Table of Contents
8.1.4 – The Principal Mechanisms involved in Electricity Production

  • Definition
  • Generators
  • Turbines
  • Dynamos
Bibliography


Production of Electrical Power: Electrical energy may be produced by rotating coils in a magnetic field, as shown in figure 8.1. The most important mechanisms are those of turbines, generators and dynamos.
rotating_coil.jpg
Figure 8.1: Rotating coils in a magnetic field
  1. Generators: A generator is the mechanism that contains the rotating coils in the magnetic field. A simple generator, as shown in figure 8.2, produces energy by spinning it with our hand. However, to commercially produce electricity, the coil must be spun much more rapidly in a stronger magnetic field. Thus, commercial generators are connected to a turbine or an engine of some sort to receive the source of energy required for the coils to turn. All generators operate on this principal and the same amount of electricity will be produced, regardless of the energy source. The many types of generators are:
      1. Electric Generators – Generators converting mechanical energy to electrical energy, see figure 8.3.
      2. Steam Turbine Generators – Generators using a steam turbine to allow pressurized steam to rotate the coils in the magnetic field
      3. Gas Turbine Generators – Generators using a gas turbine to allow hot gas to rotate the coils in the magnetic field
      4. Diesel Engine generators – The combination of a diesel engine with an electric generator to produce electricity.
  2. Turbines: A turbine is an important mechanism used to generate electricity. The mechanism consists of a shaft with blades at one end and the coils with the magnetic field at the other end, as shown in figure 8.4. Although there are different types of turbines, the basic idea is that the type of energy source given to the turbine is used to push the blades. The magnets start to spin, thus, compelling the electrons in the coils surrounding them to move as well. As a result, electricity is generated. The different types of turbines are:
      1. Gas Turbines – Turbines using hot gases, created from the burning of fuels, as a source of energy to generate electricity.
      2. Steam Turbines – Turbines that use pressurized steam as a source of energy to generate electricity.
      3. Wind Turbines – Turbines using wind as a source of energy to generate electricity.
      4. Hydroelectric Turbines – Turbines using water as a source of energy to generate electricity.
  3. Dynamos: A dynamo is basically a generator that produces direct current, consisting of the rotation of a coil between the poles of an electromagnet. This rotation causes the flow of current in the coils, thus, producing electricity. However, dynamos have become relatively obsolete, since it is more efficient to use alternating currents for electricity rather than direct currents. An example of a dynamo can be seen in figure 8.5.
simple_generator.jpg
Electrical_generator.jpg
Figure 8.2: A simple hand-turned generator
Figure 8.3: Electrical Generators

turbine.jpg
dynamo_001.jpg
Figure 8.4: Turbines
Figure 8.5: A dynamo



Bibliography
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"Electrical generator." Wikipedia, The Free Encyclopedia. 14 Mar 2009, 03:28 UTC. 17 Mar 2009 <http://en.wikipedia.org/w/index.php?title=Electrical_generator&oldid=277112093>.
· "Steam turbine." Wikipedia, The Free Encyclopedia. 2 Mar 2009, 10:49 UTC. 17 Mar 2009 <http://en.wikipedia.org/w/index.php?title=Steam_turbine&oldid=274393176>.
· "Glossary." Welcome to Avista. 16 Mar. 2009 <http://www.avistautilities.com/wattson/safetyworld/esw/glossary/index.html>.
· "Electricity generation." Electricity and Electrical Energy - Search 3,000 Pages. 16 Mar. 2009 <http://www.electricityforum.com/electricity-generation.html>.
· "Diesel generator." Wikipedia, The Free Encyclopedia. 28 Feb 2009, 11:14 UTC. 17 Mar 2009 <http://en.wikipedia.org/w/index.php?title=Diesel_generator&oldid=273853188>.
· "Web Iberdrola Renovables - English glossary." Web Iberdrola Renovables - Página de inicio. 16 Mar. 2009 <http://www.iberdrolarenovables.es/wcren/corporativa/iberdrola?IDPAG=ENGLOSARIO&codCache=12203751174674#E>.
· "WordNet Search - 3.0." 16 Mar. 2009 http://wordnetweb.princeton.edu/perl/webwn?s=dynamo.