Wind Power’s Present and Potential
As the global supply of fossil fuels becomes steadily lower, need is growing for new energy sources that are beneficial to the environment and cost-effective. Wind power is one solution to this need. Wind turbines require significant investment, but are costefficient in the long term. If construction of turbines is sufficiently increased, the wind may be able to in the future provide a very major portion of global energy.
Wind Power’s Present and Potential
According to a study by Archer and Jacobson, the wind power potential provided by just the windiest 13% of the planet’s land area is five times the power that we currently use
– 72 terawatts (Archer, Jacobson, 2004). However, while the portion of the world’s total power that comes from wind is increasing, presently it is only at one percent. Two reasons for the increase are advancements in the engineering of wind turbines and greater concern for environmental well-being and waning of non-renewable resources, especially among countries in Europe. The increase in the use of wind power has amounted to a fourfold increase between 1999 and 2005 (figure 10-1). Wind power has as much potential as any other alternative energy source.
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Wind energy is a reliable source of energy. Unlike fossil fuels, whose prices keep growing as time goes by, the price of wind never rises. When fuel prices fell after World
War II, interest in wind turbines generators was more or less abandoned. But when the price of oil skyrocketed in the 1970s, interest in wind turbine generators resurged.
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Today, wind power is minor source of electricity for most countries; however, it accounts for 23% of electricity use in Denmark, 6% in Germany and around 8% in Spain
Wind turbines are the mode of wind energy’s collection, so they deserve their own major place in this discussion. A wind turbine works like a fan, but backwards; whereas, fans use electricity to generate air current, wind turbines use air current to generate electricity (figure 2). Generally speaking, wind turbines convert the kinetic energy in the wind into mechanical power. The wind turns the blades, which spins the shaft, which connects to a generator and makes electricity. This mechanical power has historically been used for specific tasks (such as grinding grain or pumping water) but in its modern
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One problem with wind energy is that it needs high velocity wind to be efficient, preferably over 25 kilometers per hour. The power available from a wind turbine increases very rapidly with wind speed: a doubling of wind speed results in as much as an eight-fold increase in power (Nova: science in the news, 1998). So it is important to site wind generators in a place where the wind speed is high, as well as reasonably constant. Wind farms are generally only located in coastal areas, and at the tops of rounded hills, where the wind is strong and reliable. Seashores tend to be windy areas and good sites for turbine installation, because the density of air at sea level causes the energy of ocean winds to be higher per unit speed than the wind in mountainous areas.
Offshore resources also average wind speeds 90% greater than that of land, and so it could contributes 7 times more energy than land (Wikipedia, 2006).
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The price of wind power has dropped more than 80% within the last 20 years, from 30 cents per KWH in
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1980s to 5 cents per KWH in 2005, thanks to technological improvements. The advances in fiberglass and carbon-fiber technology have enabled the production of lightweight rotor blades, which allows the blades to spin faster, reducing maintenance costs and allowing for larger blades and generators. These blades are capable of performing for years in the rugged conditions of some of the world's windiest locations.
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