Electrical power industry
Electric power, often known as
power or
electricity, involves the production and delivery of
electrical energy through in sufficient quantities to areas that need
electricity. Many
households and
businesses need access to electricity, especially in
developed nations, the demand being scarcer in
developing nations. Demand for electricity is derived from the requirement for electricity in order to operate domestic
appliances,
office equipment,
industrial machinery and provide sufficient energy for both domestic and commercial
lighting,
heating,
cooking and industrial processes. Because of this aspect of the industry, it is viewed as a
public utility as
infrastructure.
The electrical power industry is commonly split up into four processes. These are
electricity generation such as a
power station,
electric power transmission,
electricity distribution and
electricity retailing. In many countries, electric power companies own the whole infrastructure from generating stations to transmission and distribution infrastructure. For this reason, electric power is viewed as a
natural monopoly. The industry is generally heavily
regulated, often with
price controls and is frequently
government-owned and operated. The nature and state of market reform of the
electricity market often determines whether electric companies are able to be involved in just some of these processes without having to own the entire infrastructure, or citizens choose which components of infrastructure to patronise. In countries where electricity provision is
deregulated, end-users of electricity may opt for more costly
green electricity.
All forms of electricity generation have positive and negative aspects.
Technology will probably eventually declare the most preferred forms, but in a
market economy, the options with less overall costs generally will be chosen above other sources. It is not clear yet which form can best meet the necessary energy demands or which process can best solve the demand for electricity. There are indications that
renewable energy and
distributed generation are becoming more viable in economic terms. A diverse mix of generation sources reduces the risks of electricity price spikes.
In some markets in the
United States,
wind power costs less to construct than alternatives such as new
fossil fuel power plants, especially when including government subsidies. Additionally, wind power, like other
clean energy resources such as
solar power, does not have
costs due to the need to continuously purchase new fuel and therefore, no fluctuating or rising costs to consumers. Clean energy is cited by
national security advisors as one solution to United States' dependence on foreign sources of energy, especially on the
OPEC Cartel. Like many renewable energy sources, wind power may not be available at the times and amounts demanded by energy users.
Although electricity had been known to be produced as a result of the chemical reactions that take place in an
electrolytic cell since
Alessandro Volta developed the
voltaic pile in
1800, its production by this means was, and still is, expensive. In
1831,
Michael Faraday devised a machine that generated electricity from rotary motion, but it took almost 50 years for the technology to reach a commercially viable stage. In
1878,
Thomas Edison developed and sold a commercially viable replacement for gas lighting and heating using locally generated and distributed
direct current electricity. The reason generation close to or on the consumer's premises was necessary was that Edison had no means of voltage conversion. The voltage chosen for any electrical system is a compromise. Increasing the
voltage reduces the
current and therefore reduces resistive losses in the cable. Unfortunately it increases the
danger from direct contact and also increases the required
insulation thickness. Furthermore some load types were difficult or impossible to make for higher voltages.
Nikola Tesla, who had worked for Edison for a short time and appreciated the electrical theory in a way that Edison did not, devised an alternative system using
alternating current. Tesla realised that while doubling the voltage would halve the current and reduce losses by three-quarters, only an alternating current system allowed the
transformation between voltage levels in different parts of the system. This allowed efficient high voltages for distribution where their risks could easily be mitigated by good design while still allowing fairly safe voltages to be supplied to the loads. He went on to develop the overall theory of his system, devising theoretical and practical alternatives for all of the direct current appliances then in use, and patented his novel ideas in
1887, in thirty separate patents.
In
1888, Tesla's work came to the attention of
George Westinghouse, who owned a patent for a type of transformer that could deal with high power and was easy to make. Westinghouse had been operating an alternating current lighting plant in
Great Barrington, Massachusetts since
1886. While Westinghouse's system could use Edison's lights and had heaters, it did not have a motor. With Tesla and his patents, Westinghouse built a power system for a
gold mine in
Telluride, Colorado in
1891, with a water driven 100
horsepower (75 kW) generator powering a 100 horsepower (75 kW) motor over a 2.5-mile (4 km)
power line.
Almarian Decker finally invented the whole system of
three-phase power generating in Redlands, California in
1893. Then, in a deal with
General Electric, which Edison had been forced to sell, Westinghouse's company went on to construct a power station at the
Niagara Falls, with three 5,000 horsepower (3.7 MW) Tesla generators supplying electricity to an
aluminium smelter at
Niagara and the town of
Buffalo 22 miles (35 km) away. The Niagara power station commenced operation on
April 20 1895.
Tesla's alternating current system remains the primary means of delivering electrical energy to consumers throughout the world. While
high-voltage direct current (HVDC) is increasingly being used to transmit large quantities of electricity over long distances or to connect adjacent
asynchronous power systems, the bulk of electricity generation, transmission, distribution and retailing takes place using alternating current.
There has been a movement towards separating the monopoly parts of the industry, such as transmission and distribution sectors from the contestable sectors of generation and retailing across the world. This has occurred prominently since the reform of the electricity supply industry in England and Wales in 1990. In some countries, wholesale electricity markets operate, with
generators and
retailers trading electricity in a similar manner to
shares and
currency.
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AC power*
Circuit Breaker*
Electricity generation*
Electric power transmission*
Electricity distribution*
Power (physics)*
Distributed generation*
Electricity retailing*
Auxiliary power*
Power control*
Power factor*
Electrical wiring*
Earthing system*
Uninterruptible power supply*
Electrical generator*
Electrical bus*
New Zealand Electricity Market*
Electricity market*
Transformer*
Three-phase power*
Electronics*
Mains power plug*
Mains electricity ("household electricity" in
American English)
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Meter Point Administration Number (unique U.K. supply number)
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Industrial power plug*
Power budget*
Power connector*
Power failure transfer*
Power margin*
Power plant*
Power supply*
Power system automation*
Reddy Kilowatt (U.S. electricity corporate logo)
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Skin effect
