View source for Electricity generation

{{Short description|Process of generating electrical power}}
{{use mdy dates|date=December 2024}}
[[File:Turbogenerator01.jpg|thumb|upright=1.3|A [[turbo generator]]]]
{{Power engineering}}
'''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|delivery]] ([[Electric power transmission|transmission]], [[Electric power distribution|distribution]], etc.) to end users or its [[Grid energy storage|storage]], using for example, the [[Pumped-storage hydroelectricity|pumped-storage]] method.

Consumable electricity is not freely available in nature, so it must be "produced", transforming other forms of energy to electricity. Production is carried out in [[power station]]s, also called "power plants". Electricity is most often generated at a power plant by [[electromechanical]] [[electric generator|generators]], primarily driven by [[heat engine]]s fueled by [[combustion]] or [[nuclear fission]], but also by other means such as the [[kinetic energy]] of flowing water and wind. Other energy sources include solar [[photovoltaics]] and [[geothermal power]]. There are exotic and speculative methods to recover energy, such as proposed [[fusion reactor]] designs which aim to directly extract energy from intense magnetic fields generated by fast-moving charged particles generated by the fusion reaction (see [[magnetohydrodynamics]]).<!-- Helion Energy in particular, but it's a general physical concept, and I see no reason to pump their IPO in specific terms --> 

[[Coal phase-out|Phasing out coal-fired power stations]] and eventually [[Gas-fired power plant|gas-fired power stations]],<ref>{{Cite news|last=Chestney|first=Nina|date=2021-05-14|title=Factbox: Getting out of gas - the sold and scrapped projects|language=en|work=Reuters|url=https://www.reuters.com/business/energy/getting-out-gas-sold-scrapped-projects-2021-05-14/|access-date=2021-11-27|archive-date=2021-11-27|archive-url=https://web.archive.org/web/20211127114357/https://www.reuters.com/business/energy/getting-out-gas-sold-scrapped-projects-2021-05-14/|url-status=live}}</ref> or, if practical, [[Carbon capture and storage |capturing their greenhouse gas emissions]], is an important part of the [[energy transformation]] required to [[Climate change mitigation|limit climate change]]. Vastly more [[solar power]]<ref name = solar>{{Cite web|title=Solar PV – Analysis|url=https://www.iea.org/reports/solar-pv|access-date=2021-11-27|website=IEA|language=en-GB|archive-date=2021-11-27|archive-url=https://web.archive.org/web/20211127114139/https://www.iea.org/reports/solar-pv|url-status=live}}</ref> and [[wind power]]<ref>{{Cite news|date=2021-11-04|title=What would a world powered entirely by offshore wind look like?|newspaper=The Economist|url=https://www.economist.com/graphic-detail/2021/11/04/what-would-a-world-powered-entirely-by-offshore-wind-look-like |url-access=subscription |access-date=2021-11-27|issn=0013-0613|archive-date=2021-11-26|archive-url=https://web.archive.org/web/20211126223048/https://www.economist.com/graphic-detail/2021/11/04/what-would-a-world-powered-entirely-by-offshore-wind-look-like|url-status=live}}</ref> is forecast to be required, with [[electricity demand]] increasing strongly<ref>{{Cite web|title=Electricity – Global Energy Review 2021 – Analysis|url=https://www.iea.org/reports/global-energy-review-2021/electricity |date=April 2021 |access-date=2021-11-27|website=IEA|language=en-GB|archive-date=2021-11-27|archive-url=https://web.archive.org/web/20211127114139/https://www.iea.org/reports/global-energy-review-2021/electricity|url-status=live}}</ref> with further [[electrification]] of [[Electric vehicle|transport]], homes and industry.<ref>{{Cite web |first1=Rory |last1=Shadbolt |date=2021-11-26 |title=Accelerated renewables-based electrification for the future|url=http://www.selectscience.net/industry-news/accelerated-renewables-based-electrification-paves-the-way-for-a-post-fossil-future/?artID=56222|access-date=2021-11-27|website=SelectScience |archive-date=2021-11-27|archive-url=https://web.archive.org/web/20211127085350/https://www.selectscience.net/industry-news/accelerated-renewables-based-electrification-paves-the-way-for-a-post-fossil-future?artID=56222|url-status=live}}</ref> However, in 2023, it was reported that the global electricity supply was approaching peak CO<sub>2</sub> emissions thanks to the growth of solar and wind power.<ref>{{Cite web |last=Lempriere |first=Molly |date=2023-10-04 |title=World's electricity supply close to 'peak emissions' due to growth of wind and solar |url=https://www.carbonbrief.org/worlds-electricity-supply-close-to-peak-emissions-due-to-growth-of-wind-and-solar/ |access-date=2023-11-08 |website=Carbon Brief |language=en}}</ref>

== History ==
[[File:Edison Central Station Dynamos and Engine.jpg|thumb|Dynamos and engine installed at [[Edison General Electric Company]], New York, 1895]]

The fundamental principles of electricity generation were discovered in the 1820s and early 1830s by British scientist [[Michael Faraday]]. His method, still used today, is for electricity to be generated by the movement of a loop of wire, or [[Faraday disc]], between the poles of a [[magnet]]. Central power stations became economically practical with the development of [[alternating current]] (AC) power transmission, using power [[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]] and made possible several inventions using electricity, with the major contributors being [[Thomas Alva Edison]] and [[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]].

Electricity generation at central power stations started in 1882, when a [[steam engine]] driving a dynamo at [[Pearl Street Station]] produced a [[DC current]] that powered public lighting on [[Pearl Street (Manhattan)|Pearl Street]], [[New York City|New York]]. The new technology was quickly adopted by many cities around the world, which adapted their gas-fueled street lights to electric power. Electric lights were soon 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.<ref>{{Cite web|url=http://ethw.org/Pearl_Street_Station|title=Pearl Street Station - Engineering and Technology History Wiki|website=ethw.org|access-date=2016-08-14|archive-date=2016-08-26|archive-url=https://web.archive.org/web/20160826031218/http://ethw.org/Pearl_Street_Station|url-status=live}}</ref> Today a variety of energy sources are used, such as coal, nuclear, natural gas, hydroelectric, wind, and oil, as well as solar energy, [[tidal power]], and [[Geothermal power|geothermal]] sources.

In the 1880s the popularity of electricity grew massively with the introduction of the [[Incandescent light bulb]]. Although there are 22 recognised inventors of the light bulb prior to [[Joseph Swan]] and [[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 [[Electromagnetism|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.<ref>{{Cite web|title=History of Electrification Sites|url=https://edisontechcenter.org/HistElectPowTrans.html|access-date=2019-06-08 |website=edisontechcenter.org|archive-date=2019-05-25 |archive-url=https://web.archive.org/web/20190525012849/http://edisontechcenter.org/HistElectPowTrans.html|url-status=live}}</ref>

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]] had a massive impact on the efficiency of electrical generation but also the economics of generation as well. This conversion of heat energy into mechanical work was similar to that of [[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 [[Electric power distribution|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 was not until the 1930s that rural areas saw the large-scale establishment of electrification.<ref>{{Cite web|title=Power Grid History|url=https://www.itc-holdings.com/a-modern-power-grid/power-grid-history|access-date=2019-06-08 |website=www.itc-holdings.com|archive-date=2019-06-08 |archive-url=https://web.archive.org/web/20190608053530/https://www.itc-holdings.com/a-modern-power-grid/power-grid-history|url-status=live}}</ref>

== Methods of generation ==
{{Latest pie chart of world power by source}}
Several fundamental methods exist to convert other forms of energy into electrical energy. Utility-scale generation is achieved by rotating [[electric generator]]s or by [[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 [[piezoelectric effect]], the [[thermoelectric effect]], and [[betavoltaics]].

=== Generators ===
{{main|Electric generator}}
[[File: Turbine aalborg.jpg|thumb|right|upright|[[Wind turbine]]s usually provide electrical generation in conjunction with other methods of producing power.]]
[[Electric generator]]s transform [[kinetic energy]] into electricity. This is the most used form for generating electricity based on [[Faraday's law of induction|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 uses electromagnetic induction, in which [[mechanical energy]] forces a generator to rotate.

=== Electrochemistry ===
[[File:Hoover dam from air.jpg|thumb|Large dams, such as [[Hoover Dam]] in the United States, can provide large amounts of [[hydroelectric power]]. It has an installed capacity of 2.07 [[Gigawatt|GW]].]]

[[Electrochemistry]] is the direct transformation of [[chemical energy]] into electricity, as in a [[battery (electricity)|battery]]. Electrochemical electricity generation is important in portable and mobile applications. Currently, most electrochemical power comes from batteries.<ref>[http://www.eere.energy.gov/news/archive.cfm/pubDate=%7Bd%20'2003-09-24'%7D#6490 World's Largest Utility Battery System Installed in Alaska] {{Webarchive|url=https://web.archive.org/web/20080627023319/http://www.eere.energy.gov/news/archive.cfm/pubDate%3D%7Bd%20%272003-09-24%27%7D#6490 |date=2008-06-27 }} (press release, 2003-09-24), U.S. Department of Energy. ''"13,670 nickel-cadmium battery cells to generate up to 40 megawatts of power for about 7 minutes, or 27 megawatts of power for 15 minutes."''</ref> [[Primary cell]]s, such as the common [[Zinc–carbon battery|zinc–carbon batteries]], act as power sources directly, but [[secondary cell]]s (i.e. rechargeable batteries) are used for [[electricity storage|storage]] systems rather than primary generation systems. Open electrochemical systems, known as [[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]] is the transformation of light into electrical energy, as in [[solar cell]]s. [[Photovoltaic panel]]s convert sunlight directly to DC electricity. [[Power inverter]]s can then convert that to AC electricity if needed. The photovoltaic industry has undergone [[Growth of photovoltaics|spectacular growth]] since the 1990s.

== Economics ==
{{see also|Cost of electricity by source|Electricity pricing}}
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. [[Hydroelectric plant]]s, [[nuclear power plant]]s, [[thermal power plant]]s and [[renewable source]]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. The daily minimum<ref>{{Cite web |title=Baseload power - Energy Education |url=https://energyeducation.ca/encyclopedia/Baseload_power |access-date=2025-09-17 |website=energyeducation.ca}}</ref> 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.<ref>{{cite news |url=https://www.forbes.com/sites/modeledbehavior/2013/03/22/will-natural-gas-stay-cheap-enough-replace-coal-and-lower-us-carbon-emissions/ |work=Forbes |first=Karl |last=Smith |title=Will Natural Gas Stay Cheap Enough To Replace Coal And Lower Us Carbon Emissions |date=2013-03-22 |access-date=2015-06-20 |archive-date=2017-11-02 |archive-url=https://web.archive.org/web/20171102170549/https://www.forbes.com/sites/modeledbehavior/2013/03/22/will-natural-gas-stay-cheap-enough-replace-coal-and-lower-us-carbon-emissions/ |url-status=live}}</ref>

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.

==Generating equipment==
{{main|Electric generator}}
[[File:Stator winding at WPS.JPG|thumb|upright=1.5|A large generator with the rotor removed]]
Electric generators were known in simple forms from the discovery of [[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.<ref>{{Cite book|chapter=Type testing a 2000 MW turbogenerator|first1=K.|last1=Sedlazeck|first2=C.|last2=Richter|first3=S.|last3=Strack|first4=S.|last4=Lindholm|first5=J.|last5=Pipkin|first6=F.|last6=Fu|first7=B.|last7=Humphries|first8=L.|last8=Montgomery|title=2009 IEEE International Electric Machines and Drives Conference|date=May 1, 2009|pages=465–470|via=IEEE Xplore|doi=10.1109/IEMDC.2009.5075247|isbn=978-1-4244-4251-5|s2cid=9118902}}</ref> The only commercial scale forms of electricity production that do not employ a generator are [[Photovoltaic power station|photovoltaic solar]] and [[hydrogen fuel cell power plant|fuel cells]].

=== Turbines ===
[[File: Dreischluchtendamm hauptwall 2006.jpg|thumb|Large dams such as [[Three Gorges Dam]] in China can provide large amounts of [[hydroelectric]] power; it has a 22.5 [[Gigawatt|GW]] capability.]]
Almost all commercial electrical power on Earth is generated with a [[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]]s, hydro, wind and tidal power. Most electric generation is driven by heat engines. 

The combustion of [[fossil fuel]]s supplies most of the energy to these engines, with a significant fraction from [[nuclear fission]] and some from [[renewable source]]s. The modern [[steam turbine]], invented by [[Charles Algernon Parsons|Sir Charles Parsons]] in 1884, currently generates about 80% of the [[electric power]] in the world using a variety of heat sources. Turbine types include:
* Steam 
** Water is boiled by [[coal]] burned in a [[thermal power plant]]. About 41% of all electricity is generated this way.<ref>{{Cite web|url=http://www.worldcoal.org/coal/uses-coal/coal-electricity|title=Coal & electricity|website=World Coal Association|access-date=2016-08-14|date=2015-04-29|archive-date=2016-08-23|archive-url=https://web.archive.org/web/20160823202732/http://www.worldcoal.org/coal/uses-coal/coal-electricity|url-status=live}}</ref>
** [[Nuclear fission]] heat created in a [[nuclear reactor]] creates steam. Less than 15% of electricity is generated this way.
** Renewable energy. The steam is generated by [[biomass]], [[solar thermal energy]], or [[geothermal power]].
* Natural gas: turbines are driven directly by gases produced by combustion. [[Combined cycle]] are driven by both steam and natural gas. They generate power by burning natural gas in a [[gas turbine]] 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]] from the movement of water - from falling water, the rise and fall of tides or ocean thermal currents (see [[ocean thermal energy conversion]]). Currently, hydroelectric plants provide approximately 16% of the world's electricity.
*The [[windmill]] was a very early [[wind turbine]]. In 2018 around 5% of the world's electricity was produced from wind.
Turbines can also use other heat-transfer liquids than steam. [[Supercritical carbon dioxide]] based cycles  can provide higher conversion efficiency due to faster heat exchange, higher energy density and simpler power cycle infrastructure. [[Supercritical carbon dioxide blend|Supercritical carbon dioxide blends]], that are currently in development, can further increase efficiency by optimizing its critical pressure and temperature points.

Although turbines are most common in commercial power generation, smaller generators can be powered by [[gasoline]] or [[diesel engine]]s. These may used for backup generation or as a prime source of power within isolated villages.

== World production ==

[[File:World generation type yearly.png |thumb|upright=1.5| Yearly generation by source<ref name="Yearly" />]]

Total world generation in 2024 was 30,850 TWh, including coal (34%), gas (22%), hydro (14%), nuclear (9%), wind (8%), solar (7%), oil and other fossil fuels (3%), biomass (2%).<ref name="Yearly">{{cite web |url=https://ember-climate.org/data-catalogue/yearly-electricity-data/ |title=Yearly electricity data |date=2023-12-06 |website=ember-climate.org |access-date=2023-12-23}}</ref>

=== Production by country ===

{{main|List of countries by electricity production}}
{{see also|Electric energy consumption}}

== Environmental concerns ==
{{main||Environmental impact of electricity generation}}
{{see also|Global warming|Coal phase out}}
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%.<ref name="Statistics and Balances">{{cite web |website=IEA |url=http://www.iea.org/stats/index.asp |title=Statistics and Balances |archive-url= https://web.archive.org/web/20110515014755/http://www.iea.org/stats/index.asp |archive-date=2011-05-15 |access-date=2011-07-12 |url-status=dead}}</ref> The cleanliness of electricity depends on its source. [[Methane leaks]] (from natural gas to fuel gas-fired power plants)<ref>{{Cite web |author1=Patrick Pester |date=2022-02-10 |title=Massive methane leaks mapped from space |url=https://www.livescience.com/massive-methane-plumes-mapped-from-space |access-date=2022-06-29 |website=Live Science |language=en |archive-date=2022-06-29 |archive-url=https://web.archive.org/web/20220629191620/https://www.livescience.com/massive-methane-plumes-mapped-from-space |url-status=live}}</ref> and [[carbon dioxide emissions]] from fossil fuel-based electricity generation account for a significant portion of world [[greenhouse gas emissions]].<ref>{{cite news |url=http://seattletimes.nwsource.com/html/nationworld/2003732690_carbon03.html |work=The Seattle Times |title=Carbon-emissions culprit? Coal |first=Seth |last=Borenstein |date=2007-06-03 |url-status=dead |archive-url=https://web.archive.org/web/20110424122332/http://seattletimes.nwsource.com/html/nationworld/2003732690_carbon03.html |archive-date=2011-04-24}}</ref> In the United States, fossil fuel combustion for electric power generation is responsible for 65% of all emissions of [[sulfur dioxide]], the main component of acid rain.<ref>{{cite web|title=Sulfur Dioxide|date=2016-11-16 |publisher=US Environmental Protection Agency|url=http://www.epa.gov/air/sulfurdioxide/|access-date=2010-04-23 |archive-date=2015-08-14 |archive-url=https://web.archive.org/web/20150814185654/http://www.epa.gov/air/sulfurdioxide/|url-status=dead}}</ref> Electricity generation is the fourth highest combined source of [[NOx|NO<sub>x</sub>]], [[carbon monoxide]], and [[Atmospheric particulate matter|particulate matter]] in the US.<ref>{{cite web|title=AirData|publisher=US Environmental Protection Agency|url=http://www.epa.gov/cgi-bin/broker?_service=airdata&_program=progs.webprogs.emcatbar.scl&_debug=2&geotype=us&geocode=USA&geoname=United+States&epol=CO+NOX+VOC+SO2+PM25+PM10&years=2002&mapsize=zsc&reqtype=viewmap|access-date=2010-04-21|archive-date=2015-09-24|archive-url=https://web.archive.org/web/20150924043929/http://www.epa.gov/cgi-bin/broker?_service=airdata&_program=progs.webprogs.emcatbar.scl&_debug=2&geotype=us&geocode=USA&geoname=United+States&epol=CO+NOX+VOC+SO2+PM25+PM10&years=2002&mapsize=zsc&reqtype=viewmap|url-status=dead}}</ref>

According to the [[International Energy Agency]] (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.<ref name="CEN">{{cite news| last=Johnson| first=Jeff| title=Can nuclear power help save us from climate change? |work=Chemical & Engineering News |date=September 23, 2019| url=https://cen.acs.org/energy/nuclear-power/nuclear-power-help-save-us/97/i37 |access-date=November 23, 2021 |archive-date=November 22, 2021| archive-url=https://web.archive.org/web/20211122005421/https://cen.acs.org/energy/nuclear-power/nuclear-power-help-save-us/97/i37| url-status=live}}</ref> Like other organizations including the [[Energy Impact Center]] (EIC)<ref>{{cite news| last=Takahashi| first=Dean| title=Last Energy raises $3 million to fight climate change with nuclear energy| work=VentureBeat| date=February 25, 2020| url=https://venturebeat.com/2020/02/25/last-energy-raises-3-million-to-fight-climate-change-with-nuclear-energy/ |access-date=November 23, 2021 |archive-date=January 12, 2021 |archive-url=https://web.archive.org/web/20210112122823/https://venturebeat.com/2020/02/25/last-energy-raises-3-million-to-fight-climate-change-with-nuclear-energy/ |url-status=live}}</ref> and the [[United Nations Economic Commission for Europe]] (UNECE),<ref name="UNECE">{{cite news |title=Global climate objectives fall short without nuclear power in the mix: UNECE |publisher=United Nations Economic Commission for Europe| date =August 11, 2021| url =https://news.un.org/en/story/2021/08/1097572 |access-date=November 23, 2021 |archive-date=November 22, 2021| archive-url =https://web.archive.org/web/20211122181724/https://news.un.org/en/story/2021/08/1097572 |url-status=live}}</ref> the IEA has called for the expansion of nuclear and renewable energy to meet that objective.<ref>{{cite news| last=Chestney| first=Nina| title=End new oil, gas and coal funding to reach net zero, says IEA |publisher=Reuters |date=May 18, 2021| url=https://www.reuters.com/business/environment/radical-change-needed-reach-net-zero-emissions-iea-2021-05-18/ |access-date=November 23, 2021| archive-date=November 17, 2021| archive-url=https://web.archive.org/web/20211117161210/https://www.reuters.com/business/environment/radical-change-needed-reach-net-zero-emissions-iea-2021-05-18/ |url-status=live}}</ref> 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.<ref>{{cite news| last=Kugelmass| first=Bret| title=Want to stop climate change? Embrace the nuclear option.| newspaper=USA Today| date=January 22, 2020| url=https://www.usatoday.com/story/opinion/2020/01/22/climate-change-solution-nuclear-energy-our-best-hope-column/2821183001/| access-date=November 23, 2021| archive-date=November 28, 2020| archive-url=https://web.archive.org/web/20201128063508/https://www.usatoday.com/story/opinion/2020/01/22/climate-change-solution-nuclear-energy-our-best-hope-column/2821183001/| url-status=live}}</ref> Nuclear power plants can also create [[district heating]] and [[desalination]] projects, limiting carbon emissions and the need for expanded electrical output.<ref>{{cite news| last=Patel| first=Sonal| title=How an AP1000 Plant Is Changing the Nuclear Power Paradigm Through District Heating, Desalination| work=Power Magazine |date=November 1, 2021| url=https://www.powermag.com/how-an-ap1000-plant-is-changing-the-nuclear-power-paradigm-through-district-heating-desalination/ |access-date=November 23, 2021| archive-date=June 3, 2022| archive-url=https://web.archive.org/web/20220603054050/https://www.powermag.com/how-an-ap1000-plant-is-changing-the-nuclear-power-paradigm-through-district-heating-desalination/ |url-status=live}}</ref>

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, which greatly increases global greenhouse gases. Although nuclear power plants do not release carbon dioxide through electricity generation, there are risks associated with nuclear waste and safety concerns associated with the use of nuclear sources. 

Per unit of electricity generated coal and gas-fired power [[Life-cycle greenhouse gas emissions of energy sources|life-cycle greenhouse gas emissions]] are almost always at least ten times that of other generation methods.<ref>{{Cite journal |last1=Scarlat |first1=Nicolae |last2=Prussi |first2=Matteo |last3=Padella |first3=Monica |date=2022-01-01 |title=Quantification of the carbon intensity of electricity produced and used in Europe |s2cid-access=free |journal=Applied Energy |language=en |volume=305 |article-number=117901 |doi=10.1016/j.apenergy.2021.117901 |s2cid=244177261 |issn=0306-2619 |doi-access=free |bibcode=2022ApEn..30517901S}}</ref>

==Centralised and distributed generation==
Centralised generation is electricity generation by large-scale centralised facilities, sent through [[transmission line]]s to consumers. 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 multi-megawatt or gigawatt scale large stations create electricity for a large number 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, though nuclear or large hydroelectricity plants are also commonly used.<ref>{{Cite web|url=https://www.epa.gov/energy/centralized-generation-electricity-and-its-impacts-environment|title=Centralized Generation of Electricity and its Impacts on the Environment |date=2015-08-04 |website=US EPA|language=en|access-date=2019-05-21 |archive-date=2019-05-19 |archive-url=https://web.archive.org/web/20190519055244/https://www.epa.gov/energy/centralized-generation-electricity-and-its-impacts-environment|url-status=live}}</ref>   

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]] generation methods such as [[Rooftop solar power|rooftop solar]].<ref>{{Cite journal |last1=Joshi |first1=Siddharth |last2=Mittal |first2=Shivika |last3=Holloway |first3=Paul |last4=Shukla |first4=Priyadarshi Ramprasad |last5=Ó Gallachóir |first5=Brian |last6=Glynn |first6=James |date=2021-10-05 |title=High resolution global spatiotemporal assessment of rooftop solar photovoltaics potential for renewable electricity generation |bibcode-access=free |doi-access=free |journal=Nature Communications |language=en |volume=12 |issue=1 |pages=5738 |doi=10.1038/s41467-021-25720-2 |pmid=34611151 |pmc=8492708 |bibcode=2021NatCo..12.5738J |issn=2041-1723}}</ref>

== Technologies==
Centralised energy sources are large [[Power station|power plants]] that produce huge amounts of electricity to a large number of consumers. Most power plants used in centralised generation are [[Thermal power station|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 is the traditional way of producing energy. This process relies on several forms of technology to produce widespread electricity, these being natural coal, gas and nuclear forms of thermal generation. More recently solar and wind have become large scale.

=== Solar ===
{{Excerpt|Solar farm}}

=== Hydroelectricity ===
{{main|hydroelectricity}}
[[File:ThreeGorgesDam-China2009.jpg|thumb|The [[Three Gorges Dam]] in [[Central China]] is the [[List of largest power stations in the world#Top 20 largest power producing facilities|world's largest]] power-producing facility of any kind.]]
Hydroelectricity is electricity generated from [[hydropower]] (water power). Hydropower supplies 15% of the world's [[electricity]], almost 4,210 [[TWh]] in 2023, which is more than all other [[Renewable energy|renewable sources]] combined and also more than [[nuclear power]]. Hydropower can provide large amounts of [[Low-carbon power|low-carbon electricity]] on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and [[reservoir]] is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand.

=== Wind ===
{{Excerpt|Wind farm}}

=== Coal===
{{Excerpt|Coal-fired power station}}

=== 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]] where natural gas is added along with oxygen which in turn combusts and expands through the turbine to force a generator to spin. 

[[Gas-fired power plant|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, the extraction of gas when mined releases a significant amount of [[methane]] into the atmosphere.<ref>{{Cite web|url=https://energyeducation.ca/encyclopedia/Natural_gas_power_plant|title=Natural gas power plant |website=Energy Education|language=en|access-date=2019-06-08 |archive-date=2019-06-08 |archive-url=https://web.archive.org/web/20190608042814/https://energyeducation.ca/encyclopedia/Natural_gas_power_plant|url-status=live}}</ref>

=== Nuclear===
[[Nuclear power plant]]s create electricity through steam turbines where the heat input is from the process of [[nuclear fission]]. Currently, nuclear power produces 11% of all electricity in the world. Most nuclear reactors use [[uranium]] as a source of fuel. In a process called [[nuclear fission]], energy, in the form of heat, is released when nuclear atoms are split. 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 of nuclear reactors, all fundamentally use this process.<ref>{{Cite web|url=https://energyeducation.ca/encyclopedia/Nuclear_power|title=Nuclear power |website=Energy Education|language=en|access-date=2019-06-08 |archive-date=2019-06-08 |archive-url=https://web.archive.org/web/20190608042827/https://energyeducation.ca/encyclopedia/Nuclear_power|url-status=live}}</ref>

Normal emissions due to nuclear power plants are primarily waste heat and radioactive spent fuel. In a reactor accident, significant amounts of radioisotopes can be released to the environment, posing a long term hazard to life. This hazard has been a continuing concern of environmentalists.  Accidents such as the [[Three Mile Island accident]], [[Chernobyl disaster]] and the [[Fukushima nuclear disaster]] illustrate this problem.<ref>{{Cite web|url=https://www.eia.gov/energyexplained/index.php?page=nuclear_environment|title=Nuclear Power and the Environment – Energy Explained |website=Energy Information Administration |access-date=2019-06-08 |archive-date=2019-05-27 |archive-url=https://web.archive.org/web/20190527024111/https://www.eia.gov/energyexplained/index.php?page=nuclear_environment|url-status=live}}</ref>

== Electricity generation capacity by country ==
{{Main|List of countries by electricity production}}

The table lists 45 countries with their total electricity capacities. The data is from 2022.
According to the [[Energy Information Administration]], the total global electricity capacity in 2022 was nearly 8.9 [[terawatt]] (TW), more than four times the total global electricity capacity in 1981. The global average per-capita electricity capacity was about 1,120 [[watt]]s in 2022, nearly two and a half times the global average per-capita electricity capacity in 1981. 

[[Iceland]] has the highest installed capacity per capita in the world, at about 8,990 watts. All developed countries have an average per-capita electricity capacity above the global average per-capita electricity capacity, with the [[United Kingdom]] having the lowest average per-capita electricity capacity of all other developed countries.

{{srn}}
{{mw-datatable}}
{| class="wikitable sortable mw-datatable static-row-numbers"
|-class=static-row-header
! Country
! data-sort-type="number" | Total capacity<br />(GW)
! data-sort-type="number" | Average per capita capacity<br />(watts)
|-class="static-row-header " style="font-weight:bold;"
| World||style="text-align:left;"|8,890||1,120
|-
| {{flagicon|China}} [[China]] || 2,510 || 1,740
|-
| {{flagicon|United States}} [[United States]] || 1,330 || 3,940
|-class="static-row-header " style="font-weight:bold;"
| {{flagicon|European Union}} [[European Union]] || 1,080 || 2,420
|-
| {{flagicon|India}} [[India]] || 556 || 397
|-
| {{flagicon|Japan}} [[Japan]] || 370 || 2,940
|-
| {{flagicon|Russia}} [[Russia]] || 296 || 2,030
|-
| {{flagicon|Germany}} [[Germany]] || 267 || 3,220
|-
| {{flagicon|Brazil}} [[Brazil]] || 222 || 1,030
|-
| {{flagicon|Canada}} [[Canada]] || 167 || 4,460
|-
| {{flagicon|South Korea}} [[South Korea]] || 160 || 3,130
|-
| {{flagicon|France}} [[France]] || 148 || 2,280
|-
| {{flagicon|Italy}} [[Italy]] || 133 || 2,230
|-
| {{flagicon|Spain}} [[Spain]] || 119 || 2,580
|-
| {{flagicon|United Kingdom}} [[United Kingdom]] || 111 || 1,640
|-
| {{flagicon|Turkey}} [[Turkey]] || 107 || 1,240
|-
| {{flagicon|Mexico}} [[Mexico]] || 104 || 792
|-
| {{flagicon|Australia}} [[Australia]] || 95.8 || 3,680
|-
| {{flagicon|Saudi Arabia}} [[Saudi Arabia]] || 85.3 || 2,380
|-
| {{flagicon|Iran}} [[Iran]] || 83.3 || 977
|-
| {{flagicon|Vietnam}} [[Vietnam]] || 72.2 || 721
|-
| {{flagicon|South Africa}} [[South Africa]] || 66.7 || 1,100
|-
| {{flagicon|Poland}} [[Poland]] || 64 || 1,690
|-
| {{flagicon|Thailand}} [[Thailand]] || 63 || 901
|-
| {{flagicon|Ukraine}} [[Ukraine]] || 62.2 || 1,440
|-
| {{flagicon|Egypt}} [[Egypt]] || 61.1 || 582
|-
| {{flagicon|Taiwan}} [[Taiwan]] || 58 || 2,440
|-
| {{flagicon|Netherlands}} [[Netherlands]] || 53.3 || 3,010
|-
| {{flagicon|Sweden}} [[Sweden]] || 52.1 || 5,100
|-
| {{flagicon|Argentina}} [[Argentina]] || 51.9 || 1,130
|-
| {{flagicon|Pakistan}} [[Pakistan]] || 42.7 || 192
|-
| {{flagicon|Norway}} [[Norway]] || 41.7 || 7,530
|-
| {{flagicon|United Arab Emirates}} [[United Arab Emirates]] || 40.7 || 4,010
|-
| {{flagicon|Malaysia}} [[Malaysia]] || 37.9 || 1,110
|-
| {{flagicon|Chile}} [[Chile]] || 37 || 1,930
|-
| {{flagicon|Venezuela}} [[Venezuela]] || 34.1 || 1,210
|-
| {{flagicon|Kazakhstan}} [[Kazakhstan]] || 29.6 || 1,600
|-
| {{flagicon|Switzerland}} [[Switzerland]] || 27.8 || 2,960
|-
| {{flagicon|Austria}} [[Austria]] || 26.7 || 2,890
|-
| {{flagicon|Algeria}} [[Algeria]] || 25.9 || 590
|-
| {{flagicon|Greece}} [[Greece]] || 24.4 || 2,400
|-
| {{flagicon|Israel}} [[Israel]] || 23.7 || 2,520
|-
| {{flagicon|Finland}} [[Finland]] || 22.2 || 3,980
|-
| {{flagicon|Denmark}} [[Denmark]] || 21.3 || 3,710
|-
| {{flagicon|Ireland}} [[Ireland]] || 13.3 || 2,420
|-
| {{flagicon|New Zealand}} [[New Zealand]] || 11.6 || 2,320
|-
| {{flagicon|Iceland}} [[Iceland]] || 3.24 || 8,990
|}

== See also==
{{Portal|Energy|Renewable energy|Engineering}}
* [[Glossary of power generation]]
* [[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]]
* [[Engine–generator]]
* [[Generation expansion planning]]
* [[Steam–electric power station]]
* [[World energy supply and consumption]]

== Notes ==
{{notelist}}

== References==
{{reflist}}

{{Electricity generation}}
{{Authority control}}

{{DEFAULTSORT:Electricity Generation}}
[[Category:Power engineering]]
[[Category:Fossil fuel power stations]]
[[Category:Electric power generation| ]]
[[Category:Infrastructure]]