HOME

TheInfoList




Electric power is the rate, per unit time, at which
electrical energy Electrical energy is energy derived as a result of movement of electrically charged particles. When used loosely, ''electrical energy'' refers to energy that has been converted ''from'' electric potential energy. This energy is supplied by the comb ...
is transferred by an
electric circuit An electrical network is an interconnection of electrical component An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic componen ...

electric circuit
. The
SI
SI
unit of
power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. In older works, p ...
is the
watt The watt (symbol: W) is a unit of power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal ...

watt
, one
joule The joule ( ; symbol: J) is a derived unit of energy In physics, energy is the physical quantity, quantitative physical property, property that must be #Energy transfer, transferred to a physical body, body or physical system to perform W ...

joule
per
second The second (symbol: s, also abbreviated: sec) is the of in the (SI) (french: Système International d’unités), commonly understood and historically defined as of a – this factor derived from the division of the day first into 24 s, th ...
. Electric power is usually produced by
electric generator In electricity generation Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delive ...
s, but can also be supplied by sources such as
electric batteries A battery is a device consisting of one or more electrochemical cell An electrochemical cell is a device capable of either generating electrical energy from chemical reaction A chemical reaction is a process that leads to the chemical ...
. It is usually supplied to businesses and homes (as domestic
mains electricity Mains electricity (Commonwealth English The use of the English language English is a West Germanic languages, West Germanic language first spoken in History of Anglo-Saxon England, early medieval England, which has eventually become ...
) by the
electric power industry The electric power industry covers the generation A generation is "all of the people born and living Living or The Living may refer to: Common meanings *Life, a condition that distinguishes organisms from inorganic objects and dead organisms ...
through an
electric power grid An electrical grid is an interconnected network for electricity delivery Electricity delivery is the process that starts after generation of electricity in the power station A power station, also referred to as a power plant and someti ...
. Electric power can be delivered over long distances by
transmission lines
transmission lines
and used for applications such as
motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon in which an object changes its position (mathematics), position over time. Motion is mathematically described in terms of Displacem ...

motion
,
light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be visual perception, perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 ...
or
heat In thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these ...
with high
efficiency Efficiency is the (often measurable) ability to avoid wasting materials, energy, efforts, money, and time in doing something or in producing a desired result. In a more general sense, it is the ability to do things well, successfully, and withou ...
.


Definition

Electric power, like
mechanical power Mechanical power is a medical term which is a measure of the amount of energy imparted to a patient by a mechanical ventilator. While in many cases mechanical ventilation is a life-saving or life-preserving intervention, it also has the potential t ...
, is the rate of doing
work Work may refer to: * Work (human activity), intentional activity people perform to support themselves, others, or the community ** Manual labour, physical work done by humans ** House work, housework, or homemaking * Work (physics), the product of ...
, measured in
watt The watt (symbol: W) is a unit of power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal ...

watt
s, and represented by the letter ''P''. The term ''wattage'' is used colloquially to mean "electric power in watts." The electric power in
watt The watt (symbol: W) is a unit of power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal ...

watt
s produced by an
electric current An electric current is a stream of charged particle In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, ...
''I'' consisting of a
charge Charge or charged may refer to: Arts, entertainment, and media Films * ''Charge, Zero Emissions/Maximum Speed'', a 2011 documentary Music * Charge (David Ford album), ''Charge'' (David Ford album) * Charge (Machel Montano album), ''Charge'' (Mac ...
of ''Q'' coulombs every ''t'' seconds passing through an
electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work (physics), work energy needed to move a unit of electric charge from a reference point to the spe ...

electric potential
(
voltage Voltage, electric potential difference, electric pressure or electric tension is the difference in electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is the ...

voltage
) difference of ''V'' is P = \text = \frac = \frac \frac = VI where *''Q'' is electric charge in
coulomb The coulomb (symbol: C) is the International System of Units International is an adjective (also used as a noun) meaning "between nations". International may also refer to: Music Albums * International (Kevin Michael album), ''International'' ( ...

coulomb
s *''t'' is time in
second The second (symbol: s, also abbreviated: sec) is the of in the (SI) (french: Système International d’unités), commonly understood and historically defined as of a – this factor derived from the division of the day first into 24 s, th ...
s *''I'' is electric current in
ampere The ampere (, ; symbol: A), often shortened to "amp",SI supports only the use of symbols and deprecates the use of abbreviations for units. is the base unit of electric current An electric current is a stream of charged particles, such as ele ...

ampere
s *''V'' is electric potential or voltage in
volt The volt is the derived unit for electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is the amount of work energy needed to move a unit of electric charge ...

volt
s


Explanation

Electric power is transformed to other forms of energy when
electric charge Electric charge is the physical property A physical property is any property Property is a system of rights that gives people legal control of valuable things, and also refers to the valuable things themselves. Depending on the nature of th ...
s move through an
electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work (physics), work energy needed to move a unit of electric charge from a reference point to the spe ...

electric potential
difference (
voltage Voltage, electric potential difference, electric pressure or electric tension is the difference in electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is the ...

voltage
), which occurs in
electrical component An electronic component is any basic discrete device or physical entity in an electronic system Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductor *Electronics (magazine), ''Electronics'' (maga ...
s in electric circuits. From the standpoint of electric power, components in an electric circuit can be divided into two categories:


Active devices (power sources)

If the charges are moved by an 'exterior force' through the device in the direction from the lower electric potential to the higher, (so positive charge moves from the negative to the positive terminal),
work Work may refer to: * Work (human activity), intentional activity people perform to support themselves, others, or the community ** Manual labour, physical work done by humans ** House work, housework, or homemaking * Work (physics), the product of ...

work
will be done ''on'' the charges, and energy is being converted to electric
potential energy In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potentia ...

potential energy
from some other type of energy, such as
mechanical energy In physical sciences Physical science is a branch of natural science that studies abiotic component, non-living systems, in contrast to life science. It in turn has many branches, each referred to as a "physical science", together called the "p ...
or
chemical energy Chemical energy is the energy of chemical substance A chemical substance is a form of matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects th ...
. Devices in which this occurs are called ''
active Active may refer to: Music * Active (album), ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * Active (ship), ''Active'' (ship), several commercial ships by that name * HMS Active, HMS ''Active'', the nam ...
'' devices or ''power sources''; such as
electric generator In electricity generation Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delive ...
s and
batteries Battery may refer to: Energy source * Electric battery, an electrochemical device to provide electrical power ** Automotive battery, a device to provide power to certain functions of an automobile ** List of battery types * Energy storage, inclu ...
. Some devices can be either a source or a load, depending on the voltage and current through them. For example, a
rechargeable battery A rechargeable battery, storage battery, or secondary cell, (or archaically accumulator) is a type of electrical battery A battery is a device consisting of one or more electrochemical cell An electrochemical cell is a device capable ...
acts as a source when it provides power to a circuit, but as a load when it is connected to a battery charger and is being recharged.


Passive devices (loads)

When electric charges move through a potential difference from a higher to a lower voltage, that is when
conventional current An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge Electric charge is the physical property of matter t ...
(positive charge) moves from the positive (+) terminal to the negative (−) terminal,
work Work may refer to: * Work (human activity), intentional activity people perform to support themselves, others, or the community ** Manual labour, physical work done by humans ** House work, housework, or homemaking * Work (physics), the product of ...

work
is done by the charges on the device. The
potential energy In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potentia ...

potential energy
of the charges due to the voltage between the terminals is converted to
kinetic energy In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular ...
in the device. These devices are called ''
passive Passive may refer to: * Passive voice, a grammatical voice common in many languages, see also Pseudopassive (disambiguation), Pseudopassive * Passive language, a language from which an interpreter works * Passivity (behavior), the condition of sub ...
'' components or ''loads''; they 'consume' electric power from the circuit, converting it to other forms of energy such as
mechanical work In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the related entities of energy and force. ...
, heat, light, etc. Examples are
electrical appliance A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine which assists in household A household consists of one or several persons who live in the same dwelling and share meals. I ...
s, such as
light bulb An electric light is a device that produces visible light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum ...

light bulb
s,
electric motor
electric motor
s, and
electric heater Electric heating is a process in which electrical energy Electrical energy is energy derived from electric potential energy or kinetic energy. When used loosely, ''electrical energy'' refers to energy that has been converted ''from'' electric ...

electric heater
s. In
alternating current Alternating current (AC) is an electric current An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through ...
(AC) circuits the direction of the voltage periodically reverses, but the current always flows from the higher potential to the lower potential side.


Passive sign convention

Since electric power can flow either into or out of a component, a convention is needed for which direction represents positive power flow. Electric power flowing ''out'' of a circuit ''into'' a component is arbitrarily defined to have a positive sign, while power flowing ''into'' a circuit from a component is defined to have a negative sign. Thus passive components have positive power consumption, while power sources have negative power consumption. This is called the ''
passive sign convention
passive sign convention
''.


Resistive circuits

In the case of
resistive In electronics and electromagnetism, the electrical resistance of an object is a measure of its opposition to the flow of electric current. The Multiplicative inverse, reciprocal quantity is , and is the ease with which an electric current passe ...
(Ohmic, or linear) loads, Joule's law can be combined with
Ohm's law Ohm's law states that the electric current, current through a Electrical conductor, conductor between two points is directly Proportionality (mathematics), proportional to the voltage across the two points. Introducing the constant of proporti ...

Ohm's law
(''V'' = ''I·R'') to produce alternative expressions for the amount of power that is dissipated: P = I V = I^2 R = \frac, where ''R'' is the
electrical resistance The electrical resistance of an object is a measure of its opposition to the flow of electric current An electric current is a stream of charged particle In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epi ...
.


Alternating current without harmonics

In
alternating current Alternating current (AC) is an electric current An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through ...
circuits, energy storage elements such as
inductance Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the c ...
and
capacitance Capacitance is the ratio of the amount of stored on a to a difference in . There are two closely related notions of capacitance: ''self capacitance'' and ''mutual capacitance''. Any object that can be electrically charged exhibits ''self capa ...
may result in periodic reversals of the direction of energy flow. The portion of energy flow (power) that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as
real power Power (physics), Instantaneous power in an electric circuit is the rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals ...
(also referred to as active power). The amplitude of that portion of energy flow (power) that results in no net transfer of energy but instead oscillates between the source and load in each cycle due to stored energy, is known as the absolute value of
reactive power Instantaneous power in an electric circuit is the rate of flow of energy past a given point of the circuit. In alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude ...
. The product of the RMS value of the voltage wave and the RMS value of the current wave is known as
apparent power Power (physics), Instantaneous power in an electric circuit is the rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversal ...
. The real power ''P'' in watts consumed by a device is given by P = V_p I_p \cos \theta = V_I_ \cos \theta where *''V''p is the peak voltage in volts *''I''p is the peak current in amperes *''V''rms is the
root-mean-square In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical analysis, analysis). It h ...
voltage in volts *''I''rms is the
root-mean-square In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical analysis, analysis). It h ...
current in amperes *''θ'' = ''θ''v − ''θ''i is the phase angle by which the voltage sine wave leads the current sine wave, or equivalently the phase angle by which the current sine wave lags the voltage sine wave The relationship between real power, reactive power and apparent power can be expressed by representing the quantities as vectors. Real power is represented as a horizontal vector and reactive power is represented as a vertical vector. The apparent power vector is the hypotenuse of a right triangle formed by connecting the real and reactive power vectors. This representation is often called the ''power triangle''. Using the
Pythagorean Theorem In mathematics, the Pythagorean theorem, or Pythagoras' theorem, is a fundamental relation in Euclidean geometry among the three sides of a right triangle. It states that the area of the square whose side is the hypotenuse (the side opposite ...

Pythagorean Theorem
, the relationship among real, reactive and apparent power is: \text^2 = \text^2 + \text^2 Real and reactive powers can also be calculated directly from the apparent power, when the current and voltage are both
sinusoids A capillary is a small blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also ...

sinusoids
with a known phase angle θ between them: \text = \text \cos \theta \text = \text \sin \theta The ratio of real power to apparent power is called
power factor In electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics The field of electronics is a branch of ph ...
and is a number always between −1 and 1. Where the currents and voltages have non-sinusoidal forms, power factor is generalized to include the effects of distortion.


Electromagnetic fields

Electrical energy flows wherever electric and magnetic fields exist together and fluctuate in the same place. The simplest example of this is in electrical circuits, as the preceding section showed. In the general case, however, the simple equation ''P'' = ''IV'' may be replaced by a more complex calculation. The closed
surface integral In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical analysis, analysis). It ...

surface integral
of the
cross-product In mathematics, the cross product or vector product (occasionally directed area product, to emphasize its geometric significance) is a binary operation on two Euclidean vector, vectors in a three-dimensional Orientation (vector space), oriented Eu ...

cross-product
of the electric field intensity and magnetic field intensity
vectors Vector may refer to: Biology *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism; a disease vector *Vector (molecular biology), a DNA molecule used as a vehicle to artificially carr ...
gives the total instantaneous power (in watts) ''out of'' the volume: P = \oint_\text (\mathbf \times \mathbf) \cdot d \mathbf. The result is a scalar since it is the ''
surface integral In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical analysis, analysis). It ...

surface integral
'' of the ''
Poynting vector In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular su ...
''.


Production


Generation

The fundamental principles of much electricity generation were discovered during the 1820s and early 1830s by the British scientist
Michael Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist A scientist is a person who conducts scientific research The scientific method is an Empirical evidence, empirical method of acquiring knowledge ...

Michael Faraday
. His basic method is still used today: electric current is generated by the movement of a loop of wire, or disc of copper between the poles of a
magnet A magnet is a material or object that produces a magnetic field A magnetic field is a vector field In vector calculus and physics, a vector field is an assignment of a vector to each point in a subset of space. For instance, a ve ...

magnet
. For electric utilities, it is the first process in the delivery of electricity to consumers. The other processes, electricity
transmission Transmission may refer to: Science and technology * Power transmissionPower transmission is the movement of energy from its place of generation to a location where it is applied to perform useful Mechanical work, work. Power (physics), Power is d ...

transmission
,
distributionDistribution may refer to: Mathematics *Distribution (mathematics) Distributions, also known as Schwartz distributions or generalized functions, are objects that generalize the classical notion of functions in mathematical analysis. Distr ...
, and electrical energy storage and recovery using
pumped-storage Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectricity, hydroelectric energy storage used by electric power systems for load balancing (electrical power), load balancing. The method s ...
methods are normally carried out by the
electric power industry The electric power industry covers the generation A generation is "all of the people born and living Living or The Living may refer to: Common meanings *Life, a condition that distinguishes organisms from inorganic objects and dead organisms ...
. Electricity is mostly generated at a
power station A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation A generation is "all of the people born and living Living or The Living may refer to: ...

power station
by electromechanical generators, driven by
heat engine In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do work (physics), mechanical work. It does this by bringing a working substance from a higher state temperature to ...

heat engine
s heated by
combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion ...
,
geothermal power Geothermal power is electrical power generated from geothermal energy Geothermal energy is the thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. The geothermal energy ...
or
nuclear fission Nuclear fission is a reaction Reaction may refer to a process or to a response to an action, event, or exposure: Physics and chemistry *Chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic tr ...

nuclear fission
. Other generators are driven by the
kinetic energy In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular ...
of flowing water and wind. There are many other technologies that are used to generate electricity such as
photovoltaic Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercia ...

photovoltaic
solar panels. A
battery Battery may refer to: Energy source * Electric battery, an electrochemical device to provide electrical power ** Automotive battery, a device to provide power to certain functions of an automobile ** List of battery types * Energy storage, inclu ...
is a device consisting of one or more
electrochemical cell An electrochemical cell is a device capable of either generating electrical energy Electrical energy is energy derived from electric potential energy or kinetic energy. When used loosely, ''electrical energy'' refers to energy that has been c ...
s that convert stored chemical energy into electrical energy."battery" (def. 4b)
''Merriam-Webster Online Dictionary'' (2009). Retrieved 25 May 2009.
Since the invention of the first battery (or "
voltaic pile –zinc Zinc is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the sa ...

voltaic pile
") in 1800 by
Alessandro Volta Alessandro Giuseppe Antonio Anastasio Volta (, ; 18 February 1745 – 5 March 1827) was an Italian physicist A physicist is a scientist A scientist is a person who conducts scientific research The scientific method is an Empiric ...

Alessandro Volta
and especially since the technically improved
Daniell cell The Daniell cell is a type of electrochemical cell An electrochemical cell is a device capable of either generating electrical energy from chemical reaction A chemical reaction is a process that leads to the chemical transformation of one ...

Daniell cell
in 1836, batteries have become a common power source for many household and industrial applications. According to a 2005 estimate, the worldwide battery industry generates
US$ The United States dollar (symbol A symbol is a mark, sign, or word In linguistics, a word of a spoken language can be defined as the smallest sequence of phonemes that can be uttered in isolation with semantic, objective or pragmatics, ...
48
billion A billion is a number with two distinct definitions: *1,000,000,000 1,000,000,000 (one billion, short scale; one thousand million or milliard, yard, long scale) is the natural number In mathematics, the natural numbers are those used for ...
in sales each year, with 6% annual growth. There are two types of batteries: primary batteries (disposable batteries), which are designed to be used once and discarded, and secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times. Batteries are available in many sizes; from miniature
button cell A watch battery or button cell is a small single cell battery Battery may refer to: Energy source * Electric battery, an electrochemical device to provide electrical power ** Automotive battery, a device to provide power to certain functions of ...
s used to power
hearing aid A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss Hearing loss is a partial or total inability to hear Hearing, or auditory perception, is the ability to perceive Sound, soun ...
s and wristwatches to battery banks the size of rooms that provide standby power for
telephone exchange A telephone exchange, telephone switch, or central office is a system used in the (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish s between subscribers. In histori ...

telephone exchange
s and computer
data center A data center (American English) or data centre (British English)See American and British English spelling differences#-re, -er, spelling differences. is a building, a dedicated space within a building, or a group of buildings used to house comp ...
s.


Electric power industry

The electric power industry provides the production and delivery of power, in sufficient quantities to areas that need
electricity Electricity is the set of physical Physical may refer to: *Physical examination, a regular overall check-up with a doctor *Physical (album), ''Physical'' (album), a 1981 album by Olivia Newton-John **Physical (Olivia Newton-John song), "Physi ...

electricity
, through a
grid connection An electrical grid is an interconnected network for electricity delivery Electricity delivery is the process that starts after generation of electricity in the power station A power station, also referred to as a power plant and someti ...
. The grid distributes electrical energy to customers. Electric power is generated by central
power station A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation A generation is "all of the people born and living Living or The Living may refer to: ...

power station
s or by
distributed generation Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred t ...
. The electric power industry has gradually been trending towards deregulation – with emerging players offering consumers competition to the traditional public utility companies.


Use

Electric power, produced from central generating stations and distributed over an electrical transmission grid, is widely used in industrial, commercial and consumer applications. The per capita electric power consumption of a country correlates with its industrial development. Ignacio J. Pérez-Arriaga (ed), ''Regulation of the Power Sector'', Springer Science & Business Media, 2014 , page 8 Electric motors power manufacturing machinery and propel subways and railway trains. Electric lighting is the most important form of artificial light. Electrical energy is used directly in processes such as extraction of aluminum from its ores and in production of steel in
electric arc furnace An electric arc furnace (EAF) is a furnace A furnace is a structure in which heat is produced with the help of combustion. Furnace may also refer to: Appliances Buildings * Furnace (house heating): a furnace , or a heater or boiler , used to ...

electric arc furnace
s. Reliable electric power is essential to telecommunications and broadcasting. Electric power is used to provide air conditioning in hot climates, and in some places electric power is an economically competitive source of energy for building space heating. Use of electric power for pumping water ranges from individual household wells to irrigation projects and energy storage projects.


See also

*
EGRID The Emissions & Generation Resource Integrated Database (eGRID) is a comprehensive source of data on the environmental characteristics of almost all electric power Electric power is the rate, per unit time, at which electrical energy Electric ...
*
Electric energy consumption Electric energy consumption is the form of energy consumption Energy consumption is the amount of energy or power used. Biology In the body, energy consumption is part of energy homeostasis. It derived from food energy. Energy consumption in ...
*
Electric power system An electric power system is a network of electrical components deployed to supply, transfer, and use electric power. An example of a power system is the electrical grid An electrical grid is an interconnected network for electricity delivery ...
*
High-voltage cable A high-voltage cable (HV cable) is a cable used for electric power transmission Electric power transmission is the bulk movement of electrical energy Electrical energy is energy derived as a result of movement of electrically charged particles ...
*
Power engineering Power engineering, also called power systems engineering, is a subfield of electrical engineering that deals with the generation, transmission, distribution, and utilization of electric power Electric power is the rate, per unit time, at whic ...
*
Rural electrification Rural electrification is the process of bringing electrical power Electric power is the rate, per unit time, at which electrical energy Electrical energy is energy derived from electric potential energy or kinetic energy. When used loosely, ...


References


Bibliography


Reports on August 2003 Blackout, North American Electric Reliability Council website
* *


External links




GlobTek, Inc. Glossary of Electric power Power Supply Terms
{{Authority control
Power Power typically refers to: * Power (physics) In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. In older works, p ...
Temporal rates