The wind's energy has been harnessed by us for more than one thousand years. At first we only used windmills to pump water and grind grains. Nowadays, we use windmill's modern equivalent-wind turbine to generate electricity. They are mounted on a tower, just like windmills. At 30 meters or more above ground, they can take advantage of the faster and less turbulent wind. Turbines catch the wind's energy with their propeller-like blades. There are usually two to three blades on a turbine connected to a shaft called rotor.
A blade is like the wings of an aircraft. When wind blows, low-pressure air is formed on the downwind side of the blade. The low-pressure air then pulls the blade toward it, thus makes the rotor turns. This force is called lift. The lift is much stronger than drag-the wind's force against the front side of the blade. Lift and drag combines and causes the rotor to spin like a propeller, and then the turning shaft spins a generator to generate electricity.
Wind turbines can be used stand-alone, or they can be connected to a power grid or even combined with a solar power system. For utility-scale (megawatt-sized) sources of wind energy, a lot of turbines are usually built close together to form a wind plant. Many power companies now use wind plants to supply electricity to their customers. Stand-alone turbines are mostly used for communications or water-pumping. However, homeowners, farmers, and ranchers in windy areas can also use turbines as a way to supply electricity. Small wind systems also have potential as distributed energy resources. Distributed energy resources refer to a variety of small, modular power-generating technologies that can be combined to improve the operation of the electricity delivery system.
If you are interested in using wind power to produced electricity,click here to learn more.
