Electric Generation
Electric Generators, group of devices used to convert mechanical energy into electrical energy, or electrical energy into mechanical energy, by electromagnetic means. A machine that converts mechanical energy into electrical energy is called a generator. There are three different types of generators that are used to produce massive amounts of electricity: hydroelectric, steam-powered turbines and wind powered turbines.
Hydro-Electricity
Hydroelectric dams generate electricity. Hydroelectric dams harness the energy of water released from the reservoir to turn hydraulic turbines. The turbines convert the energy of the falling water into mechanical energy, which is used to power electric generators.
Steam-powered Turbines
The turbine achieves high efficiency by utilizing the kinetic energy of steam flow. The turbine can be made smaller, lighter, and cheaper than a reciprocating steam engine of comparable power. It can be made in far larger sizes than the conventional steam engine. Mechanically, it has the advantage of producing rotating motion directly without the necessity of using a crankshaft or other means of transforming reciprocal to rotary motion. As a result, the steam turbine has supplanted the reciprocating engine as a prime mover in large electricity-generating plants and is also used as
means of jet propulsion. One of the main disadvantages of the steam-powered turbines is that it requires a limited power source, while releasing pollutants into the air.
Wind-powered Turbines
Modern wind turbines are propelled by one of two effects: drag, by which wind pushes the blades; and lift, by which the blades are moved in the same way an airplane's wing rises on an air current. Turbines operated by lift turn more rapidly and are inherently more efficient. Wind turbines can be classified as horizontal-axis machines, with their main shafts parallel to the ground, or vertical-axis machines, with shafts perpendicular to the ground. Horizontal-axis turbines used to generate electricity have one to three blades; those used for pumping may have many more. Although it uses a renewable resource, wind-powered generators are only productive in certain environments.
