Electrical energy can be produced in one of two ways, using either heat or mechanical energy. At a thermal power plant, the combustion of oil, gas, coal or nuclear fission emits heat, causing a generator to rotate and produce electricity. Mechanical energy requires the force of the wind or the power of water to make the generator rotate.

The production of electricity using wind is relatively simple. A wind turbine is really a huge wheel equipped with blades. The force of the wind causes the generator to rotate and produce electrical energy.
 
In a nuclear power plant, uranium atoms are split to produce nuclear fission that emits a great deal of heat. The heat is used to transform water into steam that in turn causes a turbine coupled with a generator to rotate. Other thermal power plants use fossil fuels such as petroleum, gasoline, fuel-oil and even coal to boil water and generate steam. This energy is used to rotate a turbine connected to a generator. There are also gas turbine power plants where hot gas causes the turbine to rotate and activate the generator. 

Measurement Units

There are several units of measurement of electricity. These units often bear the name associated with a scientist who contributed to the study of electrical phenomena. Following are the main units used:

  • Volt: unit measuring the electromotive force required to produced an electric current, named in honour of Italian Alessandro Volta (1745-1827), the inventor of the electric cell, in 1800
  • Ampere: unit of electric current flow moving through a conductor for a precise amount of time, named in honour of André-Marie Ampère (1775-1836), who built a coil to create a magnetic field
  • Watt: unit measuring the power of an electric current, named in honour of James Watt (1736-1819), who made improvements to the first steam engine
  • Ohm: measurement of the electric resistance between two points in a conductor, named in honour of Georg Simon Ohm (1789-1854), the author of a law on electric current
  • Joule: unit that quantifies energy (electric, heat or other) named in honour of James Prescott Joule (1818-1889), who developed a theory on the conservation of energy
  • Hertz: unit that measures the frequency of alternating current, or the number of cycles per second, named in honour of Heinrich Hertz (1857-1894), who detected electromagnetic waves

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