Alternative Energy Essay Example | Topics and Well Written Essays - 1750 words

Alternative Energy - Essay Example Small turbines can generate 100 kilowatts and are used to provide electricity to one home. Batteries store the energy from the turbine which powers the home. Large turbines are generally grouped together. These â€Å"wind farms† provide power directly to the electric grid. (â€Å"Energy Basics,† 2011) Horizontal axis turbines consist of two or three blades attached to a rotor that is placed on tall tower structure facing either away from or into the prevailing wind current. The wind is less turbulent and stronger at elevated heights, generally of 100 feet or more. Each blade is curved much like the wing of an airplane to maximize its potential. As the wind blows across a blade, the side of the blade facing downwind creates a lower-pressure pocket. The pressure differential between the front and backside of the blade turns the rotor. This phenomenon is called â€Å"lift†, the same as the wind dynamics on the wing of a plane. The wind striking the front of the blad e is called â€Å"drag† which is much weaker than the â€Å"lift† force on the backside. â€Å"The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.† (â€Å"Energy Basics,† 2011) Vertical axis wind turbines come in two varieties, Darrieus and Savonius. Neither of these types is widely utilized. The Savonius is used for pumping water and grinding grains but due to its relatively slow rotation velocity is impractical for generating electricity. The turbines appear to be S-shaped when viewed from above the unit. The Darrieus, invented in the 1920’s, is usually described as an eggbeater in appearance. This type may become used more often due to its greater amount of lift per rotation. (â€Å"Energy Basics,† 2011) Wind turbines... Horizontal axis turbines consist of two or three blades attached to a rotor that is placed on tall tower structure facing either away from or into the prevailing wind current. The wind is less turbulent and stronger at elevated heights, generally of 100 feet or more. Each blade is curved much like the wing of an airplane to maximize its potential. As the wind blows across a blade, the side of the blade facing downwind creates a lower-pressure pocket. The pressure differential between the front and backside of the blade turns the rotor. This phenomenon is called â€Å"lift†, the same as the wind dynamics on the wing of a plane. The wind striking the front of the blade is called â€Å"drag† which is much weaker than the â€Å"lift† force on the backside. â€Å"The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.† (â€Å"Energy Basics,† 2011) Vertical axis wind turbines come in two varieties, Darrieus and Savonius. Neither of these types is widely utilized. The Savonius is used for pumping water and grinding grains but due to its relatively slow rotation velocity is impractical for generating electricity. The turbines appear to be S-shaped when viewed from above the unit. The Darrieus, invented in the 1920’s, is usually described as an eggbeater in appearance. This type may become used more often due to its greater amount of lift per rotation. Wind turbines produce electricity but does not pollute the atmosphere nor are chemicals used that could contaminate the land.