
90%
Farmyard Waste
90%
Energy Crops
85%
Landfill Gas
70-90%
Combined Cycle Gas Turbine (CCGT)
70-85%
Waste Combustion
60-90%
Coal
65-85%
Nuclear Power
65-85%
Hydro
30-50%
Wind Energy
25-40%
Wave Power
25%

The load factor of wind varies according to the site and the type of turbine, but it is generally around 30%. It is higher during the winter than the summer. An average windfarm with an installed capacity of say 5 MW will produce an output of 13,140 MWhours/year, i.e. 30% of what it would produce if it were operating continually at maximum output.
"BWEA - Can we rely on the wind?." BWEA: Delivering UK wind, wave and tidal energy. BWEA, n.d. Web. 11 Jan. 2010. <http://www.bwea.com/energy/rely.html>. (dlus8)



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Classical modern 3-blades wind turbine
  • Horizontal axis
  • Number of blades : 3
Examples of wind turbines : __Enercon E66/2000__, __Gamesa G80/2000__, __Nordex N90/2300__
Picture : Michaël Pierrot - All rights reserved
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Classical modern 2-blades wind turbine
  • Horizontal axis
  • Number of blades : 2
Examples of wind turbines : __Vergnet GEV MP 275__, __Vergnet GEV HP__, __Vergnet GEV 26/200__
Picture : Vergnet - All rights reserved
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Single blade wind turbine
  • Horizontal axis
  • Number of blades : 1
Picture : www.hvirvelvinden.dk - All rights reserved
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Pumping wind turbine
  • Horizontal axis
  • Number of blades : ~ 20
Picture : Michaël Pierrot - All rights reserved
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Savonius wind turbine
  • Vertical axis
  • Number of blades : 2
Picture : Wikimedia Commons - Attribution ShareAlike 2.0
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Darrieus wind turbine
  • Vertical axis
  • Number of blades : 2-3
Picture : Michaël Pierrot - All rights reserved
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Helical wind turbine
  • Vertical axis
  • Number of blades : 3
Examples of wind turbines : __Quiet Revolution Qr5__
Picture : Quiet Revolution - All rights reserved
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Vertical rotor wind turbine
  • Vertical axis
  • Number of blades : 2-3
Examples of wind turbines : __Ropatec Double Vertical__, __Ropatec Twister__, __Ropatec Bora Extreme__
Picture : Ropatec - All rights reserved
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Windside wind turbine
  • Vertical axis
  • Number of blades : 2
Examples of wind turbines : __Windside WS-12__, __Windside WS-2B__, __Windside WS-0,15 C/B__
Picture : Windside - All rights reserved
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Horizontal Darrieus wind turbine
  • Transverse horizontal axis
  • Number of blades : 6
Picture : www.twanetwerk.nl - All rights reserved
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Aerofoil wind turbine
  • Vertical axis
  • Number of blades : ~ 10
Picture : Gilbert Gal, Marc Ménager - All rights reserved

"The different types of wind turbines." Eoliennes et parcs éoliens. N.p., n.d. Web. 11 Jan. 2010. <http://www.thewindpower.net/33-wind-turbines-type.php>. (dlus8)


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Reysa, Gary. "Wind Power Generators -- Windmills." BuildItSolar: Solar energy projects for Do It Yourselfers to save money and reduce pollution. N.p., n.d. Web. 11 Jan. 2010. <http://www.builditsolar.com/Projects/Wind/wind.htm>. (dlus8)


Ancient mariners used sails to capture the wind and explore the world. Farmers once used windmills to grind their grains and pump water. Today, more and more people are using wind turbines to wring electricity from the breeze. Over the past decade, wind turbine use has increased at more than 25 percent a year. Still, it only provides a small fraction of the world's energy.
Most wind energy comes from turbines that can be as tall as a 20-story building and have three 200-foot-long (60-meter-long) blades. These contraptions look like giant airplane propellers on a stick. The wind spins the blades, which turn a shaft connected to a generator that produces electricity. Other turbines work the same way, but the turbine is on a vertical axis and the blades look like a giant egg beater.
The biggest wind turbines generate enough electricity to supply about 600 U.S. homes. Wind farms have tens and sometimes hundreds of these turbines lined up together in particularly windy spots, like along a ridge. Smaller turbines erected in a backyard can produce enough electricity for a single home or small business.
Wind is a clean source of renewable energy that produces no air or water pollution. And since the wind is free, operational costs are nearly zero once a turbine is erected. Mass production and technology advances are making turbines cheaper, and many governments offer tax incentives to spur wind-energy development.
Nevertheless, the wind energy industry is booming. Globally, generation more than quadrupled between 2000 and 2006. At the end of last year, global capacity was more than 70,000 megawatts. In the energy-hungry United States, a single megawatt is enough electricity to power about 250 homes. Germany has the most installed wind energy capacity, followed by Spain, the United States, India, and Denmark. Development is also fast growing in France and China.
"Wind Power Information, Wind Power Facts - National Geographic." Environment Facts, Environment Science, Global Warming, Natural Disasters, Ecosystems, Green Living - National Geographic. National Geographic Society, n.d. Web. 11 Jan. 2010. <http://environment.nationalgeographic.com/environment/global-warming/wind-power-profile.html>. (dlus8)

In what states is there significant wind power development? Are there any utility-scale wind turbines in my state?
California is the state in which most wind power development has occurred up to now. As of the end of 2004, the Golden State had a total of 2,096 MW of wind generating capacity, with Texas ranking second at 1,293 MW. Other states with sizable wind plants include Colorado, Iowa, Kansas, Minnesota, Nebraska, New Mexico, New York, North Dakota, Oklahoma, Oregon, Pennsylvania, South Dakota, Washington, West Virginia, Wisconsin, and Wyoming.
Wind plants are now operating in many regions of the country. For state-by-state totals of installed wind capacity, as well as information on wind projects in individual states, visit the AWEA Web site at __http://www.awea.org__ and click on Wind Projects.
(One megawatt of wind capacity is enough to supply 240 to 300 average American homes. Thus, the 2,096 MW installed in California is enough to supply 500,000 to 620,000 average households.)
" Wind Industry Statistics." American Wind Energy Association. AMERICAN WIND ENERGY ASSOCIATION, n.d. Web. 11 Jan. 2010. <http://www.awea.org/faq/wwt_statistics.html>. (dlus8)

GE is one of the world's leading wind turbine suppliers. With over 10,000 worldwide wind turbine installations comprising more than 15,000 MW of capacity, our knowledge and expertise spans more than two decades.
With wind manufacturing and assembly facilities in Germany, Spain, China, Canada and the United States, our current product portfolio includes wind turbines with rated capacities ranging from 1.5 to 3.6 megawatts and support services ranging from development assistance to operation and maintenance.
"GE Energy - Wind Energy at GE." GE Energy. General Electric Company, n.d. Web. 11 Jan. 2010. <http://www.gepower.com/businesses/ge_wind_energy/en/index.htm>. (dlus8)

"I didn't really expect them to come all the way out here in northern Iowa to start a wind farm. But this is really great. Now we grow corn on the ground and generate power in the air—all on the same piece of property."
—Delbert Watson, farmer near Clear Lake, Iowa, quoted in the Christian Science Monitor
DOE projects meant to achieve this goal will provide $60 billion in capital investment to rural America, $1.2 billion in new income to farmers and rural landowners, and 80,000 new jobs during the next 20 years.
Until recently, wind power was concentrated in California. Now it can be found in most states. Farming regions in the Midwest, Great Plains, and West have emerged as major growth areas. Wind power is growing partly as a result of technology improvements and cost reductions and partly in response to state and federal laws and incentives.
"Farming the Wind: Wind Power and Agriculture | Union of Concerned Scientists." Homepage | Union of Concerned Scientists. Union of Concerned Scientists, n.d. Web. 11 Jan. 2010. <http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/farming-the-wind-wind-power.html>. (dlus8)

Rooftop Wind Farm Planned for Massive Chicago Office Tower
March 31, 2008 - Architectural firm Adrian Smith + Gordon Gill, best known for designing Chicago's 108-story Sears Tower, is planning a 2 million square foot, wind- and solar-powered office complex for the Windy City. The Clean Technology Tower, designed according to the principles of biomimicry, will maximize energy efficiency by harnessing the power of its natural environment.
A series of wind turbines will be positioned at the corners of the tower, increasing in density toward the top of the building where wind speeds are highest. Turbines conduct fast-moving air into domed roof, which houses a wind farm for generating electricity. The dome itself will by topped by solar panels.
The Clean Technology Tower will feature more than 1.8 million square feet of office space, plus a 300,000 square foot hotel, a spa, and street-level retail area. Office space will be located on the higher floors to take advantage of the direct natural daylight.
"Rooftop Wind Farm Planned for Massive Chicago Office Tower | Sustainable Life Media." Sustainable Life Media | Smart. Sustainable. Business.. Sustainable Life Media, n.d. Web. 11 Jan. 2010. <http://www.sustainablelifemedia.com/content/story/design/rooftop_wind_farm_planned_for_massive_chicago_office_tower>. (dlus8)

Chicago is home to a regional office of Pepsico, and it recently located in a new building at 555 West Monroe Street. One of the features of the building is a public park on the podium's roof. Most impressive, is the rooftop wind and solar energy farm. Here's a video showing the turbines and panels. The farm and the green roof are two of the contributing factors that helped this building attain its LEED status. And for as long as the roof remains a public amenity, we're happy to have Pepsico in the neighborhood. Most people don't know it exists. You enter through a dedicated elevator from an anonymous foyer on Monroe Street. Once upstairs, there are some patches of grass, a few plantings, and lots of tables and chairs for a picnic.
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"The Chicago Architecture Blog: Pepsi's Chicago Wind Farm." The Chicago Architecture Blog. N.p., 31 July 2009. Web. 11 Jan. 2010. <http://blog.chicagoarchitecture.info/2009/07/pepsis-chicago-wind-farm.html>. (dlus8)

Denmark-based Vestas, the world’s biggest maker of wind turbines, this week announced plans to axe 1,900 jobs despite a 70% increase in profit.
Net profits for the first three months of 2009 were €56 million, up from €33 million in the first quarter of 2008.
However, Vestas said it needs to cut jobs in northern Europe because demand for wind turbines is slacking off in the recession.
Around 600 of the job cuts will be in the UK, whilst the other jobs axed will mainly be in Denmark.
Vestas’s turbine plant on the Isle of Wight, which employs 450 people on the island, will be shut down completely.
The company said commitments by European governments, including Germany in the UK, to increase renewable energy output has not yet translated into a rise in demand for wind turbines.
One day after announcing the job cuts, Vestas reported a successful share issue of 18.5 million shares, raising €800 million.
Masters, David. " Vesta axes 1,900 wind turbine jobs ." Fair Home: Fairtrade, Recycling, Environment and Green issues. Fair Home, 30 Apr. 2009. Web. 11 Jan. 2010. <http://www.fairhome.co.uk/2009/04/30/wind-turbine-maker-axes-1900-jobs-despite-increased-profit/>. (dlus8)

"Wind is positioned to help take a lot of those manufacturing jobs that have been lost, especially in the auto industry, and move them into the work we're trying to do," said Roby Roberts, a senior vice president with Vestas, the world's largest wind turbine maker, which produced about one-fifth of U.S. wind turbines.
Vestas has made none of its turbines in the United States. But Roberts said that by 2010, it plans to make all of them here, using four factories in Colorado — one completed last year and three expected to be producing by early 2010.
According to the U.S. International Trade Commission:
  • The number of companies assembling nacelles (the big box that sits on the tower containing the gear box and generator) went from one in 2004 — GE Wind — to five in 2008 — Clipper Windpower of Carpinteria, Calif.; Acciona and Gamesa of Spain, and the Composite Technology Corp. subsidiary DeWind of Irvine, Calif. Five other foreign firms plan to build U.S. plants.
  • At least 11 blade manufacturers and 16 tower manufacturers have plants or plan to open plants in the United States.
  • The new plants announced in the first three quarters of 2008 could add 4,000 jobs, at wages generally between $13 and $20 per hour.
  • Imports leveled off from $2.4 billion in 2007 to $2.5 billion in 2008. That could indicate more U.S. production taking up some of the demand at a time when wind energy grew dramatically. That's not entirely clear from import data, however, because turbines don't always arrive in the same year they're installed.
Schoof, Renee. "Wind turbine imports increase; Can U.S. factories catch up? | McClatchy." McClatchy | Homepage. McClatchy Newspapers, 10 Apr. 2009. Web. 11 Jan. 2010. <http://www.mcclatchydc.com/260/story/65903.html>. (dlus8)