McNamara.Hutchinson

=Wind Power =

What is the problem at hand?
 Global warming is now almost universally accepted. It is a serious problem caused by human activity, mainly burning fossil fuels. It demands strong remedial action as soon as possible. The world has become extremely dependent upon using natural resources and we are using natural resources in a non-responsible manor. The United States alone is to blame for around 25% of the world’s pollution. Scientists have been working to create new more efficient means of producing energy that is renewable and has minimal harmful emissions. An ideal answer to the problem is wind power.



Causes of global warming
 Scientists have determined that a number of human activities are contributing to global warming by adding excessive amounts of greenhouse gasses to the atmosphere. Greenhouse gasses such as carbon dioxide accumulate in the atmosphere and trap heat that normally would exit into outer space. While many greenhouse gases occur naturally and are needed to create the greenhouse effect that keeps the Earth warm enough to support life, human use of fossil fuels is the main source of excess greenhouse gases. By driving cars, using electricity from coal-fired power plants, or heating our homes with oil or natural gas, we release carbon dioxide and other heat-trapping gases into the atmosphere. Deforestation is another significant source of greenhouse gases, because fewer trees mean less carbon dioxide conversion to oxygen. During the 150 years of the industrial age, the atmospheric concentration of carbon dioxide has increased by 31 percent. Over the same period, the level of atmospheric methane has risen by 151 percent, mostly from agricultural activities such as raising cattle and growing rice.



 The Consequences of Global Warming
There are also a number of effects to the nature and atmosphere. One of the most serious effects of Global Warming that humans have to think about is the effect on the health of individuals, nations and therefore civilizations. The rise in temperature due to Global Warming is known to be supportive to various viral diseases like the West Nile virus and malaria. This will result in economic as well as health effects on human beings. For example, Global Warming will increase the incidence of such diseases in poorer countries where these diseases exist. Global Warming will also cause countries that have eradicated these diseases to spend more on vaccinations and other ways of eradication like pesticides, etc.  Other than these effects, Global Warming has other effects on the health of human beings. Global Warming results in a drastic rise in temperature. This rise in temperature will finally result in an increase in the mortality rate of people. A higher temperature causes problems to people with cardiovascular problems. In extreme cases, people are known to have died of heatstroke. People may also have heat exhaustion problems. Respiratory problems are also known to arise out of a high temperature. High temperature also causes the concentration of ozone in the lower atmosphere. Ozone is a harmful pollutant and causes respiratory problems Ozone is also known to damage lung tissues and therefore cause more complications for people with asthma. These are some of the health effects of Global Warming. 

Options for Alternative Energy
Humans have traditionally used fossil fuels to provide most of our energy needs. These fossil fuels, like gasoline and coal, have some significant disadvantages. First, the world's supply of these nonrenewable resources is diminishing. Second, the prices continue to skyrocket, making it unaffordable for many people. Third, fossil fuels are damaging to the environment. Due to these three reasons, we are beginning to look at alternative energy sources. We really need to look carefully at these sources. Fossil fuels will not be around forever, and we are currently using them as if we have an unlimited supply. This supply, if we continue as we are today, will be gone. Fortunately, there are other options out there, and many of them do not have the same concerns that fossil fuels have, as these alternative sources are environmentally friendly, renewable, and more affordable in some cases. There are a number of advantages to exploring alternative energy sources. One advantage is that many alternative energy sources reduce greenhouse gases and pollutants, which not only lead to us being unhealthier but also contribute to global warming. Usingalternative energy sources reduce the amount of toxins in the air. They also help us preserve the natural resources.

[[image:wind_tower.jpg width="450" height="300" align="right"]]Wind Power Introduction
<span style="font-family: Arial,Helvetica,sans-serif;">Wind is a natural energy source. When the wind blows, the blades of the turbine rotate. The rotation is then converted into an electrical current through the use <span style="font-family: Arial,Helvetica,sans-serif;">of an electrical generator. These wind turbines are usually built on wind farms. Electrical currents today are harnessed by large wind farms that are used by national electrical grids. They are also used on a smaller scale for providing electricity to smaller homes or locations. <span style="font-family: Arial,Helvetica,sans-serif;"> There are a number of advantages to using wind power. First, it produces no pollution. This means there are no harmful by-products and our environment stays healthy. Secondly, wind energy is a renewable source, so we will never run out of wind. Third, wind turbines can be placed on farms in which livestock are raised. Finally, wind farms can also be built offshore. Clearly, wind power has some advantages. <span style="font-family: Arial,Helvetica,sans-serif;"> As with any energy source, there are some concerns as well. Once concern is that wind power is not constant. Some days are windier than others. On some days, there is little to no wind. In order for this energy source to be more reliable, it needs to be more consistent so that electricity is being produced all the time. Another concern is that some people believe that the wind turbines are ugly and they do not want them around. Those are just a few concerns about wind power.

<span style="font-family: Arial,Helvetica,sans-serif;">History of Wind Power
<span style="font-family: Arial,Helvetica,sans-serif;">Humans have been using wind power for at least 5,500 years to propel sailboats and sailing ships. Windmills have been used for irrigation pumping and for milling grain since the 7th century AD in what is now the Middle East. In the United States, the development of the water pumping windmill was the major factor in allowing the farming and ranching of vast areas otherwise devoid of readily accessible water. Wind-pumps contributed to the expansion of rail transport systems throughout the world, by pumping water from water wells for the steam engines. The multi-bladed wind turbine atop a lattice tower made of wood or steel was, for many years, a fixture of the landscape throughout rural America. When fitted with generators and battery banks, small wind machines provided electricity to isolated farms. In July 1887, a Scottish academic, James Boyth, undertook wind power experiments that culminated in a UK patent in 1891. In the United States, Charles F. Bunker 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 Colr constructed wind turbines to generate electricity, which was then used to produce hydrogen. These were the first of what was to become the modern form of wind turbine. Small wind turbines for lighting of isolated rural buildings were widespread in the first part of the 20th century. Larger units intended for connection to a distribution network were tried at several locations including Balalaika USSR in 1931 and in a 1.25 megawatt experimental unit in Vermont in 1941. The modern wind power industry began in 1979 with the serial production of wind turbines by Danish manufacturers Kuriant, Vestas, Nordtank, and Bonus. These early turbines were small by today's standards, with capacities of 20–30 kilo watt each. Since then, they have increased greatly in size, with the Enercon E-126 capable of delivering up to 7 megawatt, while wind turbine production has expanded to many countries.

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<span style="font-family: Arial,Helvetica,sans-serif;">What Causes Wind
<span style="font-family: Arial,Helvetica,sans-serif;">Wind is caused by air flowing from high pressure to low pressure. Since the Earth is rotating, however, the air does not flow directly from high to low pressure, but it is deflected to the right so that the wind flows mostly around the high and low pressure areas.This effect of the wind "feeling the Earth turn underneath it" is important for very large and long-lived pressure systems. For small, short-lived systems, such as in the cold outflow of a thunderstorm the wind will flow directly from high pressure to low pressure.The closer the high and low-pressure areas are together, the stronger the "pressure gradient", and the stronger the winds. On weather maps, lines of constant pressure are drawn as in the example, above which are called "isobars". These isobars are usually labeled with their pressure value in milli-bars. The closer these lines are together, the stronger the wind.The curvature of the isobars is also important to the wind speed. Given the same pressure gradient (isobar spacing), if the isobars are curved around the high pressure in the above example the wind will be stronger. If the isobars are curved cyclonically (around the low pressure in the example above) the wind will be weaker.Near the surface of the Earth, friction from the ground slows the wind down. During the day, when convective mixing is stirring up the lower atmosphere, this effect is minimized. At night, however, when convective mixing has stopped, the surface wind can slow considerably, or even stop altogether.Wind can be thought of one way that the atmosphere moves excess heat around. Directly or indirectly, wind forms for the primary purpose of helping to transport excess heat either away from the surface of the Earth, where sunlight causes excess energy buildup, or from warm regions (usually the tropics) to cooler regions, usually the higher latitudes.



<span style="font-family: Arial,Helvetica,sans-serif;">Wind Speed
<span style="font-family: Arial,Helvetica,sans-serif;">The strength of wind varies, and an average value for a given location does not alone indicate the amount of energy a wind turbine could produce there. To assess the frequency of wind speeds at a particular location, a probability distribution function is often fit to the observed data. Different locations will have different wind speed distributions. The Weibull model closely mirrors the actual distribution of hourly wind speeds at many locations. The Weibull factor is often close to 2 and therefore a Rayleigh distribution can be used as a less accurate, but simpler model.Due to the fact that so much power is generated by higher wind speed, much of the energy comes in short bursts. The 2002 Lee Ranch sample is telling that half of the energy available arrived in just 15% of the operating time. The consequence is that wind energy from a particular turbine or wind farm does not have as consistent an output as fuel-fired power plants; utilities that use wind power provide power from starting existing generation for times when the wind is weak thus wind power is primarily a fuel saver rather than a capacity saver. Making wind power more consistent requires that various existing technologies and methods be extended, in particular the use of stronger inter-regional transmission lines to link widely distributed wind farms. Problems of variability are addressed by grid energy storage, batteries, pumped-storage hydroelectricity and energy demand management.



<span style="font-family: Arial,Helvetica,sans-serif;">Electric Generation
<span style="font-family: Arial,Helvetica,sans-serif;">In a wind farm, individual turbines are interconnected with a medium voltage, often 34.5 kV, power collection system and communications network. At a substation, this medium-voltage electric current is increased in voltage with a transformer for connection to the high voltage electric power transmission system.The surplus power produced by domestic micro generators can, in some jurisdictions, be fed into the network and sold to the utility company, producing a retail credit for the micro generators' owners to offset their energy costs.

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<span style="font-family: Arial,Helvetica,sans-serif;">Induction generators, often used for wind power, require reactive power for excitation so substations used in wind-power collection systems include substantial capacitor banks for power factor correction. Different types of wind turbine generators behave differently during transmission grid disturbances; so extensive modeling of the dynamic electromechanical characteristics of a new wind farm is required by transmission system operators to ensure predictable stable behavior during system faults. In particular, induction generators cannot support the system voltage during faults, unlike steam or hydro turbine-driven synchronous generators. Doubly fed machines generally have more desirable properties for grid interconnection. Transmission systems operators will supply a wind farm developer with a grid code to specify the requirements for interconnection to the transmission grid. This will include power factor, constancy of frequency and dynamic behavior of the wind farm turbines during a system fault.

<span style="font-family: Arial,Helvetica,sans-serif;">Cost of a Wind Turbine
<span style="font-family: Arial,Helvetica,sans-serif;">Cost components for wind projects vary greatly. They include wind resource assessment and site analysis expenses, construction expenses, utility system upgrades, transformers, protection, insurance, operations, warranty, maintenance, and repair. Others factors include taxes, location and the desired size and quantity of the 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.” - William Persey Most of the commercial-scale turbines installed today are two megawatts 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.



<span style="font-family: Arial,Helvetica,sans-serif;">Local Wind Power
<span style="font-family: Arial,Helvetica,sans-serif;">The Nantucket Sound Wind farm will consist of 130 wind turbines produced by GE. The Model they will be using is their 3.6 MW model. This farm is to be located in a shallow area of water toward the center of Nantucket Sound called Horseshoe Shoal. The actual turbines will be 258 feet tall, not including the blade height at the top of its revolution. The lowest blade tip height will be 75 feet above the surface of the water and the highest blade tip height will be 440 feet above the surface of the water. The base of the wind turbine towers will be 16 feet in diameter. Although the program was highly controversial, it will be of no real harm to the environment; no obstruction to wildlife can be predicted. And if anything, the wind farm will not only bring a free, renewable energy to the Cape and the Islands, it will help to lower the need for other courses of power that create CO2 and other green gases that we are so desperately trying to get under control.

<span style="font-family: Arial,Helvetica,sans-serif;">Some of the numbers figured are: <span style="font-family: Arial,Helvetica,sans-serif;">3.6 megawatts X 130 Turbines= 468 Mega watts Maximum power produced.Cape Cod, Nantucket and Martha’s Vineyard have an estimated electrical demand of 230 Mega watt demand. The Nantucket wind farm will produce an average of 170 Mega watts due to inconsistent wind speeds, malfunctions and other problems that will not give maximum output, but rather 36% efficiency. Nonetheless the 170 megawatts produced will provide roughly 74% of the electrical demand to Cape Cod, Nantucket and Martha’s Vineyard.But in scientific data and computer calculations, scientists at Cape wind have determined that if we had had the turbines up and running since the idea was first put into place about building a wind farm, 12,322,771 cumulative megawatt hours would have been produced and 6,414,735 tons of C02 would have been offset.



<span style="font-family: Arial,Helvetica,sans-serif;">Critics
<span style="font-family: Arial,Helvetica,sans-serif;">“Wind Power promises a clean and free source of electricity. It will reduce our dependence on imported fossil fuels and reduce the output of greenhouse gases and other pollution. Many governments are therefore promoting the construction of vast wind "farms," encouraging private companies with generous subsidies and regulatory support, requiring utilities to buy from them, and setting up markets for the trade of "green credits" in addition to actual energy. The U.S. Department of Energy (DOE) aims to see 5% of our electricity produced by wind turbine in 2010. Energy companies are eagerly investing in wind power, finding the arrangement quite profitable.” – Eric Rosenbloom



<span style="font-family: Arial,Helvetica,sans-serif;">Summary
<span style="font-family: Arial,Helvetica,sans-serif;">All in all, wind power is generaly a good way to produce good clean energy source, but it is not cost efficient. The time and effort it takes will take a toll on the local economies and government, along with the noise and other obstruction to locals. It is a good idea, and helps to produce a sufficient amount of energy, but is rarely working at full capacity. Overall they will help overtime to take away some of the need for the burning of fossil fuels, but will never be able to fully replace them.

[|Carbon reduction scheme]

<span style="font-family: Arial,Helvetica,sans-serif;">Sources
[|**http://www.dailykos.com/story/2006/5/14/101523/811**]

[|**http://www.otherpower.com/otherpower_wind.shtml**]

[|**http://www.alternative-energy-news.info/technology/wind-power/**]

[|**http://www.bergey.com/**]

[|**http://www.windustry.org/how-much-do-wind-turbines-cost**]

[|**http://www.ens-newswire.com/ens/jan2008/2008-01-28-092.html**]

[|**http://www.renewableenergyworld.com/rea/news/article/2006/04/utility-scale-wind-turbine-for-mass-maritime-academy-44708**]

[|**http://www1.eere.energy.gov/windandhydro/wind_how.html**]

[|**http://www.youtube.com/watch?v=gwBZTrnXsvA&feature=related**]