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Electricity generation is the process of generating
electric power 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 conve ...
from sources of
primary energy Primary energy (PE) is an energy In , energy is the that must be to a or to perform on the body, or to it. Energy is a ; the law of states that energy can be in form, but not created or destroyed. The unit of measurement in the ...
. For
utilities A public utility company (usually just utility) is an organization that maintains the infrastructure Infrastructure is the set of fundamental facilities and systems that support the sustainable functionality of households and firms. Serving a ...
in 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 ...
, it is the stage prior to its
delivery Delivery may refer to: *Delivery (commerce), of goods, e.g.: **Pizza delivery **Milk delivery Film and television *Delivering (film), ''Delivering'' (film), a 1993 short film by Todd Field *Delivery (film), ''Delivery'' (film), a 2005 animated sho ...
(
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 ...
, etc.) to end users or its storage (using, for example, the
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 ...
method). Electricity is not freely available in nature, so it must be "produced" (that is, transforming other forms of energy to electricity). Production is carried out in
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 (also called "power plants"). Electricity is most often generated at a power plant by
electromechanical In engineering Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad ran ...
generators, primarily 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 fueled 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 ...
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
but also by other means such as 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. Other energy sources include solar
photovoltaics 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 commercially u ...
and
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 ...
. Phasing out coal-fired power stations and eventually gas-fired power stations, or
capturing their greenhouse gas emissions
capturing their greenhouse gas emissions
, is an important part of the
energy transformation In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physics), motion and behavior thro ...
required to limit climate change. Vastly more
solar power Solar power is the conversion of renewable energy Renewable energy is energy that is collected from renewable resource File:Global Vegetation.jpg, Global vegetation A renewable resource, also known as a flow resource, is a natural re ...

solar power
and
wind power Wind power or wind energy is the use of wind turbine A wind turbine is a device that converts Religious conversion is the adoption of a set of beliefs identified with one particular religious denomination A religious denomination ...

wind power
is forecast to be required, with
electricity demand World energy supply and consumption is global production and preparation of fuel, generation of electricity, energy transport and energy consumption. It is a basic part of economic activity. It does not include energy from food. Many countries p ...
increasing strongly with further
electrification Electrification is the process of powering by electricity Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, mo ...

electrification
of
transport Transport (in British English British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, and standard) is a language variety that has undergone substantial codification of grammar and ...

transport
, homes and industry.


History

The fundamental principles of electricity generation were discovered in the 1820s and early 1830s by 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 method, still used today, is for electricity to be generated by the movement of a loop of wire, or
Faraday disc A homopolar generator is a DC electrical generator In electricity generation, a generator is a device that converts motive power ( mechanical energy) into electrical power for use in an external circuit. Sources of mechanical energy include st ...

Faraday disc
, 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
. Central power stations became economically practical with the development of
alternating current Alternating current (AC) is 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'' 'natu ...
(AC) power transmission, using power
transformer A transformer is a passive electrical device that transfers electrical energy from one electrical circuit to another, or multiple Electrical network, circuits. A varying current in any one coil of the transformer produces a varying magnetic flux ...

transformer
s to transmit power at high voltage and with low loss. Commercial electricity production started with the coupling of the dynamo to the hydraulic turbine. The mechanical production of electric power began the
Second Industrial Revolution The Second Industrial Revolution, also known as the Technological Revolution, was a phase of rapid and from the late 19th century into the early 20th century. The , which ended in the middle of the 19th century, was punctuated by a slowdow ...
and made possible several inventions using electricity, with the major contributors being
Thomas Alva Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman who has been described as America's greatest inventor. He developed many devices in fields such as electric power generation Electricity gener ...

Thomas Alva Edison
and
Nikola Tesla Nikola Tesla ( ; sr-cyr, Никола Тесла, ; 10 July 1856 – 7 January 1943) was a Serbian-American inventor, electrical engineer, mechanical engineer, and futurist best known for his contributions to the design of the moder ...

Nikola Tesla
. Previously the only way to produce electricity was by chemical reactions or using battery cells, and the only practical use of electricity was for the
telegraph Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus is a method of telegraphy, whereas is not. Ancien ...

telegraph
. Electricity generation at central power stations started in 1882, when a
steam engine from Stott Park Bobbin Mill, Cumbria, England A steam engine is a heat engine In thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energ ...

steam engine
driving a dynamo at
Pearl Street Station Pearl Street Station was the first commercial central power plant in the United States. It was located at 255–257 Pearl Street in the Financial District of Manhattan Manhattan (), known regionally as the City and the urban core of the Ne ...
produced a
DC current DC, D.C., Dc, or dc may refer to: Arts and entertainment Music * ''Da capo Da capo (, also , ) is an Italian language, Italian musical term that means "from the beginning" (literally, "from the head"). It is often abbreviated as D.C. The term ...
that powered public lighting on Pearl Street,
New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * New ...

New York
. The new technology was quickly adopted by many cities around the world, which adapted their gas-fueled street lights to electric power. Soon after electric lights would be used in public buildings, in businesses, and to power public transport, such as trams and trains. The first power plants used water power or coal. Today a variety of energy sources are used, such as
coal Coal is a combustible , Germany ) , image_map = , map_caption = , map_width = 250px , capital = Berlin , coordinates = , largest_city = capital , languages_type = Official language , languages = German language, German , ...

coal
,
nuclear
nuclear
,
natural gas Natural gas (also called fossil gas; sometimes just gas) is a naturally occurring hydrocarbon gas mixture consisting of methane and commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxid ...

natural gas
,
hydroelectric Hydroelectricity, or hydroelectric power, is electricity produced from hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water Water (chemical formula H2O) is a ...
,
wind Wind is the natural movement of air or other gases relative to a planet's surface. Wind occurs on a range of scales, from thunderstorm A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by th ...

wind
, and
oil An oil is any nonpolar In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound ...

oil
, as well as
solar energy Solar energy is Solar irradiance, radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy including solar water heating, and solar architecture. It ...

solar energy
,
tidal power#REDIRECT Tidal power Tidal power or tidal energy is harnessed by converting energy from tide (U.S.), low tide occurs roughly at moonrise and high tide with a high Moon, corresponding to the simple gravity model of two tidal bulges; at most ...
, and geothermal sources. In the 1880s the popularity of electricity grew massively with the introduction of the
Incandescent light bulb An incandescent light bulb, incandescent lamp or incandescent light globe is an with a wire heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from . Current is supplied to the ...

Incandescent light bulb
. Although there are 22 recognised inventors of the light bulb prior to
Joseph Swan Sir Joseph Wilson Swan Fellow of the Royal Society, FRS (31 October 1828 – 27 May 1914) was an English physicist, chemist, and inventor. He is known as an independent early developer of a successful incandescent light bulb, and is the per ...
and
Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation Electricity generation is the process of generating electric power from s ...

Thomas Edison
, Edison and Swan's invention became by far the most successful and popular of all. During the early years of the 19th century, massive jumps in
electrical sciences
electrical sciences
were made. And by the later 19th century the advancement of electrical technology and engineering led to electricity being part of everyday life. With the introduction of many electrical inventions and their implementation into everyday life, the demand for electricity within homes grew dramatically. With this increase in demand, the potential for Profit was seen by many entrepreneurs who began investing into electrical systems to eventually create the first electricity public utilities. This process in history is often described as electrification. The earliest distribution of electricity came from companies operating independently of one another. A consumer would purchase electricity from a producer, and the producer would distribute it through their own power grid. As technology improved so did the productivity and efficiency of its generation. Inventions such as the
steam turbine A steam turbine is a machine A machine is any physical system with ordered structural and functional properties. It may represent human-made or naturally occurring device molecular machine that uses Power (physics), power to apply Force, f ...
had a massive impact on the efficiency of electrical generation but also the economics of generation as well. This conversion ofheat energy into mechanical work was similar to that of
Steam engine from Stott Park Bobbin Mill, Cumbria, England A steam engine is a heat engine In thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energ ...

Steam engine
s, however at a significantly larger scale and far more productively. The improvements of these large-scale generation plants were critical to the process of centralised generation as they would become vital to the entire power system that we now use today. Throughout the middle of the 20th century many utilities began merging their distribution networks due to economic and efficiency benefits. Along with the invention of long-distance power transmission, the coordination of power plants began to form. This system was then secured by regional system operators to ensure stability and reliability. The electrification of homes began in Northern Europe and in the Northern America in the 1920s in large cities and urban areas. It wasn't until the 1930s that rural areas saw the large-scale establishment of electrification.


Methods of generation

Several fundamental methods exist to convert other forms of energy into electrical energy. Utility-scale generation is achieved by rotating electric generators or by
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
systems. A small proportion of electric power distributed by utilities is provided by batteries. Other forms of electricity generation used in niche applications include the
triboelectric effect The triboelectric effect (also known as triboelectric charging) is a type of contact electrification on which certain materials become electric charge, electrically charged after they are separated from a different material with which they were in ...
, the
piezoelectric effect Piezoelectricity (, ) is the that accumulates in certain solid materials—such as s, certain s, and biological matter such as bone, , and various s—in response to applied . The word ''piezoelectricity'' means electricity resulting from pressu ...

piezoelectric effect
, the
thermoelectric effect The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa via a thermocouple. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely, when ...

thermoelectric effect
, and betavoltaics.


Generators

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, deliv ...
s transform
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 ...
into electricity. This is the most used form for generating electricity and is based on Faraday's law. It can be seen experimentally by rotating a magnet within closed loops of conducting material (e.g. copper wire). Almost all commercial electrical generation is done using electromagnetic induction, in which
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 ...
forces a generator to rotate.


Electrochemistry

Electrochemistry Electrochemistry is the branch of physical chemistry Physical chemistry is the study of macroscopic The macroscopic scale is the length scale on which objects or phenomena are large enough to be visible with the naked eye, without magnifying ...

Electrochemistry
is the direct transformation of
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 ...
into electricity, as in 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 ...
. Electrochemical electricity generation is important in portable and mobile applications. Currently, most electrochemical power comes from batteries.
Primary cell A primary cell is 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 ...
s, such as the common zinc–carbon batteries, act as power sources directly, but
secondary cell A rechargeable battery, storage battery, or secondary cell, (or archaically accumulator) is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or primary battery, wh ...
s (i.e. rechargeable batteries) are used for storage systems rather than primary generation systems. Open electrochemical systems, known as
fuel cell A fuel cell is an 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, ''electri ...

fuel cell
s, can be used to extract power either from natural fuels or from synthesized fuels. Osmotic power is a possibility at places where salt and fresh water merge.


Photovoltaic effect

The
photovoltaic effect The photovoltaic effect is the generation of voltage and electric current in a material upon exposure to light. It is a physical property, physical and chemical phenomenon. The photovoltaic effect is closely related to the photoelectric effect. Fo ...
is the transformation of light into electrical energy, as in
solar cell A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physics, physical and Chemical substance, chemical phenomenon.
s.
Photovoltaic panel
Photovoltaic panel
s convert sunlight directly to DC electricity.
Power inverter A power inverter, inverter or invertor is a power electronic device or circuitry that changes direct current Direct current (DC) is one-directional flow Flow may refer to: Science and technology * Flow (fluid) or fluid dynamics, the motion ...
s can then convert that to AC electricity if needed. Although sunlight is free and abundant,
solar power Solar power is the conversion of renewable energy Renewable energy is energy that is collected from renewable resource File:Global Vegetation.jpg, Global vegetation A renewable resource, also known as a flow resource, is a natural re ...

solar power
electricity is still usually more expensive to produce than large-scale mechanically generated power due to the cost of the panels. Low-efficiency silicon solar cells have been decreasing in cost and multijunction cells with close to 30% conversion efficiency are now commercially available. Over 40% efficiency has been demonstrated in experimental systems. Until recently, photovoltaics were most commonly used in remote sites where there is no access to a commercial power grid, or as a supplemental electricity source for individual homes and businesses. Recent advances in manufacturing efficiency and photovoltaic technology, combined with subsidies driven by environmental concerns, have dramatically accelerated the deployment of solar panels. Installed capacity is growing by 40% per year led by increases in Germany, Japan, United States, China, and India.


Economics

The selection of electricity production modes and their economic viability varies in accordance with demand and region. The economics vary considerably around the world, resulting in widespread residential selling prices, e.g. the price in Iceland is 5.54 cents per kWh while in some island nations it is 40 cents per kWh.
Hydroelectric plant Hydroelectricity, or hydroelectric power, is electricity produced from hydropower. In 2015, hydropower generated 16.6% of the world's total electricity and 70% of all renewable electricity,http://www.ren21.net/wp-content/uploads/2016/06/GSR ...
s,
nuclear power plant A nuclear power plant (sometimes abbreviated as NPP) is a thermal power station A thermal power station is a power station in which heat energy is converted to electricity. Typically, fuel is used to boil water in a large pressure vessel to ...

nuclear power plant
s,
thermal power plant A thermal power station is a power stationPower Station or The Power Station may refer to: * Power station, a facility for the generation of electricity Music * The Power Station (band), a 1980s supergroup ** ''The Power Station'' (album), ...
s and
renewable source Renewable energy is useful energy that is collected from renewable resources, which are naturally replenished on a Orders of magnitude (time), human timescale, including carbon neutral sources like sunlight, wind power, wind, rain, tidal power ...
s have their own pros and cons, and selection is based upon the local power requirement and the fluctuations in demand. All power grids have varying loads on them but the daily minimum is the base load, often supplied by plants which run continuously. Nuclear, coal, oil, gas and some hydro plants can supply base load. If well construction costs for natural gas are below $10 per MWh, generating electricity from natural gas is cheaper than generating power by burning coal.
Thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal energy refers to several distinct physical concepts, such as the internal energy of a system; heat or sensible heat, which are defined as types of energy transfer (as is ...
may be economical in areas of high industrial density, as the high demand cannot be met by local renewable sources. The effect of localized pollution is also minimized as industries are usually located away from residential areas. These plants can also withstand variation in load and consumption by adding more units or temporarily decreasing the production of some units. Nuclear power plants can produce a huge amount of power from a single unit. However, nuclear disasters have raised concerns over the safety of nuclear power, and the capital cost of nuclear plants is very high. Hydroelectric power plants are located in areas where the potential energy from falling water can be harnessed for moving turbines and the generation of power. It may not be an economically viable single source of production where the ability to store the flow of water is limited and the load varies too much during the annual production cycle. Due to advancements in technology, and with mass production, renewable sources other than hydroelectricity (solar power, wind energy) experienced decreases in cost of production, and the energy is now in many cases as expensive or less expensive than fossil fuels. Many governments around the world provide subsidies to offset the higher cost of any new power production, and to make the installation of
renewable energy Renewable energy is energy that is collected from renewable resource File:Global Vegetation.jpg, Global vegetation A renewable resource, also known as a flow resource, is a natural resource which will replenish to replace the portion resou ...
systems economically feasible.


Generating equipment

Electric generators were known in simple forms from the discovery of
electromagnetic induction Electromagnetic or magnetic induction is the production of an electromotive force In electromagnetism Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs b ...

electromagnetic induction
in the 1830s. In general, some form of prime mover such as an engine or the turbines described above, drives a rotating magnetic field past stationary coils of wire thereby turning mechanical energy into electricity. The only commercial scale electricity production that does not employ a generator is solar PV.


Turbines

Almost all commercial electrical power on Earth is generated with a
turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', ...

turbine
, driven by wind, water, steam or burning gas. The turbine drives a generator, thus transforming its mechanical energy into electrical energy by electromagnetic induction. There are many different methods of developing mechanical energy, including
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, hydro, wind and tidal power. Most electric generation is 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. The combustion of
fossil fuel A fossil fuel is a hydrocarbon In , a hydrocarbon is an consisting entirely of and . Hydrocarbons are examples of s. Hydrocarbons are generally colourless and hydrophobic with only weak odours. Because of their diverse molecular structure ...
s supplies most of the energy to these engines, with a significant fraction from
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
and some from
renewable source Renewable energy is useful energy that is collected from renewable resources, which are naturally replenished on a Orders of magnitude (time), human timescale, including carbon neutral sources like sunlight, wind power, wind, rain, tidal power ...
s. The modern
steam turbine A steam turbine is a machine A machine is any physical system with ordered structural and functional properties. It may represent human-made or naturally occurring device molecular machine that uses Power (physics), power to apply Force, f ...
(invented by
Sir Charles Parsons
Sir Charles Parsons
in 1884) currently generates about 80% of the
electric power 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 conve ...
in the world using a variety of heat sources. Turbine types include: * Steam ** Water is boiled by
coal Coal is a combustible , Germany ) , image_map = , map_caption = , map_width = 250px , capital = Berlin , coordinates = , largest_city = capital , languages_type = Official language , languages = German language, German , ...

coal
burned in a
thermal power plant A thermal power station is a power stationPower Station or The Power Station may refer to: * Power station, a facility for the generation of electricity Music * The Power Station (band), a 1980s supergroup ** ''The Power Station'' (album), ...
. About 41% of all electricity is generated this way. **
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
heat created in a
nuclear reactor A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a fission nuclear chain reaction 300px, A possible nuclear fission chain reaction: 1) A uranium-235 atom absorbs a neutron">uranium-235.html" ;"ti ...

nuclear reactor
creates steam. Less than 15% of electricity is generated this way. ** Renewable energy. The steam is generated by
biomass Biomass is plant or animal material used as fuel to produce electricity Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position ...

biomass
,
solar thermal energy Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in Industrial sector, industry, and in the residential and commercial sectors. Solar thermal collectors are classified ...
, or
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 ...
. * Natural gas: turbines are driven directly by gases produced by combustion.
Combined cycle A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. On land, when used to make electricity the most common type is called a combined cycle gas turbi ...
are driven by both steam and natural gas. They generate power by burning natural gas in a
gas turbine A gas turbine, also called a combustion turbine, is a type of continuous Continuity or continuous may refer to: Mathematics * Continuity (mathematics), the opposing concept to discreteness; common examples include ** Continuous probability di ...
and use residual heat to generate steam. At least 20% of the world's electricity is generated by natural gas. *Water Energy is captured by a
water turbine A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, the ...

water turbine
from the movement of water - from falling water, the rise and fall of tides or ocean thermal currents (see
ocean thermal energy conversion Ocean Thermal Energy Conversion (OTEC) uses the ocean thermal gradient between cooler deep and warmer shallow or surface seawaters to run a heat engine In thermodynamics Thermodynamics is a branch of physics that deals with heat, Work ( ...
). Currently, hydroelectric plants provide approximately 16% of the world's electricity. *The
windmill A windmill is a structure that converts wind power into rotational energy by means of vanes called windmill sail, sails or blades, specifically to mill (grinding), mill grain (gristmills), but the term is also extended to windpumps, wind turbine ...

windmill
was a very early
wind turbine A wind turbine is a device that converts Religious conversion is the adoption of a set of beliefs identified with one particular religious denomination A religious denomination is a subgroup within a religion Religion is a social s ...

wind turbine
. In 2018 around 5% of the world's electricity was produced from wind. Although turbines are most common in commercial power generation, smaller generators can be powered by
gasoline Gasoline () or petrol () (see the #Etymology, etymology for naming differences and the use of the term ''gas'') is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignition engine, spark-ignite ...

gasoline
or
diesel engine The diesel engine, named after Rudolf Diesel Rudolf Christian Karl Diesel ( (); 18 March 1858 – 29 September 1913) was a German inventor and mechanical engineer, famous for the invention of the Diesel engine The diesel engine, name ...

diesel engine
s. These may used for backup generation or as a prime source of power within isolated villages.


Production

Total worldwide gross production of electricity in 2016 was 25,082 TWh. Sources of electricity were coal and peat 38.3%, natural gas 23.1%, hydroelectric 16.6%, nuclear power 10.4%, oil 3.7%, solar/wind/geothermal/tidal/other 5.6%, biomass and waste 2.3%. :


Historical results of production of electricity


Production by country

The United States has long been the largest producer and consumer of electricity, with a global share in 2005 of at least 25%, followed by
China China (), officially the People's Republic of China (PRC; ), is a country in East Asia East Asia is the eastern region of Asia Asia () is Earth's largest and most populous continent, located primarily in the Eastern Hemisphere ...
, Japan, Russia, and India. In 2011, China overtook the United States to become the largest producer of electricity.


Environmental concerns

Variations between countries generating electrical power affect concerns about the environment. In France only 10% of electricity is generated from fossil fuels, the US is higher at 70% and China is at 80%.IE
Statistics and Balances
retrieved 2011-5-8
The cleanliness of electricity depends on its source. Most scientists agree that emissions of pollutants and greenhouse gases from fossil fuel-based electricity generation account for a significant portion of world greenhouse gas emissions. In the United States, fossil fuel combustion for electric power generation is responsible for 65% of all emissions of
sulfur dioxide Sulfur dioxide (IUPAC The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering OrganizationsNational Adhering Organizations in chemistry are the organizations that work as the autho ...
, the main component of acid rain. Electricity generation is the fourth highest combined source of
NOx In atmospheric chemistry Atmospheric chemistry is a branch of in which the of the and that of other planets is studied. It is a of research and draws on , , , , , and and other disciplines. Research is increasingly connected with other a ...

NOx
,
carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom. It is the simplest molecule of the oxocarbon family. In ...

carbon monoxide
, and
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in the US. According to the
International Energy Agency The International Energy Agency (IEA; french: Agence internationale de l'énergie) is a Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estima ...
(IEA), low-carbon electricity generation needs to account for 85% of global electrical output by 2040 in order to ward off the worst effects of climate change. Like other organizations including the Energy Impact Center (EIC) and the United Nations Economic Commission for Europe (UNECE), the IEA has called for the expansion of nuclear and renewable energy to meet that objective. Some, like EIC founder Bret Kugelmass, believe that nuclear power is the primary method for Low-carbon economy, decarbonizing electricity generation because it can also power direct air capture that removes existing carbon emissions from the atmosphere. Nuclear power plants can also create district heating and desalination projects, limiting carbon emissions and the need for expanded electrical output. A fundamental issue regarding centralised generation and the current electrical generation methods in use today is the significant negative environmental effects that many of the generation processes have. Processes such as coal and gas not only release carbon dioxide as they combust, but their extraction from the ground also impacts the environment. Open pit coal mines use large areas of land to extract coal and limit the potential for productive land use after the excavation. Natural gas extraction releases large amounts of methane into the atmosphere when extracted from the ground greatly increase global greenhouse gasses. Although nuclear power plants to not release carbon dioxide through electricity generation, there are significant risks associated with nuclear waste and safety concerns associated with the use of nuclear sources. This fear of nuclear power stems from large-scale nuclear catastrophes such as the Chernobyl Disaster and the Fukushima Daiichi nuclear disaster. Both tragedies led to significant casualties and the radioactive contamination of large areas.


Centralised generation

Centralised generation refers the common process of electricity generation through large-scale centralised facilities, through Transmission lines to consumer. These facilities are usually located far away from consumers and distribute the electricity through high voltage transmission lines to a substation where it is then distributed to consumers. The basic concept being that incredibly large stations create electricity for a large group of people. The Vast majority of electricity used is created from Centralised Generation. Most Centralised Power Generation comes from large power plants run by fossil fuels such as coal or natural gas. Nuclear or large hydroelectricity plants are also commonly used. Many disagree with the processes of Centralised Generation as it often relies on electrical generation through processes of the combustion of fossil fuels, which are bad for the environment. However unsustainable the current system is, it is by far the most widely used, reliable and efficient system that is currently in use. Centralised Generation is fundamentally the opposite of distributed generation. Distributed generation is the small-scale generation of electricity to smaller groups of consumers. This can also include independently producing electricity by either solar or wind power. In recent years Distributed generation as has seen a spark in popularity due to its propensity to use
renewable energy Renewable energy is energy that is collected from renewable resource File:Global Vegetation.jpg, Global vegetation A renewable resource, also known as a flow resource, is a natural resource which will replenish to replace the portion resou ...
generation methods such as wind and solar.


Technologies

Centralised energy sources are large Thermal power stations that produce huge amounts of electricity to a large number of consumers. This is the traditional way of producing energy. Almost all power plants used in centralised generation are thermal power plants meaning that they use a fuel to heat steam to produce a pressurised gas which in turn spins a turbine and generates electricity. This process relies on several forms of technology to produce widespread electricity, these being natural coal, gas and nuclear forms of thermal generation.


Coal

Coal power stations produce steam by burning coal dug up from the earth. This steam, under intensely high-pressure forces into a turbine. These turbines are connected to generators that spin at high speeds creating electricity. Following the generation, the steam is cooled back into water to be heated once again to produce electricity. A single coal power plant can produce electricity for 700,00 homes, however, can use up to 14,000 tonnes of coal a day to heat its boiler. The fundamental issues regarding the use of coal in electricity generation is to with the Greenhouse gasses released by the burning of coal, and the limited amount of coal on earth, leading many to agree that is a very unsustainable way of producing electricity.


Natural gas

Natural gas is ignited to create pressurised gas which is used to spin turbines to generate electricity. Natural gas plants use a
gas turbine A gas turbine, also called a combustion turbine, is a type of continuous Continuity or continuous may refer to: Mathematics * Continuity (mathematics), the opposing concept to discreteness; common examples include ** Continuous probability di ...
where natural gas is added along with oxygen which in turn combusts and expands through the turbine to force a generator to spin. Natural gas power plants are more efficient than coal power generation, they however contribute to climate change but not as highly as coal generation. Not only do they produce carbon dioxide from the ignition of natural gas, but also the extraction of gas when mined releases a significant amount of methane into the atmosphere.


Nuclear

Nuclear power plants create electricity through the process of
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
. Currently nuclear power produces 11% of all electricity in the world. Nuclear reactors use uranium as a source of fuel to power the reactors. When these Atomic theory, nuclear atoms are split a sudden release in energy is formed and can be converted into heat. This process is called nuclear fission. Electricity is created through the use of a nuclear reactor where heat produced by nuclear fission is used to produce steam which in turn spins turbines and powers the generators. Although there are several types on nuclear reactors, but all fundamentally use this process. Although nuclear energy produces very little emissions, several accidents throughout history have led many to speculate the safety and risk associated with these plants. Accidents such as the Chernobyl disaster and the Fukushima Daiichi nuclear disaster have led many to disagree with the practice of nuclear energy generation.


Uses

Although there is variation in the amount of electricity needed at all times, the base load is the minimum amount of energy required at one time, this is the majority of all energy and must be created by large power stations that have the ability to run all day, every day. Only Nuclear, coal, oil, gas and some hydro plants can reliably supply the base load. Many greener methods rely heavily on variables such as the sun and wind and thus their output varies too much to support the base load. Highly industrial areas tend to be powered almost entirely by thermal energy plants such as coal or gas-powered plants, as their huge power output is necessary to power industry in the region. The localised effect of pollution is also minimal as industrial regions are usually far from suburban areas. The plants can also cope with large variation in power output by adjusting the production of the turbines. Large thermal power plants produce the vast majority of electricity for residential areas, although there has been an increase in renewable sources of energy, it still only makes up around 8% of all electricity consumed. However, these renewable sources of electricity, aid in fluctuations of electricity demand as they are often easy to adjust the output required to meet the needs of the grid. Through Transmission line the majority of electricity is distributed to residential areas.


Features

The total amount of electricity used fluctuates depends highly on factors such as the time of the day, date and the weather. When demand varies operators must vary total output from the power plants. This is usually done through collaboration with other power plants thus keeping on power grid in an equilibrium. This adds a complication for the entire Electrical grid, power grid as it is often difficult to adjust the power output of large thermal power plants. Although confusing and often inefficient, Centralised generation is the most popular way of energy production and distribution in the world. The three major aspects of centralised generation are: generation, Transmission tower, transmission and
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.


Generation

Electricity is generated throughout the world in many ways using a variety of resources. The three most common resources used are natural gas, nuclear and coal. But renewable sources of generation are quickly growing. the most common way to generate electricity is through the transformation of kinetic energy into electricity by large Electric generators. The vast majority of electrical generation is produced through
electromagnetic induction Electromagnetic or magnetic induction is the production of an electromotive force In electromagnetism Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs b ...

electromagnetic induction
, where mechanical energy through a turbine drives a generator rotate to produce electricity. Often utilities need to purchase more electricity through a wholesale market from a rival utility or wholesale retailer, this is brokered and organised by a regional transmission reliability organisation. It is necessary for utilities to produce electricity far away from consumers as the plants are large and release extensive greenhouse gasses. Thus, there is a major process of transporting electricity from the generation plants to consumers.


Centralised generation vs distributed generation

Centralised generation vs distributed generation is an argument that has recently surfaced, with many claiming that centralised generation is a way of the past and that distributed generation is the future of electricity production. Distributed Generation is the process of small-scale production of electricity often by individuals having their own way of producing energy that they then use. Distributed energy is usually described as using environmentally sustainable practices such as solar or wind opposed to nuclear, gas or coal. An example of this would be solar panels on one's house or a small local energy producer. Distributed energy is usually seen as far better for the environment as it does not use large thermal combustion to produce energy. It also does not rely on a network of power grids that can often be unreliable and leave many without power. Over the past few years many there has been a major increase in the use of Distributed Generation as many governments are promoting the use of this technology through subsidies as a way of reducing greenhouse gas emissions, greenhouse emissions. But others say that the economies of scale of centralised generation outweigh the transmission costs.


See also

* Cogeneration: the use of a heat engine or power station to generate electricity and useful heat at the same time. * Cost of electricity by source * Diesel generator *
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, deliv ...
* Engine-generator * Electric power transmission * World energy consumption: the total energy used by all of human civilization. * Electrification *
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
* Generation expansion planning * Cogeneration: the use of a heat engine or power station to generate electricity and useful heat at the same time. * Diesel generator * Distributed generation * Electric power transmission * Engine-generator * Power station * World energy consumption: the total energy used by all of human civilization.


References

{{DEFAULTSORT:Electricity Generation Power engineering Fossil fuel power stations Electric power generation, Infrastructure