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Wind Energy. Emma O’Reilly Sam Pennington . About Wind 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.
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Wind Energy Emma O’Reilly Sam Pennington
About Wind 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.
Wind Turbines • Wind Turbines use blades to collect the wind’s kinetic energy. • The wind flows over the blades creating lift (like the effect on airplane wings) which causes them to turn. • The blades are connected to a drive shaft that turns an electric generator to produce electricity. • A turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity.
Types of Wind Turbines • Horizontal-axis : • like the traditional farm windmills used for pumping water • Vertical-axis : • eggbeater-style Darrieus model, named after its French inventor. • Most large modern wind turbines are horizontal-axis turbines.
Who? • Wind resources are characterized by wind-power density classes • Class 1 (the lowest) to class 7 (the highest). • Class 3 is the average class with good wind resources because they have an average annual wind speed of at least 13 miles per hour • These locations in the United States include: • Alaska • mid north western states such as Colorado, Wyoming, and Indiana, the Dakotas and Montana
Cost • 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. • However, wind costs compared to fossil fuels are much more competitive with other generating technologies because there is no fuel to purchase and minimal operating expenses. • Costs $0.04 per kWh • The initial cost of wind turbine is split into 3 categories • 500 for 400 W • 6,000 dollars for 4kWh • 50,000 dollars for 20 kWh
Cost • Cost of tower • The higher tower the better because of wind consistency and less turbulence • 30-50 ft tower = 5,000-8,000 dollars • 80-120 ft= 12,000-30,000 • Cost of instillation (foundation/electrical): • equipment could cost between $3,000-7,000 • Instillation cost also depends on terrain and heat • Maintenance costs: • 1-3% of initial cost of wind turbine each year on maintenance. • Ex: $200-600 for a 20,000 $ turbine • Making a turbine can be a lower cost • EX; 200 $ for 800 W.
Cons- Environmental • There is some concern over the noise produced by the rotor blades, • Visual impacts • Birds and bats having been killed by flying into the rotors. • Most of these problems have been resolved or greatly reduced through technological development. • Can be damaged by heavy winds or storms
Cons • Wind does not flow when energy is needed so this power can be inconsistent and intermittent. • Wind cannot be stored • although wind-generated electricity can be stored, if batteries are used • Not all winds can be harnessed to meet the timing of electricity demands.
Pros • Wind energy is a free, renewable resource • Power cuts and power failures are almost non existent. • 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, • 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.
Pros • In 2008, wind machines in the United States generated a total of 52 billion kilowatthours, about 1.3% of total U.S. electricity generation. • Cheapest forms of energy available therefore can be used by mostly everyone • Many utilities around the country offer green pricing options that allow customers the choice to pay more for electricity that comes from renewable sources to support new technologies
Pros • Generation from wind in the United States nearly doubled between 2006 and 2008. • New technologies have decreased • the cost of producing electricity from wind, and growth in wind power has been encouraged by tax breaks for renewable energy and green pricing programs.
Surplus • Batteries in wind turbines store and harvest wind energy.
http://windeis.anl.gov/guide/basics/index.cfm • http://www.eia.doe.gov/kids/energy.cfm?page=wind_home-basics • http://www.buzzle.com/articles/wind-energy-pros-and-cons.html