Просмотр кода страницы Английская Википедия:Electrification

{{Английская Википедия/Панель перехода}}
{{Short description|Process of changing something to use electricity}}
{{About|the process of changing something to use electricity|other uses}}
{{redirect|Electrify|the song by Jakwob|Electrify (song)}}

'''Electrification''' is the process of powering by [[electricity]] and, in many contexts, the introduction of such power by changing over from an earlier power source.

In the context of [[history of technology]] and [[economic development]], electrification refers to the build-out of the [[electricity generation]] and [[electric power distribution]] systems in Britain, the United States, and other now-[[developed country|developed]] countries from the mid-1880s until around 1950. In the context of [[sustainable energy]], electrification refers to the build-out of [[super grid]]s with [[energy storage]] to accommodate the [[energy transition]] to [[renewable energy]] and the switch of end-uses to electricity.

The electrification of particular sectors of the economy is called by terms such as [[Mass production#Factory electrification|''factory electrification'']], ''household electrification'', ''[[rural electrification]]'' or ''[[railway electrification]]''.  In the context of [[sustainable energy]], terms such as ''transport electrification'' (referring to [[electric vehicle]]s) or ''heating electrification'' (referring to [[heat pump]]s) are used. It may also apply to changing industrial processes such as smelting, melting, separating or refining from coal or coke heating, or chemical processes to some type of electric process such as [[electric arc furnace]], [[electric induction]] or [[Joule heating|resistance]] heating, or [[electrolysis]] or electrolytic separating.

== History of electrification ==
{{See also|Electricity|Timeline of electrical and electronic engineering}}
The earliest commercial uses of electricity were [[electroplating]] and the [[electrical telegraph|telegraph]].<ref>{{Cite web |date=2015-09-14 |title=Early Applications of Electricity |url=https://ethw.org/Early_Applications_of_Electricity |access-date=2023-11-16 |website=ETHW |language=en}}</ref>

===Development of magnetos, dynamos and generators===
{{Main|Electric generator}}
[[File:Faraday disk generator.jpg|thumb|right|Faraday disk, the first electric generator. The horseshoe-shaped magnet ''(A)'' created a magnetic field through the disk ''(D)''. When the disk was turned, this induced an electric current radially outward from the center toward the rim.  The current flowed out through the sliding spring contact ''m'', through the external circuit, and back into the center of the disk through the axle.]]

In the years 1831–1832, [[Michael Faraday]] discovered the operating principle of electromagnetic generators. The principle, later called [[Faraday's law of induction|Faraday's law]], is based on an [[electromotive force]] generated in an electrical conductor that is subjected to a varying [[magnetic flux]] as, for example, a wire moving through a magnetic field. Faraday built the first electromagnetic generator, called the [[Faraday disk]], a type of [[homopolar generator]], using a [[copper]] disc rotating between the poles of a horseshoe [[magnet]]. Faraday's first electromagnetic generator produced a small DC voltage.

Around 1832, [[Hippolyte Pixii]] improved the magneto by using a wire wound horseshoe, with the extra coils of conductor generating more current, but it was AC. [[André-Marie Ampère]] suggested a means of converting current from Pixii's magneto to DC using a rocking switch. Later segmented commutators were used to produce direct current.{{sfn|McNeil|1990|p={{page needed|date=October 2020}}}}

Around 1838-40, [[William Fothergill Cooke]] and [[Charles Wheatstone]] developed a telegraph. In 1840 Wheatstone was using a magneto that he developed to power the telegraph. Wheatstone and Cooke made an important improvement in electrical generation by using a battery-powered electromagnet in place of a permanent magnet, which they patented in 1845.{{sfn|McNeil|1990|p=359}} The self-excited magnetic field dynamo did away with the battery to power electromagnets. This type of dynamo was made by several people in 1866.

The first practical generator, the [[Gramme machine]], was made by Z.T. Gramme, who sold many of these machines in the 1870s. British engineer [[R. E. B. Crompton|R.E.B. Crompton]] improved the generator to allow better air cooling and made other mechanical improvements. Compound winding, which gave more stable voltage with load, improved the operating characteristics of generators.{{sfn|McNeil|1990|p=360}}

The improvements in electrical generation technology in the 19th century increased its efficiency and reliability greatly. The first magnetos only converted a few percent of mechanical energy to electricity. By the end of the 19th century the highest efficiencies were over 90%.

===Electric lighting===

====Arc lighting====
{{Main|Carbon arc lamp}}
[[File:Yablochkov candles illuminating Avenue de l'Opera ca1878.jpg|thumb|left|Yablochkov's demonstration of his brilliant arc lights at the 1878 Paris Exposition along the [[Avenue de l'Opéra]] triggered a steep sell off of gas utility stocks.]]
Sir [[Humphry Davy]] invented the [[carbon arc lamp]] in 1802 upon discovering that electricity could produce a light [[electric arc|arc]] with carbon electrodes. However, it was not used to any great extent until a practical means of generating electricity was developed.

Carbon arc lamps were started by making contact between two carbon electrodes, which were then separated to within a narrow gap. Because the carbon burned away, the gap had to be constantly readjusted. Several mechanisms were developed to regulate the arc. A common approach was to feed a carbon electrode by gravity and maintain the gap with a pair of electromagnets, one of which retracted the upper carbon after the arc was started and the second controlled a brake on the gravity feed.{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}}

Arc lamps of the time had very intense light output – in the range of 4,000 [[candlepower]] (candelas) – and released a lot of heat, and they were a fire hazard, all of which made them inappropriate for lighting homes.{{sfn|McNeil|1990|p={{page needed|date=October 2020}}}}

In the 1850s, many of these problems were solved by the arc lamp invented by [[William Petrie (electrical engineer)|William Petrie]] and William Staite. The lamp used a magneto-electric generator and had a self-regulating mechanism to control the gap between the two carbon rods. Their light was used to light up the [[National Gallery]] in London and was a great novelty at the time. These arc lamps and designs similar to it, powered by large magnetos, were first installed on English lighthouses in the mid 1850s, but the power limitations prevented these models from being a proper success.{{sfn|McNeil|1990|pp=360–365}}

The first successful arc lamp (the [[Yablochkov candle]]) was developed by Russian engineer [[Pavel Yablochkov]] using the [[Gramme machine|Gramme generator]]. Its advantage lay in the fact that it did not require the use of a mechanical regulator like its predecessors. It was first exhibited at the [[Exposition Universelle (1878)|Paris Exposition of 1878]] and was heavily promoted by Gramme.<ref>{{cite book |last=Woodbury |first=David Oakes |title=A Measure for Greatness: A Short Biography of Edward Weston |year=1949 |page=83 |url=https://archive.org/stream/measureforgreatn001419mbp/measureforgreatn001419mbp_djvu.txt |access-date=2009-01-04 |publisher=McGraw-Hill}}</ref> The [[arc lamp|arc light]] was installed along the half mile length of [[Avenue de l'Opéra]], Place du Theatre Francais and around the [[Place de l'Opéra]] in 1878.<ref>{{cite book |last=Barrett |first=John Patrick |title=Electricity at the Columbian Exposition |publisher=R. R. Donnelley & sons company |url=https://archive.org/details/electricityatco00barrgoog |page=[https://archive.org/details/electricityatco00barrgoog/page/n21 1] |access-date=2009-01-04 |year=1894}}</ref>

R. E. B. Crompton developed a more sophisticated design in 1878 which gave a much brighter and steadier light than the Yablochkov candle. In 1878, he formed [[R. E. B. Crompton#Crompton & Co.|Crompton & Co.]] and began to manufacture, sell and install the Crompton lamp. His concern was one of the first electrical engineering firms in the world.

====Incandescent light bulbs====
Various forms of [[incandescent light bulbs]] had numerous inventors; however, the most successful early bulbs were those that used a carbon filament sealed in a high vacuum. These were invented by [[Joseph Swan]] in 1878 in Britain and by [[Thomas Edison]] in 1879 in the US. Edison’s lamp was more successful than Swan’s because Edison used a thinner filament, giving it higher resistance and thus conducting much less current. Edison began commercial production of carbon filament bulbs in 1880. Swan's light began commercial production in 1881.{{sfn|McNeil|1990|pp=366–368}}

Swan's house, in [[Low Fell]], Gateshead, was the world's first to have working light bulbs installed. The Lit & Phil Library in [[Newcastle upon Tyne|Newcastle]], was the first public room lit by electric light,<ref>{{Cite news |last=Glover |first=Andrew |title=Alexander Armstrong in appeal to save Lit and Phil |quote=The society’s lecture theatre was the first public room to be lit by electric light, during a lecture by Sir Joseph Swan on October 20, 1880. |newspaper=The Journal |date=8 February 2011 |url=http://www.journallive.co.uk/north-east-news/todays-news/2011/02/08/alexander-armstrong-in-appeal-to-save-lit-and-phil-61634-28133303/ |access-date=8 February 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110215165559/http://www.journallive.co.uk/north-east-news/todays-news/2011/02/08/alexander-armstrong-in-appeal-to-save-lit-and-phil-61634-28133303/ |archive-date=15 February 2011 }}</ref><ref>[http://www.bbc.co.uk/tyne/content/image_galleries/lit_and_phil_gallery.shtml?12 History in pictures - The Lit & Phil] {{Webarchive|url=https://archive.today/20120719124154/http://www.bbc.co.uk/tyne/content/image_galleries/lit_and_phil_gallery.shtml?12 |date=2012-07-19 }} BBC. Retrieved 8 August 2011</ref> and the [[Savoy Theatre]] was the first public building in the world lit entirely by electricity.<ref name=Burgess>Burgess, Michael. "Richard D'Oyly Carte", ''The Savoyard'', January 1975, pp. 7–11</ref>

===Central power stations and isolated systems===
[[File:Electricity grid simple- North America.svg|thumb|Electricity grid simple- North America]]
The first central station providing public power is believed to be one at [[Godalming#Public electricity supply|Godalming]], Surrey, UK, in autumn 1881. The system was proposed after the town failed to reach an agreement on the rate charged by the gas company, so the town council decided to use electricity. The system lit up arc lamps on the main streets and incandescent lamps on a few side streets with hydroelectric power. By 1882 between 8 and 10 households were connected, with a total of 57 lights. The system was not a commercial success and the town reverted to gas.{{sfn|McNeil|1990|p=369}}

The first large scale central distribution supply plant was opened at [[Holborn Viaduct]] in London in 1882.<ref>{{cite web|url=http://www.engineering-timelines.com/how/electricity/electricity_07.asp |title=History of public supply in the UK |archive-url=https://web.archive.org/web/20101201194910/http://www.engineering-timelines.com/how/electricity/electricity_07.asp |archive-date=2010-12-01 |url-status=dead}}</ref> Equipped with 1000 incandescent lightbulbs that replaced the older gas lighting, the station lit up Holborn Circus including the offices of the [[General Post Office]] and the famous [[City Temple, London|City Temple church]]. The supply was a direct current at 110 V; due to power loss in the copper wires, this amounted to 100 V for the customer.

Within weeks, a parliamentary committee recommended passage of the landmark 1882 Electric Lighting Act, which allowed the licensing of persons, companies or local authorities to supply electricity for any public or private purposes.

The first large scale central power station in America was Edison's [[Pearl Street Station]] in New York, which began operating in September 1882. The station had six 200 horsepower Edison dynamos, each powered by a separate steam engine. It was located in a business and commercial district and supplied 110 volt direct current to 85 customers with 400 lamps. By 1884 Pearl Street was supplying 508 customers with 10,164 lamps.{{sfn|Hunter|Bryant|1991|p=191}}

By the mid-1880s, other electric companies were establishing central power stations and distributing electricity, including Crompton & Co. and the [[Edison and Swan Electric Light Company|Swan Electric Light Company]] in the UK, [[Thomson-Houston Electric Company]] and [[Westinghouse Electric (1886)|Westinghouse]] in the US and [[Siemens]] in [[Germany]]. By 1890 there were 1000 central stations in operation.{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}} The 1902 census listed 3,620 central stations. By 1925 half of power was provided by central stations.{{sfn|Hunter|Bryant|1991|p=242}}

====Load factor and isolated systems====
{{See also|Continuous production}}[[File:Electricity Grid Schematic English.svg|thumb|Electrical Grid Schematic - European]]
One of the biggest problems facing the early power companies was the hourly variable demand. When lighting was practically the only use of electricity, demand was high during the first hours before the workday and the evening hours when demand peaked.{{sfn|Hunter|Bryant|1991|pp=276–279}} As a consequence, most early electric companies did not provide daytime service, with two-thirds providing no daytime service in 1897.{{sfn|Hunter|Bryant|1991|pp=212, Note 53}}

The ratio of the average load to the peak load of a central station is called the load factor.{{sfn|Hunter|Bryant|1991|pp=276–279}} For electric companies to increase profitability and lower rates, it was necessary to increase the load factor. The way this was eventually accomplished was through motor load.{{sfn|Hunter|Bryant|1991|pp=276–279}} Motors are used more during daytime and many run continuously. Electric street railways were ideal for load balancing. Many electric railways generated their own power and also sold power and operated distribution systems.{{sfn|Nye|1990|p={{page needed|date=October 2020}}}}

The load factor adjusted upward by the turn of the 20th century—at [[Pearl Street Station|Pearl Street]] the load factor increased from 19.3% in 1884 to 29.4% in 1908. By 1929, the load factor around the world was greater than 50%, mainly due to motor load.{{sfn|Hunter|Bryant|1991|pp=283–284}}

Before widespread power distribution from central stations, many factories, large hotels, apartment and office buildings had their own power generation. Often this was economically attractive because the exhaust steam could be used for building and industrial process heat, which today is known as [[cogeneration]] or combined heat and power (CHP). Most self-generated power became uneconomical as power prices fell. As late as the early 20th century, isolated power systems greatly outnumbered central stations.{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}} Cogeneration is still commonly practiced in many industries that use large amounts of both steam and power, such as pulp and paper, chemicals and refining. The continued use of private electric generators is called [[microgeneration]].

===Direct current electric motors===
{{Main|Electric motor|DC motor}}
The first commutator DC electric motor capable of turning machinery was invented by the British scientist [[William Sturgeon]] in 1832.<ref>{{cite ODNB|last=Gee|first=William|title=Oxford Dictionary of National Biography|year=2004|chapter=Sturgeon, William (1783–1850)|doi=10.1093/ref:odnb/26748 }}</ref> The crucial advance that this represented over the motor demonstrated by Michael Faraday was the incorporation of a [[Commutator (electric)|commutator]]. This allowed Sturgeon's motor to be the first capable of providing continuous rotary motion.<ref>{{cite web|url=http://www.solarbotics.net/starting/200111_dcmotor/200111_dcmotor.html|title=DC Motors|access-date=2013-10-06|archive-date=2013-05-16|archive-url=https://web.archive.org/web/20130516183745/http://www.solarbotics.net/starting/200111_dcmotor/200111_dcmotor.html|url-status=live}}</ref>

[[Frank J. Sprague]] improved on the DC motor in 1884 by solving the problem of maintaining a constant speed with varying load and reducing sparking from the brushes. Sprague sold his motor through Edison Co.{{sfn|Nye|1990|p=195}} It is easy to vary speed with DC motors, which made them suited for a number of applications such as electric street railways, machine tools and certain other industrial applications where speed control was desirable.{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}}

Manufacturing was transitioned from [[line shaft]] and belt drive using [[steam engine]]s and [[hydropower|water power]] to [[electric motor]]s.{{sfn|Nye|1990|p={{page needed|date=October 2020}}}}<ref name=Devine83>{{Cite journal
 | last1 = Devine Jr.
 | first1 = Warren D.
 | title = From Shafts to Wires: Historical Perspective on Electrification |journal=Journal of Economic History |volume=43 |issue=2
 | year = 1983
 | url = http://www.j-bradford-delong.net/teaching_folder/Econ_210c_spring_2002/Readings/Devine.pdf
 | page = 355
 | doi = 10.1017/S0022050700029673
 | s2cid = 153414525
 | access-date = 2011-07-03
 | archive-url = https://web.archive.org/web/20190412093317/http://www.j-bradford-delong.net/teaching_folder/Econ_210c_spring_2002/Readings/Devine.pdf
 | archive-date = 2019-04-12
 | url-status = dead
 }}</ref>

===Alternating current===
{{main|Alternating current}}
{{See also|Transformer|Electric power transmission|War of currents}}
Although the first power stations supplied [[direct current]], the distribution of [[alternating current]] soon became the most favored option. The main advantages of AC were that it could be transformed to high voltage to reduce transmission losses and that AC motors could easily run at constant speeds.

Alternating current technology was rooted in Faraday's 1830–31 discovery that a changing [[magnetic field]] can induce an [[electric current]] in a [[Electrical circuit|circuit]].<ref>{{cite book|title=Historical Encyclopedia of Natural and Mathematical Sciences, Volume 1|date=6 March 2009|publisher=Springer|isbn=9783540688310|url=https://books.google.com/books?id=9tUrarQYhKMC&q=AC+power+system+and+William+Stanley&pg=PA2640|access-date=25 October 2020|archive-date=25 January 2021|archive-url=https://web.archive.org/web/20210125180417/https://books.google.com/books?id=9tUrarQYhKMC&q=AC+power+system+and+William+Stanley&pg=PA2640|url-status=live}}</ref>

[[File:3phase-rmf-noadd-60f-airopt.gif|thumb|right|[[Three-phase electric power|Three-phase]] rotating magnetic field of an [[AC motor]]. The three poles are each connected to a separate wire. Each wire carries current 120 degrees apart in phase. Arrows show the resulting magnetic force vectors. Three phase current is used in commerce and industry.]]
The first person to conceive of a rotating magnetic field was Walter Baily who gave a workable demonstration of his battery-operated [[Polyphase system|polyphase]] motor aided by a commutator on June 28, 1879, to the Physical Society of London.<ref name="ReferenceA">{{cite book|title=Wizard: the life and times of Nikola Tesla : biography of a genius|year=1998|publisher=Citadel Press|page=24|isbn=9780806519609|url=https://books.google.com/books?id=h2DTNDFcC14C&q=Walter+Baily|access-date=2020-10-25|archive-date=2021-08-16|archive-url=https://web.archive.org/web/20210816073229/https://books.google.com/books?id=h2DTNDFcC14C&q=Walter+Baily|url-status=live}}</ref> Nearly identical to Baily’s apparatus, French electrical engineer [[Marcel Deprez]] in 1880 published a paper that identified the rotating magnetic field principle and that of a two-phase AC system of currents to produce it.<ref>{{cite book|title=Polyphase electric currents and alternate-current motors|year=1895|publisher=Spon|page=[https://archive.org/details/bub_gb_TvwHAAAAMAAJ/page/n96 87]|url=https://archive.org/details/bub_gb_TvwHAAAAMAAJ}}</ref>  In 1886, English engineer [[Elihu Thomson]] built an AC motor by expanding upon the induction-repulsion principle and his [[wattmeter]].<ref>{{cite book|title=Innovation as a Social Process|date=13 February 2003|publisher=Cambridge University Press|page=258|isbn=9780521533126|url=https://books.google.com/books?id=KUB5KFjTHhwC&q=Elihu+Thomson+and+AC+motor&pg=PA258|access-date=25 October 2020|archive-date=14 August 2021|archive-url=https://web.archive.org/web/20210814183923/https://books.google.com/books?id=KUB5KFjTHhwC&q=Elihu+Thomson+and+AC+motor&pg=PA258|url-status=live}}</ref>

It was in the 1880s that the technology was commercially developed for large scale electricity generation and transmission. In 1882 the British inventor and [[electrical engineer]] [[Sebastian de Ferranti]], working for the company [[Siemens]] collaborated with the distinguished physicist [[William Thomson, 1st Baron Kelvin|Lord Kelvin]] to pioneer AC power technology including an early transformer.<ref>{{cite web|url=http://www.swehs.co.uk/tactive/_S29-1.html?zoom_highlight=museum|title=Nikola Tesla The Electrical Genius|access-date=2013-10-06|archive-url=https://web.archive.org/web/20150909023444/http://www.swehs.co.uk/tactive/_S29-1.html?zoom_highlight=museum|archive-date=2015-09-09|url-status=dead}}</ref>

A [[Transformer|power transformer]] developed by [[Lucien Gaulard]] and [[John Dixon Gibbs]] was demonstrated in London in 1881, and attracted the interest of [[Westinghouse Electric (1886)|Westinghouse]]. They also exhibited the invention in [[Turin]] in 1884, where it was adopted for an electric lighting system. Many of their designs were adapted to the particular laws governing electrical distribution in the UK.{{Citation needed|date=February 2009}}

[[Sebastian Ziani de Ferranti]] went into this business in 1882 when he set up a shop in London designing various electrical devices. Ferranti believed in the success of alternating current power distribution early on, and was one of the few experts in this system in the UK. With the help of [[Lord Kelvin]], Ferranti pioneered the first AC power generator and [[transformer]] in 1882.<ref>{{cite web|url=http://edisontechcenter.org/AC-PowerHistory.html|title=AC Power History and Timeline|access-date=2013-10-06|archive-date=2013-10-17|archive-url=https://web.archive.org/web/20131017103832/http://edisontechcenter.org/AC-PowerHistory.html|url-status=live}}</ref> [[John Hopkinson]], a [[United Kingdom|British]] [[physicist]], invented the three-wire ([[three-phase]]) system for the distribution of electrical power, for which he was granted a [[patent]] in 1882.<ref>[[Oxford Dictionary of National Biography]]: ''Hopkinson, John'' by T. H. Beare</ref>

The Italian inventor [[Galileo Ferraris]] invented a polyphase AC [[induction motor]] in 1885. The idea was that two out-of-phase, but synchronized, currents might be used to produce two magnetic fields that could be combined to produce a rotating field without any need for switching or for moving parts. Other inventors were the American engineers Charles S. Bradley and [[Nikola Tesla]], and the German technician [[Friedrich August Haselwander]].<ref>{{cite book |url=https://books.google.com/books?id=g07Q9M4agp4C&pg=PA118 |title=Networks of Power |isbn=9780801846144 |last1=Hughes |first1=Thomas Parke |date=March 1993 |publisher=JHU Press |access-date=2016-05-18 |archive-date=2020-10-30 |archive-url=https://web.archive.org/web/20201030024430/https://books.google.com/books?id=g07Q9M4agp4C&pg=PA118 |url-status=live }}</ref> They were able to overcome the problem of starting up the AC motor by using a rotating magnetic field produced by a poly-phase current.{{sfn|Hunter|Bryant|1991|p=248}} [[Mikhail Dolivo-Dobrovolsky]] introduced the first three-phase induction motor in 1890, a much more capable design that became the prototype used in Europe and the U.S.<ref>{{cite book |editor1=Arnold Heertje |editor-link=Arnold Heertje |editor2=Mark Perlman |year=1990 |url=https://books.google.com/books?id=qQMOPjUgWHsC&pg=PA138 |title=Evolving Technology and Market Structure: Studies in Schumpeterian Economics |page=138 |publisher=University of Michigan Press |isbn=0472101927 |access-date=2016-05-18 |archive-date=2018-05-05 |archive-url=https://web.archive.org/web/20180505141442/https://books.google.com/books?id=qQMOPjUgWHsC&pg=PA138 |url-status=live }}</ref> By 1895 GE and Westinghouse both had AC motors on the market.{{sfn|Hunter|Bryant|1991|p=250}} With single phase current either a capacitor or coil (creating inductance) can be used on part of the circuit inside the motor to create a rotating magnetic field.{{sfn|McNeil|1990|p=383}} Multi-speed AC motors that have separately wired poles have long been available, the most common being two speed. Speed of these motors is changed by switching sets of poles on or off, which was done with a special motor starter for larger motors, or a simple multiple speed switch for fractional horsepower motors.

====AC power stations====
The first AC power station was built by the English electrical engineer [[Sebastian de Ferranti]]. In 1887 the London Electric Supply Corporation hired Ferranti for the design of their power station at [[Deptford]]. He designed the building, the generating plant and the distribution system. It was built at the Stowage, a site to the west of the mouth of [[Deptford Creek]] once used by the [[Honourable East India Company|East India Company]]. Built on an unprecedented scale and pioneering the use of high voltage (10,000 V) AC current, it generated 800 kilowatts and supplied central London. On its completion in 1891 it was the first truly modern power station, supplying high-voltage AC power that was then "stepped down" with transformers for consumer use on each street. This basic system remains in use today around the world.

In the U.S., [[George Westinghouse]], who had become interested in the power transformer developed by Gaulard and Gibbs, began to develop his AC lighting system, using a transmission system with a 20:1 step up voltage with step-down. In 1890 Westinghouse and Stanley built a system to transmit power several miles to a mine in Colorado. A decision was taken to use AC for power transmission from the Niagara Power Project to Buffalo, New York. Proposals submitted by vendors in 1890 included DC and compressed air systems.  A combination DC and compressed air system remained under consideration until late in the schedule.  Despite the protestations of the Niagara commissioner [[William Thomson, 1st Baron Kelvin|William Thomson]] (Lord Kelvin) the decision was taken to build an AC system, which had been proposed by both Westinghouse and General Electric. In October 1893 Westinghouse was awarded the contract to provide the first three 5,000&nbsp;hp, 250 rpm, 25&nbsp;Hz, two phase generators.{{sfn|Hunter|Bryant|1991|pp=285–286}} The hydro power plant went online in 1895,<ref>{{cite news | author = A. Madrigal | url = https://www.wired.com/2010/06/0603long-distance-power-line/ | title = June 3, 1889: Power Flows Long-distance | date = Mar 6, 2010 | journal = [[Wired (magazine)#Website|wired.com]] | archive-url = https://web.archive.org/web/20170701222752/https://www.wired.com/2010/06/0603long-distance-power-line/ | archive-date = 2017-07-01 | url-status = live | access-date = 2019-01-30 }}</ref> and it was the largest one until that date.<ref>{{cite web | url = http://edisontechcenter.org/HistElectPowTrans.html | title = The History of Electrification: List of important early power stations | website = edisontechcenter.org | archive-url = https://web.archive.org/web/20180825031930/http://edisontechcenter.org/HistElectPowTrans.html | archive-date = 2018-08-25 | url-status = live | access-date = 2019-01-30 }}</ref>

By the 1890s, single and poly-phase AC was undergoing rapid introduction.{{sfn|Hunter|Bryant|1991|p=221}} In the U.S. by 1902, 61% of generating capacity was AC, increasing to 95% in 1917.{{sfn|Hunter|Bryant|1991|pp=253, Note 18}} Despite the superiority of alternating current for most applications, a few existing DC systems continued to operate for several decades after AC became the standard for new systems.

===Steam turbines===
{{Main|Steam turbine}}
The efficiency of steam prime movers in converting the heat energy of fuel into mechanical work was a critical factor in the economic operation of steam central generating stations.  Early projects used reciprocating [[steam engine]]s, operating at relatively low speeds. The introduction of the steam turbine fundamentally changed the economics of central station operations. Steam turbines could be made in larger ratings than reciprocating engines, and generally had higher efficiency. The speed of steam turbines did not fluctuate cyclically during each revolution. This made parallel operation of AC generators feasible, and improved the stability of rotary converters for production of direct current for traction and industrial uses.  Steam turbines ran at higher speed than reciprocating engines, not being limited by the allowable speed of a piston in a cylinder. This made them more compatible with AC generators with only two or four poles; no gearbox or belted speed increaser was needed between the engine and the generator. It was costly and ultimately impossible to provide a belt-drive between a low-speed engine and a high-speed generator in the very large ratings required for central station service.

The modern steam turbine was invented in 1884 by British engineer [[Sir Charles Parsons]], whose first model was connected to a [[dynamo]] that generated 7.5&nbsp;kW (10&nbsp;hp) of electricity.<ref>{{cite web |url=http://www.birrcastle.com/steamTurbineAndElectricity.asp |archive-url=https://web.archive.org/web/20100513211302/http://www.birrcastle.com/steamTurbineAndElectricity.asp |archive-date=May 13, 2010 |url-status=dead |title=The Steam Turbine |website=Birr Castle Demesne}}</ref> The invention of Parsons's steam turbine made cheap and plentiful electricity possible. [[C. A. Parsons and Company|Parsons turbines]] were widely introduced in English central stations by 1894; the first electric supply company in the world to generate electricity using [[turbo generator]]s was Parsons's own electricity supply company [[Newcastle and District Electric Lighting Company]], set up in 1894.<ref name=siemens>{{cite web|url=http://www.wiki-north-east.co.uk/article.aspx?id=201525|title=A marriage took place last week that wedded two technologies possibly 120 years too late.|access-date=2009-01-02 |last=Forbes |first=Ross|date=17 April 1997|work=wiki-north-east.co.uk/|publisher=[[The Journal (Newcastle upon Tyne newspaper)|The Journal]]}}{{Dead link|date=November 2010|bot=H3llBot}}</ref> Within Parsons's lifetime, the generating capacity of a unit was scaled up by about 10,000 times.<ref>{{cite web |title=The Steam Turbine |last=Parsons|first=Charles A. |author-link=Charles A. Parsons |url=http://www.history.rochester.edu/steam/parsons/part1.html |archive-url= https://web.archive.org/web/20110114174009/http://www.history.rochester.edu/steam/parsons/part1.html |archive-date=2011-01-14 |url-status=dead}}</ref>
[[File:PSM V56 D0717 Parsons steam turbine linked directly to a dynamo.png|thumb|An 1899 [[C. A. Parsons and Company|Parsons steam turbine]] linked directly to a dynamo]]

The first U.S. turbines were two De Leval units at Edison Co. in New York in 1895. The first U.S. Parsons turbine was at [[Westinghouse Air Brake Company|Westinghouse Air Brake Co.]] near [[Pittsburgh]].{{sfn|Hunter|Bryant|1991|p=336}}

Steam turbines also had capital cost and operating advantages over reciprocating engines. The condensate from steam engines was contaminated with oil and could not be reused, while condensate from a turbine is clean and typically reused.  Steam turbines were a fraction of the size and weight of comparably rated reciprocating steam engine. Steam turbines can operate for years with almost no wear. Reciprocating steam engines required high maintenance.  Steam turbines can be manufactured with capacities far larger than any steam engines ever made, giving important [[economies of scale]].

Steam turbines could be built to operate on higher pressure and temperature steam. A fundamental principle of [[thermodynamics]] is that the higher the temperature of the steam entering an engine, the higher the  efficiency. The introduction of steam turbines motivated a series of improvements in temperatures and pressures. The resulting increased conversion efficiency lowered electricity prices.<ref>{{cite book
|title=Steam-its generation and use |year=1913 |url=https://archive.org/details/steamitsgenerat00compgoog |publisher =Babcock & Wilcox}}</ref>

The power density of boilers was increased by using forced combustion air and by using compressed air to feed pulverized coal. Also, coal handling was mechanized and automated.<ref name="Jerome 1934">{{Cite book
 | last1 = Jerome
 | first1 = Harry
 | title = Mechanization in Industry, National Bureau of Economic Research
 | year = 1934
 | url = https://www.nber.org/chapters/c5238.pdf
 | access-date = 2018-03-09
 | archive-date = 2017-10-18
 | archive-url = https://web.archive.org/web/20171018180623/http://www.nber.org/chapters/c5238.pdf
 | url-status = live
 }}</ref>

===Electrical grid===
{{Main|Electrical grid}}
[[File:Construction workers raising power lines - DPLA - fd565d9aa7d12ccb81f4f2000982d48a.jpg|alt=This black and white photograph shows construction workers raising power lines next to the railroad tracks of the Toledo, Port Clinton, Lakeside Railroad tracks in a rural area. The workers are using a railroad car as their vehicle to carry supplies and themselves down the line. It was taken in approximately 1920.|thumb|Construction workers raising power lines, 1920]]
With the realization of long distance power transmission it was possible to interconnect different central stations to balance loads and improve load factors. Interconnection became increasingly desirable as electrification grew rapidly in the early years of the 20th century.

[[Charles Merz]], of the [[Merz & McLellan]] consulting partnership, built the [[Neptune Bank Power Station]] near [[Newcastle upon Tyne]] in 1901,<ref>{{cite web|url=http://www.royalsoced.org.uk/enquiries/energy/evidence/ShawA1.pdf|title=Kelvin to Weir, and on to GB SYS 2005|date=29 September 2005|first=Alan|last=Shaw|publisher=Royal Society of Edinburgh|access-date=6 October 2013|archive-date=4 March 2009|archive-url=https://web.archive.org/web/20090304090015/http://www.royalsoced.org.uk/enquiries/energy/evidence/ShawA1.pdf|url-status=live}}</ref> and by 1912 had developed into the largest integrated power system in Europe.<ref>{{cite web |url=http://www.nnouk.com/survey/survey-utilities.shtml |title=Survey of Belford 1995 |publisher=North Northumberland Online |access-date=2013-10-06 |archive-date=2016-04-12 |archive-url=https://web.archive.org/web/20160412000737/http://www.nnouk.com/survey/survey-utilities.shtml |url-status=live }}</ref> In 1905 he tried to influence Parliament to unify the variety of voltages and frequencies in the country's electricity supply industry, but it was not until [[World War I]] that Parliament began to take this idea seriously, appointing him head of a Parliamentary Committee to address the problem. In 1916 Merz pointed out that the UK could use its small size to its advantage, by creating a dense distribution grid to feed its industries efficiently. His findings led to the [[Archibald Williamson, 1st Baron Forres|Williamson Report]] of 1918, which in turn created the Electricity Supply Bill of 1919. The bill was the first step towards an integrated electricity system in the UK.

The more significant Electricity (Supply) Act of 1926, led to the setting up of the National Grid.<ref>{{cite web|url=http://www.nationaltrust.org.uk/main/w-chl/w-places_collections/w-collections-main/w-collections-highlights/w-collections-lighting-electricity.html |title=Lighting by electricity |publisher=[[National Trust for Places of Historic Interest or Natural Beauty|The National Trust]] |url-status=dead |archive-url=https://web.archive.org/web/20110629091025/http://www.nationaltrust.org.uk/main/w-chl/w-places_collections/w-collections-main/w-collections-highlights/w-collections-lighting-electricity.html |archive-date=2011-06-29 }}</ref> The [[Central Electricity Board]] standardised the nation's [[electrical power|electricity supply]] and established the first synchronised AC grid, running at 132 [[volt|kilovolts]] and 50 [[Hertz]]. This started operating as a national system, the [[National Grid (UK)|National Grid]], in 1938.

In the United States it became a national objective after the power crisis during the summer of 1918 in the midst of World War I to consolidate supply. In 1934 the [[Public Utility Holding Company Act]] recognized electric utilities as [[Public good (economics)|public good]]s of importance along with gas, water, and telephone companies and thereby were given outlined restrictions and regulatory oversight of their operations.<ref name="Electric Power Planning">Mazer, A. (2007). Electric Power Planning for Regulated and Deregulated Markets. John, Wiley, and Sons, Inc., Hoboken, NJ. 313pgs.</ref>

=== Household electrification ===
{{Globalize section|date=May 2021}}
The electrification of households in Europe and North America began in the early 20th century in major cities and in areas served by electric railways and increased rapidly until about 1930 when 70% of households were electrified in the U.S.

Rural areas were electrified first in Europe, and in the U.S. the [[Rural Electric Administration]], established in 1935 brought electrification to rural areas.<ref>{{Cite report |last1=Moore |first1=Stephen |last2=Simon |first2=Julian |title=The Greatest Century That Ever Was: 25 Miraculous Trends of the last 100 Years |publisher=The Cato Institute |work=Policy Analysis |id=No. 364 |date=December 15, 1999 |url=http://www.cato.org/pubs/pas/pa364.pdf |page=20 Fig. 16 |access-date=June 16, 2011 |archive-date=October 12, 2012 |archive-url=https://web.archive.org/web/20121012020452/http://www.cato.org/pubs/pas/pa364.pdf |url-status=live }}</ref>

===Historical cost of electricity===
Central station electric power generating provided power more efficiently and at lower cost than small generators. The capital and operating cost per unit of power were also cheaper with central stations.<ref name=Devine83/> The cost of electricity fell dramatically in the first decades of the twentieth century due to the introduction of [[steam turbines]] and the improved load factor after the introduction of AC motors. As electricity prices fell, usage increased dramatically and central stations were scaled up to enormous sizes, creating significant economies of scale.<ref>{{cite book |title=Transforming the Twentieth Century: Technical Innovations and Their Consequences |last=Smil |first=Vaclav |year=2006 |location=Oxford, New York |publisher=Oxford University Press |page=[https://archive.org/details/transformingtwen00smil/page/n43 33] |isbn=978-0-19-516875-4 |url=https://archive.org/details/transformingtwen00smil |url-access=limited}} (Maximum turbine size grew to about 200 MW in the 1920s and again to about 1000 MW in 1960.  Significant increases in efficiency accompanied each increase in scale.)</ref>  For the historical cost see Ayres-Warr (2002) Fig. 7.<ref name="fraw.org.uk">{{cite web |author1=Robert U. Ayres |author2=Benjamin Warr |title=Two Paradigms of Production and Growth |url=http://www.fraw.org.uk/files/economics/ayres_2001.pdf |url-status=dead |archive-url=https://web.archive.org/web/20130502195703/http://www.fraw.org.uk/files/economics/ayres_2001.pdf |archive-date=2013-05-02}}</ref>

==Benefits of electrification==
Electrification was called "the greatest engineering achievement of the 20th Century" by the [[National Academy of Engineering]],<ref name="Constable1999">{{cite book |title=A Century of Innovation: Twenty Engineering Achievements That Transformed Our Lives |last1=Constable |first1=George |last2=Somerville |first2=Bob |year=2003 |publisher=Joseph Henry Press |location=Washington, DC |isbn=0-309-08908-5 |url=http://www.greatachievements.org/?id=2988 |access-date=2010-09-22 |archive-date=2012-04-04 |archive-url=https://web.archive.org/web/20120404192421/http://www.greatachievements.org/?id=2988 |url-status=live }}</ref> and it continues in both rich and poor countries.<ref>{{Cite journal |last1=Agutu |first1=Churchill |last2=Egli |first2=Florian |last3=Williams |first3=Nathaniel J. |last4=Schmidt |first4=Tobias S. |last5=Steffen |first5=Bjarne |date=2022-06-09 |title=Accounting for finance in electrification models for sub-Saharan Africa |url=https://www.nature.com/articles/s41560-022-01041-6 |journal=Nature Energy |volume=7 |issue=7 |language=en |pages=631–641 |doi=10.1038/s41560-022-01041-6 |bibcode=2022NatEn...7..631A |s2cid=249563183 |issn=2058-7546}}</ref><ref>{{Cite magazine |last=Hakimian |first=Rob |date=2022-06-10 |title=Procurement launched for largest rail electrification project in the world |url=https://www.newcivilengineer.com/latest/procurement-launched-for-largest-rail-electrification-project-in-the-world-10-06-2022/ |access-date=2022-06-10 |magazine=New Civil Engineer |language=en}}</ref>

===Benefits of electric lighting===
Electric lighting is highly desirable. The light is much brighter than oil or gas lamps, and there is no soot. Although early electricity was very expensive compared to today, it was far cheaper and more convenient than oil or gas lighting. Electric lighting was so much safer than oil or gas that some companies were able to pay for the electricity with the insurance savings.{{sfn|Nye|1990|p={{page needed|date=October 2020}}}}

===Pre-electric power===
{{Main|Line shaft}}In 1851, [[Charles Babbage]] stated:<blockquote>One of the inventions most important to a class of highly skilled workers (engineers) would be a small motive power - ranging perhaps from the force of from half a man to that of two horses, which might commence as well as cease its action at a moment's notice, require no expense of time for its management and be of modest cost both in original cost and in daily expense.<ref>{{cite book 
|title= Technology Science and History
|last= Cardwell
|first= D. S. L.
|year=1972 |publisher= Heinemann |location=London |page=[https://archive.org/details/technologyscienc0000card/page/163 163] |url=https://archive.org/details/technologyscienc0000card|url-access= registration
}}</ref>
</blockquote>
[[File:Batteuse 1881.jpg|upright=1.15|right|thumb|Threshing machine in 1881.]]
To be efficient steam engines needed to be several hundred horsepower.  Steam engines and boilers also required operators and maintenance.  For these reasons the smallest commercial steam engines were about 2 horsepower. This was above the need for many small shops.  Also, a small steam engine and boiler cost about $7,000 while an old blind horse that could develop 1/2 horsepower cost $20 or less.<ref>Unskilled labor made approximately $1.25 per 10- to 12-hour day. Hunter and Bryant cite a letter from [[Benjamin Henry Latrobe|Benjamin Latrobe]] to [[John Stevens (inventor, born 1749)|John Stevens]] ca. 1814 giving the cost of two old blind horses used to power a mill at $20 and $14.  A good dray horse cost $165.</ref>  Machinery to use horses for power cost $300 or less.{{sfn|Hunter|Bryant|1991|pp=29–30}}

Many power requirements were less than that of a horse.  Shop machines, such as woodworking lathes, were often powered with a one- or two-man crank.  Household sewing machines were powered with a foot treadle; however, factory sewing machines were steam-powered from a [[line shaft]].  Dogs were sometimes used on machines such as a treadmill, which could be adapted to churn butter.{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}}

In the late 19th century specially designed ''power buildings'' leased space to small shops.  These building supplied power to the tenants from a steam engine through line shafts.{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}}

Electric motors were several times more efficient than small steam engines because central station generation was more efficient than small steam engines and because line shafts and belts had high friction losses.<ref name=Devine83/>{{sfn|Hunter|Bryant|1991|p={{page needed|date=October 2020}}}}

Electric motors were more efficient than human or animal power.  The conversion efficiency for animal feed to work is between 4 and 5% compared to over 30% for electricity generated using coal.<ref name="Ayers-Warr 2002"/><ref name="fraw.org.uk"/>

===Economic impact of electrification===
{{Main|Mass production#history}}

Electrification and economic growth are highly correlated.<ref name="Electricity_in_Economic Growth"/> In economics, the efficiency of electrical generation has been shown to correlate with ''technological progress''.<ref name="Ayers-Warr 2002">{{Cite journal| last1=Ayres| last2=Ayres| last3=Warr| first1=R. U.| first2=L. W.| first3=B.| title=Exergy, Power and Work in the U. S. Economy 1900-1998| year=2003| url=http://econpapers.repec.org/article/eeeenergy/v_3a28_3ay_3a2003_3ai_3a3_3ap_3a219-273.htm| journal=Energy| volume=28| issue=3| pages=219–273| doi=10.1016/S0360-5442(02)00089-0| access-date=2015-06-04| archive-date=2015-09-09| archive-url=https://web.archive.org/web/20150909023445/http://econpapers.repec.org/article/eeeenergy/v_3a28_3ay_3a2003_3ai_3a3_3ap_3a219-273.htm| url-status=live}}</ref><ref name="Electricity_in_Economic Growth">{{cite book
 |title        = Electricity in Economic Growth
 |last1        = Committee on Electricity in Economic Growth Energy Engineering Board Commission on Engineering and Technical Systems National Research Council
 |year         = 1986
 |publisher    = National Academy Press
 |location     = Washington, DC
 |isbn         = 0-309-03677-1
 |pages        = 16, 40
 |url          = http://www.nap.edu/catalog.php?record_id=900
 |access-date  = 2013-10-07
 |archive-date = 2014-06-07
 |archive-url  = https://web.archive.org/web/20140607001154/http://www.nap.edu/catalog.php?record_id=900
 |url-status   = live
}} <Available as free .pdf download></ref>

In the U.S. from 1870 to 1880 each man-hour was provided with .55&nbsp;hp.  In 1950 each man-hour was provided with 5&nbsp;hp, or a 2.8% annual increase, declining to 1.5% from 1930 to 1950.<ref>{{cite book|title=Productivity in the United States: Trends and Cycles |last=Kendrick |first= John W.|year= 1980 |publisher = The Johns Hopkins University Press|isbn= 978-0-8018-2289-6 |page=97}}</ref>  The period of electrification of factories and households from 1900 to 1940, was one of high [[productivity]] and economic growth.

Most studies of electrification and electric grids focused on industrial core countries in Europe and the United States. Elsewhere, wired electricity was often carried on and through the circuits of colonial rule. Some historians and sociologists considered the interplay of colonial politics and the development of electric grids: in India, Rao <ref>Rao, Y. Srinivasa (2010) “Electricity, Politics and Regional Economic Imbalance in Madras
Presidency, 1900–1947.” Economic and Political Weekly 45(23), 59–66</ref> showed that linguistics-based regional politics—not techno-geographical considerations—led to the creation of two separate grids; in colonial Zimbabwe (Rhodesia), Chikowero <ref>Chikowero, Moses (2007) “Subalternating Currents: Electrification and Power Politics
in Bulawayo, Colonial Zimbabwe, 1894–1939.” Journal of Southern African Studies
33(2), 287–306</ref> showed that electrification was racially based and served the white settler community while excluding Africans; and in Mandate Palestine, Shamir <ref>Shamir, Ronen (2013) Current Flow: The Electrification of Palestine. Stanford: Stanford University Press</ref>{{page needed|date=November 2017}} claimed that  British electric concessions to a Zionist-owned company deepened the economic disparities between Arabs and Jews.

== Relevance of Automation in Electrification ==
Electrification, the process of powering systems with electricity, has been pivotal in advancing industrial automation. This is particularly evident in the use of older [[Programmable Logic Controller|Programmable Logic Controllers (PLCs)]] and Sequential Logic Controllers (SLCs), which are types of computers used to control industrial processes. Originally introduced over half a century ago, these controllers have been essential in managing the complex tasks in factories and automation environments.

The evolution of automation through [[Industry 4.0]] has further elevated the importance of PLCs and SLCs. In modern automated systems, the focus is not just on mechanical control but also on managing and analyzing data. These controllers have adapted to this shift, becoming more integrated with advanced digital systems. Modern PLCs, for instance, now feature capabilities such as cloud connectivity, which allows them to send and receive data over the internet, and edge computing, which means processing data closer to where it is generated.

This technological advancement is particularly crucial in challenging environments, like in remote industrial sites. Here, PLCs equipped with new technologies ensure reliable operation even in harsh conditions. They can handle complex tasks such as monitoring machinery and managing data flow, proving that even older automation technologies have adapted and remain relevant in today's rapidly evolving industrial landscape.

Overall, the ongoing evolution of PLCs and SLCs exemplifies the dynamic nature of automation technology, continually adapting to meet the changing needs of industries and maintaining their critical role in modern industrial processes.

==Current extent of electrification==
[[File:Access to Electricity.svg|thumb|upright=1.2|right|World map showing the percentage of the population in each country with access to [[mains electricity]], as of 2017.<ref name="el-access">{{cite web |title=Access to electricity (% of population) |url=https://data.worldbank.org/indicator/eg.Elc.Accs.Zs |website=Data |publisher=The World Bank |access-date=5 October 2019 |archive-date=16 September 2017 |archive-url=https://web.archive.org/web/20170916153704/https://data.worldbank.org/indicator/EG.ELC.ACCS.ZS |url-status=live }}</ref>
{{legend|#005ce6|80%–100%}}
{{legend|#1ba87c|60%–80%}}
{{legend|#7bed00|40%–60%}}
{{legend|#f0b411|20%–40%}}
{{legend|#c2523c|0–20%}}]]
While electrification of cities and homes has existed since the late 19th century, about 840 million people (mostly in Africa) had no access to grid electricity in 2017, down from 1.2 billion in 2010.<ref>{{Cite journal |url=https://www.wri.org/blog/2019/08/closing-sub-saharan-africa-electricity-access-gap-why-cities-must-be-part-solution |title=Closing Sub-Saharan Africa's Electricity Access Gap: Why Cities Must Be Part of the Solution |date=14 August 2019 |access-date=2019-11-26 |archive-date=2019-12-19 |archive-url=https://web.archive.org/web/20191219114347/https://www.wri.org/blog/2019/08/closing-sub-saharan-africa-electricity-access-gap-why-cities-must-be-part-solution |url-status=live |last1=Odarno |first1=Lily |journal=World Resources Institute }}</ref>

Most recent progress in electrification took place between the 1950s and 1980s. Vast gains were seen in the 1970s and 1980s—from 49% of the world's population in 1970 to 76% in 1990.<ref>{{cite web |url=http://www.worldenergyoutlook.org/resources/energydevelopment/ |title=IEA - Energy Access |work=worldenergyoutlook.org |access-date=2013-05-30 |archive-date=2013-05-31 |archive-url=https://web.archive.org/web/20130531115817/http://www.worldenergyoutlook.org/resources/energydevelopment/ |url-status=live }}</ref><ref>{{cite journal |title=From ac¸aı´ to access: distributed electrification in rural Brazil |author=Hisham Zerriffi |journal=International Journal of Energy Sector Management |volume=2 |issue=1 |date=2008 |pages=90–117 |issn=1750-6220 |doi=10.1108/17506220810859114 |url=http://iis-db.stanford.edu/pubs/22196/From_Acai_to_Access_(Published_Version).pdf |url-status=dead |archive-url=https://web.archive.org/web/20150610193847/http://iis-db.stanford.edu/pubs/22196/From_Acai_to_Access_%28Published_Version%29.pdf |archive-date=2015-06-10 |publisher=Emerald Group Publishing}}</ref> Recent gains have been more modest; by the early 2010s, 81–83% of the world's population had access to electricity.<ref>{{cite web |url=http://www.trust.org/item/20130531145822-jlky7/?source=hpeditorial |title=Population growth erodes sustainable energy gains - UN report |publisher=Thomson Reuters Foundation |work=trust.org |access-date=2013-06-17 |archive-date=2014-11-10 |archive-url=https://web.archive.org/web/20141110210145/http://www.trust.org/item/20130531145822-jlky7/?source=hpeditorial |url-status=live }}</ref>

{{clear}}

==Electrification for sustainable energy==
{{Further|Sustainable energy}}
[[File:20210119 Renewable energy investment - 2004- BloombergNEF.svg |thumb|upright=1.3|Electrified transport and renewable energy are key parts of investment for the [[renewable energy transition]]]]
Clean energy is mostly generated in the form of electricity, such as [[renewable energy]] or [[nuclear power]]. Switching to these energy sources requires that end uses, such as transport and heating, be electrified for the world's energy systems to be sustainable. Recent work has shown that in the U.S. and Canada the use of [[Heat pump|heat pumps]] (HP) is economic if powered with [[Photovoltaics|solar photovoltaic]] (PV) devices to offset [[propane]] heating in rural areas<ref>{{Cite journal |last1=Padovani |first1=Filippo |last2=Sommerfeldt |first2=Nelson |last3=Longobardi |first3=Francesca |last4=Pearce |first4=Joshua M. |date=2021-11-01 |title=Decarbonizing rural residential buildings in cold climates: A techno-economic analysis of heating electrification |url=https://www.sciencedirect.com/science/article/pii/S0378778821005685 |journal=Energy and Buildings |language=en |volume=250 |pages=111284 |doi=10.1016/j.enbuild.2021.111284 |s2cid=237669282 |issn=0378-7788|doi-access=free }}</ref> and natural gas heating in cities.<ref>{{Cite journal |last1=Pearce |first1=Joshua M. |last2=Sommerfeldt |first2=Nelson |date=2021 |title=Economics of Grid-Tied Solar Photovoltaic Systems Coupled to Heat Pumps: The Case of Northern Climates of the U.S. and Canada |journal=Energies |language=en |volume=14 |issue=4 |pages=834 |doi=10.3390/en14040834 |issn=1996-1073|doi-access=free }}</ref> A 2023 study<ref name=":0">{{Cite journal |last1=Sommerfeldt |first1=Nelson |last2=Pearce |first2=Joshua M. |date=2023-04-15 |title=Can grid-tied solar photovoltaics lead to residential heating electrification? A techno-economic case study in the midwestern U.S. |url=https://www.sciencedirect.com/science/article/pii/S0306261923002027 |journal=Applied Energy |language=en |volume=336 |pages=120838 |doi=10.1016/j.apenergy.2023.120838 |s2cid=257066236 |issn=0306-2619|doi-access=free }}</ref> investigated: (1) a residential natural gas-based heating system and grid electricity, (2) a residential natural gas-based heating system with PV to serve the electric load, (3) a residential HP system with grid electricity, and (4) a residential HP+PV system. It found that under typical inflation conditions, the lifecycle cost of [[natural gas]] and reversible, air-source heat pumps are nearly identical, which in part explains why heat pump sales have surpassed gas furnace sales in the U.S. for the first time during a period of high inflation.<ref>{{Cite web |title=Chart: Americans bought more heat pumps than gas furnaces last year |url=https://www.canarymedia.com/articles/heat-pumps/chart-americans-bought-more-heat-pumps-than-gas-furnaces-last-year |access-date=2023-03-01 |website=Canary Media |date=10 February 2023 |language=en}}</ref> With higher rates of inflation or lower PV capital costs, PV becomes a hedge against rising prices and encourages the adoption of heat pumps by also locking in both electricity and heating cost growth. The study<ref name=":0" /> concludes: "The real internal rate of return for such prosumer technologies is 20x greater than a long-term [[certificate of deposit]], which demonstrates the additional value PV and HP technologies offer prosumers over comparably secure investment vehicles while making substantive reductions in carbon emissions." This approach can be improved by integrating a thermal battery into the heat pump+solar energy heating system.<ref>{{Cite journal |last1=Li |first1=Yuanyuan |last2=Rosengarten |first2=Gary |last3=Stanley |first3=Cameron |last4=Mojiri |first4=Ahmad |date=2022-12-10 |title=Electrification of residential heating, cooling and hot water: Load smoothing using onsite photovoltaics, heat pump and thermal batteries |url=https://www.sciencedirect.com/science/article/pii/S2352152X22018618 |journal=Journal of Energy Storage |language=en |volume=56 |pages=105873 |doi=10.1016/j.est.2022.105873 |s2cid=253858807 |issn=2352-152X}}</ref><ref>{{Cite journal |last1=Ermel |first1=Conrado |last2=Bianchi |first2=Marcus V. A. |last3=Cardoso |first3=Ana Paula |last4=Schneider |first4=Paulo S. |date=2022-10-01 |title=Thermal storage integrated into air-source heat pumps to leverage building electrification: A systematic literature review |url=https://www.sciencedirect.com/science/article/pii/S1359431122009103 |journal=Applied Thermal Engineering |language=en |volume=215 |pages=118975 |doi=10.1016/j.applthermaleng.2022.118975 |s2cid=250416024 |issn=1359-4311}}</ref>  

===Transport electrification===
{{main|Electric vehicle}}
It is easier to sustainably produce electricity than it is to sustainably produce liquid fuels. Therefore, adoption of electric vehicles is a way to make transport more sustainable.<ref>{{Cite journal|last1=Bogdanov|first1=Dmitrii|last2=Farfan|first2=Javier|last3=Sadovskaia|first3=Kristina|last4=Aghahosseini|first4=Arman|last5=Child|first5=Michael|last6=Gulagi|first6=Ashish|last7=Oyewo|first7=Ayobami Solomon|last8=de Souza Noel Simas Barbosa|first8=Larissa|last9=Breyer|first9=Christian|display-authors=4|date=2019|title=Radical transformation pathway towards sustainable electricity via evolutionary steps|url= |journal=Nature Communications|language=en|volume=10|issue=1|pages=1077|bibcode=2019NatCo..10.1077B|doi=10.1038/s41467-019-08855-1|issn=|pmc=6403340|pmid=30842423}}</ref> [[Hydrogen vehicle]]s may be an option for larger vehicles which have not yet been widely electrified, such as long distance lorries.<ref>{{Cite web|last=Miller|first=Joe|date=2020-09-09|title=Hydrogen takes a back seat to electric for passenger vehicles|url=https://www.ft.com/content/98a386ee-1a04-40fd-b6a4-8cf13ff1d0da|access-date=2020-09-20|website=Financial Times|language=en-GB|archive-date=2020-09-20|archive-url=https://web.archive.org/web/20200920154027/https://www.ft.com/content/98a386ee-1a04-40fd-b6a4-8cf13ff1d0da|url-status=live}}</ref> Many of the techniques needed to lower emissions from shipping and aviation are still early in their development.{{Sfn|International Energy Agency|2020|p=139}}

===Heating electrification===
A large fraction of the world population cannot afford sufficient cooling for their homes. In addition to [[air conditioning]], which requires electrification and additional power demand, [[Passive house|passive building]] design and urban planning will be needed to ensure cooling needs are met in a sustainable way.<ref>{{Cite journal|last1=Mastrucci |first1=Alessio |last2=Byers |first2=Edward |last3=Pachauri |first3=Shonali |last4=Rao |first4=Narasimha D. |date=2019 |title=Improving the SDG energy poverty targets: Residential cooling needs in the Global South|journal=Energy and Buildings|language=en|volume=186|pages=405–415|doi=10.1016/j.enbuild.2019.01.015|issn=0378-7788|doi-access=free}}</ref> Similarly, many households in the developing and developed world suffer from [[fuel poverty]] and cannot heat their houses enough.<ref>{{Cite journal |last1=Bouzarovski |first1=Stefan |last2=Petrova |first2=Saska |date=2015 |title=A global perspective on domestic energy deprivation: Overcoming the energy poverty–fuel poverty binary|journal=Energy Research & Social Science|language=en|volume=10|pages=31–40|doi=10.1016/j.erss.2015.06.007|issn=2214-6296|doi-access=free}}</ref> Existing heating practices are often polluting.

A key sustainable solution to heating is electrification ([[heat pump]]s, or the less efficient [[Electric resistance heater|electric heater]]). The IEA estimates that heat pumps currently provide only 5% of space and [[water heating]] requirements globally, but could provide over 90%.<ref>{{cite web |last1=Abergel |first1=Thibaut |title=Heat Pumps |url=https://www.iea.org/reports/heat-pumps |website=IEA |access-date=12 April 2021 |date=June 2020 |archive-date=3 March 2021 |archive-url=https://web.archive.org/web/20210303162213/https://www.iea.org/reports/heat-pumps |url-status=live }}</ref> Use of [[geothermal heat pump|ground source heat pump]]s not only reduces total annual energy loads associated with heating and cooling, it also flattens the electric demand curve by eliminating the extreme summer peak electric supply requirements.<ref>{{cite web |last1=Mueller |first1=Mike |title=5 Things You Should Know about Geothermal Heat Pumps |url=https://www.energy.gov/eere/articles/5-things-you-should-know-about-geothermal-heat-pumps |website=Office of Energy Efficiency & Renewable Energy |publisher=US Department of Energy |access-date=17 April 2021 |date=August 1, 2017 |archive-date=15 April 2021 |archive-url=https://web.archive.org/web/20210415113304/https://www.energy.gov/eere/articles/5-things-you-should-know-about-geothermal-heat-pumps |url-status=live }}</ref> However, heat pumps and [[resistive heating]] alone will not be sufficient for the electrification of industrial heat. This because in several processes higher temperatures are required which cannot be achieved with these types of equipment. For example, for the production of ethylene via steam cracking temperatures as high as 900&nbsp;°C are required. Hence, drastically new processes are required. Nevertheless, power-to-heat is expected to be the first step in the electrification of the [[chemical industry]] with an expected large-scale implementation by 2025.<ref>{{Cite web|title=Dream or Reality? Electrification of the Chemical Process Industries|url=https://www.aiche-cep.com/cepmagazine/march_2021/MobilePagedArticle.action?articleId=1663852|access-date=2022-01-16|website=www.aiche-cep.com|language=en}}</ref>

Some cities in the United States have started prohibiting gas hookups for new houses, with state laws passed and under consideration to either require electrification or prohibit local requirements.<ref>{{Cite web |url=https://cleantechnica.com/2021/03/09/dozens-of-us-cities-are-banning-natural-gas-hookups-in-new-buildings-cancelgas-electrifyeverything/ |title=Dozens Of US Cities Are Banning Natural Gas Hookups In New Buildings — #CancelGas #ElectrifyEverything |date=9 March 2021 |access-date=2021-08-09 |archive-date=2021-08-09 |archive-url=https://web.archive.org/web/20210809182254/https://cleantechnica.com/2021/03/09/dozens-of-us-cities-are-banning-natural-gas-hookups-in-new-buildings-cancelgas-electrifyeverything/ |url-status=live }}</ref> The UK government is experimenting with electrification for home heating to meet its climate goals.<ref>{{cite web |url=https://www.gov.uk/government/groups/heat-in-buildings |accessdate=2021-08-09 |title=Heat in Buildings |archive-date=2021-08-18 |archive-url=https://web.archive.org/web/20210818051608/https://www.gov.uk/government/groups/heat-in-buildings |url-status=live }}</ref> Ceramic and Induction heating for cooktops as well as industrial applications (for instance steam crackers) are examples of technologies that can be used to transition away from natural gas.<ref>{{Cite web|title=BASF, SABIC and Linde join forces to realize the world's first electrically heated steam cracker furnace|url=https://www.basf.com/global/en/who-we-are/sustainability/whats-new/sustainability-news/2021/basf-sabic-and-linde-join-forces-to-realize-wolds-first-electrically-heated-steam-cracker-furnace.html|access-date=2021-09-24|website=www.basf.com|language=en-US|archive-date=2021-09-24|archive-url=https://web.archive.org/web/20210924020646/https://www.basf.com/global/en/who-we-are/sustainability/whats-new/sustainability-news/2021/basf-sabic-and-linde-join-forces-to-realize-wolds-first-electrically-heated-steam-cracker-furnace.html|url-status=live}}</ref>

==Energy resilience==
{{Main|Energy resilience}}
[[File:Hybrid Power System.gif|thumb|Hybrid Power System]]
Electricity is a "sticky" form of energy, in that it tends to stay in the continent or island where it is produced. It is also multi-sourced; if one source suffers a shortage, electricity can be produced from other sources, including [[renewable source]]s. As a result, in the long term it is a relatively resilient means of energy transmission.<ref>{{cite web |url=http://www.american.com/archive/2008/july-august-magazine-contents/our-electric-future |title=Our Electric Future — The American, A Magazine of Ideas |publisher=American.com |date=2009-06-15 |access-date=2009-06-19 |url-status=dead |archive-url=https://web.archive.org/web/20140825064622/http://www.american.com/archive/2008/july-august-magazine-contents/our-electric-future/ |archive-date=2014-08-25 }}</ref> In the short term, because electricity must be supplied at the same moment it is consumed, it is somewhat unstable, compared to fuels that can be delivered and stored on-site. However, that can be mitigated by [[grid energy storage]] and [[distributed generation]].

===Managing variable energy sources===
Solar and wind are [[variable renewable energy]] sources that supply electricity intermittently depending on the weather and the time of day.<ref>{{Cite journal|last1=Jerez|first1=Sonia|last2=Tobin|first2=Isabelle|last3=Turco|first3=Marco|last4=María López-Romero|first4=Jose|last5=Montávez|first5=Juan Pedro|last6=Jiménez-Guerrero|first6=Pedro|last7=Vautard|first7=Robert|year=2018|title=Resilience of the combined wind-plus-solar power production in Europe to climate change: a focus on the supply intermittence|journal=EGUGA|language=en|pages=15424|bibcode=2018EGUGA..2015424J}}</ref><ref>{{Cite book|last1=Lave|first1=M.|last2=Ellis|first2=A.|title=2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC) |chapter=Comparison of solar and wind power generation impact on net load across a utility balancing area |year=2016|pages=1837–1842|doi=10.1109/PVSC.2016.7749939|isbn=978-1-5090-2724-8|osti=1368867|s2cid=44158163|chapter-url=https://www.osti.gov/biblio/1368867|access-date=2021-05-21|archive-date=2020-02-22|archive-url=https://web.archive.org/web/20200222212841/https://www.osti.gov/biblio/1368867|url-status=live}}</ref> Most [[electrical grid]]s were constructed for non-intermittent energy sources such as coal-fired power plants.<ref>{{Cite web|title=Introduction to System Integration of Renewables – Analysis|url=https://www.iea.org/reports/introduction-to-system-integration-of-renewables|website=IEA|language=en-GB|access-date=2020-05-30|archive-date=2020-05-15|archive-url=https://web.archive.org/web/20200515213454/https://www.iea.org/reports/introduction-to-system-integration-of-renewables|url-status=live}}</ref> As larger amounts of solar and wind energy are integrated into the grid, changes have to be made to the energy system to ensure that the supply of electricity is matched to demand.<ref name=":13">{{Cite journal|last1=Blanco|first1=Herib|last2=Faaij|first2=André|date=2018|title=A review at the role of storage in energy systems with a focus on Power to Gas and long-term storage|journal=Renewable and Sustainable Energy Reviews|language=en|volume=81|pages=1049–1086|doi=10.1016/j.rser.2017.07.062|issn=1364-0321|doi-access=free}}</ref> In 2019, these sources generated 8.5% of worldwide electricity, a share that has grown rapidly.<ref>{{Cite web|title=Wind & Solar Share in Electricity Production Data|url=https://yearbook.enerdata.net/renewables/wind-solar-share-electricity-production.html|website=Enerdata|access-date=2021-05-21|archive-date=2019-07-19|archive-url=https://web.archive.org/web/20190719014426/https://yearbook.enerdata.net/renewables/wind-solar-share-electricity-production.html|url-status=live}}</ref>

There are various ways to make the electricity system more flexible. In many places, wind and solar production are complementary on a daily and a season scale: There is more wind during the night and in winter, when solar energy production is low.<ref name=":13" /> Linking different geographical regions through [[High-voltage direct current|long-distance transmission lines]] allows for further cancelling out of variability.{{Sfn|REN21|2020|p=177}} Energy demand can be shifted in time through [[energy demand management]] and the use of [[smart grid]]s, matching the times when variable energy production is highest. With storage, energy produced in excess can be released when needed.<ref name=":13" /> Building additional capacity for wind and solar generation can help to ensure that enough electricity is produced even during poor weather; during optimal weather energy generation may have to be [[Curtailment (electricity)|curtailed]]. The final mismatch may be covered by using dispatchable energy sources such as hydropower, bioenergy, or natural gas.{{Sfn|International Energy Agency|2020|p=109}}

===Energy storage===
{{Main|Energy storage}}
[[File:Abengoa Solar (7336087392).jpg|thumb|Construction of [[Thermal energy storage|salt tanks]] to store thermal energy|alt=refer to caption]]
Energy storage helps overcome barriers for intermittent renewable energy, and is therefore an important aspect of a sustainable energy system.<ref name=":16">{{Cite journal|last1=Koohi-Fayegh|first1=S.|last2=Rosen|first2=M.A.|date=2020|title=A review of energy storage types, applications and recent developments|url=https://www.sciencedirect.com/science/article/pii/S2352152X19306012|journal=Journal of Energy Storage|language=en|volume=27|pages=101047|doi=10.1016/j.est.2019.101047|s2cid=210616155|issn=2352-152X|access-date=2021-05-21|archive-date=2021-07-17|archive-url=https://web.archive.org/web/20210717132743/https://www.sciencedirect.com/science/article/abs/pii/S2352152X19306012|url-status=live}}</ref> The most commonly used storage method is [[pumped-storage hydroelectricity]], which requires locations with large differences in height and access to water.<ref name=":16" /> [[Battery storage|Batteries]], and specifically [[Lithium-ion battery|lithium-ion batteries]], are also deployed widely.<ref>{{Cite web|last=Katz|first=Cheryl|title=The batteries that could make fossil fuels obsolete|url=https://www.bbc.com/future/article/20201217-renewable-power-the-worlds-largest-battery|access-date=2021-01-10|website=[[BBC]]|archive-date=2021-01-11|archive-url=https://web.archive.org/web/20210111075439/https://www.bbc.com/future/article/20201217-renewable-power-the-worlds-largest-battery|url-status=live}}</ref> They contain [[cobalt]], which is largely [[Mining industry of the Democratic Republic of the Congo|mined in Congo]], a politically unstable region. More diverse geographical sourcing may ensure the stability of the supply-chain and their environmental impacts can be reduced by [[downcycling]] and recycling.<ref>{{Cite journal|last=Babbitt|first=Callie W.|date=2020|title=Sustainability perspectives on lithium-ion batteries|journal=Clean Technologies and Environmental Policy|language=en|volume=22|issue=6|pages=1213–1214|doi=10.1007/s10098-020-01890-3|s2cid=220351269|issn=1618-9558|doi-access=free}}</ref><ref>{{Cite web|last=Baumann-Pauly|first=Dorothée|date=16 September 2020|title=Cobalt can be sourced responsibly, and it's time to act|url=https://www.swissinfo.ch/eng/cobalt-can-be-sourced-responsibly--and-it-s-time-to-act/46031364|url-status=live|access-date=2021-04-10|website=SWI swissinfo.ch|language=en|archive-date=2020-11-26|archive-url=https://web.archive.org/web/20201126123605/https://www.swissinfo.ch/eng/cobalt-can-be-sourced-responsibly--and-it-s-time-to-act/46031364}}</ref> Batteries typically store electricity for short periods; research is ongoing into technology with sufficient capacity to last through seasons.<ref>{{Cite journal|last1=Herib|first1=Blanco|last2=André|first2=Faaij|date=2018|title=A review at the role of storage in energy systems with a focus on Power to Gas and long-term storage|journal=Renewable and Sustainable Energy Reviews|language=en|volume=81|pages=1049–1086|doi=10.1016/j.rser.2017.07.062|issn=1364-0321|doi-access=free}}</ref> Pumped hydro storage and [[power-to-gas]] with capacity for multi-month usage has been implemented in some locations.<ref>{{Cite journal|last1=Hunt|first1=Julian D.|last2=Byers|first2=Edward|last3=Wada|first3=Yoshihide|last4=Parkinson|first4=Simon|last5=Gernaat|first5=David E. H. J.|last6=Langan|first6=Simon|last7=van Vuuren|first7=Detlef P.|last8=Riahi|first8=Keywan|date=2020|title=Global resource potential of seasonal pumped hydropower storage for energy and water storage|journal=Nature Communications|language=en|volume=11|issue=1|pages=947|doi=10.1038/s41467-020-14555-y|pmid=32075965|pmc=7031375|bibcode=2020NatCo..11..947H|issn=2041-1723|doi-access=free}}</ref><ref>{{Cite web|last=Balaraman|first=Kavya|date=2020-10-12|title=To batteries and beyond: With seasonal storage potential, hydrogen offers 'a different ballgame entirely'|url=https://www.utilitydive.com/news/to-batteries-and-beyond-with-seasonal-storage-potential-hydrogen-offers/584959/|url-status=live|archive-url=https://web.archive.org/web/20210118052735/https://www.utilitydive.com/news/to-batteries-and-beyond-with-seasonal-storage-potential-hydrogen-offers/584959/|archive-date=2021-01-18|access-date=2021-01-10|website=Utility Dive|language=en-US}}</ref>

As of 2018, [[thermal energy storage]] is typically not as convenient as burning [[fossil fuels]]. High upfront costs form a barrier for implementation. [[Seasonal thermal energy storage]] requires large capacity; it has been implemented in some high-latitude regions for household heat.<ref>{{Cite journal|last1=Alva|first1=Guruprasad|last2=Lin|first2=Yaxue|last3=Fang|first3=Guiyin|date=2018|title=An overview of thermal energy storage systems|url=http://www.sciencedirect.com/science/article/pii/S036054421732056X|journal=Energy|language=en|volume=144|pages=341–378|doi=10.1016/j.energy.2017.12.037|issn=0360-5442|access-date=2021-05-21|archive-date=2021-07-17|archive-url=https://web.archive.org/web/20210717132734/https://www.sciencedirect.com/science/article/abs/pii/S036054421732056X|url-status=live}}</ref>

{{clear left}}

==See also==
{{Portal|Energy}}
*[[GOELRO plan]]
*[[Mains electricity by country]] - Plugs, voltages and frequencies
*[[Renewable electricity]]
*[[Renewable energy development]]

== References ==
=== Citations ===
{{Reflist}}

=== General and cited references ===
* {{cite book |title      = A History of Industrial Power in the United States, 1730–1930, Vol. 3: The Transmission of Power
 |last1      = Hunter
 |first1     = Louis C.
 |last2      = Bryant
 |first2     = Lynwood
 |year       = 1991
 |publisher  = MIT Press
 |location   = Cambridge, Massachusetts
 |isbn       = 0-262-08198-9
 |url-access = registration
 |url        = https://archive.org/details/historyofindustr00hunt
}}
* {{cite book |last=Hills |first=Richard Leslie |author-link=Richard L. Hills |title=Power from Steam: A History of the Stationary Steam Engine |publisher=Cambridge University Press |edition=paperback |year=1993 |page=244|isbn= 0-521-45834-X |url=https://books.google.com/books?id=t6TLOQBhd0YC}}
* {{Cite book|author-link=International Energy Agency|author=International Energy Agency|title=World Energy Outlook 2020|year=2020 |publisher=International Energy Agency |isbn=978-92-64-44923-7|url=https://www.iea.org/reports/world-energy-outlook-2020|url-status=live |archive-date=22 August 2021 |archive-url=https://web.archive.org/web/20210822044327/https://www.iea.org/reports/world-energy-outlook-2020}}
* {{cite book |title=An Encyclopedia of the History of Technology |last=McNeil |first=Ian |year=1990 |publisher=Routledge |location=London |isbn=0-415-14792-1 |url=https://archive.org/details/isbn_9780415147927}}
* {{cite book |title=Electrifying America: Social Meanings of a New Technology |last=Nye |first=David E.|year=1990 |publisher= The MIT Press |location=Cambridge, MA, USA and London, England}}
* {{Cite book|author=[[REN21]]|title=Renewables 2020: Global Status Report|publisher=REN21 Secretariat |url=https://www.ren21.net/wp-content/uploads/2019/05/gsr_2020_full_report_en.pdf |year=2020|isbn=978-3-948393-00-7 |archive-url=https://web.archive.org/web/20200923065621/https://www.ren21.net/wp-content/uploads/2019/05/gsr_2020_full_report_en.pdf|archive-date=23 September 2020|url-status=live}}

== External links ==
{{Commons category|Electrification}}
* {{Wiktionary-inline}}
* [https://www.youtube.com/watch?v=4cR2Iy97hHc&t=9s 20190809 The Truth of Lightning 01 (English)2-An`s Safe Zone] 
* [https://www.youtube.com/watch?v=bTbyekjoOC4&t=50s 20190809 The Truth of Lightning 01 (Japanese)2-An`s Safe Zone] 
* [https://www.youtube.com/watch?v=9mRhQ5G97C4&t=172s 20190809 The Truth of Lightning 02 (English)2-An`s Safe Zone]
* [https://web.archive.org/web/20120314191536/http://www.ossberger.de/cms/index.php?id=89 Zambesi Rapids] - [[Rural electrification]] with water power. {{in lang|fr}}

{{environmental technology}}
{{sustainability}}

{{Authority control}}

[[Category:Electrification| ]]
[[Category:Electric power]]
[[Category:Energy development]]
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