Editing Electricity (section)

==Production, storage and uses==
===Generation and transmission===
{{Main|Electricity generation}}
{{See also|Electric power transmission|Mains electricity}}
[[File:Gorskii 04414u.jpg|thumb|upright=1.35|Early 20th-century [[alternator]] made in [[Budapest]], [[Hungary]], in the power generating hall of a [[hydroelectric]] station (photograph by [[Prokudin-Gorsky]], 1905–1915).]]

In the 6th century BC the Greek philosopher [[Thales of Miletus]] experimented with amber rods: these were the first studies into the production of electricity. While this method, now known as the [[triboelectric effect]], can lift light objects and generate sparks, it is extremely inefficient.<ref name=batteries>
{{citation
| first1 = Ronald | last1 = Dell
| first2 = David | last2 = Rand
| title = Understanding Batteries
| journal = NASA Sti/Recon Technical Report N
| pages = 2–4
| year = 2001
| publisher = Royal Society of Chemistry
| isbn =0-85404-605-4
| bibcode = 1985STIN...8619754M
| volume = 86
}}
</ref> It was not until the invention of the [[voltaic pile]] in the eighteenth century that a viable source of electricity became available. The voltaic pile, and its modern descendant, the [[Battery (electricity)|electrical battery]], store energy chemically and make it available on demand in the form of electricity.<ref name=batteries/>

Electrical power is usually generated by electro-mechanical [[electrical generator|generators]]. These can be driven by [[steam]] produced from [[fossil fuel]] combustion or the heat released from nuclear reactions, but also more directly from the [[kinetic energy]] of wind or flowing water. The [[steam turbine]] invented by [[Charles Algernon Parsons|Sir Charles Parsons]] in 1884 is still used to convert the thermal energy of steam into a rotary motion that can be used by electro-mechanical generators. Such generators bear no resemblance to Faraday's homopolar disc generator of 1831, but they still rely on his electromagnetic principle that a conductor linking a changing magnetic field induces a potential difference across its ends.<ref>
{{citation
| first = Peter G.
| last = McLaren
| title = Elementary Electric Power and Machines
| pages = [https://archive.org/details/elementaryelectr0000mcla/page/182 182–83]
| year = 1984
| publisher = Ellis Horwood
| isbn = 0-85312-269-5
| url = https://archive.org/details/elementaryelectr0000mcla/page/182
}}
</ref> Electricity generated by [[solar panel]]s rely on a different mechanism: [[Solar irradiance|solar radiation]] is converted directly into electricity using the [[photovoltaic effect]].<ref>{{Cite web |date=9 November 2022 |title=How electricity is generated |url=https://www.eia.gov/energyexplained/electricity/how-electricity-is-generated.php |access-date=2023-02-19 |website=U.S. Energy Information Administration (EIA)}}</ref>

[[File:Parque eólico La Muela.jpg|thumb|alt=A wind farm of about a dozen three-bladed white wind turbines.|[[Wind power]] is of increasing importance in many countries.]]
Demand for electricity grows with great rapidity as a nation modernises and its economy develops.<ref>{{citation
 | last =Bryce
 | first =Robert
 | author-link =Robert Bryce (writer)
 | title =A Question of Power: Electricity and the Wealth of Nations
 | publisher =PublicAffairs
 | date =2020
 | pages =352
 | url =https://www.publicaffairsbooks.com/titles/robert-bryce/a-question-of-power/9781610397490/
 | isbn =978-1-61039-749-0
 | access-date =2021-11-07
 | archive-date =2021-11-07
 | archive-url =https://web.archive.org/web/20211107190916/https://www.publicaffairsbooks.com/titles/robert-bryce/a-question-of-power/9781610397490/
 | url-status =live
 }}</ref> The United States showed a 12% increase in demand during each year of the first three decades of the twentieth century,<ref>{{Citation
| last = Edison Electric Institute
| title = History of the U.S. Electric Power Industry, 1882–1991
| url = http://www.eia.doe.gov/cneaf/electricity/chg_stru_update/appa.html
| access-date = 2007-12-08
| archive-date = 2010-12-06
| archive-url = https://web.archive.org/web/20101206094624/http://www.eia.doe.gov/cneaf/electricity/chg_stru_update/appa.html
| url-status = live
}}</ref> a rate of growth that is now being experienced by emerging economies such as those of India or China.<ref>
{{Citation
 |last=Carbon Sequestration Leadership Forum
 |title=An Energy Summary of India
 |url=http://www.cslforum.org/india.htm
 |access-date=2007-12-08
 |archive-url=https://web.archive.org/web/20071205080916/http://www.cslforum.org/india.htm
 |archive-date=2007-12-05
 |url-status=dead
}}
</ref><ref>{{Citation
| last = IndexMundi
| title = China Electricity – consumption
| url = http://www.indexmundi.com/china/electricity_consumption.html
| access-date = 2007-12-08
| archive-date = 2019-06-17
| archive-url = https://web.archive.org/web/20190617183052/https://www.indexmundi.com/china/electricity_consumption.html
| url-status = live
}}</ref>

[[Environmental concerns with electricity generation]], in specific the contribution of fossil fuel burning to [[climate change]], have led to an increased focus on generation from [[Renewable energy|renewable sources]]. In the power sector, [[wind power|wind]] and [[solar PV|solar]] have become cost effective, speeding up an [[energy transition]] away from fossil fuels.<ref>{{Cite book|last1=Kutscher|first1=C.F.|last2=Milford|first2=J.B.|last3=Kreith|first3=F.|title=Principles of Sustainable Energy Systems|edition=Third|publisher=[[CRC Press]]|series=Mechanical and Aerospace Engineering Series |year=2019|isbn=978-0-429-93916-7|url=https://books.google.com/books?id=wQhpDwAAQBAJ |url-status=live|archive-date=6 June 2020|archive-url=https://web.archive.org/web/20200606195825/https://books.google.com/books?id=wQhpDwAAQBAJ|page=5}}</ref>

=== Transmission and storage ===
The invention in the late nineteenth century of the [[transformer]] meant that electrical power could be transmitted more efficiently at a higher voltage but lower current. Efficient [[electrical transmission]] meant in turn that electricity could be generated at centralised [[power station]]s, where it benefited from [[economies of scale]], and then be despatched relatively long distances to where it was needed.<ref name="Patterson_p44-48">
{{citation |last=Patterson |first=Walter C. |title=Transforming Electricity: The Coming Generation of Change |pages=44–48 |year=1999 |publisher=Earthscan |isbn=1-85383-341-X}}
</ref><ref>
{{citation |last=Edison Electric Institute |title=History of the Electric Power Industry |url=http://www.eei.org/industry_issues/industry_overview_and_statistics/history |archive-url=https://web.archive.org/web/20071113132557/http://www.eei.org/industry_issues/industry_overview_and_statistics/history |access-date=2007-12-08 |archive-date=November 13, 2007 |url-status=dead}}
</ref>

Normally, demand for electricity must match the supply, as storage of electricity is difficult.<ref name="Patterson_p44-48" /> A certain amount of generation must always be held in [[Operating reserve|reserve]] to cushion an electrical grid against inevitable disturbances and losses.<ref>{{Cite journal |last1=Castillo |first1=Anya |last2=Gayme |first2=Dennice F.|author2-link=Dennice Gayme |date=2014 |title=Grid-scale energy storage applications in renewable energy integration: A survey |url=https://www.sciencedirect.com/science/article/pii/S0196890414007018 |journal=Energy Conversion and Management |language=en |volume=87 |pages=885–894 |doi=10.1016/j.enconman.2014.07.063 |bibcode=2014ECM....87..885C |issn=0196-8904}}</ref> With increasing levels of [[variable renewable energy]] (wind and solar energy) in the grid, it has become more challenging to match supply and demand. Storage plays an increasing role in bridging that gap. There are four types of energy storage technologies, each in varying states of [[Technology readiness level|technology readiness]]: [[Electric battery|batteries]] (electrochemical storage), chemical storage such as [[hydrogen]], thermal or mechanical (such as [[Pumped-storage hydroelectricity|pumped hydropower]]).<ref>{{Cite book |url=https://energy.mit.edu/wp-content/uploads/2022/05/The-Future-of-Energy-Storage.pdf |title=The Future of Energy Storage |publisher=Massachusetts Institute of Technology |year=2022 |isbn=978-0-578-29263-2 |pages=xi-xvi}}</ref>

===Applications===
[[File:Gluehlampe 01 KMJ.png|thumb|upright|The [[incandescent light bulb]], an early application of electricity, operates by [[Joule heating]]: the passage of [[current (electricity)|current]] through [[Electrical resistance|resistance]] generating heat.|alt=a photo of a light bulb|left]]

Electricity is a very convenient way to transfer energy, and it has been adapted to a huge, and growing, number of uses.<ref>{{Citation
| first = Matthew
| last = Wald
| title = Growing Use of Electricity Raises Questions on Supply
| newspaper = New York Times
| url = https://query.nytimes.com/gst/fullpage.html?res=9C0CE6DD1F3AF932A15750C0A966958260
| date = 21 March 1990
| access-date = 2007-12-09
| archive-date = 2008-01-08
| archive-url = https://web.archive.org/web/20080108022330/http://query.nytimes.com/gst/fullpage.html?res=9C0CE6DD1F3AF932A15750C0A966958260
| url-status = live
}}</ref> The invention of a practical [[incandescent light bulb]] in the 1870s led to [[lighting]] becoming one of the first publicly available applications of electrical power. Although electrification brought with it its own dangers, replacing the naked flames of gas lighting greatly reduced fire hazards within homes and factories.<ref>
{{Citation
| first = Peter | last = d'Alroy Jones
| title = The Consumer Society: A History of American Capitalism
| page = 211
| publisher = Penguin Books}}
</ref> Public utilities were set up in many cities targeting the burgeoning market for electrical lighting. In the late 20th century and in modern times, the trend has started to flow in the direction of deregulation in the electrical power sector.<ref>{{cite web | url = https://www.en-powered.com/blog/the-bumpy-road-to-energy-deregulation | title = The Bumpy Road to Energy Deregulation | publisher = EnPowered | date = 2016-03-28 | access-date = 2017-05-29 | archive-date = 2017-04-07 | archive-url = https://web.archive.org/web/20170407145323/https://www.en-powered.com/blog/the-bumpy-road-to-energy-deregulation | url-status = live }}</ref>

The resistive [[Joule heating]] effect employed in filament light bulbs also sees more direct use in [[electric heating]]. While this is versatile and controllable, it can be seen as wasteful, since most electrical generation has already required the production of heat at a power station.<ref>
{{Citation
| first = Charles and Penelope
| last = ReVelle
| title = The Global Environment: Securing a Sustainable Future
| publisher = Jones & Bartlett
| page = [https://archive.org/details/globalenvironmen0000reve/page/298 298]
| year = 1992
| isbn = 0-86720-321-8
| url = https://archive.org/details/globalenvironmen0000reve/page/298
}}
</ref> A number of countries, such as Denmark, have issued legislation restricting or banning the use of resistive electric heating in new buildings.<ref>{{Citation|last=Danish Ministry of Environment and Energy |work=Denmark's Second National Communication on Climate Change |title=F.2 The Heat Supply Act |url=http://glwww.mst.dk/udgiv/Publications/1997/87-7810-983-3/html/annexf.htm |access-date=2007-12-09 |url-status=dead |archive-url=https://web.archive.org/web/20080108011443/http://glwww.mst.dk/udgiv/Publications/1997/87-7810-983-3/html/annexf.htm |archive-date=January 8, 2008 }}
</ref> Electricity is however still a highly practical energy source for heating and [[refrigeration]],<ref>
{{Citation
| first = Charles E. | last = Brown
| title = Power resources
| publisher = Springer
| year = 2002
| isbn = 3-540-42634-5}}
</ref> with [[air conditioning]]/[[heat pump]]s representing a growing sector for electricity demand for heating and cooling, the effects of which electricity utilities are increasingly obliged to accommodate.<ref>
{{Citation
 |first1 = B.
 |last1 = Hojjati
 |first2 = S.
 |last2 = Battles
 |title = The Growth in Electricity Demand in U.S. Households, 1981–2001: Implications for Carbon Emissions
 |url = http://www.eia.doe.gov/emeu/efficiency/2005_USAEE.pdf
 |access-date = 2007-12-09
 |url-status = dead
 |archive-url = https://web.archive.org/web/20080216100857/http://www.eia.doe.gov/emeu/efficiency/2005_USAEE.pdf
 |archive-date = 2008-02-16
}}
</ref><ref>{{Cite news |title=Demand for air conditioning is set to surge by 2050 |newspaper=The Economist |url=https://www.economist.com/graphic-detail/2021/08/10/demand-for-air-conditioning-is-set-to-surge-by-2050 |access-date=2023-03-13 |issn=0013-0613}}</ref> Electrification is expected to play a major role in the [[decarbonisation]] of sectors that rely on direct fossil fuel burning, such as transport (using [[electric vehicles]]) and heating (using [[heat pumps]]).<ref>{{cite book |last1=Pathak |first1=M. |title=Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change |last2=Slade |first2=R. |last3=Shukla |first3=P.R. |last4=Skea |first4=J. |page=91 |chapter=Technical Summary |year=2023 |doi=10.1017/9781009157926.002 |isbn=9781009157926 |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_TechnicalSummary.pdf}}</ref><ref>{{Cite journal |last1=Watson |first1=S.D. |last2=Crawley |first2=J. |last3=Lomas |first3=K.J. |last4=Buswell |first4=R.A. |date=2023 |title=Predicting future GB heat pump electricity demand |journal=Energy and Buildings |volume=286 |pages=112917 |doi=10.1016/j.enbuild.2023.112917 |s2cid=257067540 |issn=0378-7788|doi-access=free }}</ref>

The effects of electromagnetism are most visibly employed in the [[electric motor]], which provides a clean and efficient means of motive power. A stationary motor such as a [[winch]] is easily provided with a supply of power, but a motor that moves with its application, such as an [[electric vehicle]], is obliged to either carry along a power source such as a battery or to collect current from a sliding contact such as a [[Pantograph (rail)|pantograph]]. Electrically powered vehicles are used in public transportation, such as electric buses and trains,<ref>{{Citation
| title = Public Transportation
| newspaper = Alternative Energy News
| date = 2010-03-10
| url = http://www.alternative-energy-news.info/technology/transportation/public-transit/
| access-date = 2010-12-02
| archive-date = 2010-12-04
| archive-url = https://web.archive.org/web/20101204204748/http://www.alternative-energy-news.info/technology/transportation/public-transit/
| url-status = live
}}</ref> and an increasing number of battery-powered [[electric car]]s in private ownership.{{cn|date=March 2025}}

Electricity is used within [[telecommunications]], and indeed the [[electrical telegraph]], demonstrated commercially in 1837 by [[William Fothergill Cooke|Cooke]] and [[Charles Wheatstone|Wheatstone]],<ref>{{Cite journal |last=Liffen |first=John |date=July 2010 |title=The Introduction of the Electric Telegraph in Britain, a Reappraisal of the Work of Cooke and Wheatstone |url=http://www.tandfonline.com/doi/full/10.1179/175812110X12714133353911 |journal=The International Journal for the History of Engineering & Technology |language=en |volume=80 |issue=2 |pages=268–299 |doi=10.1179/175812110X12714133353911 |s2cid=110320981 |issn=1758-1206}}</ref> was one of its earliest applications. With the construction of first [[First Transcontinental Telegraph|transcontinental]], and then [[Transatlantic telegraph cable|transatlantic]], telegraph systems in the 1860s, electricity had enabled communications in minutes across the globe. [[Optical fibre]] and [[Communications satellite|satellite communication]] have taken a share of the market for communications systems, but electricity can be expected to remain an essential part of the process.{{cn|date=March 2025}}

Electronic devices make use of the [[transistor]], perhaps one of the most important inventions of the twentieth century,<ref>
{{Citation
| first = Dennis F.
| last = Herrick
| title = Media Management in the Age of Giants: Business Dynamics of Journalism
| publisher = Blackwell Publishing
| year = 2003
| isbn =0-8138-1699-8
| url-access = registration
| url = https://archive.org/details/mediamanagementi0000herr
}}
</ref> and a fundamental building block of all modern circuitry. A modern [[integrated circuit]] may contain many billions of miniaturised transistors in a region only a few centimetres square.<ref>{{Citation
| first = Saswato R.
| last = Das
| title = The tiny, mighty transistor
| newspaper = Los Angeles Times
| date = 2007-12-15
| url = http://www.latimes.com/news/opinion/la-oe-das15dec15,0,4782957.story?coll=la-opinion-rightrail
| access-date = 2008-01-12
| archive-date = 2008-10-11
| archive-url = https://web.archive.org/web/20081011191958/http://www.latimes.com/news/opinion/la-oe-das15dec15,0,4782957.story?coll=la-opinion-rightrail
| url-status = live
}}</ref>