View source for Energy development

{{Short description|Methods bringing energy into production}}
{{Further|Outline of energy development}}
{{Update|type=|date=October 2020|reason=}}

[[File:World energy consumption 2022.png |thumb|upright=1.75| World consumption by source in 2022<ref>{{cite web |url = https://www.energyinst.org/statistical-review |title = 2023 Statistical Review of World Energy |date = 23 Jul 2023 |website = energyinst.org |access-date = 23 Jan 2024}}</ref>]]

[[File:World energy production yearly.png |thumb|upright=1.75| Yearly production by continent<ref>{{cite web |url = https://www.eia.gov/international/data/world |title = International |website = EIA |access-date = 24 Jan 2024}}</ref>]]

[[File:US Energy 2022.png |thumb|upright=1.75| US energy use, 2022<ref>{{cite web |url = https://flowcharts.llnl.gov/ |title = Flowcharts |date = Jul 2023 |website = llnl.gov |access-date = 23 Jan 2024}}</ref>]]

'''Energy development''' is the field of activities focused on obtaining sources of [[energy]] from natural resources. These activities include the production of [[Renewable energy|renewable]], [[nuclear power|nuclear]], and [[fossil fuel]] derived sources of energy, and for the [[Waste heat|recovery and reuse of energy]] that would otherwise be wasted. [[Energy conservation]] and [[Efficient energy use|efficiency measures]] reduce the demand for energy development, and can have benefits to society with improvements to [[environmental issue]]s.

Societies use energy for transportation, manufacturing, illumination, heating and air conditioning, and communication, for industrial, commercial, and domestic purposes.  Energy resources may be classified as primary resources, where the resource can be used in substantially its original form, or as secondary resources, where the energy source must be converted into a more conveniently usable form. Non-renewable resources are significantly depleted by human use, whereas renewable resources are produced by ongoing processes that can sustain indefinite human exploitation.

Thousands of people are employed in the [[energy industry]]. The conventional industry comprises the [[petroleum industry]], the natural gas industry, the [[electrical power industry]], and the [[nuclear industry]]. New energy industries include the [[renewable energy industry]], comprising alternative and sustainable manufacture, distribution, and sale of [[alternative fuel]]s.

== Classification of resources ==

{{further|World energy supply and consumption}}
{{see also|Energy industry|Energy planning|Energy policy}}

[[File:Basic Open System Model.gif|thumb|right|Open System Model (basics)]]

Energy resources may be classified as primary resources, suitable for end use without conversion to another form, or secondary resources, where the usable form of energy required substantial conversion from a primary source.  Examples of primary energy resources are [[wind power]], [[solar power]], wood fuel, fossil fuels such as coal, oil and natural gas, and uranium. Secondary resources are those such as electricity, [[hydrogen economy|hydrogen]], or other synthetic fuels.

Another important classification is based on the time required to regenerate an energy resource.  "Renewable" resources are those that recover their capacity in a time significant by human needs. Examples are hydroelectric power or wind power, when the natural phenomena that are the primary source of energy are ongoing and not depleted by human demands.  Non-renewable resources are those that are significantly depleted by human usage and that will not recover their potential significantly during human lifetimes. An example of a non-renewable energy source is coal, which does not form naturally at a rate that would support human use.

== Fossil fuels ==

[[File:Moss Landing Power Plant p1270026.jpg|thumb|right|The [[Moss Landing Power Plant]] in California is a [[fossil-fuel power station]] that [[Natural gas power plant|burns natural gas in a turbine]] to produce electricity]]

{{Main|Fossil fuel|Peak oil}}

Fossil fuel (''primary non-renewable fossil'') sources burn [[coal]] or [[hydrocarbon]] fuels, which are the remains of the decomposition of plants and animals. There are three main types of fossil fuels: coal, [[petroleum]], and [[natural gas]]. Another fossil fuel, [[liquefied petroleum gas]] (LPG), is principally derived from the production of natural gas. Heat from burning fossil fuel is used either directly for space heating and process heating, or converted to mechanical energy for vehicles, [[industrial process]]es, or [[electrical power generation]]. These fossil fuels are part of the [[carbon cycle]] and allow solar energy stored in the fuel to be released.

The use of fossil fuels in the 18th and 19th century set the stage for the [[Industrial Revolution]].

Fossil fuels make up the bulk of the world's current [[primary energy]] sources. In 2005, 81% of the world's energy needs was met from fossil sources.<ref>International Energy Agency: Key World Energy Statistics 2007. S. 6</ref> The technology and infrastructure for the use of fossil fuels already exist. Liquid fuels derived from petroleum deliver much usable energy per unit of weight or volume, which is advantageous when compared with lower [[energy density]] sources such as [[battery (electricity)|batteries]]. Fossil fuels are currently economical for decentralized energy use.

[[File:BarnettShaleDrilling-9323.jpg|thumb|left|upright=0.85|A ([[horizontal drilling|horizontal]]) [[drilling rig]] for [[natural gas]] in Texas]]

[[Energy dependence]] on imported fossil fuels creates [[energy security]] risks for dependent countries.<ref>Energy Security and Climate Policy: Assessing Interactions. [https://books.google.com/books?id=VtCs6of8F-UC&pg=PA125 p125]</ref><ref>Energy Security: Economics, Politics, Strategies, and Implications. Edited by Carlos Pascual, Jonathan Elkind. p210</ref><ref>Geothermal Energy Resources for Developing Countries. By D. Chandrasekharam, J. Bundschuh. [https://books.google.com/books?id=Ne846IokXB4C&pg=PA91 p91]</ref><ref>Congressional Record, V. 153, PT. 2, January 18, 2007 to February 1, 2007 edited by U S Congress, Congress (U.S.). p [https://books.google.com/books?id=DaFQ_F0bdnYC&pg=PA1618 1618]</ref><ref>India s Energy Security. Edited by Ligia Noronha, Anant Sudarshan.</ref> Oil dependence in particular has led to war,<ref>National security, safety, technology, and employment implications of increasing CAFE standards : hearing before the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Seventh Congress, second session, January 24, 2002. DIANE Publishing. p10</ref> funding of radicals,<ref>[http://americansecurityproject.org/wp-content/uploads/2010/10/Ending-our-Dependence-on-Oil.pdf Ending our-Dependence on Oil] {{webarchive|url=https://web.archive.org/web/20130319085119/http://americansecurityproject.org/wp-content/uploads/2010/10/Ending-our-Dependence-on-Oil.pdf |date=2013-03-19 }} - American Security Project. americansecurityproject.org</ref> monopolization,<ref>Energy Dependency, Politics and Corruption in the Former Soviet Union. By Margarita M. Balmaceda. Psychology Press, December 6, 2007.</ref> and socio-political instability.<ref>[https://politicalscience.stanford.edu/sites/default/files/documents/KarlEoE.pdf Oil-Led Development] {{webarchive |url=https://web.archive.org/web/20130513001903/https://politicalscience.stanford.edu/sites/default/files/documents/KarlEoE.pdf |date=May 13, 2013 }}: Social, Political, and Economic Consequences. Terry Lynn Karl. Stanford University. Stanford, California, United States.</ref>

Fossil fuels are non-renewable resources, which will eventually decline in production <ref>Peaking of World Oil Production: Impacts, Mitigation, and Risk Management. Was at: www.pppl.gov/polImage.cfm?doc_Id=44&size_code=Doc</ref> and become exhausted.  While the processes that created fossil fuels are ongoing, fuels are consumed far more quickly than the natural rate of replenishment.  Extracting fuels becomes increasingly costly as society consumes the most accessible fuel deposits.<ref>{{cite web|url=http://www.rigzone.com/analysis/rigs/insight.asp?i_id=213 |title=Big Rig Building Boom |date=2006-04-13 |publisher=Rigzone.com |archive-url=https://web.archive.org/web/20071021000239/http://rigzone.com/analysis/rigs/insight.asp?i_id=213 |archive-date=2007-10-21 |access-date=2008-01-18 |url-status=dead }}</ref> Extraction of fossil fuels results in [[environmental degradation]], such as the [[strip mining]] and [[mountaintop removal]] for coal.

[[Fuel efficiency]] is a form of [[thermal efficiency]], meaning the efficiency of a process that converts chemical potential energy contained in a carrier [[fuel]] into [[kinetic energy]] or [[Mechanical work|work]]. The [[fuel economy in automobiles|fuel economy]] is the energy efficiency of a particular vehicle, is given as a [[ratio]] of distance travelled per unit of [[Motor fuel|fuel]] consumed. Weight-specific efficiency (efficiency per unit weight) may be stated for [[freight]], and passenger-specific efficiency (vehicle efficiency) per passenger. The inefficient atmospheric [[combustion]] (burning) of fossil fuels in vehicles, buildings, and power plants contributes to [[urban heat island]]s.<ref>{{cite web|url=http://eetd.lbl.gov/HeatIsland/ |title=Heat Island Group Home Page |date=2000-08-30 |publisher=[[Lawrence Berkeley National Laboratory]] |access-date=2008-01-19 |url-status=dead |archive-url=https://web.archive.org/web/20080109110534/http://eetd.lbl.gov/HeatIsland/ |archive-date=January 9, 2008 }}</ref>

Conventional production of oil [[peak oil|peaked]], conservatively, between 2007 and 2010. In 2010, it was estimated that an investment of $8 trillion in non-renewable resources would be required to maintain current levels of production for 25 years.<ref>{{cite web|url=http://news.nationalgeographic.com/news/energy/2010/11/101109-peak-oil-iea-world-energy-outlook/|title=Has the World Already Passed "Peak Oil"?|work=nationalgeographic.com|url-status=dead|archive-url=https://web.archive.org/web/20140812065328/http://news.nationalgeographic.com/news/energy/2010/11/101109-peak-oil-iea-world-energy-outlook/|archive-date=2014-08-12|date=2010-11-11}}</ref> In 2010, governments subsidized [[fossil fuel]]s by an estimated $500 billion a year.<ref name="sciencedaily1">''ScienceDaily.com'' (April 22, 2010) [https://www.sciencedaily.com/releases/2010/04/100421133110.htm "Fossil-Fuel Subsidies Hurting Global Environment, Security, Study Finds"] {{webarchive|url=https://web.archive.org/web/20160410225830/https://www.sciencedaily.com/releases/2010/04/100421133110.htm |date=2016-04-10 }}</ref>  Fossil fuels are also a source of [[greenhouse gas emissions]], leading to concerns about [[global warming]] if consumption is not reduced.

The combustion of fossil fuels leads to the release of [[pollution]] into the atmosphere. The fossil fuels are mainly carbon compounds. During [[combustion]], [[carbon dioxide]] is released, and also [[nitrogen oxides]], [[soot]] and other fine [[particulates]]. The carbon dioxide is the main contributor to recent [[climate change]].<ref>Intergovernmental Panel on Climate Change (2007): IPCC Fourth Assessment Report - Working Group I Report on "The Physical Science Basis".</ref>
Other emissions from fossil fuel power station include [[sulfur dioxide|sulphur dioxide]], [[carbon monoxide]] (CO), [[hydrocarbons]], [[volatile organic compounds]] (VOC), [[Mercury (element)|mercury]], [[arsenic]], [[lead]], [[cadmium]], and other [[heavy metals]] including traces of [[uranium]].<ref>{{cite web | url=http://www.ucsusa.org/clean_energy/coalvswind/c02c.html | title=Environmental impacts of coal power: air pollution | date=18 August 2005 | publisher=[[Union of Concerned Scientists]] | access-date=18 January 2008 | url-status=live | archive-url=https://web.archive.org/web/20080115204952/http://www.ucsusa.org/clean_energy/coalvswind/c02c.html | archive-date=15 January 2008 }}</ref><ref>NRDC: [http://www.nrdc.org/globalwarming/files/coalmining.pdf There Is No Such Thing as "Clean Coal"] {{webarchive |url=https://web.archive.org/web/20120730142650/http://www.nrdc.org/globalwarming/files/coalmining.pdf |date=July 30, 2012 }}</ref>

A typical [[coal plant]] generates billions of [[kilowatt hour]]s of electrical power per year.<ref>[http://www.eia.gov/tools/faqs/faq.cfm?id=104&t=3 How much electricity does a typical nuclear power plant generate] {{webarchive|url=https://web.archive.org/web/20130729095759/http://www.eia.gov/tools/faqs/faq.cfm?id=104&t=3 |date=2013-07-29 }}? - FAQ - U.S. Energy Information Administration (EIA)</ref>

== Nuclear ==
=== Fission ===

{{multiple image
|direction = vertical
|align = right
|width = 225
|image1=
|image2=USS Enterprise (CVAN-65), USS Long Beach (CGN-9) and USS Bainbridge (DLGN-25) underway in the Mediterranean Sea during Operation Sea Orbit, in 1964.jpg
|image3=NSF picture of Yamal.jpg
|caption1=The [[Susquehanna Steam Electric Station]], a [[boiling water reactor]]. The reactors are located inside the rectangular [[containment building]]s towards the front of the [[cooling tower]]s. The power station produces 63 million [[kilowatt hour]]s per day.
|caption2=American nuclear powered ships,(top to bottom) cruisers [[USS Bainbridge (CGN-25)|USS ''Bainbridge'']], the [[USS Long Beach (CGN-9)|USS ''Long Beach'']] and the ''[[USS Enterprise (CVN-65)|USS Enterprise]]'', the [[List of longest naval ships|longest ever naval vessel]], and the first nuclear-powered [[aircraft carrier]]. Picture taken in 1964 during a record setting voyage of 26,540 nmi (49,190&nbsp;km) around the world in 65 days without refueling. Crew members are spelling out [[Albert Einstein|Einstein]]'s [[mass-energy equivalence]] formula ''E&nbsp;=&nbsp;mc<sup>2</sup>'' on the flight deck.
|caption3=The Russian [[nuclear-powered icebreaker]] [[Yamal (icebreaker)|NS Yamal]] on a joint scientific expedition with the [[National Science Foundation|NSF]] in 1994
}}

[[Nuclear power]] is the use of [[nuclear fission]]  to generate useful [[heat]] and [[electricity]]. Fission of uranium produces nearly all economically significant nuclear power. [[Radioisotope thermoelectric generator]]s form a very small component of energy generation, mostly in specialized applications such as deep space vehicles.

[[Nuclear power plant]]s, excluding [[Nuclear marine propulsion|naval reactors]], provided about 5.7% of the world's energy and 13% of the world's electricity in 2012.<ref>
{{Cite web
 |url         = https://www.iea.org/publications/freepublications/publication/kwes.pdf
 |title       = Key World Energy Statistics 2012
 |access-date  = 2012-12-17
 |publisher   = [[International Energy Agency]]
 |year        = 2012
 |archive-url  = https://web.archive.org/web/20121118210551/http://www.iea.org/publications/freepublications/publication/kwes.pdf
 |archive-date = 2012-11-18
}}
</ref>

In 2013, the [[International Atomic Energy Agency|IAEA]] report that there are 437&nbsp;operational nuclear power reactors,<ref name="iaea.org">{{cite web |url=http://www.iaea.org/pris/ |title=PRIS - Home |publisher=Iaea.org |access-date=2013-06-14 |url-status=live |archive-url=https://web.archive.org/web/20130602010449/http://www.iaea.org/pris/ |archive-date=2013-06-02 }}</ref> in [[nuclear power by country|31&nbsp;countries]],<ref name="UIC">{{cite web  | url= http://www.uic.com.au/reactors.htm  | title= World Nuclear Power Reactors 2007-08 and Uranium Requirements | publisher= World Nuclear Association | date= 2008-06-09  | access-date=2008-06-21 |archive-url = https://web.archive.org/web/20080303234143/http://www.uic.com.au/reactors.htm |archive-date = March 3, 2008}}</ref>  although not every reactor is producing electricity.<ref>{{cite news |url=http://www.taipeitimes.com/News/front/archives/2012/06/17/2003535527 |title=Japan approves two reactor restarts |newspaper=Taipei Times |date=2013-06-07 |access-date=2013-06-14 |url-status=live |archive-url=https://web.archive.org/web/20130927182338/http://www.taipeitimes.com/News/front/archives/2012/06/17/2003535527 |archive-date=2013-09-27 }}</ref> In addition, there are approximately 140 naval vessels using [[nuclear propulsion]] in operation, powered by some 180 reactors.<ref>{{cite web |url=http://www.engineersgarage.com/articles/nuclear-power-plants?page=2 |title=What is Nuclear Power Plant - How Nuclear Power Plants work &#124; What is Nuclear Power Reactor - Types of Nuclear Power Reactors |publisher=EngineersGarage |access-date=2013-06-14 |url-status=dead |archive-url=https://web.archive.org/web/20131004215527/http://www.engineersgarage.com/articles/nuclear-power-plants?page=2 |archive-date=2013-10-04 }}</ref><ref>{{cite web |url=http://www.world-nuclear.org/info/Non-Power-Nuclear-Applications/Transport/Nuclear-Powered-Ships/#.UV5yQsrpyJM |title=Nuclear-Powered Ships &#124; Nuclear Submarines |publisher=World-nuclear.org |access-date=2013-06-14 |url-status=live |archive-url=https://web.archive.org/web/20130612204746/http://www.world-nuclear.org/info/Non-Power-Nuclear-Applications/Transport/Nuclear-Powered-Ships/#.UV5yQsrpyJM |archive-date=2013-06-12 }}</ref><ref>{{cite web |url=http://www.ewp.rpi.edu/hartford/~ernesto/F2010/EP2/Materials4Students/Misiaszek/NuclearMarinePropulsion.pdf |title=Archived copy |access-date=2015-06-04 |url-status=dead |archive-url=https://web.archive.org/web/20150226055625/http://www.ewp.rpi.edu/hartford/~ernesto/F2010/EP2/Materials4Students/Misiaszek/NuclearMarinePropulsion.pdf |archive-date=2015-02-26 }} Naval Nuclear Propulsion, Magdi Ragheb.
''As of 2001, about 235 naval reactors had been built''</ref> As of 2013, attaining a [[Joint European Torus|net energy gain]] from sustained nuclear fusion reactions, excluding natural fusion power sources such as the [[Sun]], remains an ongoing area of international [[International Thermonuclear Experimental Reactor|physics]] and [[International Fusion Materials Irradiation Facility|engineering research]]. More than 60 years after the first attempts, commercial fusion power production remains unlikely before 2050.<ref name="ITERorg">{{cite web |work=The ITER Project |title=Beyond ITER |publisher=Information Services, Princeton Plasma Physics Laboratory |url=http://www.iter.org/Future-beyond.htm |access-date=5 February 2011 |archive-url=https://web.archive.org/web/20061107220145/http://www.iter.org/Future-beyond.htm |archive-date=7 November 2006 }} - Projected fusion power timeline</ref>

<!-- Debate -->
There is an ongoing [[Nuclear power debate|debate about nuclear power]].<ref>{{cite web |url=http://www.signonsandiego.com/news/2011/mar/27/nuclear-controversy/ |title=The nuclear controversy |author=Union-Tribune Editorial Board |date=March 27, 2011 |work=Union-Tribune |url-status=live |archive-url=https://web.archive.org/web/20111119222347/http://www.signonsandiego.com/news/2011/mar/27/nuclear-controversy/ |archive-date=November 19, 2011 }}</ref><ref name="jstor.org">James J. MacKenzie. [https://www.jstor.org/pss/2823429 Review of The Nuclear Power Controversy] by [[Arthur W. Murphy]] ''The Quarterly Review of Biology'', Vol. 52, No. 4 (Dec., 1977), pp. 467-468.</ref><ref name="A Reasonable Bet on Nuclear Power">In February 2010 the nuclear power debate played out on the pages of ''[[The New York Times]]'', see [https://www.nytimes.com/2010/02/18/opinion/18thur2.html?scp=1&sq=a%20reasonable%20bet%20on%20nuclear%20power&st=cse A Reasonable Bet on Nuclear Power] {{webarchive|url=https://web.archive.org/web/20170201063241/http://www.nytimes.com/2010/02/18/opinion/18thur2.html?scp=1&sq=a%20reasonable%20bet%20on%20nuclear%20power&st=cse |date=2017-02-01 }} and [https://www.nytimes.com/2010/02/20/opinion/l20nuclear.html Revisiting Nuclear Power: A Debate] {{webarchive|url=https://web.archive.org/web/20170409003059/http://www.nytimes.com/2010/02/20/opinion/l20nuclear.html |date=2017-04-09 }} and [http://roomfordebate.blogs.nytimes.com/2010/02/16/a-comeback-for-nuclear-power/ A Comeback for Nuclear Power?] {{webarchive|url=https://web.archive.org/web/20100226150025/http://roomfordebate.blogs.nytimes.com/2010/02/16/a-comeback-for-nuclear-power/ |date=2010-02-26 }}</ref>  Proponents, such as the [[World Nuclear Association]], the [[International Atomic Energy Agency|IAEA]] and [[Environmentalists for Nuclear Energy]] contend that nuclear power is a safe, [[sustainable energy]] source that reduces [[carbon emissions]].<ref name="bloomberg.com">[https://www.bloomberg.com/apps/news?pid=10000103&sid=aXb5iuqdZoD4&refer=us U.S. Energy Legislation May Be 'Renaissance' for Nuclear Power] {{webarchive|url=https://web.archive.org/web/20090626182130/http://www.bloomberg.com/apps/news?pid=10000103 |date=2009-06-26 }}.</ref> [[Anti-nuclear movement|Opponents]] contend that nuclear power poses many threats to [[Environmental radioactivity|people and the environment]].<ref>{{cite book|author=[[Spencer R. Weart]]|url=https://books.google.com/books?id=9KBD-YrGOVkC|title=The Rise of Nuclear Fear|date=2012|publisher=Harvard University Press|isbn = 9780674065062}}</ref><ref name="Sturgis">{{cite web |last=Sturgis |first=Sue |url=http://www.southernstudies.org/2009/04/post-4.html |title=Investigation: Revelations about Three Mile Island disaster raise doubts over nuclear plant safety |publisher=[[Institute for Southern Studies]]|access-date=2010-08-24 |url-status=dead |archive-url=https://web.archive.org/web/20100418063024/http://www.southernstudies.org/2009/04/post-4.html |archive-date=2010-04-18 }}</ref>

<!-- Accidents, safety and greenhouse gases emissions -->
[[Nuclear and radiation accidents|Nuclear power plant accidents]] include the [[Chernobyl disaster]] (1986), [[Fukushima Daiichi nuclear disaster]] (2011), and the [[Three Mile Island accident]] (1979).<ref name=timenuke/> There have also been some nuclear submarine accidents.<ref name=timenuke>{{cite magazine  |url=http://www.time.com/time/photogallery/0,29307,1887705,00.html |title=The Worst Nuclear Disasters |magazine=Time.com |date=2009-03-25 |access-date=2013-06-22 |url-status=dead |archive-url=https://web.archive.org/web/20130826132324/http://www.time.com/time/photogallery/0,29307,1887705,00.html |archive-date=2013-08-26 }}</ref><ref name=rad>[http://www.iaea.org/Publications/Magazines/Bulletin/Bull413/article1.pdf Strengthening the Safety of Radiation Sources]  {{webarchive|url=https://web.archive.org/web/20090326181428/http://www.iaea.org/Publications/Magazines/Bulletin/Bull413/article1.pdf |date=2009-03-26 }} p. 14.</ref><ref name=johnston2007>{{cite web |url=http://www.johnstonsarchive.net/nuclear/radevents/radevents1.html |title=Deadliest radiation accidents and other events causing radiation casualties |author=Johnston, Robert |date=September 23, 2007 |publisher=Database of Radiological Incidents and Related Events |url-status=live |archive-url=https://web.archive.org/web/20071023104305/http://www.johnstonsarchive.net/nuclear/radevents/radevents1.html |archive-date=October 23, 2007 }}</ref> In terms of lives lost per unit of energy generated, analysis has determined that nuclear power has caused less fatalities per unit of energy generated than the other major sources of energy generation. Energy production from [[coal]], [[petroleum]], [[natural gas]] and [[hydropower]] has caused a greater number of fatalities per unit of energy generated due to [[air pollution]] and [[Energy accidents|energy accident]] effects.<ref name="autogenerated2007">{{Cite journal 
| doi = 10.1016/S0140-6736(07)61253-7 
| last1 = Markandya | first1 = A. 
| last2 = Wilkinson | first2 = P. 
| title = Electricity generation and health 
| journal = Lancet 
| volume = 370 
| issue = 9591 
| pages = 979–990 
| year = 2007 
| pmid = 17876910
| s2cid = 25504602 }}</ref><ref name="without the hot air">{{cite web |url= http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_168.shtml |title= Dr. MacKay ''Sustainable Energy without the hot air'' |page= 168 |work= Data from studies by the [[Paul Scherrer Institute]] including non EU data |access-date= 15 September 2012 |url-status= live |archive-url= https://web.archive.org/web/20120902001529/http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_168.shtml |archive-date= 2 September 2012 }}</ref><ref>{{cite web |url=https://www.forbes.com/sites/jamesconca/2012/06/10/energys-deathprint-a-price-always-paid/ |title=How Deadly is Your Kilowatt? We Rank the Killer Energy Sources |website=[[Forbes]] |access-date=2017-05-13 |url-status=live |archive-url=https://web.archive.org/web/20120610182708/http://www.forbes.com/sites/jamesconca/2012/06/10/energys-deathprint-a-price-always-paid/ |archive-date=2012-06-10 }} with Chernobyl's total predicted [[linear no-threshold]] cancer deaths included, nuclear power is safer when compared to many alternative energy sources' immediate, death rate.</ref><ref name="theage2006">{{cite news|url=http://www.theage.com.au/news/national/nuclear-power-cheaper-safer-than-coal-and-gas/2006/06/04/1149359609052.html|title=Nuclear power 'cheaper, safer' than coal and gas|author=Brendan Nicholson|date=2006-06-05|newspaper=[[The Age]]|access-date=2008-01-18|url-status=live|archive-url=https://web.archive.org/web/20080208123433/http://www.theage.com.au/news/national/nuclear-power-cheaper-safer-than-coal-and-gas/2006/06/04/1149359609052.html|archive-date=2008-02-08}}</ref><ref name="tandfonline1">{{cite journal | doi = 10.1080/10807030802387556 | url = http://gabe.web.psi.ch/pdfs/_2012_LEA_Audit/TA01.pdf | volume=14 | issue = 5 | title=A Comparative Analysis of Accident Risks in Fossil, Hydro, and Nuclear Energy Chains | journal=Human and Ecological Risk Assessment | pages=947–973, 962–5 | author=Burgherr Peter| year = 2008 | s2cid = 110522982 }} Comparing Nuclear's ''latent'' cancer deaths, such as cancer with other energy sources ''immediate'' deaths per unit of energy generated(GWeyr). This study does not include fossil fuel related cancer and other indirect deaths created by the use of fossil fuel consumption in its "severe accident", an accident with more than 5 fatalities, classification.</ref> However, the economic costs of nuclear power accidents is high, and meltdowns can take decades to clean up. The human costs of evacuations of affected populations and lost livelihoods is also significant.<ref name="Richard Schiffman">{{cite web |url=https://www.theguardian.com/commentisfree/2013/mar/12/fukushima-nuclear-accident-lessons-for-us |title=Two years on, America hasn't learned lessons of Fukushima nuclear disaster |author=Richard Schiffman |date=12 March 2013 |work=The Guardian |url-status=live |archive-url=https://web.archive.org/web/20170202143654/https://www.theguardian.com/commentisfree/2013/mar/12/fukushima-nuclear-accident-lessons-for-us |archive-date=2 February 2017 }}</ref><ref name="Martin Fackler">{{cite web |url=https://www.nytimes.com/2011/06/02/world/asia/02japan.html?_r=1&ref=world |title=Report Finds Japan Underestimated Tsunami Danger |author=Martin Fackler |date=June 1, 2011 |work=The New York Times |url-status=live |archive-url=https://web.archive.org/web/20170205043423/http://www.nytimes.com/2011/06/02/world/asia/02japan.html?_r=1&ref=world |archive-date=February 5, 2017 }}</ref>

Comparing Nuclear's ''latent'' cancer deaths, such as cancer with other energy sources ''immediate'' deaths per unit of energy generated(GWeyr). This study does not include fossil fuel related cancer and other indirect deaths created by the use of fossil fuel consumption in its "severe accident" classification, which would be an accident with more than 5 fatalities.

<!-- Future of the industry --> 
As of 2012, according to the [[IAEA]], worldwide there were 68 civil nuclear power reactors under construction in 15 countries,<ref name="iaea.org"/> approximately 28 of which in the [[People's Republic of China]] (PRC), with the most recent nuclear power reactor, as of May 2013, to be connected to the [[electrical grid]], occurring on February 17, 2013, in [[Hongyanhe Nuclear Power Plant]] in the PRC.<ref>{{cite web |url=http://www.worldnuclearreport.org/Worldwide-First-Reactor-to-Start.html |title=Worldwide First Reactor to Start Up in 2013, in China - World Nuclear Industry Status Report |date=18 February 2013 |publisher=Worldnuclearreport.org |access-date=2013-06-14 |url-status=live |archive-url=https://web.archive.org/web/20130602081151/http://www.worldnuclearreport.org/Worldwide-First-Reactor-to-Start.html |archive-date=2013-06-02 }}</ref> In the United States, two new [[Generation III reactor]]s are under construction at [[Vogtle]]. U.S. nuclear industry officials expect five new reactors to enter service by 2020, all at existing plants.<ref name=us12>{{cite web |url=https://www.reuters.com/article/us-usa-nuclear-nrc-idUSTRE8182J720120209 |title=U.S. approves first new nuclear plant in a generation |author=Ayesha Rascoe |date=February 9, 2012 |work=Reuters |url-status=live |archive-url=http://archive.wikiwix.com/cache/20170701145249/https://www.reuters.com/article/2012/02/09/us-usa-nuclear-nrc-idUSTRE8182J720120209 |archive-date=July 1, 2017 }}</ref> In 2013, four aging, uncompetitive, reactors were permanently closed.<ref name="Mark Cooper">{{cite web |url=http://www.thebulletin.org/nuclear-aging-not-so-graceful |title=Nuclear aging: Not so graceful |author=Mark Cooper |date=18 June 2013 |work=Bulletin of the Atomic Scientists |url-status=live |archive-url=https://web.archive.org/web/20130705145151/http://www.thebulletin.org/nuclear-aging-not-so-graceful |archive-date=5 July 2013 }}</ref><ref name=mw11111>{{cite web |url=https://www.nytimes.com/2013/06/15/business/energy-environment/aging-nuclear-plants-are-closing-but-for-economic-reasons.html?ref=matthewlwald |title=Nuclear Plants, Old and Uncompetitive, Are Closing Earlier Than Expected |author=Matthew Wald |date=June 14, 2013 |work=The New York Times |url-status=live |archive-url=https://web.archive.org/web/20170126093314/http://www.nytimes.com/2013/06/15/business/energy-environment/aging-nuclear-plants-are-closing-but-for-economic-reasons.html?ref=matthewlwald |archive-date=January 26, 2017 }}</ref>

Recent experiments in extraction of uranium use polymer ropes that are coated with a substance that selectively absorbs uranium from seawater. This process could make the considerable volume of uranium dissolved in seawater exploitable for energy production.  Since ongoing geologic processes carry uranium to the sea in amounts comparable to the amount that would be extracted by this process, in a sense the sea-borne uranium becomes a sustainable resource.<ref>{{cite web|url=https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/#34e87e246e2a|title=Uranium Seawater Extraction Makes Nuclear Power Completely Renewable|first=James|last=Conca|website=forbes.com|access-date=4 May 2018|url-status=live|archive-url=https://web.archive.org/web/20180424213313/https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/#34e87e246e2a|archive-date=24 April 2018}}</ref><ref>[http://pubs.acs.org/toc/iecred/55/15#UraniuminSeawater April 20, 2016 Volume 55, Issue 15 Pages 4101-4362 In this issue:Uranium in Seawater] Page 962 to 965</ref>{{Relevance inline|date=October 2020}}

Nuclear power is a [[low carbon power generation]] method of producing electricity, with an analysis of the literature on its [[Life cycle assessment|total life cycle]] [[emission intensity]] finding that it is similar to renewable sources in a comparison of [[greenhouse gas]] (GHG) emissions per unit of energy generated.<ref>{{cite web |url=http://www.nrel.gov/analysis/sustain_lca_nuclear.html |title=Collectively, life cycle assessment literature shows that nuclear power is similar to other renewable and much lower than fossil fuel in total life cycle GHG emissions. |publisher=Nrel.gov |date=2013-01-24 |access-date=2013-06-22 |url-status=dead |archive-url=https://web.archive.org/web/20130702205635/http://www.nrel.gov/analysis/sustain_lca_nuclear.html |archive-date=2013-07-02 }}</ref><ref name="Wagner2021">{{cite journal|last1=Wagner|first1=Friedrich|title=CO2 emissions of nuclear power and renewable energies: a statistical analysis of European and global data|journal=The European Physical Journal Plus|volume=136|issue=5|year=2021|page=562 |issn=2190-5444|doi=10.1140/epjp/s13360-021-01508-7|bibcode=2021EPJP..136..562W |doi-access=free}}</ref> Since the 1970s, nuclear fuel has displaced about 64 [[gigaton]]nes of [[carbon dioxide equivalent]] (GtCO2-eq) [[greenhouse gases]], that would have otherwise resulted from the burning of oil, coal or natural gas in [[fossil-fuel power station]]s.<ref>{{cite journal |title=Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power - global nuclear power has prevented an average of 1.84 million air pollution-related deaths and 64 gigatonnes of CO2-equivalent (GtCO2-eq) greenhouse gas (GHG) emissions that would have resulted from fossil fuel burning |doi=10.1021/es3051197 |pmid=23495839 |volume=47 |issue=9 |journal=Environmental Science |pages=4889–4895 |author=Kharecha Pushker A|bibcode=2013EnST...47.4889K |year=2013 |doi-access=free |hdl=2060/20140017100 |hdl-access=free }}</ref>

==== Nuclear power phase-out and pull-backs ====
{{Further|Nuclear power phase-out}}
Japan's 2011 [[Fukushima Daiichi nuclear accident]], which occurred in a reactor design from the [[Generation II reactor|1960]]s, prompted a rethink of [[nuclear safety]] and [[nuclear energy policy]] in many countries.<ref name=sciamer2011/> Germany decided to close all its reactors by 2022, and Italy has banned nuclear power.<ref name=sciamer2011>{{cite web |url=http://www.scientificamerican.com/article.cfm?id=iaea-head-sees-wide-support |title=IAEA Head Sees Wide Support for Stricter Nuclear Plant Safety |author1=Sylvia Westall |author2=Fredrik Dahl |date=June 24, 2011 |work=Scientific American |url-status=live |archive-url=https://archive.today/20110625042535/http://www.scientificamerican.com/article.cfm?id=iaea-head-sees-wide-support |archive-date=June 25, 2011 }}</ref> Following Fukushima, in 2011 the [[International Energy Agency]] halved its estimate of additional nuclear generating capacity to be built by 2035.<ref name="economist-20110428">{{cite news |url=http://www.economist.com/node/18621367?story_id=18621367 |title=Gauging the pressure |date=28 April 2011 |newspaper=The Economist |url-status=live |archive-url=https://web.archive.org/web/20120831040950/http://www.economist.com/node/18621367?story_id=18621367 |archive-date=31 August 2012 }}</ref><ref name=late>{{cite web |url=http://www.eea.europa.eu/publications/late-lessons-2 |title=Late lessons from early warnings: science, precaution, innovation: Full Report |author=European Environment Agency |date=January 23, 2013 |page=476 |url-status=live |archive-url=https://web.archive.org/web/20130517104807/http://www.eea.europa.eu/publications/late-lessons-2 |archive-date=May 17, 2013 }}</ref>

===== Fukushima =====
Following the 2011 [[Fukushima Daiichi nuclear disaster]] – the second worst [[nuclear incident]], that displaced 50,000 households after [[radioactivity|radioactive material]] leaked into the air, soil and sea,<ref>{{cite news |url=https://www.bloomberg.com/news/2011-06-26/fukushima-retiree-to-lead-anti-nuclear-motion.html |title=Fukushima Retiree Leads Anti-Nuclear Shareholders at Tepco Annual Meeting |author1=Tomoko Yamazaki |author2=Shunichi Ozasa |date=27 June 2011 |work=Bloomberg |url-status=live |archive-url=https://web.archive.org/web/20110630151243/http://www.bloomberg.com/news/2011-06-26/fukushima-retiree-to-lead-anti-nuclear-motion.html |archive-date=30 June 2011 }}</ref> and with subsequent radiation checks leading to bans on some shipments of vegetables and fish<ref>{{cite news  |url=https://www.reuters.com/article/us-japan-nuclear-idUSTRE74610J20110507  |title=Japan anti-nuclear protesters rally after PM call to close plant  |author=Mari Saito  |date=7 May 2011  |work=Reuters  |url-status=live  |archive-url=https://web.archive.org/web/20110507220053/http://www.reuters.com/article/2011/05/07/us-japan-nuclear-idUSTRE74610J20110507  |archive-date=7 May 2011  }}</ref> – a global public support survey by [[Ipsos]] (2011) for energy sources was published and nuclear fission was found to be the least popular<ref name="Ipsos-Fukushima">{{citation
 |author      = Ipsos
 |title       = Global Citizen Reaction to the Fukushima Nuclear Plant Disaster (theme: environment / climate) Ipsos Global @dvisor
 |date        = 23 June 2011
 |url         = http://www.ipsos-mori.com/Assets/Docs/Polls/ipsos-global-advisor-nuclear-power-june-2011.pdf
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20141224033030/https://www.ipsos-mori.com/Assets/Docs/Polls/ipsos-global-advisor-nuclear-power-june-2011.pdf
 |archive-date = 24 December 2014
}}. Survey website: [http://www.ipsos-mori.com/researchpublications/researcharchive/2817/Strong-global-opposition-towards-nuclear-power.aspx Ipsos MORI: Poll: Strong global opposition towards nuclear power] {{webarchive|url=https://web.archive.org/web/20160403234041/https://www.ipsos-mori.com/researchpublications/researcharchive/2817/strong-global-opposition-towards-nuclear-power.aspx |date=2016-04-03 }}.</ref>

==== Fission economics ====
{{Main|Economics of nuclear power plants}}
[[File:Fukushima I by Digital Globe crop.jpg|thumb|[[Fukushima Daiichi nuclear disaster]]]]
[[File:Global public support for energy sources (Ipsos 2011).png|thumb|Low global public support for nuclear fission in the aftermath of Fukushima ([[Ipsos]]-survey, 2011)<ref name="Ipsos-Fukushima" />]]

The economics of new nuclear power plants is a controversial subject, since there are diverging views on this topic, and multibillion-dollar investments ride on the choice of an energy source. [[Nuclear power plant]]s typically have high capital costs for building the plant, but low direct fuel costs. In recent years there has been a slowdown of electricity demand growth and financing has become more difficult, which affects large projects such as nuclear reactors, with very large upfront costs and long project cycles which carry a large variety of risks.<ref name=kidd2011/> In Eastern Europe, a number of long-established projects are struggling to find finance, notably Belene in Bulgaria and the additional reactors at Cernavoda in Romania, and some potential backers have pulled out.<ref name=kidd2011>{{cite web|url=http://www.neimagazine.com/story.asp?sectioncode=147&storyCode=2058653 |title=New reactors—more or less? |author=Kidd, Steve |date=January 21, 2011 |work=Nuclear Engineering International |url-status=dead |archive-url=https://web.archive.org/web/20111212195417/http://www.neimagazine.com/story.asp?sectioncode=147&storyCode=2058653 |archive-date=2011-12-12 }}</ref> Where cheap gas is available and its future supply relatively secure, this also poses a major problem for nuclear projects.<ref name=kidd2011/>

Analysis of the economics of nuclear power must take into account who bears the risks of future uncertainties. To date all operating nuclear power plants were developed by [[Nationalized|state-owned]] or [[Regulated market|regulated]] [[Electric utility|utility monopolies]]<ref name="ft-20100912">{{cite news |url=http://www.ft.com/cms/s/0/ad15fcfe-bc71-11df-a42b-00144feab49a.html |archive-url=https://ghostarchive.org/archive/20221210/http://www.ft.com/cms/s/0/ad15fcfe-bc71-11df-a42b-00144feab49a.html |archive-date=2022-12-10 |url-access=subscription |title=Nuclear: New dawn now seems limited to the east |author=Ed Crooks |newspaper=Financial Times |date=12 September 2010 |access-date=12 September 2010}}</ref><ref name="NERA-20120316">{{cite web|url=http://elliott.gwu.edu/assets/docs/events/kee-0312.pdf |title=Future of Nuclear Energy |author=Edward Kee |publisher=NERA Economic Consulting |date=16 March 2012 |access-date=2 October 2013 |url-status=dead |archive-url=https://web.archive.org/web/20131005000713/http://elliott.gwu.edu/assets/docs/events/kee-0312.pdf |archive-date=5 October 2013 }}</ref> where many of the risks associated with construction costs, operating performance, fuel price, and other factors were borne by consumers rather than suppliers. Many countries have now liberalized the [[electricity market]] where these risks, and the risk of cheaper competitors emerging before capital costs are recovered, are borne by plant suppliers and operators rather than consumers, which leads to a significantly different evaluation of the economics of new nuclear power plants.<ref name="MIT-2003">{{Cite book |url=http://web.mit.edu/nuclearpower/ |title=The Future of Nuclear Power |publisher=[[Massachusetts Institute of Technology]] |year=2003 |isbn=978-0-615-12420-9 |access-date=2006-11-10 |url-status=live |archive-url=https://web.archive.org/web/20170518215841/http://web.mit.edu/nuclearpower/ |archive-date=2017-05-18 }}</ref>

==== Costs ====
Costs are likely to go up for currently operating and new nuclear power plants, due to increased requirements for on-site spent fuel management and elevated design basis threats.<ref name="Massachusetts Institute of Technology 2011 xv">{{cite web |url=http://web.mit.edu/mitei/research/studies/documents/nuclear-fuel-cycle/The_Nuclear_Fuel_Cycle-all.pdf |title=The Future of the Nuclear Fuel Cycle |author=Massachusetts Institute of Technology |year=2011 |page=xv |url-status=live |archive-url=https://web.archive.org/web/20110601120150/http://web.mit.edu/mitei/research/studies/documents/nuclear-fuel-cycle/The_Nuclear_Fuel_Cycle-all.pdf |archive-date=2011-06-01 }}</ref> While first of their kind designs, such as the EPRs under construction are behind schedule and over-budget, of the seven South Korean [[APR-1400]]s presently under construction worldwide, two are in S.Korea at the [[Hanul Nuclear Power Plant]] and four are at the largest nuclear station construction project in the world as of 2016, in the [[United Arab Emirates]] at the planned [[Barakah nuclear power plant]]. The first reactor, Barakah-1 is 85% completed and on schedule for grid-connection during 2017.<ref>{{cite web|url=http://www.world-nuclear-news.org/NN-UAEs-fourth-power-reactor-under-construction-0209155.html|title=UAE's fourth power reactor under construction|website=www.world-nuclear-news.org|access-date=4 May 2018|url-status=live|archive-url=https://web.archive.org/web/20170916153535/http://www.world-nuclear-news.org/NN-UAEs-fourth-power-reactor-under-construction-0209155.html|archive-date=16 September 2017}}</ref><ref>{{cite web|url=http://www.fananews.com/en/uae/307075/|title=The Emirates Nuclear Energy Corporation ( ENEC ) provided a project update on the status of the UAE peaceful nuclear energy program|website=www.fananews.com|access-date=4 May 2018|url-status=dead|archive-url=https://web.archive.org/web/20161006125335/http://www.fananews.com/en/uae/307075/|archive-date=6 October 2016}}</ref> 
Two of the four [[European Pressurized Reactor|EPR]]s under construction (in [[Finland]] and France) are significantly behind schedule and substantially over cost.<ref name="Patel">{{cite news | url= https://www.bloomberg.com/news/2010-11-24/china-builds-french-designed-nuclear-reactor-for-40-less-areva-ceo-says.html | title= China Builds Nuclear Reactor for 40% Less Than Cost in France, Areva Says | first= Tara | last= Patel | author2= Francois de Beaupuy | date= 24 November 2010 | publisher= [[Bloomberg L.P.|Bloomberg]] | access-date= 2011-03-08 | url-status= live | archive-url= https://web.archive.org/web/20101128111033/http://www.bloomberg.com/news/2010-11-24/china-builds-french-designed-nuclear-reactor-for-40-less-areva-ceo-says.html | archive-date= 28 November 2010 }}</ref>

== Renewable sources ==
{{Main|Renewable energy commercialization}}
[[File:2011- Renewable energy capacity - International Energy Agency.svg |thumb|Renewable energy capacity has steadily grown, led by [[Photovoltaic system|solar photovoltaic]] power.<ref name=IEA_202306>Source for data beginning in 2017: {{cite web |title=Renewable Energy Market Update Outlook for 2023 and 2024 |url=https://iea.blob.core.windows.net/assets/63c14514-6833-4cd8-ac53-f9918c2e4cd9/RenewableEnergyMarketUpdate_June2023.pdf |website=IEA.org |publisher=International Energy Agency (IEA) |archive-url=https://web.archive.org/web/20230711115355/https://iea.blob.core.windows.net/assets/63c14514-6833-4cd8-ac53-f9918c2e4cd9/RenewableEnergyMarketUpdate_June2023.pdf |archive-date=11 July 2023 |page=19 |date=June 2023 |quote=IEA. CC BY 4.0. |url-status=live}} ● Source for data through 2016: {{cite web |title=Renewable Energy Market Update / Outlook for 2021 and 2022 |url=https://iea.blob.core.windows.net/assets/18a6041d-bf13-4667-a4c2-8fc008974008/RenewableEnergyMarketUpdate-Outlookfor2021and2022.pdf |website=IEA.org |publisher=International Energy Agency |archive-url=https://web.archive.org/web/20230325084025/https://iea.blob.core.windows.net/assets/18a6041d-bf13-4667-a4c2-8fc008974008/RenewableEnergyMarketUpdate-Outlookfor2021and2022.pdf |archive-date=25 March 2023 |page=8 |date=May 2021 |url-status=live |quote=IEA. Licence: CC BY 4.0 }}</ref>]]
{{multiple image | total_width=225px 
| image2= 20211104 Percentage of electricity from fossil fuels, nuclear, renewables - biggest fossil fuel emitters.svg |caption2= The countries most reliant on fossil fuels for electricity vary widely on how great a percentage of that electricity is generated from renewables, leaving wide variation in renewables' growth potential.<ref name=BP-Ember_20211103>{{cite web |author1=Data: BP Statistical Review of World Energy, and Ember Climate |title=Electricity consumption from fossil fuels, nuclear and renewables, 2020 |url=https://ourworldindata.org/grapher/elec-mix-bar |website=OurWorldInData.org |publisher=Our World in Data consolidated data from BP and Ember |archive-url=https://web.archive.org/web/20211103100119/https://ourworldindata.org/grapher/elec-mix-bar |archive-date=3 November 2021 |date=3 November 2021 |url-status=live }}</ref>
}}
[[Renewable energy]] is generally defined as energy that comes from resources which are naturally replenished on a human timescale such as [[sunlight]], [[wind]], [[rain]], [[tidal power|tides]], [[wave power|waves]] and [[geothermal energy|geothermal heat]].<ref>{{cite web |url=http://thebulletin.org/myth-renewable-energy |title=The myth of renewable energy &#124; Bulletin of the Atomic Scientists |publisher=Thebulletin.org |date=2011-11-22 |access-date=2013-10-03 |url-status=live |archive-url=https://web.archive.org/web/20131007161531/http://www.thebulletin.org/myth-renewable-energy |archive-date=2013-10-07 }}</ref> Renewable energy replaces conventional fuels in four distinct areas: [[electricity generation]], [[solar hot water|hot water]]/[[space heating]], [[motor fuel]]s, and [[Stand-alone power system|rural (off-grid)]] energy services.<ref name=ren15>REN21 (2010). [http://www.ren21.net/Portals/97/documents/GSR/REN21_GSR_2010_full_revised%20Sept2010.pdf Renewables 2010 Global Status Report] p. 15. {{webarchive |url=https://web.archive.org/web/20120416031610/http://www.ren21.net/Portals/97/documents/GSR/REN21_GSR_2010_full_revised%20Sept2010.pdf |date=April 16, 2012 }}</ref>

About 16% of global final energy consumption presently comes from [[renewable resource]]s{{Contradictory inline|reason=Below, the sum of percentages of electricity produced by renewable sources exceeds this total|date=September 2019}}, with 10% <ref>{{cite web |date=2006|url=http://www.iea.org/publications/freepublications/publication/cooking.pdf |title=Energy for Cooking in Developed Countries |access-date=2018-07-13 |url-status=live |archive-url=https://web.archive.org/web/20171115224542/https://www.iea.org/publications/freepublications/publication/cooking.pdf |archive-date=2017-11-15 }}</ref> of all energy from traditional [[biomass]], mainly used for [[heating]], and 3.4% from [[hydroelectricity]]. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) account for another 3% and are growing rapidly.<ref name="ria21">{{cite web |url=http://www.ren21.net/Portals/0/documents/Resources/GSR2011_FINAL.pdf |title=Renewables 2011: Global Status Report |author=REN21 |year=2011 |pages=17, 18 |url-status=live |archive-url=https://web.archive.org/web/20150924085959/http://www.ren21.net/Portals/0/documents/Resources/GSR2011_FINAL.pdf |archive-date=2015-09-24 |author-link=REN21 }}</ref> At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply. National renewable energy markets are projected to continue to grow strongly in the coming decade and beyond.<ref>{{cite web|url=http://new.ren21.net/Portals/0/REN21_GFR_2013_print.pdf |title=Renewables global futures report 2013 |author=REN21 |year=2013 }}{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> [[Wind power]], for example, is growing at the rate of 30% annually, with a worldwide [[Installed wind power capacity|installed capacity]] of 282,482 [[megawatt]]s (MW) at the end of 2012.

Renewable energy resources exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries. Rapid deployment of renewable energy and [[efficient energy use|energy efficiency]] is resulting in significant [[Energy security and renewable technology|energy security]], [[climate change mitigation]], and economic benefits.<ref>{{cite web |url=http://www.iea.org/Textbase/npsum/ETP2012SUM.pdf |title=Energy Technology Perspectives 2012 |author=International Energy Agency |year=2012 |url-status=live |archive-url=https://web.archive.org/web/20120708132858/http://www.iea.org/Textbase/npsum/ETP2012SUM.pdf |archive-date=2012-07-08 }}</ref> In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power.<ref name="UNEP">United Nations Environment Programme [http://sefi.unep.org/fileadmin/media/sefi/docs/publications/SEFI_Investment_Report_2007.pdf ''Global Trends in Sustainable Energy Investment 2007: Analysis of Trends and Issues in the Financing of Renewable Energy and Energy Efficiency in OECD and Developing Countries''] {{webarchive |url=https://web.archive.org/web/20090325060117/http://sefi.unep.org/fileadmin/media/sefi/docs/publications/SEFI_Investment_Report_2007.pdf |date=March 25, 2009 }} (PDF), p. 3.</ref>

While many renewable energy projects are large-scale, renewable technologies are also suited to [[rural]] and remote areas and [[Renewable energy in developing countries|developing countries]], where energy is often crucial in [[Human development (humanity)|human development]].<ref>World Energy Assessment (2001). [http://www.undp.org/energy/activities/wea/drafts-frame.html Renewable energy technologies] {{webarchive |url=https://web.archive.org/web/20070609101755/http://www.undp.org/energy/activities/wea/drafts-frame.html |date=June 9, 2007 }}, p. 221.</ref> [[United Nations]]' Secretary-General [[Ban Ki-moon]] has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity.<ref name="renewableenergyworld1">{{cite web |url=http://www.renewableenergyworld.com/rea/news/article/2011/08/u-n-secretary-general-renewables-can-end-energy-poverty |title=U.N. Secretary-General: Renewables Can End Energy Poverty |author=Steve Leone |date=25 August 2011 |work=Renewable Energy World |url-status=live |archive-url=https://web.archive.org/web/20130928135741/http://www.renewableenergyworld.com/rea/news/article/2011/08/u-n-secretary-general-renewables-can-end-energy-poverty |archive-date=28 September 2013 }}</ref>

=== Hydroelectricity ===

[[File:ThreeGorgesDam-China2009.jpg|thumb| The 22,500 [[Megawatt|MW]] [[Three Gorges Dam]] in China – the [[List of conventional hydroelectric power stations#Hydroelectric power stations|world's largest]] hydroelectric power station]]

[[Hydroelectricity]]  is electric power generated by [[hydropower]]; the force of falling or flowing water. In 2015 hydropower generated 16.6% of the world's total electricity and 70% of all renewable electricity <ref>{{cite web|url=http://www.ren21.net/wp-content/uploads/2016/06/GSR_2016_Full_Report_REN21.pdf|access-date=2017-05-24|title=Renewables 2016: Global Status Report|url-status=live|archive-url=https://web.archive.org/web/20170525173336/http://www.ren21.net/wp-content/uploads/2016/06/GSR_2016_Full_Report_REN21.pdf|archive-date=2017-05-25}}</ref>{{page needed|date=May 2017}} and was expected to increase about 3.1% each year for the following 25 years.

Hydropower is produced in 150 countries, with the Asia-Pacific region generating 32 percent of global hydropower in 2010. China is the largest hydroelectricity producer, with 721 terawatt-hours of production in 2010, representing around 17 percent of domestic electricity use. There are now three hydroelectricity plants larger than 10 GW: the [[Three Gorges Dam]] in China, [[Itaipu Dam]] across the Brazil/Paraguay border, and [[Guri Dam]] in Venezuela.<ref name=wi2012>{{cite web |url=http://www.worldwatch.org/node/9527 |title=Use and Capacity of Global Hydropower Increases |author=Worldwatch Institute |date=January 2012 |url-status=dead |archive-url=https://web.archive.org/web/20140924062448/http://www.worldwatch.org/node/9527 |archive-date=2014-09-24 |access-date=2014-01-11 }}</ref>

The cost of hydroelectricity is relatively low, making it a competitive source of renewable electricity. The average cost of electricity from a hydro plant larger than 10 megawatts is 3 to 5 U.S. cents per kilowatt-hour.<ref name=wi2012/> Hydro is also a flexible source of electricity since plants can be ramped up and down very quickly to adapt to changing energy demands. However, damming interrupts the flow of rivers and can harm local ecosystems, and building large dams and reservoirs often involves displacing people and wildlife.<ref name=wi2012/> Once a hydroelectric complex is constructed, the project produces no direct waste, and has a considerably lower output level of the [[greenhouse gas]] [[carbon dioxide]] than [[fossil fuel]] powered energy plants.<ref name="REN21-2011">[http://www.ren21.net/Portals/97/documents/GSR/REN21_GSR2011.pdf Renewables 2011 Global Status Report, page 25, Hydropower] {{webarchive |url=https://web.archive.org/web/20120409013321/http://www.ren21.net/Portals/97/documents/GSR/REN21_GSR2011.pdf |date=April 9, 2012 }}, ''[[REN21]]'', published 2011, accessed 2011-11-7.</ref>

=== Wind ===
{{multiple image
 |direction = vertical
 |align = right
 |width = 218
 |image2=Global Wind Power Cumulative Capacity.svg
 |image1=Pretty flamingos - geograph.org.uk - 578705.jpg
 |caption2=[[Wind power by country|Global growth]] of wind power capacity
 |caption1=[[Burbo Bank Offshore Wind Farm]] in Northwest England
}}

[[Wind power]] harnesses the power of the wind to propel the blades of [[wind turbine]]s. These turbines cause the rotation of [[magnet]]s, which creates electricity. Wind towers are usually built together on [[wind farm]]s. There are [[List of offshore wind farms|offshore]] and [[List of onshore wind farms|onshore]] wind farms. [[Wind power by country|Global wind power capacity]] has expanded rapidly to 336 [[Gigawatt|GW]] in June 2014, and wind energy production was around 4% of total worldwide electricity usage, and growing rapidly.<ref name="wwea2014-halfyear">{{cite book |author=The World Wind Energy Association |title=2014 Half-year Report |year=2014|pages=1–8 |publisher=WWEA}}</ref>

Wind power is widely used in [[Wind power in the European Union|Europe]], [[Wind power in China|Asia]], and the [[Wind power in the United States|United States]].<ref name="Glob">[http://www.gwec.net/uploads/media/07-02_PR_Global_Statistics_2006.pdf Global wind energy markets continue to boom – 2006 another record year] {{webarchive|url=https://web.archive.org/web/20110407175732/http://www.gwec.net/uploads/media/07-02_PR_Global_Statistics_2006.pdf |date=2011-04-07 }} (PDF).</ref> Several countries have achieved relatively high levels of wind power penetration, such as 21% of stationary electricity production in [[Wind power in Denmark|Denmark]],<ref name="wwea">{{cite web 
 |publisher=[[World Wind Energy Association]]  |title=World Wind Energy Report 2010  |work=Report  |date=February 2011  |url= http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf  |access-date=8 August 2011  |url-status=dead |archive-url= https://web.archive.org/web/20110904232058/http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf 
 |archive-date=4 September 2011  }}</ref> 18% in [[Wind power in Portugal|Portugal]],<ref name="wwea"/> 16% in [[Wind power in Spain|Spain]],<ref name="wwea"/> 14% in [[Wind power in Ireland|Ireland]],<ref>{{cite web |url=http://www.eirgrid.com/renewables/ |title=Renewables |publisher=eirgrid.com |access-date=22 November 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110815202535/http://www.eirgrid.com/renewables/ |archive-date=15 August 2011 }}</ref> and 9% in [[Wind power in Germany|Germany]] in 2010.<ref name="wwea"/><ref name=ren212011>{{cite web|url=http://www.ren21.net/Portals/97/documents/GSR/GSR2011_Master18.pdf |title=Renewables 2011: Global Status Report |author=REN21 |year=2011 |url-status=dead |archive-url=https://web.archive.org/web/20110905003859/http://www.ren21.net/Portals/97/documents/GSR/GSR2011_Master18.pdf |archive-date=2011-09-05 |author-link=REN21 }}</ref>{{rp|11}} By 2011, at times over 50% of electricity in Germany and Spain came from wind and solar power.<ref>{{cite web|url=https://www.theguardian.com/environment/2012/may/28/solar-power-world-record-germany|title=This page has been removed - News - The Guardian|work=The Guardian|url-status=live|archive-url=https://web.archive.org/web/20170226071255/https://www.theguardian.com/environment/2012/may/28/solar-power-world-record-germany|archive-date=2017-02-26}}</ref><ref>[http://www.wind-works.org/FeedLaws/Spain/SpainRenewableEnergyandHighPenetration.html Spain Renewable Energy and High Penetration] {{webarchive |url=https://web.archive.org/web/20120609235738/http://www.wind-works.org/FeedLaws/Spain/SpainRenewableEnergyandHighPenetration.html |date=June 9, 2012 }}</ref> As of 2011, 83 countries around the world are using wind power on a commercial basis.<ref name=ren212011/>{{rp|11}}

Many of the [[List of onshore wind farms#Largest operational onshore wind farms|world's largest onshore wind farms]] are located in the [[Wind power in the United States|United States]], [[Wind power in China|China]], and [[Wind power in India|India]]. Most of the [[List of offshore wind farms|world's largest offshore wind farms]] are located in [[Wind power in Denmark|Denmark]], [[Wind power in Germany|Germany]] and the [[Wind power in the United Kingdom|United Kingdom]]. The two largest offshore wind farm are currently the 630 [[Megawatt|MW]] [[London Array]] and [[Gwynt y Môr]].

{| class="wikitable"
|+ Large onshore wind farms
|-
! Wind farm
! Current<br />capacity<br />([[Megawatt|MW]])
! Country
! Notes
|-
| [[Alta Wind Energy Center|Alta (Oak Creek-Mojave)]] || align=center | 1,320 || {{Flagu|USA}} ||<ref name=terragen>[http://www.terra-genpower.com/News/Terra-Gen-Power-Announces-Closing-of-$650-Million-.aspx Terra-Gen Press Release] {{webarchive|url=https://web.archive.org/web/20120510173856/http://www.terra-genpower.com/News/Terra-Gen-Power-Announces-Closing-of-%24650-Million-.aspx |date=2012-05-10 }}, 17 April 2012</ref>
|-
| [[Jaisalmer Wind Park]] || align=center | 1,064 || {{Flagu|India}} ||<ref name=Jaisalmer>{{cite news|url=http://www.business-standard.com/india/news/suzlon-creates-country/s-largest-wind-park/164779/on|title=Suzlon creates country's largest wind park|author=BS Reporter|date=11 May 2012|work=business-standard.com|url-status=live|archive-url=https://web.archive.org/web/20121001062608/http://www.business-standard.com/india/news/suzlon-creates-country/s-largest-wind-park/164779/on|archive-date=1 October 2012}}</ref>
|-
| [[Roscoe Wind Farm]] || align=center | 781 || {{Flagu|USA}} ||<ref>{{cite web|url=http://www.renewableenergyworld.com/rea/news/story?id=53650|title=Top News|website=www.renewableenergyworld.com|access-date=4 May 2018|url-status=live|archive-url=https://web.archive.org/web/20160105145506/http://www.renewableenergyworld.com/rea/news/story?id=53650|archive-date=5 January 2016}}</ref>
|-
| [[Horse Hollow Wind Energy Center]] || align=center | 735 || {{Flagu|USA}} ||<ref name=drilling/><ref name=tex>[http://www.awea.org/projects/Projects.aspx?s=Texas AWEA: U.S. Wind Energy Projects – Texas] {{webarchive |url=https://web.archive.org/web/20071229033413/http://www.awea.org/projects/Projects.aspx?s=Texas |date=December 29, 2007 }}</ref>
|-
| [[Capricorn Ridge Wind Farm]] || align=center | 662 || {{Flagu|USA}} ||<ref name=drilling>{{cite web|url=http://www.renewableenergyworld.com/rea/news/article/2009/02/drilling-down-what-projects-made-2008-such-a-banner-year-for-wind-power|title=Drilling Down: What Projects Made 2008 Such a Banner Year for Wind Power?|work=renewableenergyworld.com|url-status=live|archive-url=https://web.archive.org/web/20110715173218/http://www.renewableenergyworld.com/rea/news/article/2009/02/drilling-down-what-projects-made-2008-such-a-banner-year-for-wind-power|archive-date=2011-07-15}}</ref><ref name=tex/>
|-
| [[Fântânele-Cogealac Wind Farm]] || align=center | 600 || {{Flagu|Romania}} ||<ref name=cez>{{cite web|url=http://www.cez.cz/en/cez-group/media/press-releases/4051.html|title=CEZ Group - The Largest Wind Farm in Europe Goes Into Trial Operation|author1=FG Forrest|author2=a. s.|author3=fg {zavináč } fg {tečka} cz - Content Management System - Edee CMS; SYMBIO Digital, s. r. o. - Webdesign|work=cez.cz|url-status=live|archive-url=https://web.archive.org/web/20150701163434/http://www.cez.cz/en/cez-group/media/press-releases/4051.html|archive-date=2015-07-01}}</ref>
|-
| [[Fowler Ridge Wind Farm]] || align=center | 599 || {{Flagu|USA}} ||<ref name=ind>[http://www.awea.org/projects/Projects.aspx?s=Indiana AWEA: U.S. Wind Energy Projects – Indiana] {{webarchive|url=https://web.archive.org/web/20100918151714/http://www.awea.org/projects/Projects.aspx?s=Indiana |date=2010-09-18 }}</ref>
|}

=== Solar ===
{{Excerpt|Solar Energy|only=paragraphs}}

=== Biofuels ===
{{Main|Biofuel|Sustainable biofuel}}
{{multiple image|direction = vertical | align = right | width = 225 |image1=Soybeanbus.jpg|image2=EthanolPetrol.jpg|caption1=A bus fueled by [[biodiesel]]|caption2=Information on pump regarding [[ethanol fuel]] blend up to&nbsp;10%, [[California]]}}

A biofuel is a [[fuel]] that contains energy from geologically recent [[carbon fixation]]. These fuels are produced from [[living organisms]]. Examples of this [[carbon fixation]] occur in [[plants]] and [[microalgae]]. These fuels are made by a [[biomass]] conversion (biomass refers to recently living organisms, most often referring to [[plants]] or plant-derived materials). This biomass can be converted to convenient energy containing substances in three different ways: thermal conversion, chemical conversion, and biochemical conversion. This biomass conversion can result in fuel in [[solid]], [[liquid]], or [[gas]] form. This new biomass can be used for biofuels. Biofuels have increased in popularity because of rising [[oil prices]] and the need for [[energy security]].

[[Bioethanol]] is an [[Alcohol (chemistry)|alcohol]] made by [[Ethanol fermentation|fermentation]], mostly from [[carbohydrate]]s produced in [[sugar]] or [[starch]] crops such as [[Maize|corn]] or [[sugarcane]]. [[cellulose|Cellulosic biomass]], derived from non-food sources, such as trees and grasses, is also being developed as a [[feedstock]] for ethanol production. Ethanol can be used as a fuel for vehicles in its pure form, but it is usually used as a [[gasoline]] [[Fuel additive|additive]] to increase octane and improve vehicle emissions. Bioethanol is widely used in the [[Biofuel in the United States|USA]] and in [[Ethanol fuel in Brazil|Brazil]]. Current plant design does not provide for converting the [[lignin]] portion of plant raw materials to fuel components by fermentation.

[[Biodiesel]] is made from [[vegetable oil]]s and [[animal fat]]s. Biodiesel can be used as a fuel for vehicles in its pure form, but it is usually used as a [[diesel fuel|diesel]] additive to reduce levels of particulates, [[carbon monoxide]], and [[hydrocarbon]]s from diesel-powered vehicles. Biodiesel is produced from oils or fats using [[transesterification]] and is the most common biofuel in Europe. However, research is underway on producing renewable fuels from [[Renewable fuels by decarboxylation|decarboxylation]]<ref>{{cite journal|title = Continuous catalytic deoxygenation of model and algal lipids to fuel-like hydrocarbons over Ni–Al layered double hydroxide|doi=10.1016/j.cattod.2014.12.004|volume=258|pages=284–293|journal=Catalysis Today|author=Santillan-Jimenez Eduardo|year = 2015}}</ref>

In 2010, worldwide biofuel production reached 105 billion liters (28 billion gallons US), up 17% from 2009,<ref name=Biofuels2010>{{cite web|url=http://www.worldwatch.org/biofuels-make-comeback-despite-tough-economy|title=Biofuels Make a Comeback Despite Tough Economy|publisher=[[Worldwatch Institute]]|date=2011-08-31|access-date=2011-08-31|url-status=dead|archive-url=https://web.archive.org/web/20120530232916/http://www.worldwatch.org/biofuels-make-comeback-despite-tough-economy|archive-date=2012-05-30}}</ref> and biofuels provided 2.7% of the world's fuels for road transport, a contribution largely made up of ethanol and biodiesel.{{citation needed|date=September 2012}} Global [[ethanol fuel]] production reached 86 billion liters (23 billion gallons US) in 2010, with the United States and Brazil as the world's top producers, accounting together for 90% of global production. The world's largest biodiesel producer is the [[European Union]], accounting for 53% of all biodiesel production in 2010.<ref name=Biofuels2010/> As of 2011, mandates for blending biofuels exist in 31 countries at the national level and in 29 states or provinces.<ref name=ren212011/>{{rp|13–14}} The [[International Energy Agency]] has a goal for biofuels to meet more than a quarter of world demand for transportation fuels by 2050 to reduce dependence on petroleum and coal.<ref>{{cite web |url=http://www.iea.org/publications/freepublications/publication/biofuels_roadmap.pdf |year=2011 |title=Technology Roadmap, Biofuels for Transport |url-status=live |archive-url=https://web.archive.org/web/20140722231200/http://www.iea.org/publications/freepublications/publication/biofuels_roadmap.pdf |archive-date=2014-07-22 }}</ref>

=== Geothermal ===
{{Main|Geothermal energy}}
[[File:NesjavellirPowerPlant edit2.jpg|thumb|Steam rising from the [[Nesjavellir Geothermal Power Station]] in [[Iceland]]]]

Geothermal energy is [[thermal energy]] generated and stored in the Earth. Thermal energy is the energy that determines the [[temperature]] of matter. The geothermal energy of the Earth's [[Crust (geology)|crust]] originates from the original formation of the planet (20%) and from [[radioactive decay]] of minerals (80%).<ref name=ucsusa>[http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-geothermal-energy-works.html How Geothermal energy works] {{webarchive|url=https://web.archive.org/web/20140925080922/http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-geothermal-energy-works.html |date=2014-09-25 }}. Ucsusa.org. Retrieved on 2013-04-24.</ref>  The [[geothermal gradient]], which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of [[heat]] from the core to the surface. The adjective ''geothermal'' originates from the Greek roots ''γη (ge)'', meaning earth, and ''θερμος (thermos)'', meaning hot.

[[Earth's internal heat budget|Earth's internal heat]] is thermal energy generated from [[radioactive decay]] and continual heat loss from Earth's formation. Temperatures at the [[core mantle boundary|core-mantle boundary]] may reach over 4000&nbsp;°C (7,200&nbsp;°F).<ref>{{cite journal | author = Lay T., Hernlund J., Buffett B. A. | year = 2008 | title = Core–mantle boundary heat flow | journal = Nature Geoscience | volume = 1 | issue = 1| pages = 25–32 | bibcode = 2008NatGe...1...25L | doi = 10.1038/ngeo.2007.44 }}</ref> The high temperature and pressure in Earth's interior cause some rock to melt and solid [[mantle (geology)|mantle]] to behave plastically, resulting in portions of [[mantle convection|mantle convecting]] upward since it is lighter than the surrounding rock.  Rock and water is heated in the crust, sometimes up to 370&nbsp;°C (700&nbsp;°F).<ref>{{cite web|last=Nemzer|first=J|title=Geothermal heating and cooling|url=http://www.geothermal.marin.org/|url-status=dead|archive-url=https://web.archive.org/web/19980111021839/http://geothermal.marin.org/|archive-date=1998-01-11}}</ref>

From [[hot springs]], geothermal energy has been used for bathing since [[Paleolithic]] times and for [[space heating]] since ancient Roman times, but it is now better known for [[electricity generation]]. Worldwide, 11,400 [[megawatts]] (MW) of geothermal power is online in 24 countries in 2012.<ref>{{cite web |url=http://www.bp.com/en/global/corporate/about-bp/statistical-review-of-world-energy-2013/review-by-energy-type/renewable-energy/geothermal-capacity.html |title=Geothermal capacity &#124; About BP &#124; BP Global |publisher=Bp.com |access-date=2013-10-05 |url-status=live |archive-url=https://web.archive.org/web/20131006185306/http://www.bp.com/en/global/corporate/about-bp/statistical-review-of-world-energy-2013/review-by-energy-type/renewable-energy/geothermal-capacity.html |archive-date=2013-10-06 }}</ref>  An additional 28 gigawatts of direct [[geothermal heating]] capacity is installed for district heating, space heating, spas, industrial processes, desalination and agricultural applications in 2010.<ref name="IPCC">Fridleifsson, Ingvar B.; Bertani, Ruggero; Huenges, Ernst; Lund, John W.; Ragnarsson, Arni; Rybach, Ladislaus (2008-02-11), O. Hohmeyer and T. Trittin, ed., The possible role and contribution of geothermal energy to the mitigation of climate change (pdf), IPCC Scoping Meeting on Renewable Energy Sources, Luebeck, Germany, pp. 59–80, retrieved 2009-04-06</ref>

Geothermal power is cost effective, reliable, sustainable, and environmentally friendly,<ref>Glassley, William E. (2010). ''Geothermal Energy: Renewable Energy and the Environment'', CRC Press, {{ISBN|9781420075700}}.</ref> but has historically been limited to areas near [[tectonic plate boundaries]]. Recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate [[global warming]] if widely deployed in place of fossil fuels.

The Earth's geothermal resources are theoretically more than adequate to supply humanity's energy needs, but only a very small fraction may be profitably exploited. Drilling and exploration for deep resources is very expensive. Forecasts for the future of geothermal power depend on assumptions about technology, energy prices, [[energy subsidies|subsidies]], and interest rates. Pilot programs like EWEB's customer opt in Green Power Program <ref>[http://www.eweb.org/greenpower Green Power] {{webarchive|url=https://web.archive.org/web/20141015040912/http://www.eweb.org/greenpower |date=2014-10-15 }}. eweb.org</ref> show that customers would be willing to pay a little more for a renewable energy source like geothermal. But as a result of government assisted research and industry experience, the cost of generating geothermal power has decreased by 25% over the past two decades.<ref>{{Citation|last=Cothran|first=Helen|title=Energy Alternatives|year=2002|publisher=Greenhaven Press|isbn=978-0737709049}}</ref> In 2001, geothermal energy cost between two and ten US cents per kWh.<ref>{{cite journal|last=Fridleifsson|first=Ingvar|title= Geothermal energy for the benefit of the people|doi=10.1016/S1364-0321(01)00002-8|volume=5|issue=3|journal=Renewable and Sustainable Energy Reviews|pages=299–312|year=2001|citeseerx=10.1.1.459.1779}}</ref>

=== Oceanic ===
{{Main|Marine energy}}

'''Marine energy''' or '''marine power''' (also sometimes referred to as '''ocean energy''', '''ocean power''', or '''marine and hydrokinetic energy''') refers to the energy carried by [[ocean wave]]s, [[tide]]s, [[salinity]], and [[Ocean thermal energy|ocean temperature differences]]. The movement of water in the world's oceans creates a vast store of [[kinetic energy]], or energy in motion. This energy can be harnessed to [[Electricity generation|generate]] electricity to power homes, transport and industries.

The term marine energy encompasses both [[wave power]] i.e. power from surface waves, and [[tidal power]] i.e. obtained from the kinetic energy of large bodies of moving water. [[Offshore wind power]] is not a form of marine energy, as wind power is derived from the wind, even if the [[wind turbine]]s are placed over water.
The oceans have a tremendous amount of energy and are close to many if not most concentrated populations. Ocean energy has the potential of providing a substantial amount of new [[renewable energy]] around the world.

=== 100% renewable energy ===
{{Main|100% renewable energy}}

The incentive to use 100% renewable energy, for electricity, transport, or even total primary energy supply globally, has been motivated by [[global warming]] and other ecological as well as economic concerns. [[Renewable energy commercialization|Renewable energy use]] has grown much faster than anyone anticipated.<ref name=pg11>{{cite web |url=http://www.renewableenergyworld.com/rea/news/article/2013/04/100-percent-renewable-vision-building?amp;buffer_share=fdc06 |title=100 Percent Renewable Vision Building |author=Paul Gipe |date=4 April 2013 |work=Renewable Energy World |url-status=live |archive-url=https://web.archive.org/web/20141006104925/http://www.renewableenergyworld.com/rea/news/article/2013/04/100-percent-renewable-vision-building?amp;buffer_share=fdc06 |archive-date=6 October 2014 }}</ref> The [[Intergovernmental Panel on Climate Change]] has said that there are few fundamental technological limits to integrating a portfolio of renewable energy technologies to meet most of total global energy demand.<ref name="IPCC 2011 17">{{cite web|url=http://srren.ipcc-wg3.de/report/IPCC_SRREN_SPM.pdf |title=Special Report on Renewable Energy Sources and Climate Change Mitigation |author=IPCC |year=2011 |work=Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA |page=17 |url-status=dead |archive-url=https://web.archive.org/web/20140111081913/http://srren.ipcc-wg3.de/report/IPCC_SRREN_SPM.pdf |archive-date=2014-01-11 }}</ref> At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply.  Also, [[Stephen W. Pacala]] and [[Robert H. Socolow]] have developed a series of "[[stabilization wedges]]" that can allow us to maintain our quality of life while avoiding catastrophic climate change, and "renewable energy sources," in aggregate, constitute the largest number of their "wedges."<ref name=Pacala>{{cite journal|url=http://www.princeton.edu/mae/people/faculty/socolow/Science-2004-SW-1100103-PAPER-AND-SOM.pdf|title=Stabilization Wedges: Solving the Climate Problem for the Next 50 Years with Current Technologies|author1-link=Stephen W. Pacala|author1=S. Pacala|author2=R. Socolow|journal=Science|year=2004|volume=305|issue=5686|pages=968–972|publisher=Science Vol. 305|doi=10.1126/science.1100103|pmid=15310891|bibcode=2004Sci...305..968P|s2cid=2203046|url-status=live|archive-url=https://web.archive.org/web/20150812230420/http://www.princeton.edu/mae/people/faculty/socolow/Science-2004-SW-1100103-PAPER-AND-SOM.pdf|archive-date=2015-08-12}}</ref>

[[Mark Z. Jacobson]] says producing all new energy with [[wind power]], [[solar power]],  and [[hydropower]] by 2030 is feasible and existing energy supply arrangements could be replaced by 2050. Barriers to implementing the renewable energy plan are seen to be "primarily social and political, not technological or economic". Jacobson says that energy costs with a wind, solar, water system should be similar to today's energy costs.<ref name=enpol2011>{{cite web |url=http://www.stanford.edu/group/efmh/jacobson/Articles/I/DJEnPolicyPt2.pdf |title=Providing all global energy with wind, water, and solar power, Part II: Reliability, system and transmission costs, and policies |author1=Mark A. Delucchi |author2=Mark Z. Jacobson |year=2011 |volume=39 |work=Energy Policy |pages=1170–1190 |publisher=Elsevier Ltd. |url-status=live |archive-url=https://web.archive.org/web/20120616162420/http://www.stanford.edu/group/efmh/jacobson/Articles/I/DJEnPolicyPt2.pdf |archive-date=2012-06-16 }}</ref>

Similarly, in the United States, the independent National Research Council has noted that "sufficient domestic renewable resources exist to allow renewable electricity to play a significant role in future electricity generation and thus help confront issues related to climate change, energy security, and the escalation of energy costs ... Renewable energy is an attractive option because renewable resources available in the United States, taken collectively, can supply significantly larger amounts of electricity than the total current or projected domestic demand." .<ref name=NRC>{{cite book|url=http://www.nap.edu/catalog.php?record_id=12619|title=Electricity from Renewable Resources: Status, Prospects, and Impediments|author=National Research Council|year=2010|pages=4|publisher=National Academies of Science|url-status=live|archive-url=https://web.archive.org/web/20140327124031/http://www.nap.edu/catalog.php?record_id=12619|archive-date=2014-03-27|doi=10.17226/12619|isbn=978-0-309-13708-9}}</ref>

Critics of the "100% renewable energy" approach include [[Vaclav Smil]] and [[James E. Hansen]]. Smil and Hansen are concerned about the [[variable renewable energy|variable output]] of solar and wind power, but [[Amory Lovins]] argues that the [[electricity grid]] can cope, just as it routinely backs up nonworking coal-fired and nuclear plants with working ones.<ref name=lovi12>{{cite journal |url=http://www.foreignaffairs.com/articles/137246/amory-b-lovins/a-farewell-to-fossil-fuels |title=A Farewell to Fossil Fuels |author=Amory Lovins |date=March–April 2012 |journal=Foreign Affairs |volume=329 |issue=5997 |pages=1292–1294 |url-status=live |archive-url=https://web.archive.org/web/20120707031832/http://www.foreignaffairs.com/articles/137246/amory-b-lovins/a-farewell-to-fossil-fuels |archive-date=2012-07-07 |bibcode=2010Sci...329.1292H |doi=10.1126/science.1195449 |pmid=20829473 |s2cid=206529026 }}</ref>

Google spent $30 million on their "Renewable Energy Cheaper than Coal" project to develop renewable energy and stave off catastrophic climate change. The project was cancelled after concluding that a best-case scenario for rapid advances in renewable energy could only result in emissions 55 percent below the fossil fuel projections for 2050.<ref>{{cite web|url=https://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change|title=What It Would Really Take to Reverse Climate Change|date=2014-11-18|website=ieee.org|access-date=4 May 2018|url-status=live|archive-url=https://web.archive.org/web/20161124081052/https://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change|archive-date=24 November 2016}}</ref>

== Increased energy efficiency ==

[[File:Compact-Fluorescent-Bulb.jpg|thumb|A spiral-type integrated [[compact fluorescent lamp]], which has been popular among North American consumers since its introduction in the mid-1990s<ref>{{cite web | title=Philips Tornado Asian Compact Fluorescent | publisher=Philips | access-date=2007-12-24 | url= http://www.lamptech.co.uk/Spec%20Sheets/Philips%20CFL%20Tornado.htm | url-status=live | archive-url= https://archive.today/20120804103517/http://www.lamptech.co.uk/Spec%20Sheets/Philips%20CFL%20Tornado.htm | archive-date=2012-08-04 }}</ref>]]

{{main|Efficient energy use}}

Although increasing the efficiency of energy use is not energy development per se, it may be considered under the topic of energy development since it makes existing energy sources available to do work.<ref>Richard L. Kauffman
[https://web.archive.org/web/20100624132903/http://environment.research.yale.edu/documents/downloads/0-9/03-Kauffman.pdf Obstacles to Renewable Energy and Energy Efficiency]. in:  From Silos to Systems: Issues in Clean Energy and Climate Change.  A report on the work of the REIL Network, 2008-2010.  Edited by Parker L et al.  Yale School of Forestry & Environmental Studies 2010</ref>{{rp|22}}

Efficient energy use reduces the amount of energy required to provide products and services. For example, [[building insulation|insulating a home]] allows a building to use less heating and cooling energy to maintain a comfortable temperature. Installing [[fluorescent lamp]]s or natural [[Skylight (window)|skylights]] reduces the amount of energy required for illumination compared to [[incandescent light bulbs]]. [[Compact fluorescent lights]] use two-thirds less energy and may last 6 to 10 times longer than incandescent lights.  Improvements in energy efficiency are most often achieved by adopting an efficient technology or production process.<ref>[[Mark Diesendorf|Diesendorf, Mark]] (2007). ''[[Greenhouse Solutions with Sustainable Energy]]'', UNSW Press, p. 86.</ref>

Reducing energy use may save consumers money,  if the energy savings offsets the cost of an energy efficient technology.  Reducing energy use reduces emissions.  According to the [[International Energy Agency]], improved energy efficiency in [[Energy efficient buildings|buildings]], industrial processes and [[Sustainable transportation|transportation]] could reduce the global energy demand in 2050 to around 8% smaller than today, but serving an economy more than twice as big and a population of about  2  billion more people.<ref>IEA (2021), Net Zero by 2050, IEA, Paris https://www.iea.org/reports/net-zero-by-2050, License: CC BY 4.0</ref>

Energy efficiency and [[renewable energy]] are said to be the ''twin pillars'' of sustainable energy policy.<ref>{{cite web|url=http://aceee.org/store/proddetail.cfm?CFID=2957330&CFTOKEN=50269931&ItemID=432&CategoryID=7 |archive-url=http://webarchive.loc.gov/all/20090429195906/http://www.aceee.org/store/proddetail.cfm?CFID=785209&CFTOKEN=22090724&ItemID=432&CategoryID=7 |url-status=dead |archive-date=2009-04-29 |title=The Twin Pillars of Sustainable Energy: Synergies between Energy Efficiency and Renewable Energy Technology and Policy |publisher=Aceee.org |access-date=2010-07-16 }}</ref> In many countries energy efficiency is also seen to have a national security benefit because it can be used to reduce the level of energy imports from foreign countries and may slow down the rate at which domestic energy resources are depleted.

It's been discovered "that for OECD countries, wind, geothermal, hydro and nuclear have the lowest hazard rates among energy sources in production".<ref>{{Cite journal|last=Ross|first=Cullen|date=26 August 2016|title=Evaluating renewable energy policies|journal=The Australian Journal of Agricultural and Resource Economics|volume=61 |issue=1|pages=1–18|doi=10.1111/1467-8489.12175|s2cid=157313814|url=http://ageconsearch.umn.edu/record/301128/files/ajar12175.pdf|hdl=10.1111/1467-8489.12175|hdl-access=free}}</ref>

== Transmission ==

[[File:Pipeline-small image, seen from below.jpeg|thumb|right|An elevated section of the [[Trans-Alaska Pipeline System|Alaska Pipeline]]]]

While new sources of energy are only rarely discovered or made possible by new [[technologies|technology]], [[distribution (business)|distribution]] technology continually evolves.<ref>{{cite web|url=https://publicaffairs.llnl.gov/news/energy/content/international/United_States_Energy_2007.png|title=News|work=Lawrence Livermore National Laboratory|url-status=dead|archive-url=https://web.archive.org/web/20100922062127/https://publicaffairs.llnl.gov/news/energy/content/international/United_States_Energy_2007.png|archive-date=2010-09-22}}</ref> The use of [[fuel cell]]s in cars, for example, is an anticipated delivery technology.<ref>Fuel Cell Materials Technology in Vehicular Propulsion: Report. National Academies, 1983.</ref> This section presents the various delivery technologies that have been important to historic energy development. They all rely in way on the energy sources listed in the previous section.

=== Shipping and pipelines ===

{{See also|Pipeline transport}}

[[Coal]], [[petroleum]] and their derivatives are delivered by boat, [[Rail transport|rail]], or road. Petroleum and natural gas may also be delivered by [[pipeline transport|pipeline]], and coal via a [[Slurry pipeline]]. Fuels such as [[gasoline]] and [[Liquified petroleum gas|LPG]] may also be delivered via [[aircraft]]. Natural gas pipelines must maintain a certain minimum pressure to function correctly. The higher costs of ethanol transportation and storage are often prohibitive.<ref>
{{cite web
 | url = http://www.ornl.gov/info/ornlreview/v40_1_07/article08.shtml
 | title = Oak Ridge National Laboratory — Biomass, Solving the science is only part of the challenge
 | access-date = 2008-01-06
 | url-status = dead
 | archive-url = https://web.archive.org/web/20130702051754/http://www.ornl.gov/info/ornlreview/v40_1_07/article08.shtml
 | archive-date = 2013-07-02
 }}</ref>

=== Wired energy transfer ===

[[File:Two transmission towers.jpg|thumb|[[Electrical grid]] – pylons and cables distribute power]]

{{main|Electrical grid}}

Electricity grids are the [[electrical network|networks]] used to [[Electric power transmission|transmit]] and [[Electricity distribution|distribute]] [[electric power|power]] from production source to end user, when the two may be hundreds of kilometres away.  Sources include electrical generation plants such as a [[nuclear reactor]], coal burning power plant, etc.  A combination of sub-stations and transmission lines are used to maintain a constant flow of electricity. Grids may suffer from transient [[Power blackout|blackouts]] and [[power outage|brownouts]], often due to weather damage. During certain extreme [[space weather]] events [[solar wind]] can interfere with transmissions. Grids also have a predefined [[carrying capacity]] or load that cannot safely be exceeded. When power requirements exceed what's available, failures are inevitable. To prevent problems, power is then rationed.

Industrialised countries such as Canada, the [[United States|US]], and Australia are among the highest per capita consumers of electricity in the world, which is possible thanks to a widespread electrical distribution network. The US grid is one of the most advanced,{{citation needed|date=August 2023}} although [[infrastructure]] maintenance is becoming a problem. [https://web.archive.org/web/20041014214845/http://currentenergy.lbl.gov/ CurrentEnergy] provides a realtime overview of the electricity supply and demand for [[California]], [[Texas]], and the Northeast of the US. African countries with small scale electrical grids have a correspondingly low annual per capita usage of electricity. One of the most powerful power grids in the world supplies power to the state of [[Queensland]], Australia.

=== Wireless energy transfer ===

[[Wireless power transfer]] is a process whereby electrical energy is transmitted from a power source to an electrical load that does not have a built-in power source, without the use of interconnecting wires. Currently available technology is limited to short distances and relatively low power level.

Orbiting solar power collectors would require wireless transmission of power to Earth. The proposed method involves creating a large beam of microwave-frequency radio waves, which would be aimed at a collector antenna site on the Earth. Formidable technical challenges exist to ensure the safety and profitability of such a scheme.

== Storage ==

[[File:Stwlan.dam.jpg|thumb|right|The [[Ffestiniog Power Station]] in [[Wales]], United Kingdom. [[Pumped-storage hydroelectricity]] (PSH) is used for [[grid energy storage]].]]

{{Main|Energy storage|List of energy storage power plants}}

Energy storage is accomplished by devices or physical media that store [[energy]] to perform useful operation at a later time. A device that stores energy is sometimes called an [[Accumulator (energy)|accumulator]].

All forms of energy are either [[potential energy]] (e.g. [[Chemical energy|Chemical]], [[gravitation]]al, [[Electric potential energy|electrical energy]], temperature differential, [[latent heat]], etc.) or [[kinetic energy]] (e.g. [[momentum]]). Some technologies provide only short-term energy storage, and others can be very long-term such as [[power to gas]] using [[hydrogen]] or [[methane]] and the [[Seasonal thermal energy storage|storage of heat or cold between opposing seasons]] in deep aquifers or bedrock.  A wind-up clock stores potential energy (in this case mechanical, in the spring tension), a [[Battery (electricity)|battery]] stores readily convertible chemical energy to operate a mobile phone, and a [[Hydroelectricity|hydroelectric]] dam stores [[Electrical power industry|energy]] in a [[reservoir]] as gravitational [[potential energy]]. [[Thermal energy storage#Air conditioning|Ice storage]] tanks store ice ([[thermal energy]] in the form of latent heat) at night to meet peak demand for cooling. [[Fossil fuel]]s such as coal and gasoline store ancient energy derived from sunlight by organisms that later died, became buried and over time were then converted into these fuels. Even [[food]] (which is made by the same process as fossil fuels) is a form of energy stored in [[chemical]] form.

== History ==
[[File:Doel Kerncentrale.JPG|thumb|Energy generators past and present at [[Doel]], Belgium: 17th-century windmill ''Scheldemolen'' and 20th-century [[Doel Nuclear Power Station]]]]

Since prehistory, when humanity discovered fire to warm up and roast food, through the Middle Ages in which populations built windmills to grind the wheat, until the modern era in which nations can get electricity splitting the atom. Man has sought endlessly for energy sources.

Except nuclear, geothermal and [[tidal power|tidal]], all other energy sources are from current solar isolation or from fossil remains of plant and animal life that relied upon sunlight. Ultimately, [[solar power|solar energy]] itself is the result of the [[Sun]]'s nuclear fusion. [[Geothermal power]] from hot, hardened [[Rock (geology)|rock]] above the [[magma]] of the Earth's core is the result of the decay of radioactive materials present beneath the Earth's crust, and [[nuclear fission]] relies on man-made fission of heavy radioactive elements in the Earth's crust; in both cases these elements were produced in [[supernova]] explosions before the formation of the [[Solar System]].

Since the beginning of the [[Industrial Revolution]], the question of the future of energy supplies has been of interest. In 1865, [[William Stanley Jevons]] published ''The Coal Question'' in which he saw that the reserves of coal were being depleted and that oil was an ineffective replacement. In 1914, [[United States Bureau of Mines|U.S. Bureau of Mines]] stated that the total production was {{convert|5.7|Goilbbl|m3}}. In 1956, Geophysicist [[M. King Hubbert]] deduces that U.S. oil production would [[Hubbert peak theory|peak]] between 1965 and 1970 and that oil production will peak "within half a century" on the basis of 1956 data. In 1989, predicted peak by [[Colin Campbell (geologist)|Colin Campbell]]<ref>"Oil Price Leap in the Early Nineties," Noroil, December 1989, pages 35–38.</ref> In 2004, OPEC estimated, with substantial investments, it would nearly double oil output by 2025<ref>Opec Oil Outlook to 2025 Table 4, Page 12</ref>

=== Sustainability ===

[[File:Energy-consumption-World2.png|thumb|upright=1.8|Energy consumption from 1989 to 1999]]

{{main|Sustainable energy}}

The [[environmental movement]] has emphasized [[sustainability]] of energy use and development.<ref>Sustainable Development and Innovation in the Energy Sector. Ulrich Steger, Wouter Achterberg, Kornelis Blok, Henning Bode, Walter Frenz, Corinna Gather, Gerd Hanekamp, Dieter Imboden, Matthias Jahnke, Michael Kost, Rudi Kurz, Hans G. Nutzinger, Thomas Ziesemer. Springer, December 5, 2005.</ref> [[Renewable energy]] is sustainable in its production; the available supply will not be diminished for the foreseeable future - millions or billions of years.  "Sustainability" also refers to the ability of the environment to cope with waste products, especially [[air pollution]].  Sources which have no direct waste products (such as wind, solar, and hydropower) are brought up on this point. With global demand for energy growing, the need to adopt various energy sources is growing. [[Energy conservation]] is an alternative or complementary process to energy development.  It reduces the demand for energy by using it efficiently.

=== Resilience ===

Some observers contend that idea of "[[energy independence]]" is an unrealistic and opaque concept.<ref>{{cite web |url=http://www.deloitte.com/assets/Dcom-UnitedStates/Local%20Assets/Documents/Federal/us_fed_Election_Series_101012.pdf  |title=Energy independence and security: A reality check|website=deloitte.com|archive-url=https://web.archive.org/web/20130405230251/http://www.deloitte.com/assets/Dcom-UnitedStates/Local%20Assets/Documents/Federal/us_fed_Election_Series_101012.pdf  |archive-date=April 5, 2013 |url-status=dead}}</ref> The alternative offer of "energy resilience" is a goal aligned with economic, security, and energy realities. The notion of resilience in energy was detailed in the 1982 book ''[[Brittle Power]]: Energy Strategy for National Security''.<ref>[http://www.natcapsolutions.org/publications_files/brittlepower.htm Brittle Power: Energy Plan for National Security] {{webarchive|url=https://web.archive.org/web/20090702233352/http://www.natcapsolutions.org/publications_files/brittlepower.htm |date=2009-07-02 }}. [[Amory B. Lovins]] and L. Hunter Lovins (1982).</ref> The authors argued that simply switching to domestic energy would not be secure inherently because the true weakness is the often interdependent and vulnerable energy infrastructure of a country. Key aspects such as gas lines and the electrical power grid are often centralized and easily susceptible to disruption. They conclude that a "resilient energy supply" is necessary for both national security and the environment. They recommend a focus on energy efficiency and renewable energy that is decentralized.<ref>[http://www.natcapsolutions.org/publications_files/FragileDomEnergy_AtlanticMonthly_Nov1983.pdf "The Fragility of Domestic Energy."] {{webarchive|url=https://web.archive.org/web/20090106001526/http://www.natcapsolutions.org/publications_files/FragileDomEnergy_AtlanticMonthly_Nov1983.pdf |date=2009-01-06 }} [[Amory B. Lovins]] and L. Hunter Lovins. ''Atlantic Monthly''. November 1983.</ref>

In 2008, former [[Intel Corporation]] Chairman and CEO [[Andrew Grove]] looked to energy resilience, arguing that complete independence is unfeasible given the global market for energy.<ref>[http://www.american.com/archive/2008/july-august-magazine-contents/our-electric-future "Our Electric Future."] {{webarchive|url=https://web.archive.org/web/20140825064622/http://www.american.com/archive/2008/july-august-magazine-contents/our-electric-future/ |date=2014-08-25 }} [[Andrew Grove]]. ''The American''. July/August 2008.</ref> He describes energy resilience as the ability to adjust to interruptions in the supply of energy. To that end, he suggests the U.S. make greater use of electricity.<ref>{{cite web|url=http://www.american.com/archive/2008/july-august-magazine-contents/our-electric-future|title=An Electric Plan for Energy Resilience|author=[[Andrew Grove]] and Robert Burgelman|publisher=McKinsey Quarterly|date=December 2008|access-date=2010-07-20|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> Electricity can be produced from a variety of sources. A diverse energy supply will be less affected by the disruption in supply of any one source. He reasons that another feature of [[electrification]] is that electricity is "sticky" – meaning the electricity produced in the U.S. is to stay there because it cannot be transported overseas.  According to Grove, a key aspect of advancing electrification and energy resilience will be converting the U.S. automotive fleet from gasoline-powered to electric-powered. This, in turn, will require the modernization and expansion of the electrical power grid. As organizations such as [[The Reform Institute]] have pointed out, advancements associated with the developing [[smart grid]] would facilitate the ability of the grid to absorb vehicles ''en masse'' connecting to it to charge their batteries.<ref>[https://www.policyarchive.org/bitstream/handle/10207/16484/Electric_Car_Reform_Brief_FINAL_PDF_3-4-09.pdf?sequence=1 Resilience in Energy: Building Infrastructure Today for Tomorrow's Automotive Fuel. Reform Institute. March 2009.]{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

=== {{anchor|Future}} Present and future ===

[[File:World energy consumption outlook.png|thumb|upright=1.8|Outlook—World Energy Consumption by Fuel (as of 2011)<ref>World energy consumption outlook from the International Energy Outlook, published by the U.S. DOE Energy Information Administration</ref><br />
{{legend2|#2589ba}} [[Liquid fuel]]s incl. [[Biofuel]]s
{{legend2|#b57537}} [[Coal]]
{{legend2|#5f943a}} [[Natural Gas]]<br />
{{legend2|#8d3742}} [[Renewable fuel]]s
{{legend2|#87732c}} [[Nuclear fuel]]s
]]

[[File:World energy consumption by region 1970-2025.png|thumb|400px|right|Increasing share of energy consumption by developing nations<ref>Source: [[Energy Information Administration]] – [http://www.eia.doe.gov/oiaf/ieo/index.html International Energy Outlook 2004] {{webarchive|url=https://web.archive.org/web/20170727110053/https://www.eia.gov/outlooks/ieo/pdf/0484(2016).pdf |date=2017-07-27 }}</ref><br />
{{legend2|#4747bf}} [[Industrialized nation]]s<br />
{{legend2|#0e7a0d}} [[Developing nation]]s<br />
{{legend2|#730774}} [[European Economic Community|EE]]/[[Former Soviet Union]]
]]

Extrapolations from current knowledge to the future offer a choice of energy futures.<ref>[http://sapiens.revues.org/index70.html Mandil, C. (2008) "Our energy for the future". ''S.A.P.I.EN.S.'' '''1''' (1) ] {{webarchive|url=https://web.archive.org/web/20090428015629/http://sapiens.revues.org/index70.html |date=2009-04-28 }}</ref> Predictions parallel the [[Malthusian catastrophe]] hypothesis. Numerous are complex [[scientific modeling|models]] based [[scenario]]s as pioneered by ''[[Limits to Growth]]''. Modeling approaches offer ways to analyze diverse [[strategy|strategies]], and hopefully find a road to rapid and [[sustainable development]] of humanity. Short term [[energy crisis|energy crises]] are also a concern of energy development. Extrapolations lack plausibility, particularly when they predict a continual increase in oil consumption.{{citation needed|date=August 2013}}

Energy production usually requires an energy investment. Drilling for oil or building a wind power plant requires energy. The fossil fuel resources that are left are often increasingly difficult to extract and convert. They may thus require increasingly higher energy investments. If investment is greater than the value of the energy produced by the resource, it is no longer an effective energy source.  These resources are no longer an energy source but may be exploited for value as raw materials.  New technology may lower the energy investment required to extract and convert the resources, although ultimately basic physics sets limits that cannot be exceeded.

Between 1950 and 1984, as the [[Green Revolution]] transformed [[agriculture]] around the globe, world grain production increased by 250%. The energy for the Green Revolution was provided by [[fossil fuels]] in the form of [[fertilizers]] (natural gas), [[pesticides]] (oil), and [[hydrocarbon]] fueled [[irrigation]].<ref>{{cite web|url=http://www.energybulletin.net/281.html|title=Eating Fossil Fuels|work=Resilience|url-status=dead|archive-url=https://web.archive.org/web/20070611071544/http://www.energybulletin.net/281.html|archive-date=2007-06-11}}</ref> The peaking of world hydrocarbon production ([[peak oil]]) may lead to significant changes, and require sustainable methods of production.<ref>[http://www.soilassociation.org/peakoil Peak Oil: the threat to our food security] {{webarchive |url=https://web.archive.org/web/20090714220834/http://www.soilassociation.org/peakoil |date=July 14, 2009 }} retrieved 28 May 2009</ref> One vision of a sustainable energy future involves all human structures on the earth's surface (i.e., buildings, vehicles and roads) doing [[artificial photosynthesis]] (using sunlight to split water as a source of hydrogen and absorbing carbon dioxide to make fertilizer) efficiently than plants.<ref>Faunce TA, Lubitz W, Rutherford AW, MacFarlane D, Moore, GF, Yang P, Nocera DG, Moore TA, Gregory DH, Fukuzumi S, Yoon KB, Armstrong FA, Wasielewski MR, Styring S. ‘Energy and Environment Case for a Global Project on Artificial Photosynthesis.’ Energy and Environmental Science 2013, 6 (3), 695 - 698 {{doi|10.1039/C3EE00063J}} {{cite journal |title=Energy and environment policy case for a global project on artificial photosynthesis |journal=Energy & Environmental Science |volume=6 |issue=3 |pages=695–698 |doi=10.1039/C3EE00063J |date=2013-02-20 |last1=Styring |first1=Stenbjorn |last2=Wasielewski |first2=Michael R. |last3=Armstrong |first3=Fraser A. |last4=Yoon |first4=Kyung Byung |last5=Fukuzumi |first5=Shunichi |last6=Gregory |first6=Duncan H. |last7=Moore |first7=Tom A. |last8=Nocera |first8=Daniel G. |last9=Yang |first9=Peidong |last10=Moore |first10=Gary F. |last11=MacFarlane |first11=Douglas |last12=Rutherford |first12=A. W. (Bill) |last13=Lubitz |first13=Wolfgang |author-link13=Wolfgang Lubitz |last14=Faunce |first14=Thomas A. }} (accessed 13 March 2013)</ref>

With contemporary [[space industry]]'s economic activity<ref name="Bromberg2000-1">{{cite book|author=Joan Lisa Bromberg|title=NASA and the Space Industry|url=https://books.google.com/books?id=-UebVg1YqsoC&pg=PA1|access-date=10 June 2011|date=October 2000|publisher=JHU Press|isbn=978-0-8018-6532-9|page=1}}</ref><ref name="Schrogl2010">{{cite book|author=Kai-Uwe Schrogl|title=Yearbook on Space Policy 2008/2009: Setting New Trends|url=https://books.google.com/books?id=gcZwzmPnqxkC&pg=PA49|access-date=10 June 2011|date=2 August 2010|publisher=Springer|isbn=978-3-7091-0317-3|page=49}}</ref> and the related [[private spaceflight]], with the [[manufacturing industries]], that go into Earth's orbit or beyond, delivering them to those regions will require further energy development.<ref>Propulsion Techniques: Action and Reaction edited by Peter J. Turchi. [https://books.google.com/books?id=-o9TJa2F4qsC&pg=PA341 p341]</ref><ref>Climate Change: The Science, Impacts and Solutions. Edited by A. Pittock</ref> Researchers have contemplated [[space-based solar power]] for collecting solar power for use on Earth. Space-based solar power has been in research since the early 1970s. Space-based solar power would require construction of collector structures in space. The advantage over ground-based solar power is higher intensity of light, and no weather to interrupt power collection.

==Energy technology==

Energy technology is an [[interdisciplinary]] [[engineering]] [[science]] having to do with the efficient, safe, [[environmentally friendly]], and economical extraction, conversion, transportation, storage, and use of [[energy]], targeted towards yielding high efficiency whilst skirting [[adverse effect|side effects]] on humans, nature, and the environment.

For people, energy is an overwhelming need, and as a scarce [[resource]], it has been an underlying cause of political conflicts and wars. The gathering and use of energy resources can be harmful to local ecosystems and may have global outcomes.

Energy is also the capacity to do work. We can get energy from food. Energy can be of different forms such as kinetic, potential, mechanical, heat, light etc. Energy is required for individuals and the whole society for lighting, heating, cooking, running, industries, operating transportation and so forth. Basically there are two types of energy depending on the source s they are;
1.Renewable Energy Sources
2.Non-Renewable Energy Sources

===Interdisciplinary fields===
As an interdisciplinary science Energy technology is linked with many interdisciplinary fields in sundry, overlapping ways.

* [[Physics]], for [[thermodynamics]] and [[nuclear physics]]
* [[Chemistry]] for [[fuel]], [[combustion]], [[air pollution]], [[flue gas]], [[battery (electricity)|battery]] technology and [[fuel cells]].
* [[Electrical engineering]]
* [[Engineering]], often for fluid energy machines such as [[combustion engines]], turbines, pumps and [[compressors]].
* [[Geography]], for [[Geothermal energy|geothermal]] energy and exploration for resources.
* [[Mining]], for [[petrochemical]] and [[fossil fuels]].
* [[Agriculture]] and [[forestry]], for sources of [[renewable energy]].
* [[Meteorology]] for [[wind]] and [[solar energy]].
* [[Water]] and [[Waterways]], for [[hydropower]].
* [[Waste management]], for environmental impact.
* [[Transportation]], for energy-saving transportation systems.
* [[Environmental studies]], for studying the effect of energy use and production on the [[environment (biophysical)|environment]], [[nature]] and [[climate change]].
* (Lighting Technology), for Interior and Exterior Natural as well as Artificial Lighting Design, Installations, and Energy Savings
* (Energy Cost/Benefit Analysis), for Simple Payback and Life Cycle Costing of Energy Efficiency/Conservation Measures Recommended

===Electrical engineering===
[[Image:Qatar, power lines (6).jpg|thumb|High-voltage lines for the long distance transportation of electrical energy]]

[[Electric power engineering]] deals with the production and use of [[electrical energy]], which can entail the study of machines such as [[Electrical generator|generators]], [[electric motor]]s and [[transformer]]s. [[Infrastructure]] involves [[Electrical substation|substations]] and [[transformer station]]s, [[power line]]s and [[Power cable|electrical cable]]. [[Load management]] and [[power management]] over networks have meaningful sway on overall energy efficiency. [[Electric heating]] is also widely used and researched.

===Thermodynamics===
{{Main article|Thermodynamics}}

[[Thermodynamics]] deals with the fundamental laws of energy conversion and is drawn from theoretical [[Physics]].

===Thermal and chemical energy===
[[Image:Wood-fired grate stoker.jpg|thumb|left|A [[wikt:grate|grate]] for a wood fire]]
Thermal and chemical energy are intertwined with [[chemistry]] and [[environmental studies]]. [[Combustion]] has to do with [[Gas burner|burner]]s and chemical [[engine]]s of all kinds, grates and [[incinerator]]s along with their energy efficiency, [[pollution]] and operational safety.

[[Exhaust gas]] purification technology aims to lessen [[air pollution]] through sundry mechanical, thermal and chemical cleaning methods. [[Emission control (disambiguation)|Emission control]] technology is a field of [[process engineering|process]] and [[chemical engineering]]. [[Boiler]] technology deals with the design, construction and operation of [[steam]] boilers and [[steam turbine|turbine]]s (also used in nuclear power generation, see below), drawn from [[applied mechanics]] and [[materials engineering]].

[[Energy conversion]] has to do with internal combustion engines, turbines, pumps, fans and so on, which are used for transportation, mechanical energy and power generation. High thermal and mechanical loads bring about operational safety worries which are dealt with through many branches of applied engineering science.
{{Clear}}

===Nuclear energy===
[[Image:Turbogenerator01.jpg|thumb|A [[steam turbine]].]]
[[Nuclear technology]] deals with [[nuclear power]] production from [[nuclear reactor]]s, along with the processing of nuclear fuel and disposal of radioactive waste, drawing from applied [[nuclear physics]], [[nuclear chemistry]] and [[radiation]] science.

Nuclear power generation has been politically controversial in many countries for several decades but the electrical energy produced through [[nuclear fission]] is of worldwide importance.<ref>{{Cite web|title=The West's Nuclear Mistake|url=https://www.msn.com/en-us/news/world/the-west-s-nuclear-mistake/ar-AARBhm0?ocid=entnewsntp&pc=U531|access-date=2021-12-08|website=www.msn.com}}</ref> There are high hopes that [[Fusion power|fusion]] technologies will one day replace most fission reactors but this is still a research area of [[nuclear physics]].

===Renewable energy===
{{Main article|Renewable energy}}
[[Image:Nellis AFB Solar panels.jpg|thumb|Solar ([[photovoltaic]]) panels at a military base in the US.]]
[[Renewable energy]] has many branches.

====Wind power====
[[Image:WindMills.jpg|right|thumb|[[Wind turbine]]s on [[Inner Mongolia]]n grassland]]
{{Main article|Wind power}}

[[Wind turbine]]s convert wind energy into electricity by connecting a spinning rotor to a generator. [[Wind turbine]]s draw energy from atmospheric currents and are designed using [[aerodynamics]] along with knowledge taken from mechanical and electrical engineering. The wind passes across the aerodynamic rotor blades, creating an area of higher pressure and an area of lower pressure on either side of the blade. The forces of lift and drag are formed due to the difference in air pressure. The lift force is stronger than the drag force; therefore the rotor, which is connected to a generator, spins. The energy is then created due to the change from the aerodynamic force to the rotation of the generator.<ref>{{Cite web|title=How Do Wind Turbines Work?|url=https://www.energy.gov/eere/wind/how-do-wind-turbines-work|access-date=2020-12-10|website=Energy.gov|language=en}}</ref>

Being recognized as one of the most efficient renewable energy sources, wind power is becoming more and more relevant and used in the world.<ref>{{Cite web|title=BiblioBoard|url=https://openresearchlibrary.org/viewer/2071c2d6-8295-4005-ac8f-eba500a6b311/44|access-date=2020-12-10|website=openresearchlibrary.org}}</ref> Wind power does not use any water in the production of energy making it a good source of energy for areas without much water. Wind energy could also be produced even if the climate changes in line with current predictions, as it relies solely on wind.<ref>{{Cite journal|last1=Ledec, George C.|last2=Rapp, Kennan W.|last3=Aiello, Roberto G.|date=2011-12-01|title=Greening the Wind : Environmental and Social Considerations for Wind Power Development|hdl=10986/2388|url=http://hdl.handle.net/10986/2388|language=en}}</ref>

====Geothermal====
{{Main article|Geothermal energy}}

Deep within the  Earth, is an extreme heat producing layer of molten rock called magma.<ref>{{Cite web|title=How Geothermal Energy Works {{!}} Union of Concerned Scientists|url=https://www.ucsusa.org/resources/how-geothermal-energy-works|access-date=2020-12-14|website=www.ucsusa.org|language=en}}</ref> The very high temperatures from the magma heats nearby groundwater. There are various technologies that have been developed in order to benefit from such heat, such as using different types of power plants (dry, flash or binary), heat pumps, or wells.<ref>{{Cite web|date=2012-11-20|title=Geothermal Energy|url=https://education.nationalgeographic.org/resource/geothermal-energy/|access-date=2020-12-14|website=National Geographic Society|language=en}}</ref> These processes of harnessing the heat incorporate an infrastructure which has in one form or another a turbine which is spun by either the hot water or the steam produced by it.<ref>{{Cite web|last=US EPA|first=OAR|title=Geothermal Energy|url=https://archive.epa.gov/climatechange/kids/solutions/technologies/geothermal.html|access-date=2020-12-14|website=archive.epa.gov|language=en}}</ref> The spinning turbine, being connected to a generator, produces energy. A more recent innovation involves the use of shallow closed-loop systems that pump heat to and from structures by taking advantage of the constant temperature of soil around 10 feet deep.<ref>{{Cite web|title=Where is Geothermal Energy Used?|url=https://www.greenfireenergy.com/where-is-geothermal-energy-used/|access-date=2020-12-14|website=GreenFire Energy Inc.|language=en-US}}</ref>

====Hydropower====
[[Image:Walchenseewerk Pelton 120.jpg|thumb|Building of [[Pelton turbine|Pelton water turbine]]s in [[Germany]].]]
{{Main article|Hydropower}}

Hydropower draws mechanical energy from rivers, [[wave power plant|ocean waves]] and [[tidal power|tides]]. [[Civil engineering]] is used to study and build [[dam]]s, [[tunnel]]s, [[waterways]] and manage coastal resources through [[hydrology]] and [[geology]]. A low speed [[water turbine]] spun by flowing water can power an [[electrical generator]] to produce electricity.

====Bioenergy====
{{Main article|Bioenergy}}
Bioenergy deals with the gathering, processing and use of biomasses grown in biological manufacturing, [[agriculture]] and [[forestry]] from which [[power plant]]s can draw burning fuel. [[Ethanol]], [[methanol]] (both controversial) or hydrogen for [[fuel cells]] can be had from these technologies and used to generate electricity.

====Enabling technologies====

[[Heat pumps]] and [[Thermal energy storage]] are classes of technologies that can enable the utilization of [[renewable energy]] sources that would otherwise be inaccessible due to a temperature that is too low for utilization or a time lag between when the energy is available and when it is needed. While enhancing the temperature of available renewable thermal energy, heat pumps have the additional property of leveraging electrical power (or in some cases mechanical or thermal power) by using it to extract additional energy from a low quality source (such as seawater, lake water, the ground, the air, or [[waste heat]] from a process).

Thermal storage technologies allow heat or cold to be stored for periods of time ranging from hours or overnight to [[Seasonal thermal energy storage|interseasonal]], and can involve storage of [[Sensible heat|sensible energy]] (i.e. by changing the temperature of a medium) or [[latent energy]] (i.e. through phase changes of a medium, such between water and slush or ice). Short-term thermal storages can be used for peak-shaving in district heating or electrical distribution systems. Kinds of renewable or alternative energy sources that can be enabled include natural energy (e.g. collected via solar-thermal collectors, or dry cooling towers used to collect winter's cold), waste energy (e.g. from HVAC equipment, industrial processes or power plants), or surplus energy (e.g. as seasonally from hydropower projects or intermittently from wind farms). The [[Drake Landing Solar Community]] (Alberta, Canada) is illustrative. [[Seasonal thermal energy storage|borehole thermal energy storage]] allows the community to get 97% of its year-round heat from solar collectors on the garage roofs, which most of the heat collected in summer.<ref>Wong, Bill (June 28, 2011), [http://www.districtenergy.org/assets/pdfs/2011Annual_Conf/Proceedings/A24WONG-v03.pdf "Drake Landing Solar Community"] {{webarchive|url=https://web.archive.org/web/20160304030520/http://www.districtenergy.org/assets/pdfs/2011Annual_Conf/Proceedings/A24WONG-v03.pdf |date=2016-03-04 }}, IDEA/CDEA District Energy/CHP 2011 Conference, Toronto, pp. 1–30, retrieved 21 April 2013</ref><ref>Wong B., Thornton J. (2013). [http://www.geo-exchange.ca/en/UserAttachments/flex1304_5-%20SAIC-%20Bill%20Wong%202013%20-%20Integrating%20Solar%20and%20Heat%20Pumps.pdf ''Integrating Solar & Heat Pumps.'']  Renewable Heat Workshop.</ref> Types of storages for sensible energy include insulated tanks, borehole clusters in substrates ranging from gravel to bedrock, deep aquifers, or shallow lined pits that are insulated on top. Some types of storage are capable of storing heat or cold [[Seasonal thermal energy storage|between opposing seasons]] (particularly if very large), and some storage applications require inclusion of a [[Heat pumps|heat pump]]. Latent heat is typically stored in ice tanks or what are called [[phase-change material]]s (PCMs).

==See also==
{{Portal|Energy|Renewable energy|Nuclear technology}}

*[[Worldwide energy supply]]
*[[Technology]]
*[[Water-energy nexus]]

;Policy: [[Energy policy]], [[Energy policy of the United States]], [[Energy policy of China]], [[Energy policy of India]], [[Energy policy of the European Union]], [[Energy policy of the United Kingdom]], [[Energy policy of Russia]], [[Energy policy of Brazil]], [[Energy policy of Canada]], [[Energy policy of the Soviet Union]], [[Energy Industry Liberalization and Privatization (Thailand)]]

;General: [[Seasonal thermal energy storage]] ([[Interseasonal thermal energy storage]]), [[Geomagnetically induced current]], [[Energy harvesting]], [[Timeline of sustainable energy research 2020–present]]

;Feedstock: [[Raw material]], [[Biomaterial]], [[Energy consumption]], [[Materials science]], [[Recycling]], [[Upcycling]], [[Downcycling]]

;Others: [[Thorium-based nuclear power]], [[List of oil pipelines]], [[List of natural gas pipelines]], [[Ocean thermal energy conversion]], [[Growth of photovoltaics]]

==References==
{{Reflist|2}}

==Sources==
* Armstrong, Robert C., Catherine Wolfram, Robert Gross, Nathan S. Lewis, and [[M.V. Ramana]] et al. [http://www.nature.com/articles/nenergy201520 The Frontiers of Energy], ''Nature Energy'', Vol 1, 11 January 2016. 
* Serra, J. "Alternative Fuel Resource Development", Clean and Green Fuels Fund, (2006).
* Bilgen, S. and K. Kaygusuz, ''[https://www.tandfonline.com/doi/abs/10.1080/00908310490441421 Renewable Energy for a Clean and Sustainable Future]'', Energy Sources 26, 1119 (2004).
* ''[https://inis.iaea.org/search/search.aspx?orig_q=RN:36011471 Energy analysis of Power Systems]'', UIC Nuclear Issues Briefing Paper 57 (2004).
* {{cite journal | author = Silvestre B. S., Dalcol P. R. T. | year = 2009| title = Geographical proximity and innovation: Evidences from the Campos Basin oil & gas industrial agglomeration — Brazil | journal = Technovation | volume =  29| issue = 8| pages =  546–561| doi = 10.1016/j.technovation.2009.01.003 }}

==Journals==
* [https://web.archive.org/web/20070930203541/http://www.tandf.co.uk/journals/titles/15567036.asp ''Energy Sources, Part A: Recovery, Utilization and Environmental Effects'']
* [https://web.archive.org/web/20060627073301/http://www.tandf.co.uk/journals/titles/15567249.asp ''Energy Sources, Part B: Economics, Planning and Policy'']
* [https://web.archive.org/web/20051102013932/http://www.tandf.co.uk/journals/titles/15435075.asp ''International Journal of Green Energy'']

==External links==
{{Commons category}}
*[https://web.archive.org/web/20120128172123/http://www.blm.gov/wo/st/en/prog/energy/renewable_energy/2012_priority_projects.html Bureau of Land Management 2012 Renewable Energy Priority Projects]
*[https://energypedia.info/ Energypedia] - a wiki about renewable energies in the context of development cooperation
*[http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=12794 Hidden Health and Environmental Costs Of Energy Production and Consumption In U.S. ]
*[http://www.iea-eces.org/ IEA-ECES] - International Energy Agency - Energy Conservation through Energy Conservation programme.
*[https://heatpumpingtechnologies.org/ IEA HPT TCP] - International Energy Agency - Technology Collaboration Programme on Heatpumping Technologies.
*[http://www.iea-shc.org/ IEA-SHC] - International Energy Agency - Solar Heating and Cooling programme.
*[http://www.solar-district-heating.eu/ SDH] - Solar District Heating Platform. (European Union)

{{Footer energy}}
{{Renewable energy by country}}
{{Wind power}}
{{Solar energy}}
{{Nuclear technology}}
{{Environmental technology}}
{{Petroleum industry|state=collapsed}}

{{Authority control}}

{{DEFAULTSORT:Energy Development}}
[[Category:Energy development| ]]
[[Category:Energy technology]]
[[Category:Sustainable technologies]]
[[Category:Power station technology]]
[[Category:Energy conversion]]