Electricity generation
Electricity generation is the first process in the delivery of
electricity to consumers. The other processes are
electric power transmission and
electricity distribution.
The importance of dependable electricity generation,
transmission and
distribution was revealed when it became apparent that
electricity was useful for providing heat, light and power for human activities. Centralised power generation became possible when it was recognised that
alternating current electric power lines can transport
electricity at low costs across great distances by taking advantage of the ability to transform the
voltage using power
transformers.
Electricity has been generated for the purpose of powering human technologies for at least 120 years from various sources of
potential energy. The first power plants were run on wood, while today we rely mainly on
petroleum,
natural gas,
coal,
hydroelectric and
nuclear power and a small amount from
hydrogen,
solar energy,
tidal harnesses,
wind generators, and
geothermal sources.
The demand for electricity can be met in two different ways. The primary method thus far has been for public or private utilities to construct large scale centralized projects to generate and transmit the electricity required to fuel economies. Many of these projects have caused unpleasant environmental effects such as air or radiation pollution and the flooding of large areas of land.
Distributed generation creates power on a smaller scale at locations throughout the electricity network. Often these sites generate electricity as a byproduct of other industrial processes such as using gas from landfills to drive turbines.
Methods for transforming other energy into electrical energy
Rotating
turbines attached to
electrical generators produce most commercially available electricity. Turbines may be driven by using steam, water, wind or other fluids as an intermediate energy carrier. The most common usage is by steam in
fossil fuel power plants or
nuclear power plants, and by water in
hydroelectric dams. Alternately, turbines can be driven directly by the
combustion of natural gas or oil.
Combined cycle gas turbine plants offer efficiencies of up to 60%. They generate power by burning natural gas in a
gas turbine and use residual heat to generate additional electricity from steam.
Wind turbines generate electricity by using the wind.
Solar updraft towers use wind that is artificially produced inside the chimney by heating it with sunlight.
Solar parabolic troughs and
solar power towers concentrate sunlight to heat a heat transfer fluid that is used to produce steam to turn a turbine. Small electricity generators are often powered by
reciprocating engines burning
diesel,
biogas or natural gas. Diesel engines are often used for back up generation, usually at low voltages. Biogas is often combusted where it is produced, such as a landfill or wastewater treatment plant, with a reciprocating engine or a microturbine, which is a small gas turbine.
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Electrical utility*
Electricity distribution*
Electricity transmission*
Electricity retailing*
Future energy development*
Lineman*
Load Profile*
Power quality*
Voltage drop*
Energy use and conservation in the United Kingdom
