View source for Renewable energy

{{Short description|Energy collected from renewable resources}}
{{for|the journal|Renewable Energy (journal){{!}}''Renewable Energy'' (journal)}}
{{Use dmy dates|date=September 2021}}

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| image1            = Andasol Guadix 4.jpg
| alt1              = Concentrated solar power parabolic troughs in the distance arranged i

| image2            = Darling_Wind_Farm.jpg
| alt2              = Wind turbines beside a red dirt road
| image3            = ThreeGorgesDam-China2009.jpg
| alt3              = The [[Three Gorges Dam]] on the [[Yangtze River]] in China
| image4            = Steven's_Croft_Biomass_Plant_-_geograph.org.uk_-_800207.jpg
| alt4              = Biomass plant in Scotland.
| footer            = Examples of renewable energy: [[concentrated solar power]] with [[Thermal energy storage#Molten salt technology|molten salt heat storage]] in Spain; [[wind energy]] in South Africa; the [[Three Gorges Dam]] on the [[Yangtze River]] in China; [[biomass energy]] plant in [[Scotland]].
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{{Renewable energy sources}}
<noinclude>{{Sustainable energy}}</noinclude>

'''Renewable energy''' (also called '''green energy''') is [[energy]] made from [[renewable resource|renewable natural resource]]s that are replenished on a [[human lifetime|human timescale]]. The most widely used renewable energy types are [[solar energy]], [[wind power]], and [[hydropower]]. [[Bioenergy]] and [[geothermal power]] are also significant in some countries. Some also consider [[Nuclear power proposed as renewable energy|nuclear power a renewable power source]], although this is controversial, as nuclear energy requires mining uranium, a nonrenewable resource. Renewable energy installations can be large or small and are suited for both urban and rural areas. Renewable energy is often deployed together with further [[electrification]]. This has several benefits: electricity can [[heat pump|move heat]] and [[Electric vehicle|vehicles]] efficiently and is clean at the point of consumption.<ref>{{cite journal |last1=Armaroli |first1=Nicola |author-link=Nicola Armaroli |last2=Balzani |first2=Vincenzo |author-link2=Vincenzo Balzani |year=2011 |title=Towards an electricity-powered world |journal=[[Energy and Environmental Science]] |volume=4 |issue=9 |pages=3193–3222 |doi=10.1039/c1ee01249e |bibcode=2011EnEnS...4.3193A | issn=1754-5692 }}</ref><ref>{{cite journal |last1=Armaroli |first1=Nicola |last2=Balzani |first2=Vincenzo |year=2016 |title=Solar Electricity and Solar Fuels: Status and Perspectives in the Context of the Energy Transition |journal=[[Chemistry – A European Journal]] |volume=22 |issue=1 |pages=32–57 |doi=10.1002/chem.201503580 |pmid=26584653 |bibcode=2016ChEuJ..22...32A }}</ref> [[Variable renewable energy]] sources are those that have a fluctuating nature, such as wind power and solar power. In contrast, ''controllable renewable energy'' sources include dammed [[hydroelectricity]], [[bioenergy]], or [[geothermal power]].
[[File:Global Renewable Energy Production by Countries and Sources in 2023.svg|thumb|alt=Percentages of various types of sources in the top renewable energy-producing countries across each geographical region in 2023.|Percentages of various types of sources in the top renewable energy-producing countries across each geographical region in 2023]]
Renewable energy systems have rapidly become more efficient and cheaper over the past 30 years.<ref>{{cite web |title=Global renewable energy trends |url=https://www2.deloitte.com/insights/us/en/industry/power-and-utilities/global-renewable-energy-trends.html |url-status=live |archive-url=https://web.archive.org/web/20190129005932/https://www2.deloitte.com/insights/us/en/industry/power-and-utilities/global-renewable-energy-trends.html |archive-date=29 January 2019 |access-date=28 January 2019 |website=Deloitte Insights}}</ref> A large majority of worldwide newly installed worldwide electricity capacity is now renewable.<ref>{{Cite web |date=2 April 2019 |title=Renewable Energy Now Accounts for a Third of Global Power Capacity |url=https://www.irena.org/newsroom/pressreleases/2019/Apr/Renewable-Energy-Now-Accounts-for-a-Third-of-Global-Power-Capacity |url-status=live |archive-url=https://web.archive.org/web/20190402133504/https://www.irena.org/newsroom/pressreleases/2019/Apr/Renewable-Energy-Now-Accounts-for-a-Third-of-Global-Power-Capacity |archive-date=2 April 2019 |access-date=2 December 2020 |website=irena.org}}</ref> Renewable energy sources, such as solar and wind power, have seen significant cost reductions over the past decade, making them more competitive with traditional fossil fuels.<ref>{{Cite web |title=2023 Levelized Cost Of Energy+ |url=https://www.lazard.com/research-insights/2023-levelized-cost-of-energyplus/ |access-date=2024-06-10 |website=www.lazard.com |language=en}}</ref> In some geographic localities, [[Photovoltaic system|photovoltaic solar]] or [[Wind power|onshore wind]] is the cheapest new-build electricity.<ref name="IEA Renewables 2020">{{cite report |url=https://www.iea.org/reports/renewables-2020 |title=Renewables 2020 Analysis and forecast to 2025 |author=IEA |page=12 |access-date=27 April 2021 |archive-url=https://web.archive.org/web/20210426063553/https://www.iea.org/reports/renewables-2020 |archive-date=26 April 2021 |url-status=live |year=2020}}</ref> From 2011 to 2021, renewable energy grew from 20% to 28% of the global electricity supply. Power from the sun and wind accounted for most of this increase, growing from a combined 2% to 10%. Use of [[fossil energy]] shrank from 68% to 62%.<ref name=":8">{{cite journal |date=14 June 2019 |title=Renewables 2022 |url=https://www.ren21.net/reports/global-status-report/ |journal=Global Status Report |issue=renewable energies |page=44 |access-date=5 September 2022}}</ref> In 2024, renewables accounted for over 30% of global electricity generation and are projected to reach over 45% by 2030.<ref>{{Cite web |title=Global Electricity Review 2025 |url=https://ember-energy.org/latest-insights/global-electricity-review-2025/ |access-date=2025-04-11 |website=Ember |language=en-US}}</ref><ref>{{Cite web |title=Renewables - Energy System |url=https://www.iea.org/energy-system/renewables |website=IEA |language=en-GB}}</ref> Many countries already have renewables contributing more than 20% of their total energy supply, with some generating over half or even all their electricity from renewable sources.<ref name=":5">{{Cite journal |last1=Ritchie |first1=Hannah |author-link=Hannah Ritchie |last2=Roser |first2=Max |author2-link=Max Roser |last3=Rosado |first3=Pablo |date=January 2024 |title=Renewable Energy |url=https://ourworldindata.org/renewable-energy |journal=[[Our World in Data]]}}</ref><ref>{{Cite web |last=Sensiba |first=Jennifer |date=2021-10-28 |title=Some Good News: 10 Countries Generate Almost 100% Renewable Electricity |url=https://cleantechnica.com/2021/10/28/some-good-news-10-countries-generate-almost-100-renewable-electricity/ |url-status=live |archive-url=https://web.archive.org/web/20211117140228/https://cleantechnica.com/2021/10/28/some-good-news-10-countries-generate-almost-100-renewable-electricity/ |archive-date=17 November 2021 |access-date=2021-11-22 |website=CleanTechnica}}</ref>

The main motivation to use renewable energy instead of fossil fuels is to slow and eventually stop [[climate change]], which is mostly caused by their [[greenhouse gas emissions]]. In general, renewable energy sources pollute much less than fossil fuels.<ref name=":2" /> The [[International Energy Agency]] estimates that to achieve [[net zero emissions]] by 2050, 90% of global electricity will need to be generated by renewables.<ref>{{Cite web |date=2024-05-30 |title=Rapid rollout of clean technologies makes energy cheaper, not more costly |url=https://www.iea.org/news/rapid-rollout-of-clean-technologies-makes-energy-cheaper-not-more-costly |access-date=2024-05-31 |website=International Energy Agency |language=en}}</ref> Renewables also cause much less [[air pollution]] than fossil fuels, improving public health, and are less [[Noise pollution|noisy]].<ref name=":2" />

The deployment of renewable energy still faces obstacles, especially [[fossil fuel subsidies]],<ref>{{Cite journal|last=Timperley|first=Jocelyn|date=2021-10-20|title=Why fossil fuel subsidies are so hard to kill|journal=Nature|volume=598|issue=7881 |pages=403–405|doi=10.1038/d41586-021-02847-2|pmid=34671143|bibcode=2021Natur.598..403T|s2cid=239052649|doi-access=free}}</ref> [[lobbying]] by incumbent power providers,<ref>{{Cite journal |last1=Lockwood |first1=Matthew |last2=Mitchell |first2=Catherine |last3=Hoggett |first3=Richard |date=May 2020 |title=Incumbent lobbying as a barrier to forward-looking regulation: The case of demand-side response in the GB capacity market for electricity |url=https://linkinghub.elsevier.com/retrieve/pii/S0301421520301798 |journal=Energy Policy |language=en |volume=140 |article-number=111426 |doi=10.1016/j.enpol.2020.111426|bibcode=2020EnPol.14011426L |hdl=10871/120327 |hdl-access=free }}</ref> and local opposition to the use of land for renewable installations.<ref>{{Cite journal |last1=Susskind |first1=Lawrence |last2=Chun |first2=Jungwoo |last3=Gant |first3=Alexander |last4=Hodgkins |first4=Chelsea |last5=Cohen |first5=Jessica |last6=Lohmar |first6=Sarah |date=June 2022 |title=Sources of opposition to renewable energy projects in the United States |journal=Energy Policy |language=en |volume=165 |article-number=112922 |doi=10.1016/j.enpol.2022.112922|bibcode=2022EnPol.16512922S |doi-access=free }}</ref><ref name=":0">{{Cite web |date=18 May 2021 |title=Net Zero by 2050 – Analysis |url=https://www.iea.org/reports/net-zero-by-2050 |access-date=2023-03-19 |website=IEA |language=en-GB}}</ref> Like all mining, the extraction of minerals required for many renewable energy technologies also results in [[Environmental effects of mining|environmental damage]].<ref>{{Cite web |last=Isaacs-Thomas |first=Bella |date=2023-12-01 |title=Mining is necessary for the green transition. Here's why experts say we need to do it better |url=https://www.pbs.org/newshour/science/mining-is-necessary-for-the-green-transition-heres-why-experts-say-we-need-to-do-it-better |access-date=2024-05-31 |website=PBS NewsHour |language=en-us}}</ref> In addition, although most renewable energy sources are [[sustainable energy|sustainable]], some are not. {{TOC limit|3}}

== Overview ==
{{multiple image
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| image1            = 1990- Renewable energy production, by source.svg
| caption1          = Renewable energy sources, especially [[Photovoltaic system|solar photovoltaic]] and [[Wind power|wind]], are generating an increasing share of electricity.<ref name=EmberElectricityProduction_2022>{{cite web |title=Electricity production by source, World |url=https://ourworldindata.org/grapher/electricity-prod-source-stacked |publisher=Our World in Data, crediting Ember |archive-url=https://web.archive.org/web/20241201191439/https://ourworldindata.org/grapher/electricity-prod-source-stacked |archive-date=1 December 2024 |url-status=live}} OWID credits "Source: Ember's Yearly Electricity Data; Ember's European Electricity Review; Energy Institute Statistical Review of World Energy".</ref>
| image2            = Global Energy Consumption.svg
| caption2          = Coal, oil, and natural gas remain the primary global energy sources even as renewables have begun rapidly increasing.<ref>{{Cite journal|last1=Friedlingstein |first1=Pierre|last2=Jones|first2=Matthew W.|last3=O'Sullivan|first3=Michael|last4=Andrew|first4=Robbie M.|last5=Hauck|first5=Judith|last6=Peters|first6=Glen P.|last7=Peters|first7=Wouter|last8=Pongratz|first8=Julia |last9=Sitch|first9=Stephen|last10=Le Quéré|first10=Corinne|last11=Bakker|first11=Dorothee C. E.|date=2019|title=Global Carbon Budget 2019|url=https://essd.copernicus.org/articles/11/1783/2019/|journal=Earth System Science Data |volume=11|issue=4|pages=1783–1838|doi=10.5194/essd-11-1783-2019|bibcode=2019ESSD...11.1783F|issn=1866-3508|via=|doi-access=free|access-date=15 February 2021|archive-date=6 May 2021|archive-url=https://web.archive.org/web/20210506142248/https://essd.copernicus.org/articles/11/1783/2019/|url-status=live|hdl=20.500.11850/385668|hdl-access=free}}</ref>
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{{See also|Lists of renewable energy topics}}

=== Definition ===
Renewable energy is usually understood as energy harnessed from continuously occurring natural phenomena. The [[International Energy Agency]] defines it as "energy derived from natural processes that are replenished at a faster rate than they are consumed". [[Solar energy|Solar power]], [[wind power]], [[hydroelectricity]], [[Geothermal energy|geothermal]] energy, and [[Biomass (energy)|biomass]] are widely agreed to be the main types of renewable energy.<ref>{{Cite journal |last1=Harjanne |first1=Atte |last2=Korhonen |first2=Janne M. |date=April 2019 |title=Abandoning the concept of renewable energy |url=https://linkinghub.elsevier.com/retrieve/pii/S0301421518308280 |journal=Energy Policy |language=en |volume=127 |pages=330–340 |doi=10.1016/j.enpol.2018.12.029|bibcode=2019EnPol.127..330H |url-access=subscription }}</ref> Renewable energy often displaces conventional fuels in four areas: [[electricity generation]], [[Solar water heating|hot water]]/[[space heating]], [[transportation]], and rural (off-grid) energy services.{{sfn|REN21 Renewables Global Status Report|2010}}

Although almost all forms of renewable energy cause much fewer carbon emissions than fossil fuels, the term is not synonymous with [[Low-carbon electricity|low-carbon energy]]. Some non-renewable sources of energy, such as [[nuclear power]],{{Contradictory inline|reason=graphic above shows nuclear as renewable whereas here says not|date=May 2024}}generate almost no emissions, while some renewable energy sources can be very carbon-intensive, such as the burning of biomass if it is not offset by planting new plants.<ref name=":2">{{Cite book |last1=Ehrlich |first1=Robert |title=Renewable energy: a first course |last2=Geller |first2=Harold A. |last3=Geller |first3=Harold |date=2018 |publisher=Taylor & Francis, CRC Press |isbn=978-1-138-29738-8 |edition=2nd |location=Boca Raton London New York}}</ref> Renewable energy is also distinct from [[sustainable energy]], a more abstract concept that seeks to group energy sources based on their overall permanent impact on future generations of humans. For example, biomass is often associated with unsustainable [[deforestation]].<ref>{{Cite book |last1=Kutscher |first1=Charles F. |title=Principles of sustainable energy systems |last2=Milford |first2=Jana B. |last3=Kreith |first3=Frank |date=2019 |publisher=CRC Press, Taylor & Francis Group |isbn=978-1-4987-8892-2 |edition=3rd |series=Mechanical and aerospace engineering |location=Boca Raton, FL}}</ref>

=== Role in addressing climate change ===
As part of the global effort to [[Climate change mitigation|limit climate change]], most countries have committed to [[Net zero emissions|net zero greenhouse gas emissions]].<ref>{{Cite web |last1=Srouji |first1=Jamal |last2=Fransen |first2=Taryn |last3=Boehm |first3=Sophie |last4=Waskow |first4=David |last5=Carter |first5=Rebecca |last6=Larsen |first6=Gaia |date=25 April 2024 |title=Next-generation Climate Targets: A 5-Point Plan for NDCs |url=https://www.wri.org/insights/next-ndcs-5-point-plan |language=en}}</ref> In practice, this means [[Fossil fuel phase-out|phasing out fossil fuels]] and replacing them with low-emissions energy sources.<ref name=":2" /> This much needed process, coined as "low-carbon substitutions"<ref name="Suzuki et al. 2023">{{Cite journal |last1=Suzuki |first1=Masahiro |last2=Jewell |first2=Jessica |last3=Cherp |first3=Aleh|date=2023-11-09 |title=Have climate policies accelerated energy transitions? Historical evolution of electricity mix in the G7 and the EU compared to net-zero targets |url=https://www.sciencedirect.com/science/article/pii/S2214629623003419 |journal=Energy Research & Social Science |volume=106| article-number=103281 |doi=10.1016/j.erss.2023.103281|bibcode=2023ERSS..10603281S |hdl=20.500.14018/14250 |hdl-access=free }}</ref> in contrast to other transition processes including energy additions, needs to be accelerated multiple times in order to successfully mitigate climate change.<ref name="Suzuki et al. 2023" /> At the [[2023 United Nations Climate Change Conference]], around three-quarters of the world's countries set a goal of tripling renewable energy capacity by 2030.<ref>{{Cite news |date=December 19, 2023 |title=COP28: New deals and evasive tactics |url=https://impact.economist.com/sustainability/cop28-new-deals-and-evasive-tactics |access-date=2024-04-04 |newspaper=The economist |language=en-gb}}</ref> The [[European Union]] aims to generate 40% of its electricity from renewables by the same year.<ref>{{Cite news |last=Abnett |first=Kate |date=2022-04-20 |title=European Commission analysing higher 45% renewable energy target for 2030 |url=https://www.reuters.com/world/europe/european-commission-analysing-higher-45-renewable-energy-target-2030-2022-04-20/ |access-date=2022-04-29 |work=[[Reuters]] |language=en}}</ref>

=== Other benefits ===
{{main|Climate change mitigation#Co-benefits}}

Renewable energy is more evenly distributed around the world than fossil fuels, which are concentrated in a limited number of countries.<ref>{{Cite journal |last1=Overland |first1=Indra |last2=Juraev |first2=Javlon |last3=Vakulchuk |first3=Roman |date=2022-11-01 |title=Are renewable energy sources more evenly distributed than fossil fuels? |url=https://www.sciencedirect.com/science/article/pii/S0960148122013969 |journal=Renewable Energy |volume=200 |pages=379–386 |doi=10.1016/j.renene.2022.09.046 |bibcode=2022REne..200..379O |issn=0960-1481|hdl=11250/3033797 |hdl-access=free }}</ref> It also brings health benefits by reducing [[air pollution]] caused by the burning of fossil fuels. The potential worldwide savings in health care costs have been estimated at trillions of dollars annually.<ref>{{Cite journal |last1=Scovronick |first1=Noah |last2=Budolfson |first2=Mark |last3=Dennig |first3=Francis |last4=Errickson |first4=Frank |last5=Fleurbaey |first5=Marc |last6=Peng |first6=Wei |last7=Socolow |first7=Robert H. |last8=Spears |first8=Dean |last9=Wagner |first9=Fabian |date=2019-05-07 |title=The impact of human health co-benefits on evaluations of global climate policy |journal=Nature Communications |volume=10 |issue=1 |page=2095 |doi=10.1038/s41467-019-09499-x |pmid=31064982 |pmc=6504956 |bibcode=2019NatCo..10.2095S |issn=2041-1723}}</ref>

=== Intermittency ===
{{Main|Variable renewable energy}}

[[File:20240706 Energy storage - renewable energy - battery - 100 ms.gif|thumb |Energy from sunlight or other renewable energy is converted to potential energy for storage in devices such as electric batteries. The stored potential energy is later converted to electricity that is added to the power grid, even when the original energy source is not available.]]
[[File:Renewables need flexible backup not baseload.png|thumb |Estimated power demand over a week in May 2012 and May 2020, Germany, showing the variability in solar and wind power both day-to-day and month-to-month]]
The two most important forms of renewable energy, solar and wind, are ''intermittent energy sources'': they are not available constantly, resulting in lower [[capacity factor]]s. In contrast, [[Fossil fuel power station|fossil fuel power plants]], nuclear power plants and hydropower are usually able to produce precisely the amount of energy an [[Electrical grid|electricity grid]] requires at a given time. Solar energy can only be captured during the day, and ideally in cloudless conditions. Wind power generation can vary significantly not only day-to-day, but even month-to-month.<ref>{{Cite book |last=Wan |first=Y. H. |url=https://www.nrel.gov/docs/fy12osti/53637.pdf |title=Long-term wind power variability |date=January 2012 |publisher=[[National Renewable Energy Laboratory]] |language=en}}</ref> This poses a challenge when transitioning away from fossil fuels: energy demand will often be higher or lower than what renewables can provide.<ref name="Olauson 16175">{{Cite journal |last1=Olauson |first1=Jon |last2=Ayob |first2=Mohd Nasir |last3=Bergkvist |first3=Mikael |last4=Carpman |first4=Nicole |last5=Castellucci |first5=Valeria |last6=Goude |first6=Anders |last7=Lingfors |first7=David |last8=Waters |first8=Rafael |last9=Widén |first9=Joakim |date=December 2016 |title=Net load variability in Nordic countries with a highly or fully renewable power system |url=http://www.nature.com/articles/nenergy2016175 |url-status=live |journal=Nature Energy |volume=1 |issue=12 |page=16175 |doi=10.1038/nenergy.2016.175 |bibcode=2016NatEn...116175O |issn=2058-7546 |s2cid=113848337 |archive-url=https://web.archive.org/web/20211004082439/https://www.nature.com/articles/nenergy2016175 |archive-date=4 October 2021 |access-date=4 October 2021|url-access=subscription }}</ref>

In the medium-term, this variability may require keeping some [[gas-fired power plant]]s or other [[dispatchable generation]] on standby<ref>{{Cite web |last=Swartz |first=Kristi E. |date=2021-12-08 |title=Can U.S. phase out natural gas? Lessons from the Southeast |url=https://www.eenews.net/articles/can-u-s-phase-out-natural-gas-lessons-from-the-southeast/ |access-date=2022-05-02 |website=E&E News |language=en-US}}</ref><ref>{{Cite web |title=Climate change: phase out gas power by 2035, say businesses including Nestle, Thames Water, Co-op |url=https://news.sky.com/story/climate-change-phase-out-gas-power-by-2035-say-businesses-including-nestle-thames-water-co-op-12415528 |access-date=2022-05-02 |website=Sky News |language=en}}</ref> until there is enough energy storage, [[demand response]], grid improvement, or [[Base load|base load power]] from non-intermittent sources. In the long-term, [[energy storage]] is an important way of dealing with intermittency.<ref>{{Cite web |last=Roberts |first=David |date=2018-11-30 |title=Clean energy technologies threaten to overwhelm the grid. Here's how it can adapt. |url=https://www.vox.com/energy-and-environment/2018/11/30/17868620/renewable-energy-power-grid-architecture |access-date=2024-04-20 |website=Vox |language=en}}</ref> Using diversified renewable energy sources and [[smart grid]]s can also help flatten supply and demand.<ref>{{Cite news |title=AI and other tricks are bringing power lines into the 21st century |url=https://www.economist.com/business/2024/05/05/ai-and-other-tricks-are-bringing-power-lines-into-the-21st-century |access-date=2024-05-12 |newspaper=The Economist |issn=0013-0613}}</ref>

Sector coupling of the power generation sector with other sectors may increase flexibility: for example the transport sector can be coupled by charging electric vehicles and sending electricity from [[Vehicle-to-grid|vehicle to grid]].<ref>{{Cite journal |last1=Ramsebner |first1=Jasmine |last2=Haas |first2=Reinhard |last3=Ajanovic |first3=Amela |last4=Wietschel |first4=Martin |date=July 2021 |title=The sector coupling concept: A critical review |url=https://onlinelibrary.wiley.com/doi/10.1002/wene.396 |journal=WIREs Energy and Environment |language=en |volume=10 |issue=4 |article-number=e396 |bibcode=2021WIREE..10E.396R |doi=10.1002/wene.396 |issn=2041-8396 |s2cid=234026069|url-access=subscription }}</ref> Similarly the industry sector can be coupled by hydrogen produced by electrolysis,<ref>{{Cite web |title=4 questions on sector coupling |url=https://www.wartsila.com/insights/article/4-questions-on-sector-coupling |access-date=2022-05-15 |website=Wartsila.com |language=en}}</ref> and the buildings sector by thermal energy storage for space heating and cooling.<ref>{{Cite web |date=2021-12-16 |title=Intelligent, flexible Sector Coupling in cities can double the potential for Wind and Solar |url=https://energypost.eu/intelligent-flexible-sector-coupling-in-cities-can-double-the-potential-for-wind-and-solar/ |access-date=2022-05-15 |website=Energy Post |language=en-GB |archive-date=27 May 2022 |archive-url=https://web.archive.org/web/20220527191915/https://energypost.eu/intelligent-flexible-sector-coupling-in-cities-can-double-the-potential-for-wind-and-solar/ }}</ref>

Building overcapacity for wind and solar generation can help ensure sufficient electricity production even during poor weather. In optimal weather, it may be necessary to curtail energy generation if it is not possible to use or store excess electricity.<ref>{{Cite book |last=IEA |author-link=International Energy Agency |url=https://www.iea.org/reports/world-energy-outlook-2020 |title=World Energy Outlook 2020 |publisher=International Energy Agency |year=2020 |isbn=978-92-64-44923-7 |page=109 |archive-url=https://web.archive.org/web/20210822044327/https://www.iea.org/reports/world-energy-outlook-2020 |archive-date=22 August 2021 |url-status=live}}</ref>

==== Electrical energy storage ====
{{main|Energy storage|Grid energy storage}}

Electrical energy storage is a collection of methods used to store electrical energy. Electrical energy is stored during times when production (especially from intermittent sources such as [[wind power]], [[tidal power]], [[solar power]]) exceeds consumption, and returned to the [[power grid|grid]] when production falls below consumption. [[Pumped-storage hydroelectricity]] accounts for more than 85% of all [[Grid energy storage|grid power storage]].<ref>{{Cite web |date=30 June 2021 |title=Hydropower Special Market Report – Analysis |url=https://www.iea.org/reports/hydropower-special-market-report |access-date=2022-01-31 |website=IEA}}</ref> Batteries are increasingly being deployed for storage<ref>{{Cite web |date=2022-05-05 |title=What role is large-scale battery storage playing on the grid today? |url=https://www.energy-storage.news/what-role-is-large-scale-battery-storage-playing-on-the-grid-today/ |access-date=2022-05-09 |website=Energy Storage News |language=en-US}}</ref> and grid [[ancillary services]]<ref>{{Cite book |last1=Zhou |first1=Chen |title=2021 2nd International Conference on Artificial Intelligence and Information Systems |last2=Liu |first2=Rao |last3=Ba |first3=Yu |last4=Wang |first4=Haixia |last5=Ju |first5=Rongbin |last6=Song |first6=Minggang |last7=Zou |first7=Nan |last8=Li |first8=Weidong |date=2021-05-28 |publisher=Association for Computing Machinery |isbn=978-1-4503-9020-0 |series=ICAIIS 2021 |location=New York, NY, USA |pages=1–6 |chapter=Study on the optimization of the day-ahead addition space for large-scale energy storage participation in auxiliary services |doi=10.1145/3469213.3471362 |chapter-url=https://doi.org/10.1145/3469213.3471362 |s2cid=237206056}}</ref> and for domestic storage.<ref>{{Cite web |last=Heilweil |first=Rebecca |date=2022-05-05 |title=These batteries work from home |url=https://www.vox.com/recode/23057167/home-battery-tesla-powerwall-biden |access-date=2022-05-09 |website=[[Vox (website)|Vox]] |language=en}}</ref> [[Green hydrogen]] is a more economical means of long-term renewable energy storage, in terms of [[capital expenditure]]s compared to pumped hydroelectric or batteries.<ref>{{Cite journal |last1=Schrotenboer |first1=Albert H. |last2=Veenstra |first2=Arjen A.T. |last3=uit het Broek |first3=Michiel A.J. |last4=Ursavas |first4=Evrim |date=October 2022 |title=A Green Hydrogen Energy System: Optimal control strategies for integrated hydrogen storage and power generation with wind energy |url=https://pure.rug.nl/ws/portalfiles/portal/230184233/1_s2.0_S1364032122006323_main.pdf |journal=Renewable and Sustainable Energy Reviews |language=en |volume=168 |article-number=112744 |doi=10.1016/j.rser.2022.112744 |arxiv=2108.00530 |bibcode=2022RSERv.16812744S |s2cid=250941369}}</ref><ref>{{Cite news |last=Lipták |first=Béla |date=January 24, 2022 |title=Hydrogen is key to sustainable green energy |url=https://www.controlglobal.com/home/article/11288951/hydrogen-is-key-to-sustainable-green-energy |access-date=February 12, 2023 |work=Control}}</ref>

==== Energy supply security ====
Two main renewable energy sources - solar power and wind power - are usually deployed in [[distributed generation]] architecture, which offers specific benefits and comes with specific risks.<ref>{{Cite journal |last1=Gordon |first1=Samuel |last2=McGarry |first2=Connor |last3=Bell |first3=Keith |date=2022 |title=The growth of distributed generation and associated challenges: A Great Britain case study |journal=IET Renewable Power Generation |language=en |volume=16 |issue=9 |pages=1827–1840 |doi=10.1049/rpg2.12416 |issn=1752-1424|doi-access=free |bibcode=2022IRPG...16.1827G }}</ref> Notable risks are associated with centralisation of 90% of the supply chains in a single country (China) in the photovoltaic sector.<ref>{{Cite web |last=O'Sullivan |first=Alexander Lipke, Janka Oertel, Daniel |date=2024-05-29 |title=Trust and trade-offs: How to manage Europe's green technology dependence on China |url=https://ecfr.eu/publication/trust-and-trade-offs-how-to-manage-europes-green-technology-dependence-on-china/ |access-date=2024-12-12 |website=ECFR |language=en-GB}}</ref> Mass-scale installation of photovoltaic [[Power inverter|power inverters]] with remote control, [[Vulnerability (computer security)|security vulnerabilities]] and [[Web shell|backdoors]] results in cyberattacks that can disable generation from millions of physically decentralised panels, resulting in disappearance of hundreds of gigawatts of installed power from the grid in one moment.<ref>{{Cite news |date=2024-12-12 |title=Hacking Rooftop Solar Is a Way to Break Europe's Power Grid |url=https://www.bloomberg.com/news/articles/2024-12-12/europe-s-power-grid-vulnerable-to-hackers-exploiting-rooftop-solar-panels |access-date=2024-12-12 |work=Bloomberg.com |language=en}}</ref><ref>{{Cite web |date=2024-08-19 |title=The gigantic and unregulated power plants in the cloud |url=https://berthub.eu/articles/posts/the-gigantic-unregulated-power-plants-in-the-cloud/ |access-date=2024-12-12 |website=Bert Hubert's writings}}</ref> Similar attacks have targeted wind power farms through vulnerabilities in their remote control and monitoring systems.<ref>{{Cite web |last=Tam |first=Kimberly |date=2024-09-05 |title=How cyberattacks on offshore wind farms could create huge problems |url=https://theconversation.com/how-cyberattacks-on-offshore-wind-farms-could-create-huge-problems-238165 |access-date=2024-12-12 |website=The Conversation |language=en-US}}</ref> The European [[Cyber-security regulation|NIS2 directive]] partially responds to these challenges by extending the scope of cybersecurity regulations to the energy generation market.<ref>{{Cite web |date=2024-07-12 |title=SolarPower Europe calls for stronger cybersecurity measures |url=https://www.pv-magazine.com/2024/07/12/solarpower-europe-calls-for-stronger-cybersecurity-measures/ |access-date=2024-12-12 |website=pv magazine International |language=en-US}}</ref>Recent analyses indicate that global solar photovoltaic capacity surpassed 1 terawatt in 2024, providing about 6–7% of global electricity supply.<ref>{{Cite journal |last=Smith |first=J. |year=2024 |title=Global solar PV capacity surpassed 1 TW |journal=Nature Energy |volume=9 |issue=3 |pages=210–218 |doi=10.1038/s41560-024-00001-x}}</ref> Renewable energy infrastructure is also increasingly vulnerable to extreme weather events linked to climate change, such as heat waves, wildfires, severe storms, and flooding. Solar farms can experience reduced output during prolonged heat or smoke conditions, while wind turbines may require shutdowns during high-wind events or face damage from icing or wave action. These climate-related stresses can threaten the continuity of electricity supply in regions with high shares of variable renewables. As a result, governments and grid operators are adopting climate-resilience standards, hardening infrastructure, and developing emergency-response protocols to maintain energy security under more frequent and severe weather conditions. <ref>{{Cite web |date=2024-07-17 |title=Catching the sun: Adapting solar power to the challenges of climate change {{!}} Swiss Re |url=https://www.swissre.com/institute/research/topics-and-risk-dialogues/climate-and-natural-catastrophe-risk/climate-change-solar-power.html?utm |access-date=2025-11-13 |website=www.swissre.com |language=en}}</ref>

== Mainstream technologies ==
<!--
This section is for a basic description of the main renewable energy technologies. New and emerging technologies should be added to the section towards the end of the article. Pros and cons of different technologies are discussed in [[Renewable energy debate]]. Thanks. -->
[[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>]]

=== Solar energy ===
{{main|Solar energy|Solar power|Outline of solar energy}}

{| class="wikitable"
! Installed capacity and other key design parameters
! Value and year
|-
| Global electricity power generation capacity || 1419.0 GW (2023){{sfn|IRENA|2024|p=21}}
|-
| Global electricity power generation capacity annual growth rate || 25% (2014-2023)<ref>{{harvnb|IRENA|2024|p=21}}. Note: Compound annual growth rate 2014-2023.</ref>
|-
| Share of global electricity generation || 5.5% (2023)<ref name="Ember 2024" />
|-
| Levelized cost per megawatt hour || Utility-scale photovoltaics: USD 38.343 (2019){{sfn|NREL ATB|2021|loc=Utility-Scale PV}}
|-
| Primary technologies || [[Photovoltaics]], [[concentrated solar power]], [[solar thermal collector]]
|-
| Main applications || Electricity, water heating, heating, ventilation, air conditioning ([[Heating, ventilation, and air conditioning|HVAC]])
|}
{{multiple image
| total_width       = 450
| image1            = SolarFachwerkhaus.jpg
| caption1          = A small, rooftop [[PV system]] in [[Bonn]], Germany
| image2            = Mount Komekura Photovoltaic power plant Jan2012.JPG
| caption2          = [[Komekurayama Solar Power Plant|Komekurayama]] [[photovoltaic power station]] in [[Kofu]], Japan
}}

Solar power produced around 1.3 terrawatt-hours (TWh) worldwide in 2022,<ref name=":5" /> representing 4.6% of the world's electricity. Almost all of this growth has happened since 2010.<ref>{{Cite web |date=2023 |title=Data Page: Share of electricity generated by solar power |url=https://ourworldindata.org/grapher/share-electricity-solar?tab=table |website=[[Our World in Data]]}}</ref> Solar energy can be harnessed anywhere that receives sunlight; however, the amount of solar energy that can be harnessed for electricity generation is influenced by [[Weather|weather conditions]], geographic location and time of day.<ref>{{Cite web|date=2021-10-27 |url=https://www.c2es.org/content/renewable-energy/|access-date=2021-11-22|title=Renewable Energy|website=Center for Climate and Energy Solutions|url-status=live|archive-url=https://web.archive.org/web/20211118150404/https://www.c2es.org/content/renewable-energy/|archive-date=18 November 2021}}</ref>

There are two mainstream ways of harnessing solar energy: [[Solar thermal energy|solar thermal]], which converts solar energy into heat; and [[photovoltaics]] (PV), which converts it into electricity.<ref name=":2" /> PV is far more widespread, accounting for around two thirds of the global solar energy capacity as of 2022.<ref name=":4">{{Cite book |last1=Weiss |first1=Werner |url=https://www.iea-shc.org/Data/Sites/1/publications/Solar-Heat-Worldwide-2023.pdf |title=Solar heat worldwide |last2=Spörk-Dür |first2=Monika |publisher=International Energy Agency |year=2023 |page=12 |language=en}}</ref> It is also growing at a much faster rate, with 170 GW newly installed capacity in 2021,<ref>{{Cite web |title=Solar - Fuels & Technologies |url=https://www.iea.org/fuels-and-technologies/solar |access-date=2022-06-27 |website=IEA |language=en-GB}}</ref> compared to 25 GW of solar thermal.<ref name=":4" />

[[Passive solar]] refers to a range of construction strategies and technologies that aim to optimize the distribution of solar heat in a building. Examples include [[solar chimney]]s,<ref name=":2" /> orienting a building to the sun, using [[Thermal mass|construction materials that can store heat]], and designing spaces that [[Ventilation (architecture)|naturally circulate air]].<ref>{{Cite journal |last1=Zaręba |first1=Anna |last2=Krzemińska |first2=Alicja |last3=Kozik |first3=Renata |last4=Adynkiewicz-Piragas |first4=Mariusz |last5=Kristiánová |first5=Katarina |date=2022-03-17 |title=Passive and Active Solar Systems in Eco-Architecture and Eco-Urban Planning |journal=Applied Sciences |language=en |volume=12 |issue=6 |page=3095 |doi=10.3390/app12063095 |doi-access=free |issn=2076-3417}}</ref>

From 2020 to 2022, solar technology investments almost doubled from USD 162 billion to USD 308 billion, driven by the sector's increasing maturity and cost reductions, particularly in solar photovoltaic (PV), which accounted for 90% of total investments. China and the United States were the main recipients, collectively making up about half of all solar investments since 2013. Despite reductions in Japan and India due to policy changes and [[COVID-19]], growth in China, the United States, and a significant increase from Vietnam's feed-in tariff program offset these declines. Globally, the solar sector added 714 gigawatts (GW) of solar PV and [[concentrated solar power]] (CSP) capacity between 2013 and 2021, with a notable rise in large-scale solar heating installations in 2021, especially in China, Europe, Turkey, and Mexico.<ref name=":1" /> In 2023, global solar power capacity grew by nearly 30%, driven by falling panel prices and expanded government incentives worldwide.<ref>{{Cite web |date=2023 |title=Renewables 2023 |url=https://www.iea.org/reports/renewables-2023 |website=IEA}}</ref>

==== Photovoltaics ====
{{Main|Growth of photovoltaics|Solar power by country|List of photovoltaic power stations}}

[[File:1975 – Price of solar panels as a function of cumulative installed capacity.svg|thumb |[[Swanson's law]]–stating that solar module prices have dropped about 20% for each doubling of installed capacity—defines the "[[Experience curve effects|learning rate]]" of [[photovoltaics|solar photovoltaics]].<ref name=SolarPVlearningCurve>{{cite web |title=Solar (photovoltaic) panel prices vs. cumulative capacity |url=https://ourworldindata.org/grapher/solar-pv-prices-vs-cumulative-capacity |website=OurWorldInData.org |archive-url=https://archive.today/20250124235542/https://ourworldindata.org/grapher/solar-pv-prices-vs-cumulative-capacity |archive-date=24 January 2025 |date=2024 |url-status=live }} OWID credits source data to: Nemet (2009); Farmer & Lafond (2016); International Renewable Energy Agency (IRENA, 2024).</ref><ref>{{cite web |url=http://www.greentechmedia.com/articles/read/Is-there-really-a-Swansons-Law |title=Swanson's Law and Making US Solar Scale Like Germany |work=Greentech Media |date=2014-11-24}}</ref>]]
A [[photovoltaic system]], consisting of [[solar cell]]s assembled into [[Solar panel|panels]], converts light into electrical [[direct current]] via the [[photoelectric effect]].<ref>{{cite journal |last1=Dai |first1=Zhenbang |last2=Rappe |first2=Andrew M. |title=Recent progress in the theory of bulk photovoltaic effect |journal=Chemical Physics Reviews |date=1 March 2023 |volume=4 |issue=1 |article-number=011303 |doi=10.1063/5.0101513|arxiv=2206.00602 }}</ref><ref>{{cite web|title=Energy Sources: Solar|work=Department of Energy |url=https://www.energy.gov/energysources/solar.htm |access-date=19 April 2011|archive-date=14 April 2011 |archive-url=https://web.archive.org/web/20110414081047/http://www.energy.gov/energysources/solar.htm|url-status=live}}</ref> PV has several advantages that make it by far the fastest-growing renewable energy technology. It is cheap, low-maintenance and scalable; adding to an existing PV installation as demanded arises is simple. Its main disadvantage is its poor performance in cloudy weather.<ref name=":2" />

PV systems range from small, residential and commercial [[Rooftop solar power|rooftop]] or [[Building-integrated photovoltaics|building integrated]] installations,<ref>{{cite journal |last1=Petter Jelle |first1=Bjørn |last2=Breivik |first2=Christer |last3=Drolsum Røkenes |first3=Hilde |title=Building integrated photovoltaic products: A state-of-the-art review and future research opportunities |journal=Solar Energy Materials and Solar Cells |date=May 2012 |volume=100 |pages=69–96 |doi=10.1016/j.solmat.2011.12.016|bibcode=2012SEMSC.100...69P |hdl=11250/2436844 |hdl-access=free }}</ref><ref>{{cite journal |last1=Luthander |first1=Rasmus |last2=Widén |first2=Joakim |last3=Nilsson |first3=Daniel |last4=Palm |first4=Jenny |title=Photovoltaic self-consumption in buildings: A review |journal=Applied Energy |date=March 2015 |volume=142 |pages=80–94 |doi=10.1016/j.apenergy.2014.12.028|bibcode=2015ApEn..142...80L |url=http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-113676 }}</ref><ref>{{cite journal |last1=Chung |first1=Hsien-Ching |title=The Long-Term Usage of an Off-Grid Photovoltaic System with a Lithium-Ion Battery-Based Energy Storage System on High Mountains: A Case Study in Paiyun Lodge on Mt. Jade in Taiwan |journal=Batteries |date=13 June 2024 |volume=10 |issue=6 |page=202 |doi=10.3390/batteries10060202|doi-access=free |arxiv=2405.04225 }}</ref> to large utility-scale [[photovoltaic power station]].<ref>{{cite journal |last1=Fereidooni |first1=Mojtaba |last2=Mostafaeipour |first2=Ali |last3=Kalantar |first3=Vali |last4=Goudarzi |first4=Hossein |title=A comprehensive evaluation of hydrogen production from photovoltaic power station |journal=Renewable and Sustainable Energy Reviews |date=February 2018 |volume=82 |pages=415–423 |doi=10.1016/j.rser.2017.09.060|bibcode=2018RSERv..82..415F }}</ref><ref>{{cite journal |last1=Buerhop |first1=Claudia |last2=Bommes |first2=Lukas |last3=Schlipf |first3=Jan |last4=Pickel |first4=Tobias |last5=Fladung |first5=Andreas |last6=Peters |first6=Ian Marius |title=Infrared imaging of photovoltaic modules: a review of the state of the art and future challenges facing gigawatt photovoltaic power stations |journal=Progress in Energy |date=1 October 2022 |volume=4 |issue=4 |page=042010 |doi=10.1088/2516-1083/ac890b|bibcode=2022PrEne...4d2010B |doi-access=free }}</ref><ref>{{cite web |title=Solar Integrated in New Jersey |url=http://jcwinnie.biz/wordpress/?p=1724 |archive-url=https://web.archive.org/web/20130719075405/http://jcwinnie.biz/wordpress/?p=1724 |archive-date=19 July 2013 |access-date=20 August 2013 |publisher=Jcwinnie.biz}}</ref> A household's solar panels can either be used for just that household or, if connected to an electrical grid, can be aggregated with millions of others.<ref>{{cite journal |last1=Sommerfeldt |first1=Nelson |last2=Madani |first2=Hatef |title=Revisiting the techno-economic analysis process for building-mounted, grid-connected solar photovoltaic systems: Part one – Review |journal=Renewable and Sustainable Energy Reviews |date=July 2017 |volume=74 |pages=1379–1393 |doi=10.1016/j.rser.2016.11.232|bibcode=2017RSERv..74.1379S }}</ref><ref>{{cite journal |last1=Sommerfeldt |first1=Nelson |last2=Madani |first2=Hatef |title=Revisiting the techno-economic analysis process for building-mounted, grid-connected solar photovoltaic systems: Part two - Application |journal=Renewable and Sustainable Energy Reviews |date=July 2017 |volume=74 |pages=1394–1404 |doi=10.1016/j.rser.2017.03.010|bibcode=2017RSERv..74.1394S }}</ref><ref>{{Cite news |title=Getting the most out of tomorrow's grid requires digitisation and demand response |url=https://www.economist.com/technology-quarterly/2022/06/23/getting-the-most-out-of-tomorrows-grid-requires-digitisation-and-demand-response |access-date=2022-06-24 |newspaper=[[The Economist]] |issn=0013-0613}}</ref>

The first utility-scale solar power plant was built in 1982 in [[Hesperia, California]] by [[ARCO]].<ref>{{cite journal |url=https://www.osti.gov/biblio/5049780 |title=Design, installation and performance of ARCO solar photovoltaic power plants |journal=Conf. Rec. IEEE Photovoltaic Spec. Conf.; (United States)|date=May 1984 |osti=5049780 |last1=Tolbert |first1=R. E. L. |last2=Arnett |first2=J. C. }}</ref><ref>{{Cite web |title=The History of Solar |url=https://www1.eere.energy.gov/solar/pdfs/solar_timeline.pdf |access-date=April 7, 2024 |website=U.S. Department of Energy}}</ref> The plant was not profitable and was sold eight years later.<ref>{{Cite web |last=Lee |first=Patrick |date=1990-01-12 |title=Arco Sells Last 3 Solar Plants for $2 Million: Energy: The sale to New Mexico investors demonstrates the firm's strategy of focusing on its core oil and gas business. |url=https://www.latimes.com/archives/la-xpm-1990-01-12-fi-323-story.html |access-date=2024-04-07 |website=Los Angeles Times |language=en-US}}</ref> However, over the following decades, PV cells became significantly more efficient and cheaper.<ref name="deutsche-2015-chasm">{{cite web |date=27 February 2015 |title=Crossing the Chasm |url=https://www.db.com/cr/en/docs/solar_report_full_length.pdf |url-status=live |archive-url=https://web.archive.org/web/20150330174336/https://www.db.com/cr/en/docs/solar_report_full_length.pdf |archive-date=30 March 2015 |publisher=Deutsche Bank Markets Research}}</ref> As a result, PV adoption has grown exponentially since 2010.<ref>{{Cite journal |last1=Ravishankar |first1=Rashmi |last2=AlMahmoud |first2=Elaf |last3=Habib |first3=Abdulelah |last4=de Weck |first4=Olivier L. |date=January 2022 |title=Capacity Estimation of Solar Farms Using Deep Learning on High-Resolution Satellite Imagery |journal=Remote Sensing |language=en |volume=15 |issue=1 |page=210 |doi=10.3390/rs15010210 |doi-access=free |bibcode=2022RemS...15..210R |issn=2072-4292|hdl=1721.1/146994 |hdl-access=free }}</ref> Global capacity increased from 230 GW at the end of 2015 to 890 GW in 2021.<ref name="IRENA2018">{{cite web |title=Renewable Electricity Capacity And Generation Statistics June 2018 |url=http://resourceirena.irena.org/gateway/dashboard/?topic=4&subTopic=54 |archive-url=https://web.archive.org/web/20181128034842/http://resourceirena.irena.org/gateway/dashboard/?topic=4&subTopic=54 |archive-date=28 November 2018 |access-date=27 November 2018}}</ref> PV grew fastest in China between 2016 and 2021, adding 560 GW, more than all advanced economies combined.<ref name="IEA-3" /> Four of the ten biggest solar power stations are in China, including the biggest, [[Huanghe Hydropower Golmud Solar Park|Golmud Solar Park]] in China.<ref>{{Cite web |last=Ahmad |first=Mariam |date=2023-05-30 |title=Top 10: Largest Solar Power Parks |url=https://energydigital.com/top10/top-10-largest-solar-power-parks |access-date=2024-04-07 |website=energydigital.com |language=en}}</ref>

[[Solar cell#Recycling|Solar panels are recycled]] to reduce [[electronic waste]] and create a source for materials that would otherwise need to be mined,<ref>{{Cite web |last= |first= |date=2021-08-23 |title=Solar Panel Recycling |url=https://www.epa.gov/hw/solar-panel-recycling |access-date=2022-05-02 |website=www.epa.gov |language=en}}</ref> but such business is still small and work is ongoing to improve and scale-up the process.<ref name="techrev">{{cite web |title=Solar panels are a pain to recycle. These companies are trying to fix that. |url=https://www.technologyreview.com/2021/08/19/1032215/solar-panels-recycling/ |url-status=live |archive-url=https://web.archive.org/web/20211108103705/https://www.technologyreview.com/2021/08/19/1032215/solar-panels-recycling/ |archive-date=8 November 2021 |access-date=8 November 2021 |website=MIT Technology Review}}</ref><ref>{{cite journal |last1=Heath |first1=Garvin A. |last2=Silverman |first2=Timothy J. |last3=Kempe |first3=Michael |last4=Deceglie |first4=Michael |last5=Ravikumar |first5=Dwarakanath |last6=Remo |first6=Timothy |last7=Cui |first7=Hao |last8=Sinha |first8=Parikhit |last9=Libby |first9=Cara |last10=Shaw |first10=Stephanie |last11=Komoto |first11=Keiichi |last12=Wambach |first12=Karsten |last13=Butler |first13=Evelyn |last14=Barnes |first14=Teresa |last15=Wade |first15=Andreas |date=July 2020 |title=Research and development priorities for silicon photovoltaic module recycling to support a circular economy |url=https://www.nature.com/articles/s41560-020-0645-2 |url-status=live |journal=Nature Energy |volume=5 |issue=7 |pages=502–510 |bibcode=2020NatEn...5..502H |doi=10.1038/s41560-020-0645-2 |issn=2058-7546 |s2cid=220505135 |archive-url=https://web.archive.org/web/20210821071335/https://www.nature.com/articles/s41560-020-0645-2 |archive-date=21 August 2021 |access-date=26 June 2021|url-access=subscription }}</ref><ref>{{cite journal |last1=Domínguez |first1=Adriana |last2=Geyer |first2=Roland |date=1 April 2019 |title=Photovoltaic waste assessment of major photovoltaic installations in the United States of America |journal=Renewable Energy |volume=133 |pages=1188–1200 |bibcode=2019REne..133.1188D |doi=10.1016/j.renene.2018.08.063 |issn=0960-1481 |s2cid=117685414}}</ref>

==== Solar thermal ====
{{Main|Solar thermal energy}}

Unlike photovoltaic cells that convert sunlight directly into electricity, solar thermal systems convert it into heat. They use mirrors or lenses to concentrate sunlight onto a receiver, which in turn heats a water reservoir. The heated water can then be used in homes. The advantage of solar thermal is that the heated water can be stored until it is needed, eliminating the need for a separate energy storage system.<ref>{{Cite news |last=Coren |first=Michael |date=February 13, 2024 |title=Meet the other solar panel |url=https://www.washingtonpost.com/climate-environment/2024/02/13/solar-thermal-water-heater/ |newspaper=[[The Washington Post]]}}</ref> Solar thermal power can also be converted to electricity by using the steam generated from the heated water to drive a [[turbine]] connected to a generator. However, because generating electricity this way is much more expensive than photovoltaic power plants, there are very few in use today.<ref>{{Cite news |last1=Kingsley |first1=Patrick |last2=Elkayam |first2=Amit |date=October 9, 2022 |title='Eye of Sauron': The Dazzling Solar Tower in the Israeli Desert |url=https://www.nytimes.com/2022/10/09/world/middleeast/israel-solar-tower.html |work=The New York Times}}</ref>

==== Floatovoltaics ====
{{Main article|Floating solar}}

Floatovoltiacs, or floating solar panels, are solar panels floating on bodies of water. There are both positive and negative points to this. Some positive points are increased efficiency and price decrease of water space compared to land space. A negative point is that making floating solar panels could be more expensive.

==== Agrivoltaics ====
{{Main|Agrivoltaics}}

Agrivoltaics is where there is simultaneous use of land for energy production and agriculture. There are again both positive and negative points. A positive viewpoint is there is a better use of land, which leads to lower land costs. A negative viewpoint is it the plants grown underneath would have to be plants that can grow well under shade, such as [[Polka Dot Plant]], [[Pineapple Sage]], and [[Begonia]].<ref>{{Cite web |title=19 Top Shade Plants - Shade-Loving Plants for Your Garden |url=https://www.provenwinners.com/learn/top-ten-lists/10-plants-for-your-shade-garden |access-date=2025-02-13 |website=Proven Winners}}</ref> Agrivoltaics not only optimizes land use and reduces costs by enabling dual revenue streams from both energy production and agriculture, but it can also help moderate temperatures beneath the panels, potentially reducing water loss and improving microclimates for crop growth. However, careful design and crop selection are crucial, as the shading effect may limit the types of plants that can thrive, necessitating the use of shade-tolerant species and innovative management practices.<ref>{{Cite web |title=Agrivoltaics: Producing Solar Energy While Protecting Farmland |url=https://cbey.yale.edu/research/agrivoltaics-producing-solar-energy-while-protecting-farmland |access-date=2025-03-30 |website=Yale Center for Business and the Environment |language=en}}</ref>

=== Wind power ===
{{Main|Wind power|Wind power by country}}

[[File:Wind energy generation by region, OWID.svg|thumb|300px|Wind energy generation by region over time<ref>{{cite web |title=Wind energy generation by region |url=https://ourworldindata.org/grapher/wind-energy-consumption-by-region |website=Our World in Data |access-date=15 August 2023 |archive-date=10 March 2020 |archive-url=https://web.archive.org/web/20200310222609/https://ourworldindata.org/grapher/wind-energy-consumption-by-region |url-status=live}}</ref>]]
[[File:Pretty flamingos - geograph.org.uk - 578705.jpg|thumb|[[Burbo Bank Offshore Wind Farm|Burbo]], [[North West England|NW-England]]]]
[[File:Fentonwindpark1.jpg|thumb|Sunrise at the [[Fenton Wind Farm]] in Minnesota, United States]]
{| class="wikitable"
! Installed capacity and other key design parameters
! Value and year
|-
| Global electricity power generation capacity || 1017.2 GW (2023){{sfn|IRENA|2024|p=14}}
|-
| Global electricity power generation capacity annual growth rate || 13% (2014-2023)<ref>{{harvnb|IRENA|2024|p=14}}. Note: Compound annual growth rate 2014-2023.</ref>
|-
| Share of global electricity generation || 7.8% (2023)<ref name="Ember 2024" />
|-
| Levelized cost per megawatt hour || Land-based wind: USD 30.165 (2019){{sfn|NREL ATB|2021|loc=Land-Based Wind}}
|-
| Primary technology || [[Wind turbine]], [[windmill]]
|-
| Main applications || Electricity, pumping water ([[windpump]])
|}Humans have harnessed wind energy since at least 3500 BC. Until the 20th century, it was primarily used to power ships, windmills and water pumps. Today, the vast majority of wind power is used to generate electricity using wind turbines.<ref name=":2" /> Modern utility-scale wind turbines range from around 600&nbsp;kW to 9 MW of rated power. The power available from the wind is a function of the cube of the wind speed, so as wind speed increases, power output increases up to the maximum output for the particular turbine.<ref name="EWEA">{{cite web | title = Analysis of Wind Energy in the EU-25 | publisher = European Wind Energy Association | url = http://www.ewea.org/fileadmin/ewea_documents/documents/publications/WETF/Facts_Summary.pdf | access-date = 11 March 2007 | archive-date = 12 March 2007 | archive-url = https://web.archive.org/web/20070312221118/http://www.ewea.org/fileadmin/ewea_documents/documents/publications/WETF/Facts_Summary.pdf | url-status = live }}</ref> Areas where winds are stronger and more constant, such as [[Offshore wind power|offshore]] and high-altitude sites, are preferred locations for wind farms.

Wind-generated electricity met nearly 4% of global electricity demand in 2015, with nearly 63&nbsp;GW of new wind power capacity installed. Wind energy was the leading source of new capacity in Europe, the US and Canada, and the second largest in China. In Denmark, wind energy met more than 40% of its electricity demand while Ireland, Portugal and [[Renewable energy in Spain|Spain]] each met nearly 20%.<ref>{{Cite web|title=Electricity – from other renewable sources - The World Factbook|url=https://www.cia.gov/the-world-factbook/field/electricity-from-other-renewable-sources|access-date=2021-10-27|website=www.cia.gov|archive-date=27 October 2021|archive-url=https://web.archive.org/web/20211027205510/https://www.cia.gov/the-world-factbook/field/electricity-from-other-renewable-sources|url-status=live}}</ref>

Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand, assuming all practical barriers needed were overcome. This would require wind turbines to be installed over large areas, particularly in areas of higher wind resources, such as offshore, and likely also industrial use of new types of VAWT turbines in addition to the horizontal axis units currently in use. As offshore wind speeds average ~90% greater than that of land, offshore resources can contribute substantially more energy than land-stationed turbines.<ref>"Offshore stations experience mean wind speeds at 80 m that are 90% greater than over land on average." [http://www.stanford.edu/group/efmh/winds/global_winds.html Evaluation of global wind power] {{Webarchive|url=https://web.archive.org/web/20080525114202/http://www.stanford.edu/group/efmh/winds/global_winds.html |date=25 May 2008 }} "Overall, the researchers calculated winds at 80 meters [300 feet] above [[sea level]] traveled over the ocean at approximately 8.6 meters per second and at nearly 4.5 meters per second over land [20 and 10 miles per hour, respectively]." [http://www.ens-newswire.com/ens/may2005/2005-05-17-09.asp#anchor6 Global Wind Map Shows Best Wind Farm Locations] {{Webarchive|url=https://web.archive.org/web/20050524075533/http://ens-newswire.com/ens/may2005/2005-05-17-09.asp#anchor6 |date=24 May 2005 }}. Retrieved 30 January 2006.</ref>

Investments in wind technologies reached USD 161 billion in 2020, with onshore wind dominating at 80% of total investments from 2013 to 2022. Offshore wind investments nearly doubled to USD 41 billion between 2019 and 2020, primarily due to policy incentives in China and expansion in Europe. Global wind capacity increased by 557 GW between 2013 and 2021, with capacity additions increasing by an average of 19% each year.<ref name=":1" />

=== Hydropower ===
{{Main|Hydroelectricity|Hydropower|}}

[[File:ThreeGorgesDam-China2009.jpg|thumb|The [[Three Gorges Dam]] for [[hydropower]] on the [[Yangtze River]] in China]]
[[File:Three gorges dam from space.jpg|thumb|[[Three Gorges Dam]] and [[Gezhouba Dam]], China]]
{| class="wikitable"
! Installed capacity and other key design parameters
! Value and year
|-
| Global electricity power generation capacity || 1,267.9 GW (2023)<ref>{{harvnb|IRENA|2024|p=9}}. Note: Excludes pure pumped storage.</ref>
|-
| Global electricity power generation capacity annual growth rate || 1.9% (2014-2023)<ref>{{harvnb|IRENA|2024|p=9}}. Note: Excludes pure pumped storage. Compound annual growth rate 2014-2023.</ref>
|-
| Share of global electricity generation || 14.3% (2023)<ref name="Ember 2024">{{cite web |date=8 May 2024 |title=Global Electricity Review 2024 |url=https://ember-energy.org/latest-insights/global-electricity-review-2024/ |access-date=8 May 2024 |publisher=[[Ember (non-profit organisation)|Ember]]}}</ref>
|-
| Levelized cost per megawatt hour || USD 65.581 (2019){{sfn|NREL ATB|2021|loc=Hydropower}}
|-
| Primary technology || [[Hydroelectricity#Generating methods|Dam]]
|-
| Main applications || Electricity, [[Pumped-storage hydroelectricity|pumped storage]], [[Hydropower#Mechanical power|mechanical power]]
|}

Since water is about 800 times [[Density of air|denser than air]], even a slow flowing stream of water, or moderate sea [[Swell (ocean)|swell]], can yield considerable amounts of energy. Water can generate electricity with a [[Energy conversion efficiency|conversion efficiency]] of about 90%, which is the highest rate in renewable energy.<ref name="Ang">{{cite journal |last1=Ang |first1=Tze-Zhang |last2=Salem |first2=Mohamed |last3=Kamarol |first3=Mohamad |last4=Das |first4=Himadry Shekhar |last5=Nazari |first5=Mohammad Alhuyi |last6=Prabaharan |first6=Natarajan |title=A comprehensive study of renewable energy sources: Classifications, challenges and suggestions |journal=Energy Strategy Reviews |date=2022 |volume=43 |article-number=100939 |doi=10.1016/j.esr.2022.100939 |s2cid=251889236 |language=en |issn=2211-467X |doi-access=free|bibcode=2022EneSR..4300939A }}</ref> There are many forms of water energy:
* Historically, hydroelectric power came from constructing large hydroelectric dams and reservoirs, which are still popular in [[Developing country|developing countries]].<ref>{{Cite journal|last1=Moran |first1=Emilio F. |last2=Lopez|first2=Maria Claudia|last3=Moore|first3=Nathan|last4=Müller|first4=Norbert |last5=Hyndman|first5=David W.|date=2018|title=Sustainable hydropower in the 21st century |journal=Proceedings of the National Academy of Sciences|volume=115|issue=47|pages=11891–11898 |doi=10.1073/pnas.1809426115|pmid=30397145|issn=0027-8424|pmc=6255148|bibcode=2018PNAS..11511891M |doi-access=free}}</ref> The [[List of largest hydroelectric power stations|largest]] of them are the [[Three Gorges Dam]] (2003) in [[China]] and the [[Itaipu Dam]] (1984) built by Brazil and Paraguay.
* [[Small hydro]] systems are hydroelectric power installations that typically produce up to {{nowrap|50 MW}} of power. They are often used on small rivers or as a low-impact development on larger rivers. China is the largest producer of hydroelectricity in the world and has more than 45,000 small hydro installations.<ref>{{cite web |url=https://www.irena.org/DocumentDownloads/Publications/RE_Technologies_Cost_Analysis-HYDROPOWER.pdf |title=DocHdl2OnPN-PRINTRDY-01tmpTarget |access-date=26 March 2019 |archive-date=9 November 2018 |archive-url=https://web.archive.org/web/20181109085415/https://www.irena.org/documentdownloads/publications/re_technologies_cost_analysis-hydropower.pdf }}</ref>
* [[Run-of-the-river hydroelectricity]] plants derive energy from rivers without the creation of a large [[reservoir]]. The water is typically conveyed along the side of the river valley (using channels, pipes or tunnels) until it is high above the valley floor, whereupon it can be allowed to fall through a penstock to drive a turbine. A run-of-river plant may still produce a large amount of electricity, such as the [[Chief Joseph Dam]] on the Columbia River in the United States.<ref>{{cite web|title=Run-of-the-river hydroelectricity|url=https://energyeducation.ca/encyclopedia/Run-of-the-river_hydroelectricity |last=Afework|first=Bethel|date=3 September 2018|work=Energy Education|access-date=27 April 2019|archive-url=https://web.archive.org/web/20190427184803/https://energyeducation.ca/encyclopedia/Run-of-the-river_hydroelectricity|archive-date=27 April 2019|url-status=live}}</ref> However many run-of-the-river hydro power plants are [[micro hydro]] or [[pico hydro]] plants.

Much hydropower is flexible, thus complementing wind and solar, as it not intermittent.<ref>{{Cite web |title=Net zero: International Hydropower Association |url=https://www.hydropower.org/net-zero |access-date=2022-06-24 |website=www.hydropower.org |language=en}}</ref> In 2021, the world renewable hydropower capacity was 1,360 GW.<ref name="IEA-3" /> Only a third of the world's estimated hydroelectric potential of 14,000 TWh/year has been developed.<ref name="iha2021">{{cite web |date=11 June 2021 |title=Hydropower Status Report |url=https://www.hydropower.org/status-report |archive-url=https://web.archive.org/web/20230403212029/https://www.hydropower.org/status-report |archive-date=3 April 2023 |access-date=30 May 2022 |website=International Hydropower Association}}</ref><ref name="etp2006">{{cite book |url=https://www.iea.org/reports/energy-technology-perspectives-2006 |title=Energy Technology Perspectives: Scenarios and Strategies to 2050 |date=2006 |publisher=International Energy Agency |isbn=92-64-10982-X |location=Paris |page=124 |access-date=30 May 2022}}</ref> New hydropower projects face opposition from local communities due to their large impact, including relocation of communities and flooding of wildlife habitats and farming land.<ref>{{Cite web |title=Environmental Impacts of Hydroelectric Power {{!}} Union of Concerned Scientists |url=https://www.ucsusa.org/resources/environmental-impacts-hydroelectric-power |url-status=live |archive-url=https://web.archive.org/web/20210715234227/https://www.ucsusa.org/resources/environmental-impacts-hydroelectric-power |archive-date=15 July 2021 |access-date=9 July 2021 |website=www.ucsusa.org}}</ref> High cost and lead times from permission process, including environmental and risk assessments, with lack of environmental and social acceptance are therefore the primary challenges for new developments.<ref>{{Cite web |title=Hydropower Special Market Report |url=https://iea.blob.core.windows.net/assets/4d2d4365-08c6-4171-9ea2-8549fabd1c8d/HydropowerSpecialMarketReport_corr.pdf |url-status=live |archive-url=https://web.archive.org/web/20210707021807/https://iea.blob.core.windows.net/assets/4d2d4365-08c6-4171-9ea2-8549fabd1c8d/HydropowerSpecialMarketReport_corr.pdf |archive-date=7 July 2021 |access-date=9 July 2021 |website=IEA |pages=34–36}}</ref> It is popular to repower old dams thereby increasing their efficiency and capacity as well as quicker responsiveness on the grid.<ref>{{cite web |author1=L. Lia |author2=T. Jensen |author3=K.E. Stensbyand |author4=G. Holm |author5=A.M. Ruud |title=The current status of hydropower development and dam construction in Norway |url=https://www.ntnu.no/documents/381182060/641036380/Leif+Lia_FINAL.PDF/32bac8f3-b443-493b-a1eb-e22ce572acd9 |url-status=live |archive-url=https://web.archive.org/web/20170525165854/https://www.ntnu.no/documents/381182060/641036380/Leif+Lia_FINAL.PDF/32bac8f3-b443-493b-a1eb-e22ce572acd9 |archive-date=25 May 2017 |access-date=26 March 2019 |website=Ntnu.no |format=PDF}}</ref> Where circumstances permit existing dams such as the [[Richard B. Russell Dam|Russell Dam]] built in 1985 may be updated with "pump back" facilities for [[pumped-storage hydroelectricity|pumped-storage]] which is useful for peak loads or to support intermittent wind and solar power. Because [[Dispatchable generation|dispatchable power]] is more valuable than VRE<ref>{{Cite web |date=2021-04-19 |title=How Norway became Europe's biggest power exporter |url=https://www.power-technology.com/analysis/how-norway-became-europes-biggest-power-exporter/ |archive-url=https://web.archive.org/web/20220627153206/https://www.power-technology.com/analysis/how-norway-became-europes-biggest-power-exporter/ |archive-date=27 June 2022 |access-date=2022-06-27 |website=Power Technology |language=en-US}}</ref><ref>{{Cite web |date=17 January 2022 |title=Trade surplus soars on energy exports {{!}} Norway's News in English — www.newsinenglish.no |url=https://www.newsinenglish.no/2022/01/17/trade-surplus-soars-on-energy-exports/ |access-date=2022-06-27 |language=en-US}}</ref> countries with large hydroelectric developments such as Canada and Norway are spending billions to expand their grids to trade with neighboring countries having limited hydro.<ref>{{cite web |title=New Transmission Line Reaches Milestone |url=http://www.vpr.net/news_detail/88975/new-transmission-line-reaches-milestone/ |url-status=live |archive-url=https://web.archive.org/web/20170203164110/http://www.vpr.net/news_detail/88975/new-transmission-line-reaches-milestone/ |archive-date=3 February 2017 |access-date=3 February 2017 |website=Vpr.net}}</ref>

=== Bioenergy ===
{{Main|Bioenergy}}

{{Further|Biomass (energy)#Environmental impacts}}
{| class="wikitable"
! Installed capacity and other key design parameters
! Value and year
|-
| Global electricity generation capacity || 150.3 GW (2023){{sfn|IRENA|2024|p=30}}
|-
| Global electricity generation capacity annual growth rate || 5.8% (2014-2023)<ref>{{harvnb|IRENA|2024|p=30}}. Note: Compound annual growth rate 2014-2023.</ref>
|-
| Share of global electricity generation || 2.4% (2022)<ref name="Ember 2024" />
|-
| Levelized cost per megawatt hour || USD 118.908 (2019){{sfn|NREL ATB|2021|loc=Other Technologies (EIA)}}
|-
| Primary technologies || [[Biomass (energy)|Biomass]], [[biofuel]]
|-
| Main applications || Electricity, heating, cooking, transportation fuels
|}

[[Biomass (energy)|Biomass]] is biological material derived from living, or recently living organisms. Most commonly, it refers to plants or plant-derived materials. As an energy source, biomass can either be used directly via [[combustion]] to produce heat, or converted to a more energy-dense [[biofuel]] like ethanol. Wood is the most significant biomass energy source as of 2012<ref name="Scheck2012">{{cite news |last1=Scheck |first1=Justin |last2=Dugan |first2=Ianthe Jeanne |title=Wood-Fired Plants Generate Violations |date=23 July 2012 |work=[[The Wall Street Journal]] |url=https://www.wsj.com/articles/SB10001424052702303740704577524822063133842 |access-date=18 July 2021 |url-status=live |archive-date=25 July 2021 |archive-url=https://web.archive.org/web/20210725004649/https://www.wsj.com/articles/SB10001424052702303740704577524822063133842}}</ref> and is usually sourced from a trees cleared for [[Silviculture|silvicultural]] reasons or [[fire prevention]]. Municipal wood waste – for instance, construction materials or sawdust – is also often burned for energy.<ref>{{Cite web |title=FAQs • What is woody biomass, and where does it come from? |url=https://www.placer.ca.gov/Faq.aspx?QID=1059 |access-date=2024-05-05 |website=[[Placer County|Placer County Government]]}}</ref> The biggest per-capita producers of wood-based bioenergy are heavily forested countries like Finland, Sweden, Estonia, Austria, and Denmark.<ref>{{Cite book |last=Pelkmans |first=Luc |url=https://www.ieabioenergy.com/wp-content/uploads/2021/11/CountriesReport2021_final.pdf |title=IEA Bioenergy Countries' Report: Implementation of bioenergy in the IEA Bioenergy member countries |date=November 2021 |publisher=International Energy Agency |isbn=978-1-910154-93-9 |page=10 |language=en}}</ref>

Bioenergy can be environmentally destructive if old-growth forests are cleared to make way for crop production. In particular, demand for palm oil to produce biodiesel has contributed to the deforestation of tropical rainforests in Brazil and Indonesia.<ref name=":10" /> In addition, burning biomass still produces carbon emissions, although much less than fossil fuels (39 grams of CO<sub>2</sub> per megajoule of energy, compared to 75 g/MJ for fossil fuels).<ref>{{Cite magazine |last=UK |first=Maria Mellor, WIRED |title=Biofuels are meant to clean up flying's carbon crisis. They won't |url=https://www.wired.com/story/biofuels-aviation-carbon-emissions/ |access-date=2024-05-05 |magazine=Wired |language=en-US |issn=1059-1028}}</ref>

Some [[biomass (energy)|biomass]] sources are unsustainable at current rates of exploitation (as of 2017).<ref name="CarbonBrief1">{{cite web |last=Timperly |first=Jocelyn |date=23 February 2017 |title=Biomass subsidies 'not fit for purpose', says Chatham House |url=https://www.carbonbrief.org/biomass-subsidies-not-fit-for-purpose-chatham-house |url-status=live |archive-url=https://web.archive.org/web/20201106210822/https://www.carbonbrief.org/biomass-subsidies-not-fit-for-purpose-chatham-house |archive-date=6 November 2020 |access-date=31 October 2020 |publisher=Carbon Brief Ltd © 2020 - Company No. 07222041}}</ref>[[File:Metz biomass power station.jpg|thumb|A [[Cogeneration|CHP power station]] using wood to supply 30,000 households in France]]

==== Biofuel ====
{{Main|Biofuel}}

{{See also|Ethanol fuel|Sustainable biofuel|Issues relating to biofuels}}
[[Biofuel]]s are primarily used in transportation, providing 3.5% of the world's transport energy demand in 2022,<ref>{{Cite web |title=Biofuels |url=https://www.iea.org/energy-system/low-emission-fuels/biofuels |access-date=2024-05-05 |website=International Energy Agency |language=en}}</ref> up from 2.7% in 2010.{{sfn|REN21 Renewables Global Status Report|2011|pp=13-14}} [[Biojet]] is expected to be important for short-term reduction of carbon dioxide emissions from long-haul flights.<ref>{{Cite web |title=Japan to create bio jet fuel supply chain in clean energy push |url=https://asia.nikkei.com/Business/Transportation/Japan-to-create-bio-jet-fuel-supply-chain-in-clean-energy-push |access-date=2022-04-26 |website=Nikkei Asia |language=en-GB}}</ref>

Aside from wood, the major sources of bioenergy are [[Ethanol fuel|bioethanol]] and [[biodiesel]].<ref name=":2" /> Bioethanol is usually produced by fermenting the sugar components of crops like [[sugarcane]] and [[maize]], while biodiesel is mostly made from oils extracted from plants, such as [[soybean oil]] and [[corn oil]].<ref name=":9">{{Cite web |last=Martin |first=Jeremy |date=2016-06-22 |title=Everything You Ever Wanted to Know About Biodiesel (Charts and Graphs Included!) |url=https://blog.ucsusa.org/jeremy-martin/all-about-biodiesel/ |access-date=2024-05-05 |website=The Equation |language=en-US}}</ref> Most of the crops used to produce bioethanol and biodiesel are grown specifically for this purpose,<ref>{{cite web|title=Energy crops|url=http://www.biomassenergycentre.org.uk/portal/page?_pageid=75,17301&_dad=portal&_schema=PORTAL|work=crops are grown specifically for use as fuel|publisher=BIOMASS Energy Centre|access-date=6 April 2013|archive-url=https://web.archive.org/web/20130310063405/http://www.biomassenergycentre.org.uk/portal/page?_pageid=75,17301&_dad=portal&_schema=PORTAL|archive-date=10 March 2013}}</ref> although used [[cooking oil]] accounted for 14% of the oil used to produce biodiesel as of 2015.<ref name=":9" /> The biomass used to produce biofuels varies by region. Maize is the major feedstock in the United States, while sugarcane dominates in Brazil.<ref>{{Cite journal |last1=Liu |first1=Xinyu |last2=Kwon |first2=Hoyoung |last3=Wang |first3=Michael |last4=O'Connor |first4=Don |date=2023-08-15 |title=Life Cycle Greenhouse Gas Emissions of Brazilian Sugar Cane Ethanol Evaluated with the GREET Model Using Data Submitted to RenovaBio |journal=Environmental Science & Technology |language=en |volume=57 |issue=32 |pages=11814–11822 |doi=10.1021/acs.est.2c08488 |pmid=37527415 |bibcode=2023EnST...5711814L |issn=0013-936X|pmc=10433513 }}</ref> In the European Union, where biodiesel is more common than bioethanol, [[rapeseed oil]] and [[palm oil]] are the main feedstocks.<ref>{{Cite web |date=2022 |title=Biofuels |url=https://www.oecd-ilibrary.org/sites/cdc97c88-en/index.html?itemId=/content/component/cdc97c88-en |access-date=2024-05-05 |website=OECD Library |language=en}}</ref> China, although it produces comparatively much less biofuel, uses mostly corn and wheat.<ref>{{Cite journal |last1=Qin |first1=Zhangcai |last2=Zhuang |first2=Qianlai |last3=Cai |first3=Ximing |last4=He |first4=Yujie |last5=Huang |first5=Yao |last6=Jiang |first6=Dong |last7=Lin |first7=Erda |last8=Liu |first8=Yaling |last9=Tang |first9=Ya |last10=Wang |first10=Michael Q. |date=February 2018 |title=Biomass and biofuels in China: Toward bioenergy resource potentials and their impacts on the environment |url=https://linkinghub.elsevier.com/retrieve/pii/S1364032117312170 |journal=Renewable and Sustainable Energy Reviews |language=en |volume=82 |pages=2387–2400 |doi=10.1016/j.rser.2017.08.073|bibcode=2018RSERv..82.2387Q }}</ref> In many countries, biofuels are either subsidized or mandated to be [[Common ethanol fuel mixtures|included in fuel mixtures]].<ref name=":10">{{Cite web |last=Loyola |first=Mario |date=2019-11-23 |title=Stop the Ethanol Madness |url=https://www.theatlantic.com/ideas/archive/2019/11/ethanol-has-forsaken-us/602191/ |access-date=2024-05-05 |website=The Atlantic |language=en}}</ref>
[[File:Faz S Sofia canavial 090607 REFON.JPG|thumb|[[Sustainable biofuel#Sugarcane in Brazil|Sugarcane plantation]] to produce [[Ethanol fuel|ethanol]] in Brazil]]
There are many other sources of bioenergy that are more niche, or not yet viable at large scales. For instance, bioethanol could be [[Cellulosic ethanol|produced from the cellulosic parts]] of crops, rather than only the seed as is common today.<ref>{{Cite journal |last=Kramer |first=David |date=2022-07-01 |title=Whatever happened to cellulosic ethanol? |url=https://pubs.aip.org/physicstoday/article/75/7/22/2848574/Whatever-happened-to-cellulosic-ethanol |journal=Physics Today |language=en |volume=75 |issue=7 |pages=22–24 |doi=10.1063/PT.3.5036 |bibcode=2022PhT....75g..22K |issn=0031-9228|url-access=subscription }}</ref> [[Sweet sorghum]] may be a promising alternative source of bioethanol, due to its tolerance of a wide range of climates.<ref>{{Cite journal |last1=Ahmad Dar |first1=Rouf |last2=Ahmad Dar |first2=Eajaz |last3=Kaur |first3=Ajit |last4=Gupta Phutela |first4=Urmila |date=2018-02-01 |title=Sweet sorghum-a promising alternative feedstock for biofuel production |url=https://www.sciencedirect.com/science/article/pii/S1364032117314430 |journal=Renewable and Sustainable Energy Reviews |volume=82 |pages=4070–4090 |doi=10.1016/j.rser.2017.10.066 |bibcode=2018RSERv..82.4070A |issn=1364-0321|url-access=subscription }}</ref> [[Cow dung]] can be converted into methane.<ref>{{cite web |last1=Howard |first1=Brian |date=28 January 2020 |title=Turning cow waste into clean power on a national scale |url=https://thehill.com/changing-america/sustainability/energy/480316-turning-cow-waste-into-clean-power-on-a-national-scale |url-status=live |archive-url=https://web.archive.org/web/20200129180933/https://thehill.com/changing-america/sustainability/energy/480316-turning-cow-waste-into-clean-power-on-a-national-scale |archive-date=29 January 2020 |access-date=30 January 2020 |website=[[The Hill (newspaper)|The Hill]]}}</ref> There is also a great deal of research involving [[algal fuel]], which is attractive because algae is a non-food resource, grows around 20 times faster than most food crops, and can be grown almost anywhere.<ref name="ZhuLiHiltunen2018">{{cite journal | last1 = Zhu | first1 = Liandong | last2 = Li | first2 = Zhaohua | last3 = Hiltunen | first3 = Erkki | title = Microalgae Chlorella vulgaris biomass harvesting by natural flocculant: effects on biomass sedimentation, spent medium recycling and lipid extraction | journal = Biotechnology for Biofuels | date = 28 June 2018 | volume = 11 | issue = 1 | page = 183 | eissn = 1754-6834 | doi = 10.1186/s13068-018-1183-z | pmid = 29988300 | pmc = 6022341 | doi-access = free | bibcode = 2018BB.....11..183Z }}</ref>[[File:Soybeanbus.jpg|thumb|A bus fueled by [[biodiesel]]]]

=== Geothermal energy ===
{{Main|Geothermal energy|Geothermal power|Renewable thermal energy|Geothermal energy in the United States}}

[[File:NesjavellirPowerPlant edit2.jpg|thumb|Steam rising from the [[Nesjavellir Geothermal Power Station]] in Iceland]]
[[File:West Ford Flat Geothermal Cooling Tower.JPG|thumb|Geothermal plant at [[The Geysers]], California, US]]
[[File:Krafla geothermal power station wiki.jpg|thumb|[[Krafla Power Station|Krafla]], a [[geothermal power station]] in Iceland]]
{| class="wikitable"
! Installed capacity and other key design parameters
! Value and year
|-
| Global electricity power generation capacity || 14.9 GW (2023){{sfn|IRENA|2024|p=43}}
|-
| Global electricity power generation capacity annual growth rate || 3.4% (2014-2023)<ref>{{harvnb|IRENA|2024|p=43}}. Note: Compound annual growth rate 2014-2023.</ref>
|-
| Share of global electricity generation || <1% (2018)<ref name="IEA Electricity 2020">{{cite web |publisher=[[International Energy Agency]] |title=Electricity |date=2020 |at=Data Browser section, Electricity Generation by Source indicator |url=https://www.iea.org/fuels-and-technologies/electricity |access-date=17 July 2021 |archive-date=7 June 2021 |archive-url=https://web.archive.org/web/20210607024650/https://www.iea.org/fuels-and-technologies/electricity |url-status=live }}</ref>
|-
| Levelized cost per megawatt hour || USD 58.257 (2019){{sfn|NREL ATB|2021|loc=Geothermal}}
|-
| Primary technologies || Dry steam, flash steam, and binary cycle power stations
|-
| Main applications || Electricity, [[Geothermal heating|heating]]
|}

Geothermal energy is [[thermal energy]] (heat) extracted from the [[Earth's crust]]. It originates from several different [[Earth's internal heat budget#Sources of heat|sources]], of which the most significant is slow [[radioactive decay]] of minerals contained in the [[Internal structure of Earth|Earth's interior]],<ref name=":2" /> as well as some leftover heat from the [[Earth#Formation|formation of the Earth]].<ref name=":11">{{Citation |last=Clauser |first=Christoph |title=Earth's Heat and Temperature Field |date=2024 |work=Introduction to Geophysics |series=Springer Textbooks in Earth Sciences, Geography and Environment |pages=247–325 |url=https://link.springer.com/10.1007/978-3-031-17867-2_6 |access-date=2024-05-06 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-031-17867-2_6 |isbn=978-3-031-17866-5|url-access=subscription }}</ref> Some of the heat is generated near the Earth's surface in the crust, but some also flows from deep within the Earth from the [[Earth's mantle|mantle]] and [[Internal structure of Earth#Core|core]].<ref name=":11" /> Geothermal energy extraction is viable mostly in countries located on [[Plate tectonics|tectonic plate]] edges, where the Earth's hot mantle is more exposed.<ref name=":13">{{Citation |last1=Dincer |first1=Ibrahim |title=3.6 Geothermal Energy Production |date=2018 |work=Comprehensive Energy Systems |pages=252–303 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780128095973003138 |access-date=2024-05-07 |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-809597-3.00313-8 |isbn=978-0-12-814925-6 |last2=Ezzat |first2=Muhammad F.|url-access=subscription }}</ref> As of 2023, the United States has by far the most geothermal capacity (2.7 GW,<ref name=":12">{{Cite web |last1=Ritchie |first1=Hannah |last2=Rosado |first2=Pablo |last3=Roser |first3=Max |date=2023 |title=Data Page: Geothermal energy capacity |url=https://ourworldindata.org/grapher/installed-geothermal-capacity |access-date=2024-05-07 |website=Our World in Data}}</ref> or less than 0.2% of the country's total energy capacity<ref>{{Cite web |title=Electricity generation, capacity, and sales in the United States |url=https://www.eia.gov/energyexplained/electricity/electricity-in-the-us-generation-capacity-and-sales.php |access-date=2024-05-07 |website=[[U.S. Energy Information Administration]]}}</ref>), followed by Indonesia and the Philippines. Global capacity in 2022 was 15 GW.<ref name=":12" />

Geothermal energy can be either used directly to heat homes, as is common in Iceland where almost all of its energy is renewable, or to generate electricity. Iceland is a global leader in renewable energy, relying almost entirely on its abundant geothermal and hydroelectric resources derived from volcanic activity and glaciers.<ref>{{cite web |last1=Toussaint-Strauss |first1=Josh |last2=Talbot |first2=Jem |last3=Morresi |first3=Elena |last4=Assaf |first4=Ali |last5=Ambrose |first5=Jillian |last6=Baxter |first6=Ryan |last7=Glew |first7=Steve |title=Why unlimited green energy is closer than people think – video |url=https://www.theguardian.com/world/video/2025/may/01/why-unlimited-green-energy-is-closer-than-people-think-video |date=2025-05-01 |website=The Guardian |access-date=2025-05-01 |language=en}}</ref> At smaller scales, geothermal power can be generated with [[Ground source heat pump|geothermal heat pumps]], which can extract heat from ground temperatures of under {{Convert|30|C|F}}, allowing them to be used at relatively shallow depths of a few meters.<ref name=":13" /> Electricity generation requires large plants and ground temperatures of at least {{Convert|150|C|F}}. In some countries, electricity produced from geothermal energy accounts for a large portion of the total, such as Kenya (43%) and Indonesia (5%).<ref>{{Cite web |date=November 22, 2023 |title=Use of geothermal energy |url=https://www.eia.gov/energyexplained/geothermal/use-of-geothermal-energy.php |access-date=2024-05-07 |website=[[U.S. Energy Information Administration]]}}</ref>

Technical advances may eventually make geothermal power more widely available. For example, [[enhanced geothermal system]]s involve drilling around {{Convert|10|km|mi}} into the Earth, breaking apart hot rocks and extracting the heat using water. In theory, this type of geothermal energy extraction could be done anywhere on Earth.<ref name=":13" />

== Emerging technologies ==
There are also other renewable energy technologies that are still under development, including [[enhanced geothermal system]]s, [[concentrated solar power]], [[cellulosic ethanol]], [[piezoelectricity]], and [[marine energy]].<ref name=":7">{{cite journal |last1=Hussain |first1=Akhtar |last2=Arif |first2=Syed Muhammad |last3=Aslam |first3=Muhammad |title=Emerging renewable and sustainable energy technologies: State of the art |journal=[[Renewable and Sustainable Energy Reviews]] |date=2017 |volume=71 |pages=12–28 |doi=10.1016/j.rser.2016.12.033|bibcode=2017RSERv..71...12H }}</ref><ref name="IEA">International Energy Agency (2007).
[http://www.iea.org/textbase/papers/2006/renewable_factsheet.pdf ''Renewables in global energy supply: An IEA facts sheet''] (PDF), OECD, p. 3. {{webarchive|url=https://web.archive.org/web/20091012052513/http://www.iea.org/textbase/papers/2006/renewable_factsheet.pdf|date=12 October 2009}}</ref> These technologies are not yet widely demonstrated or have limited commercialization. Some may have potential comparable to other renewable energy technologies, but still depend on further breakthroughs from research, development and engineering.<ref name="IEA" />

===Enhanced geothermal systems===
{{main|Enhanced geothermal systems}}

Enhanced geothermal systems (EGS) are a new type of geothermal power which does not require natural hot water reservoirs or steam to generate power. Most of the underground heat within drilling reach is trapped in solid rocks, not in water.<ref name="Duchane">{{Cite news|last1=Duchane|first1=Dave|last2=Brown|first2=Don|date=December 2002|title=Hot Dry Rock (HDR) Geothermal Energy Research and Development at Fenton Hill, New Mexico|volume=23|pages=13–19|periodical=Geo-Heat Centre Quarterly Bulletin|publisher=Oregon Institute of Technology|issue=4|location=Klamath Falls, Oregon|url=http://geoheat.oit.edu/bulletin/bull23-4/art4.pdf|access-date=5 May 2009|issn=0276-1084|archive-date=17 June 2010|archive-url=https://web.archive.org/web/20100617192841/http://geoheat.oit.edu/bulletin/bull23-4/art4.pdf|url-status=live}}</ref> EGS technologies use [[hydraulic fracturing]] to break apart these rocks and release the heat they contain, which is then harvested by pumping water into the ground. The process is sometimes known as "hot dry rock" (HDR).<ref>{{Citation |last1=Stober |first1=Ingrid |title=Enhanced-Geothermal-Systems (EGS), Hot-Dry-Rock Systems (HDR), Deep-Heat-Mining (DHM) |date=2021 |work=Geothermal Energy |pages=205–225 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-71685-1_9 |isbn=978-3-030-71684-4 |last2=Bucher |first2=Kurt|doi-access=free }}</ref> Unlike conventional geothermal energy extraction, EGS may be feasible anywhere in the world, depending on the cost of drilling.<ref>{{cite web|title=Australia's Renewable Energy Future inc Cooper Basin & geothermal map of Australia Retrieved 15 August 2015|url=https://www.science.org.au/sites/default/files/user-content/ausrenewableenergyfuture.pdf|archive-url=https://web.archive.org/web/20150327104740/https://www.science.org.au/sites/default/files/user-content/ausrenewableenergyfuture.pdf|archive-date=27 March 2015}}</ref> EGS projects have so far primarily been limited to [[demonstration plant]]s, as the technology is capital-intensive due to the high cost of drilling.<ref>{{Citation |last=Archer |first=Rosalind|author-link=Rosalind Archer |title=Geothermal Energy |date=2020 |work=Future Energy |pages=431–445 |publisher=Elsevier |language=en |doi=10.1016/b978-0-08-102886-5.00020-7 |isbn=978-0-08-102886-5|doi-access=free }}</ref>

=== Sand battery ===
Sand batteries are large tanks filled with soapstone that absorb heat. Excess heat energy from renewable energy is piped into the tank and then energy is discharged as boiling water, steam, or heated air. Finland is using this technology in [[Pornainen]] as Polar Night Energy built a 1MW sand battery that can store up to 100 MWh that went online in 2025.<ref>{{Cite web |date=2025-06-18 |title=The World's Largest Sand Battery Was Just Switched On In Finland |url=https://www.iflscience.com/the-worlds-largest-sand-battery-was-just-switched-on-in-finland-79667 |access-date=2025-06-24 |website=IFLScience |language=en}}</ref><ref>{{Cite web |last=Jose |first=Jacob |date=2023-05-15 |title=The Science Behind Sand Batteries: How They Store and Deliver Energy - NatNavi |url=https://natnavi.com/science-behind-sand-batteries/ |access-date=2025-09-28 |website=natnavi.com |language=en-US}}</ref>

=== Piezoelectricity ===
[[Piezoelectricity]] is the conversion of existing [[Stress (mechanics)|mechanical stress]] or vibration ([[classical mechanics]]) into an electrical charge without consuming or depleting a fuel source.<ref>{{Cite journal |last1=Singh |first1=P. K. |last2=Kaur |first2=G. A. |last3=Shandilya |first3=M. |last4=Rana |first4=P. |last5=Rai |first5=R. |last6=Mishra |first6=Y. K. |last7=Syväjärvi |first7=M. |last8=Tiwari |first8=A. |date=2023-12-01 |title=Trends in piezoelectric nanomaterials towards green energy scavenging nanodevices |url=https://www.sciencedirect.com/science/article/pii/S2589234723002701 |journal=Materials Today Sustainability |volume=24 |article-number=100583 |doi=10.1016/j.mtsust.2023.100583 |bibcode=2023MTSus..2400583S |issn=2589-2347}}</ref><ref>{{Cite journal |last1=Brusa |first1=Eugenio |last2=Carrera |first2=Anna |last3=Delprete |first3=Cristiana |date=2023-12-08 |title=A Review of Piezoelectric Energy Harvesting: Materials, Design, and Readout Circuits |journal=Actuators |language=en |volume=12 |issue=12 |page=457 |doi=10.3390/act12120457 |doi-access=free |issn=2076-0825}}</ref> [[Piezotronics]] enables the interaction of piezoelectric and semiconducting behaviors to modulate energy barriers at contact surface, thereby controlling charge carrier transport.<ref>{{Cite journal |last1=Wang |first1=Zhong Lin |last2=Wu |first2=Wenzhuo |date=2014-03-01 |title=Piezotronics and piezo-phototronics: fundamentals and applications |url=https://academic.oup.com/nsr/article/1/1/62/1501636 |journal=National Science Review |language=en |volume=1 |issue=1 |pages=62–90 |doi=10.1093/nsr/nwt002 |issn=2053-714X}}</ref> Since the introduction of [[Nanogenerator|nanogenerators]], the efficiency of microscale energy harvesting has improved. For instance, nanogenerators typically consist of piezoelectric [[Nanowire|nanowires]]; as these wires bend or compress, the applied mechanical stress causes the ions within the material's [[crystal lattice]] to shift their positions. This shift disrupts the nanowire's charge symmetry which causes an instantaneous charge [[Polarization (physics)|polarization]] (separation of positive and negative charges) across the nanowire's ends. Once polarized, electrons are freed from the attached electrode which generates [[Alternating current|usable alternating current]] (AC) electricity that can energize low-power sensors.<ref>{{Cite journal |last1=Chandrasekaran |first1=Sundaram |last2=Bowen |first2=Chris |last3=Roscow |first3=James |last4=Zhang |first4=Yan |last5=Dang |first5=Dinh Khoi |last6=Kim |first6=Eui Jung |last7=Misra |first7=R. D. K. |last8=Deng |first8=Libo |last9=Chung |first9=Jin Suk |last10=Hur |first10=Seung Hyun |date=2019-02-23 |title=Micro-scale to nano-scale generators for energy harvesting: Self powered piezoelectric, triboelectric and hybrid devices |url=https://www.sciencedirect.com/science/article/pii/S0370157318302990 |journal=Physics Reports |volume=792 |pages=1–33 |doi=10.1016/j.physrep.2018.11.001 |bibcode=2019PhR...792....1C |issn=0370-1573}}</ref><ref>{{Cite journal |last1=Zhang |first1=Tongtong |last2=Yang |first2=Tao |last3=Zhang |first3=Mei |last4=Bowen |first4=Chris R. |last5=Yang |first5=Ya |date=2020-11-20 |title=Recent Progress in Hybridized Nanogenerators for Energy Scavenging |journal=iScience |volume=23 |issue=11 |article-number=101689 |doi=10.1016/j.isci.2020.101689 |issn=2589-0042 |pmc=7644567 |pmid=33196020 |bibcode=2020iSci...23j1689Z }}</ref> [[Piezoelectric microelectromechanical systems]] (piezoMEMS), such as [[Actuator|actuators]] for artificial organs and [[Pacemaker|pacemakers]] or [[Micropump|micropumps]] for drug delivery and [[reagent]] transfers, are vital for medical purposes and energy harvesting.<ref>{{Cite journal |last1=Bußmann |first1=Agnes |last2=Leistner |first2=Henry |last3=Zhou |first3=Doris |last4=Wackerle |first4=Martin |last5=Congar |first5=Yücel |last6=Richter |first6=Martin |last7=Hubbuch |first7=Jürgen |date=2021-08-30 |title=Piezoelectric Silicon Micropump for Drug Delivery Applications |journal=Applied Sciences |language=en |volume=11 |issue=17 |page=8008 |doi=10.3390/app11178008 |doi-access=free |issn=2076-3417 }}</ref> Furthermore, specialized components like [[Piezoelectric resonator (disambiguation)|piezoelectric resonators]] and quartz [[Crystal oscillator|crystal oscillators]] are used to regulate electrical circuit frequencies.<ref>{{Cite journal |last1=Xianfa |first1=Cai |last2=Yiqin |first2=Wang |last3=Yunqi |first3=Cao |last4=Wenyu |first4=Yang |last5=Tian |first5=Xia |last6=Wei |first6=Li |date=January 2024 |title=Flexural-Mode Piezoelectric Resonators: Structure, Performance, and Emerging Applications in Physical Sensing Technology, Micropower Systems, and Biomedicine |journal=Sensors |language=en |volume=24 |issue=11 |page=3625 |doi=10.3390/s24113625 |pmid=38894417 |pmc=11175270 |bibcode=2024Senso..24.3625C |doi-access=free |issn=1424-8220 }}</ref>

===Marine energy===
{{main|Marine energy}}

[[File:Sihwa Lake Tidal Power Station aerial view.jpg|thumb|Aerial view of Sihwa Tidal Power Station in South Korea]]
Marine energy (also sometimes referred to as ocean energy) is the energy carried by [[ocean wave]]s, [[tide]]s, [[salinity]], and [[Ocean thermal energy conversion|ocean temperature differences]]. Technologies to harness the energy of moving water include [[wave power]], [[marine current power]], and [[tidal power]]. [[Reverse electrodialysis]] (RED) is a technology for generating electricity by mixing [[fresh water]] and salty [[Seawater|sea water]] in large power cells.<ref>{{Cite book |url=https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Dec/IRENA_Innovation_Outlook_Ocean_Energy_2020.pdf |title=Innovation Outlook: Ocean Energy Technologies |publisher=[[International Renewable Energy Agency]] |year=2020 |isbn=978-92-9260-287-1 |location=Abu Dabi |pages=51–52 |language=en |archive-url=https://web.archive.org/web/20240320141829/https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Dec/IRENA_Innovation_Outlook_Ocean_Energy_2020.pdf |archive-date=2024-03-20}}</ref> Most marine energy harvesting technologies are still at low [[technology readiness level]]s and not used at large scales. Tidal energy is generally considered the most mature, but has not seen wide deployment.<ref>{{Citation |last1=Gao |first1=Zhen |title=Committee V.4: Offshore Renewable Energy |date=2018 |work=Proceedings of the 20th International Ship and Offshore Structures Congress (ISSC 2018) Volume 2 |page=253 |url=https://ebooks.iospress.nl/doi/10.3233/978-1-61499-864-8-193 |access-date=2024-05-09 |publisher=IOS Press |doi=10.3233/978-1-61499-864-8-193 |last2=Bingham |first2=Harry B. |last3=Ingram |first3=David |last4=Kolios |first4=Athanasios |last5=Karmakar |first5=Debabrata |last6=Utsunomiya |first6=Tomoaki |last7=Catipovic |first7=Ivan |last8=Colicchio |first8=Giuseppina |last9=Rodrigues |first9=Jos&#233|series=Progress in Marine Science and Technology |hdl=11250/2582171 |hdl-access=free }}</ref> The world's largest tidal power station is on [[Sihwa Lake Tidal Power Station|Sihwa Lake]], South Korea,<ref>{{Cite journal |last1=Park |first1=Eun Soo |last2=Lee |first2=Tai Sik |date=November 2021 |title=The rebirth and eco-friendly energy production of an artificial lake: A case study on the tidal power in South Korea |journal=Energy Reports |language=en |volume=7 |pages=4681–4696 |doi=10.1016/j.egyr.2021.07.006|bibcode=2021EnRep...7.4681P |doi-access=free }}</ref> which produces around 550 gigawatt-hours of electricity per year.<ref>{{Cite book |last1=Warak |first1=Pankaj |last2=Goswami |first2=Prerna |chapter=Overview of Generation of Electricity using Tidal Energy |date=2020-09-25 |title=2020 IEEE First International Conference on Smart Technologies for Power, Energy and Control (STPEC) |publisher=IEEE |page=3 |doi=10.1109/STPEC49749.2020.9297690 |isbn=978-1-7281-8873-7}}</ref>

=== Earth infrared thermal radiation ===
Earth emits roughly 10<sup>17</sup> W of infrared thermal radiation that flows toward the cold outer space. Solar energy hits the surface and atmosphere of the earth and produces heat. Using various theorized devices like emissive energy harvester (EEH) or thermoradiative diode, this energy flow can be converted into electricity. In theory, this technology can be used during nighttime.<ref>{{Cite news|date=2022-05-17|title=Major infrared breakthrough could lead to solar power at night|url=https://www.sciencedaily.com/releases/2022/05/220517112246.htm|access-date=2022-05-21}}</ref><ref>{{Cite journal |title=Harvesting renewable energy from Earth's mid-infrared emissions |journal=PNAS |last1=Byrnes |first1=Steven |volume=111 |pages=3927–3932 |last2=Blanchard |first2=Romain |doi=10.1073/pnas.1402036111 |year=2014 |last3=Capasso |first3=Federico|issue=11 |pmid=24591604 |pmc=3964088 |bibcode=2014PNAS..111.3927B |doi-access=free }}</ref>

=== Others ===

====Algae fuels====
{{main|Algae fuels}}

Producing liquid fuels from oil-rich (fat-rich) varieties of algae is an ongoing research topic. Various microalgae grown in open or closed systems are being tried including some systems that can be set up in brownfield and desert lands.<ref>{{Cite news|date=2008-10-09|title=In bloom: growing algae for biofuel|url=https://news.bbc.co.uk/2/hi/science/nature/7661975.stm|access-date=2021-12-31}}</ref>

====Space-based solar power====
{{main|Space-based solar power}}

There have been numerous proposals for [[space-based solar power]], in which very large satellites with photovoltaic panels would be equipped with [[microwave]] transmitters to beam power back to terrestrial receivers. A 2024 study by the [[NASA]] Office of Science and Technology Policy examined the concept and concluded that with current and near-future technologies it would be economically uncompetitive.<ref>{{Cite book |last1=Rodgers |first1=Erica |url=https://www.nasa.gov/wp-content/uploads/2024/01/otps-sbsp-report-final-tagged-approved-1-8-24-tagged-v2.pdf |title=Space-Based Solar Power |last2=Gertsen |first2=Ellen |last3=Sotudeh |first3=Jordan |last4=Mullins |first4=Carie |last5=Hernandez |first5=Amanda |last6=Le |first6=Hanh Nguyen |last7=Smith |first7=Phil |last8=Joseph |first8=Nikoli |date=January 11, 2024 |publisher=[[NASA]] |location=Washington, DC |department=Office of Technology, Policy and Strategy}}</ref>

====Water vapor====
Collection of static electricity charges from water droplets on metal surfaces is an experimental technology that would be especially useful in [[Developing country|low-income countries]] with relative air humidity over 60%.<ref>{{Cite web|title=Water vapor in the atmosphere may be prime renewable energy source|url=https://techxplore.com/news/2020-06-vapor-atmosphere-prime-renewable-energy.html|access-date=9 June 2020|website=techxplore.com|archive-date=9 June 2020|archive-url=https://web.archive.org/web/20200609172357/https://techxplore.com/news/2020-06-vapor-atmosphere-prime-renewable-energy.html|url-status=live}}</ref>

====Nuclear energy====
[[Breeder reactor]]s could, in principle, depending on the fuel cycle employed, extract almost all of the energy contained in [[uranium]] or [[thorium]], decreasing fuel requirements by a factor of 100 compared to widely used once-through [[light water reactors]], which extract less than 1% of the energy in the actinide metal (uranium or thorium) mined from the earth.<ref name="Argonne">{{cite web |title=Pyroprocessing Technologies: Recycling Used Nuclear Fuel For A Sustainable Energy Future |publisher=Argonne National Laboratory |url=https://www.anl.gov/sites/www/files/2023-09/Recycling%20Used%20Nuclear%20Fuel%20Brochure.pdf |url-status=live |archive-url=https://web.archive.org/web/20130219051536/http://www.ne.anl.gov/pdfs/12_Pyroprocessing_bro_5_12_v14%5B6%5D.pdf |archive-date=19 February 2013}}</ref> The high fuel-efficiency of breeder reactors could greatly reduce concerns about fuel supply, energy used in mining, and storage of [[radioactive waste]]. With [[seawater uranium extraction]] (currently too expensive to be economical), there is enough fuel for breeder reactors to satisfy the world's energy needs for 5 billion years at 1983's total energy consumption rate, thus making nuclear energy effectively a renewable energy.<ref name="sustainablenuclear">{{cite web |title=Breeder reactors: A renewable energy source |last=Cohen |first=Bernard L. |publisher=Argonne National Laboratory |url=http://www.sustainablenuclear.org/PADs/pad11983cohen.pdf |access-date=25 December 2012 |archive-url=https://web.archive.org/web/20130114062518/http://sustainablenuclear.org/PADs/pad11983cohen.pdf |archive-date=14 January 2013}}</ref><ref>Weinberg, A. M., and R. P. Hammond (1970). "Limits to the use of energy," ''Am. Sci.'' 58, 412.</ref> In addition to seawater the average crustal granite rocks contain significant quantities of uranium and thorium with which breeder reactors can supply abundant energy for the remaining lifespan of the sun on the main sequence of stellar evolution.<ref>{{cite web |title=There's Atomic Energy in Granite |date=8 February 2013 |url=https://www.nuenergy.org/theres-atomic-energy-in-granite/}}</ref>

==== Artificial photosynthesis ====
{{main|Artificial photosynthesis}}

Artificial photosynthesis uses techniques including [[nanotechnology]] to store solar electromagnetic energy in chemical bonds by splitting water to produce hydrogen and then using carbon dioxide to make methanol.<ref>Collings AF and Critchley C (eds). Artificial Photosynthesis{{spaced ndash}}From Basic Biology to Industrial Application (Wiley-VCH Weinheim 2005) p ix.</ref> Researchers in this field strived to design molecular mimics of photosynthesis that use a wider region of the solar spectrum, employ catalytic systems made from abundant, inexpensive materials that are robust, readily repaired, non-toxic, stable in a variety of environmental conditions and perform more efficiently allowing a greater proportion of photon energy to end up in the storage compounds, i.e., carbohydrates (rather than building and sustaining living cells).<ref name="faunce">{{cite journal |last1=Faunce |first1=Thomas A. |last2=Lubitz |first2=Wolfgang |author-link2=Wolfgang Lubitz |last3=Rutherford |first3=A. W. (Bill) |last4=MacFarlane |first4=Douglas |last5=Moore |first5=Gary F. |last6=Yang |first6=Peidong |last7=Nocera |first7=Daniel G. |last8=Moore |first8=Tom A. |last9=Gregory |first9=Duncan H. |last10=Fukuzumi |first10=Shunichi |last11=Yoon |first11=Kyung Byung |last12=Armstrong |first12=Fraser A. |last13=Wasielewski |first13=Michael R. |last14=Styring |first14=Stenbjorn |year=2013 |title=Energy and environment policy case for a global project on artificial photosynthesis |journal=Energy & Environmental Science |publisher=RSC Publishing |volume=6 |issue=3 |page=695 |doi=10.1039/C3EE00063J|bibcode=2013EnEnS...6..695F }}</ref> However, prominent research faces hurdles, Sun Catalytix a MIT spin-off stopped scaling up their prototype fuel-cell in 2012 because it offers few savings over other ways to make hydrogen from sunlight.<ref>{{cite journal |author=jobs |date=23 May 2012 |title='Artificial leaf' faces economic hurdle: Nature News & Comment |url=http://www.nature.com/news/artificial-leaf-faces-economic-hurdle-1.10703 |url-status=live |journal=Nature News |publisher=Nature.com |doi=10.1038/nature.2012.10703 |s2cid=211729746 |archive-url=https://web.archive.org/web/20121201123957/http://www.nature.com/news/artificial-leaf-faces-economic-hurdle-1.10703 |archive-date=1 December 2012 |access-date=7 November 2012 |doi-access=free}}</ref> 

Recent research emphasizes that while artificial photosynthesis shows promise in splitting water to generate hydrogen, its broader significance lies in the ability to produce dense, carbon-based solar fuels suitable for transport applications, such as aviation and long-haul shipping. These fuels, if derived from carbon dioxide and water using sunlight, could close the carbon loop and reduce reliance on fossil-based hydrocarbons. However, realizing this potential requires overcoming major technical hurdles, including the development of efficient, durable catalysts for water oxidation and CO<sub>2</sub> reduction, and careful attention to land use and public perception.<ref>{{Cite journal |author1=Richard J Cogdell |author2=Tatas HP Brotosudarmo |author3=Alastair T Gardiner |author4=Pedro M Sanchez |author5=Leroy Cronin |date=2010-11-01 |title=Artificial photosynthesis – solar fuels: current status and future prospects |url=https://www.tandfonline.com/doi/full/10.4155/bfs.10.62 |journal=Biofuels |volume=1 |issue=6 |pages=861–876 |doi=10.4155/bfs.10.62 |bibcode=2010Biofu...1..861C |issn=1759-7269|url-access=subscription}}</ref>


== Comparison of the theoretical and practical potentials of different renewable energy technologies ==
 
Global energy consumption in 2019 was approximately 65 petawatt-hours (PWh) per year or 65,000 terawatt-hours (TWh) annually.<ref>{{Cite web |title=New Energy World magazine |url=https://knowledge.energyinst.org/new-energy-world/article |access-date=2025-10-17 |website=Energy Institute |language=en}}</ref>
=== Technical Potential by Technology ===
According to a comprehensive peer-reviewed study published in 2023,<ref>{{cite journal | last1=Angliviel de la Beaumelle | first1=Nils | last2=Blok | first2=Kornelis | last3=De Chalendar | first3=Jacques A. | last4=Clarke | first4=Leon | last5=Hahmann | first5=Andrea N. | last6=Huster | first6=Jonathan | last7=Nemet | first7=Gregory F. | last8=Suri | first8=Dhruv | last9=Wild | first9=Thomas B. | last10=Azevedo | first10=Inês M.L. | title=The Global Technical, Economic, and Feasible Potential of Renewable Electricity | journal=Annual Review of Environment and Resources | date=2023 | volume=48 | pages=419–449 | doi=10.1146/annurev-environ-112321-091140 | url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-091140 }}</ref> the technical potentials for utility-scale solar photovoltaic, concentrated solar power, onshore wind, and offshore wind each exceed 100 PWh/year, and thus each of them is capable of meeting the Humankind's total demand ''in theory''.
====Solar Photovoltaic (PV) ====
Technical Potential: Over 5,800 PWh per year from solar PV alone using current technology <ref> {{Cite web |last=Gray |first=Helena |date=2021-04-22 |title=Solar and wind can meet world energy demand 100 times over |url=https://carbontracker.org/solar-and-wind-can-meet-world-energy-demand-100-times-over-renewables/ |access-date=2025-10-17 |website=Carbon Tracker Initiative |language=en-US}} </ref> This represents approximately 89 times current global energy demand. Thus, utilizing only 2% of the solar power can solve Humankind's energy problems, in principle.

====Wind Energy (Onshore + Offshore) ====
Technical     Potential: Nearly 900 PWh per year from onshore and offshore wind     combined https://carbontracker.org/solar-and-wind-can-meet-world-energy-demand-100-times-over-renewables/
In     kilowatts: 900,000,000,000,000 kWh/year (900 trillion kWh/year)
This     represents approximately 14 times current global energy demand. However, it is highly intermittent, and it is not feasible to cover most of the earth surface to collect all wind.

====Combined Solar and Wind====
With current technology, at least 6,700 PWh per year can be captured from solar and wind, which is more than 100 times global energy demand.<ref> {{Cite web |title=The Sky's the Limit: Solar and wind energy potential |url=https://carbontracker.org/reports/the-skys-the-limit-solar-wind/ |access-date=2025-10-17 |website=Carbon Tracker Initiative |language=en-US}}</ref>. 
====Hydropower====
Gross  Theoretical Potential: Approximately 52 PWh/year distributed over 11.8  million potential locations worldwide.<ref>{{cite journal | last1=Hoes | first1=O. A. | last2=Meijer | first2=L. J. | last3=Van Der Ent | first3=R. J. | last4=Van De Giesen | first4=N. C. | title=Systematic high-resolution assessment of global hydropower potential | journal=PLOS ONE | date=2017 | volume=12 | issue=2 | article-number=e0171844 | doi=10.1371/journal.pone.0171844 | doi-access=free | pmid=28178329 | pmc=5298288 | bibcode=2017PLoSO..1271844H }}</ref>
In  kilowatts: 52,000,000,000,000 kWh/year (52 trillion kWh/year). 
This  equals to about 33% of annually required energy.<ref> Systematic high-resolution assessment of global hydropower potential | PLOS One Technical  Potential: Above 10 PWh/year according to robust studies. https://pmc.ncbi.nlm.nih.gov/articles/PMC5298288/</ref>

====Geothermal Energy====
Conventional     Geothermal: Technical potential above 10 PWh/year.<ref>{{cite journal | last1=Angliviel de la Beaumelle | first1=Nils | last2=Blok | first2=Kornelis | last3=De Chalendar | first3=Jacques A. | last4=Clarke | first4=Leon | last5=Hahmann | first5=Andrea N. | last6=Huster | first6=Jonathan | last7=Nemet | first7=Gregory F. | last8=Suri | first8=Dhruv | last9=Wild | first9=Thomas B. | last10=Azevedo | first10=Inês M.L. | title=The Global Technical, Economic, and Feasible Potential of Renewable Electricity | journal=Annual Review of Environment and Resources | date=2023 | volume=48 | pages=419–449 | doi=10.1146/annurev-environ-112321-091140 | url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-091140 }}</ref>
Enhanced     Geothermal Systems (EGS): About 600 terawatts (TW) of geothermal     capacity using thermal resources within 8 km of depth, equivalent to about     4,000 PWh of technical potential for annual generation.<ref>{{cite web | title=Global geothermal potential for electricity generation using EGS technologies – the Future of Geothermal Energy – Analysis | url=https://www.iea.org/reports/the-future-of-geothermal-energy/global-geothermal-potential-for-electricity-generation-using-egs-technologies }}</ref>
The     full technical potential of next-generation geothermal systems is     sufficient to meet global electricity demand 140 times over and is second     only to solar PV among renewable technologies.<ref>{{cite web | title=Executive summary – the Future of Geothermal Energy – Analysis | url=https://www.iea.org/reports/the-future-of-geothermal-energy/executive-summary }}</ref>     
====Other Ocean Technologies====
Rooftop     Solar PV, Wave, and Tidal: Technical potentials above 1 PWh/year each.<ref>{{cite journal | last1=Angliviel de la Beaumelle | first1=Nils | last2=Blok | first2=Kornelis | last3=De Chalendar | first3=Jacques A. | last4=Clarke | first4=Leon | last5=Hahmann | first5=Andrea N. | last6=Huster | first6=Jonathan | last7=Nemet | first7=Gregory F. | last8=Suri | first8=Dhruv | last9=Wild | first9=Thomas B. | last10=Azevedo | first10=Inês M.L. | title=The Global Technical, Economic, and Feasible Potential of Renewable Electricity | journal=Annual Review of Environment and Resources | date=2023 | volume=48 | pages=419–449 | doi=10.1146/annurev-environ-112321-091140 | url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-091140 }}</ref>
Ocean     Thermal Energy Conversion (OTEC): Technical potential above 10     PWh/year.<ref>{{cite journal | last1=Angliviel de la Beaumelle | first1=Nils | last2=Blok | first2=Kornelis | last3=De Chalendar | first3=Jacques A. | last4=Clarke | first4=Leon | last5=Hahmann | first5=Andrea N. | last6=Huster | first6=Jonathan | last7=Nemet | first7=Gregory F. | last8=Suri | first8=Dhruv | last9=Wild | first9=Thomas B. | last10=Azevedo | first10=Inês M.L. | title=The Global Technical, Economic, and Feasible Potential of Renewable Electricity | journal=Annual Review of Environment and Resources | date=2023 | volume=48 | pages=419–449 | doi=10.1146/annurev-environ-112321-091140 | url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-091140 }}</ref>
Salinity     Gradient: Technical potential above 0.1 PWh/year.<ref>{{cite journal | last1=Angliviel de la Beaumelle | first1=Nils | last2=Blok | first2=Kornelis | last3=De Chalendar | first3=Jacques A. | last4=Clarke | first4=Leon | last5=Hahmann | first5=Andrea N. | last6=Huster | first6=Jonathan | last7=Nemet | first7=Gregory F. | last8=Suri | first8=Dhruv | last9=Wild | first9=Thomas B. | last10=Azevedo | first10=Inês M.L. | title=The Global Technical, Economic, and Feasible Potential of Renewable Electricity | journal=Annual Review of Environment and Resources | date=2023 | volume=48 | pages=419–449 | doi=10.1146/annurev-environ-112321-091140 | url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-091140 }}</ref>
 
====Overall Technical Potential====
When including all renewable energy sources, the global technical potential ranges from 164 to 27,200 PWh/year, which is 6.6 to 1,101 times the 2021 electricity consumption of 24.7 PWh/year.<ref>{{cite web | title=The global technical, economic, and feasible potential of renewable electricity | date=30 April 2024 | url=https://www.pnnl.gov/publications/global-technical-economic-and-feasible-potential-renewable-electricity }}</ref>
====Economic Potential====
The literature assessing the global economic potential of renewables shows that the economic potential is higher than current and near-future electricity demand.<ref>{{cite journal | last1=Angliviel de la Beaumelle | first1=Nils | last2=Blok | first2=Kornelis | last3=De Chalendar | first3=Jacques A. | last4=Clarke | first4=Leon | last5=Hahmann | first5=Andrea N. | last6=Huster | first6=Jonathan | last7=Nemet | first7=Gregory F. | last8=Suri | first8=Dhruv | last9=Wild | first9=Thomas B. | last10=Azevedo | first10=Inês M.L. | title=The Global Technical, Economic, and Feasible Potential of Renewable Electricity | journal=Annual Review of Environment and Resources | date=2023 | volume=48 | pages=419–449 | doi=10.1146/annurev-environ-112321-091140 | url=https://www.annualreviews.org/content/journals/10.1146/annurev-environ-112321-091140 }}</ref> More specifically:
Around 60% of the world's solar resource and 15% of its wind resource is already economically competitive compared with local fossil fuel generation.<ref>{{cite web | title=Solar and wind can meet world energy demand 100 times over | date=22 April 2021 | url=https://carbontracker.org/solar-and-wind-can-meet-world-energy-demand-100-times-over-renewables/ }}</ref>

==Market and industry trends{{anchor|Economic_trends}}==
{{Main|Renewable energy commercialization}}

Most new renewables are solar, followed by wind then hydro then bioenergy.<ref>{{Cite web |title=Renewable Energy Market Update - May 2022 – Analysis |url=https://www.iea.org/reports/renewable-energy-market-update-may-2022 |access-date=2022-06-27 |website=IEA |date=11 May 2022 |language=en-GB |page=5}}</ref> Investment in renewables, especially solar, tends to be more effective in creating jobs than coal, gas or oil.<ref>{{cite web |url=http://www.truth-out.org/opinion/item/39306-trump-is-foolish-to-ignore-the-flourishing-renewable-energy-sector |title=Trump Is Foolish to Ignore the Flourishing Renewable Energy Sector |first=Linda Pentz |last=Gunter |website=Truthout |date=5 February 2017 |access-date=6 February 2017 |archive-date=6 February 2017 |archive-url=https://web.archive.org/web/20170206064146/http://www.truth-out.org/opinion/item/39306-trump-is-foolish-to-ignore-the-flourishing-renewable-energy-sector|url-status=live}}</ref><ref>{{Cite report |last1=Jaeger |first1=Joel |last2=Walls |first2=Ginette |last3=Clarke |first3=Ella |last4=Altamirano |first4=Juan-Carlos |last5=Harsono |first5=Arya |last6=Mountford |first6=Helen |last7=Burrow |first7=Sharan |last8=Smith |first8=Samantha |last9=Tate |first9=Alison |date=18 October 2021 |title=The Green Jobs Advantage: How Climate-friendly Investments Are Better Job Creators |url=https://www.wri.org/research/green-jobs-advantage-how-climate-friendly-investments-are-better-job-creators |journal= |language=en}}</ref> Worldwide, renewables employ about 12 million people as of 2020, with solar PV being the technology employing the most at almost 4 million.<ref>{{Cite web |title=Renewable Energy Employment by Country |url=https://www.irena.org/Statistics/View-Data-by-Topic/Benefits/Renewable-Energy-Employment-by-Country |access-date=2022-04-29 |website=/Statistics/View-Data-by-Topic/Benefits/Renewable-Energy-Employment-by-Country |language=en}}</ref> However, as of February 2024, the world's supply of workforce for solar energy is lagging greatly behind demand as universities worldwide still produce more workforce for fossil fuels than for renewable energy industries.<ref>{{Cite journal |last1=Vakulchuk |first1=Roman |last2=Overland |first2=Indra |date=2024-04-01 |title=The failure to decarbonize the global energy education system: Carbon lock-in and stranded skill sets |journal=Energy Research & Social Science |volume=110 |article-number=103446 |doi=10.1016/j.erss.2024.103446 |issn=2214-6296|doi-access=free |bibcode=2024ERSS..11003446V |hdl=11250/3128127 |hdl-access=free }}</ref>

In 2021, China accounted for almost half of the global increase in renewable electricity.<ref>{{Cite web |title=Renewables – Global Energy Review 2021 – Analysis |url=https://www.iea.org/reports/global-energy-review-2021/renewables |url-status=live |archive-url=https://web.archive.org/web/20211123021051/https://www.iea.org/reports/global-energy-review-2021/renewables |archive-date=23 November 2021 |access-date=2021-11-22 |website=IEA}}</ref>

There are 3,146 gigawatts installed in 135 countries, while 156 countries have laws regulating the renewable energy sector.<ref name=":8" />{{sfn|REN21 Renewables Global Status Report|2021}}

Globally in 2020 there are over 10 million jobs associated with the renewable energy industries, with [[solar photovoltaics]] being the largest renewable employer.<ref>{{Cite web |date=29 September 2020 |title=Renewable Energy and Jobs – Annual Review 2020 |url=https://www.irena.org/publications/2020/Sep/Renewable-Energy-and-Jobs-Annual-Review-2020 |url-status=live |archive-url=https://web.archive.org/web/20201206154355/https://irena.org/publications/2020/Sep/Renewable-Energy-and-Jobs-Annual-Review-2020 |archive-date=6 December 2020 |access-date=2 December 2020 |website=irena.org}}</ref> The clean energy sectors added about 4.7 million jobs globally between 2019 and 2022, totaling 35 million jobs by 2022.<ref>{{Cite web |last=IEA |first=International Energy Agency |date=November 2023 |title=World Energy Employment 2023 |url=https://iea.blob.core.windows.net/assets/ba1eab3e-8e4c-490c-9983-80601fa9d736/World_Energy_Employment_2023.pdf |access-date=23 April 2023 |website=www.iea.org |page=5}}</ref>{{Rp|page=5}}

=== Usage by sector or application ===
Some studies say that a global transition to [[100% renewable energy]] across all sectors – power, heat, transport and industry – is feasible and economically viable.<ref name="Bogdanov-2021">{{Cite journal |last1=Bogdanov |first1=Dmitrii |last2=Gulagi |first2=Ashish |last3=Fasihi |first3=Mahdi |last4=Breyer |first4=Christian |date=2021-02-01 |title=Full energy sector transition towards 100% renewable energy supply: Integrating power, heat, transport and industry sectors including desalination |journal=Applied Energy |language=en |volume=283 |article-number=116273 |bibcode=2021ApEn..28316273B |doi=10.1016/j.apenergy.2020.116273 |issn=0306-2619 |doi-access=free}}</ref><ref name="Teske-2019">{{Cite book |url=https://link.springer.com/book/10.1007/978-3-030-05843-2 |title=Achieving the Paris Climate Agreement Goals |journal=<!----> |year=2019 |isbn=978-3-030-05842-5 |editor-last1=Teske |editor-first1=Sven |language=en |doi=10.1007/978-3-030-05843-2 |s2cid=198078901}}</ref><ref>{{Cite journal |last1=Jacobson |first1=Mark Z. |last2=von Krauland |first2=Anna-Katharina |last3=Coughlin |first3=Stephen J. |last4=Dukas |first4=Emily |last5=Nelson |first5=Alexander J. H. |last6=Palmer |first6=Frances C. |last7=Rasmussen |first7=Kylie R. |date=2022 |title=Low-cost solutions to global warming, air pollution, and energy insecurity for 145 countries |url=http://xlink.rsc.org/?DOI=D2EE00722C |journal=Energy & Environmental Science |language=en |volume=15 |issue=8 |pages=3343–3359 |doi=10.1039/D2EE00722C |bibcode=2022EnEnS..15.3343J |issn=1754-5692 |s2cid=250126767|url-access=subscription }}</ref>

One of the efforts to decarbonize transportation is the increased use of [[electric vehicle]]s (EVs).<ref name="wg3">{{cite web |title=Climate Change 2022: Mitigation of Climate Change |url=https://www.ipcc.ch/report/ar6/wg3/ |access-date=2022-04-06 |website=IPCC Sixth Assessment Report}}</ref> Despite that and the use of [[biofuel]]s, such as [[Aviation biofuel|biojet]], less than 4% of transport energy is from renewables.<ref name="Ren21b">{{Cite web |title=Renewables 2022 Global Status Report |url=https://www.ren21.net/gsr-2022 |access-date=2022-06-20 |website=www.ren21.net |language=en}}</ref> Occasionally [[hydrogen fuel cells]] are used for heavy transport.<ref>{{Cite news |last=Mishra |first=Twesh |title=India to develop and build first indigenous Hydrogen Fuel Cell Vessel |url=https://economictimes.indiatimes.com/industry/renewables/india-to-develop-and-build-first-indigenous-hydrogen-fuel-cell-vessel/articleshow/91210545.cms |access-date=2022-05-09 |work=The Economic Times}}</ref> Meanwhile, in the future [[electrofuels]] may also play a greater role in decarbonizing hard-to-abate sectors like aviation and maritime shipping.<ref>{{Cite web |last=Trakimavicius |first=Lukas |date=December 2023 |title=Mission Net-Zero: Charting the Path for E-fuels in the Military |url=https://www.enseccoe.org/publications/mission-net-zero-charting-the-path-for-e-fuels-in-the-military/ |publisher=NATO Energy Security Centre of Excellence}}</ref>

[[Solar water heating]] makes an important contribution to [[renewable heat]] in many countries, most notably in China, which now has 70% of the global total (180&nbsp;GWth). Most of these systems are installed on multi-family apartment buildings<ref>{{Cite web |title=IEA SHC {{!}}{{!}} Solar Heat Worldwide |url=https://www.iea-shc.org/solar-heat-worldwide |access-date=2022-06-24 |website=www.iea-shc.org}}</ref> and meet a portion of the hot water needs of an estimated 50–60 million households in China. Worldwide, total installed solar water heating systems meet a portion of the water heating needs of over 70 million households.

[[Heat pumps]] provide both heating and cooling, and also flatten the electric demand curve and are thus an increasing priority.<ref name="energy.gov">{{cite web |title=Geothermal Heat Pumps - Department of Energy |url=http://energy.gov/energysaver/geothermal-heat-pumps |url-status=live |archive-url=https://web.archive.org/web/20160116185714/http://energy.gov/energysaver/geothermal-heat-pumps |archive-date=16 January 2016 |access-date=14 January 2016 |website=energy.gov}}</ref> [[Renewable thermal energy]] is also growing rapidly.<ref>{{cite web |title=Fast Growth for Copper-Based Geothermal Heating & Cooling |url=http://en.coppercanada.ca/videos-publications/videos/bright-new-age/geothermal.html |archive-url=https://web.archive.org/web/20190426225322/http://en.coppercanada.ca/videos-publications/videos/bright-new-age/geothermal.html |archive-date=26 April 2019 |access-date=26 April 2019}}</ref> About 10% of heating and cooling energy is from renewables.<ref name="Ren21a">{{Cite web |title=Renewables 2021 Global Status Report |url=https://www.ren21.net/gsr-2021 |access-date=2022-04-25 |website=www.ren21.net |language=en}}</ref>

===Cost comparison===
The [[International Renewable Energy Agency]] (IRENA) stated that ~86% (187 GW) of renewable capacity added in 2022 had lower costs than electricity generated from fossil fuels.<ref name=IRENA_20230829/> IRENA also stated that capacity added since 2000 reduced electricity bills in 2022 by at least $520 billion, and that in non-OECD countries, the lifetime savings of 2022 capacity additions will reduce costs by up to $580 billion.<ref name=IRENA_20230829>{{cite web |title=Global power sector saved fuel costs of USD 520 billion last year thanks to renewables, says new IRENA report |url=https://www.irena.org/News/pressreleases/2023/Aug/Renewables-Competitiveness-Accelerates-Despite-Cost-Inflation |website=IRENA.org |publisher=International Renewable Energy Agency (IRENA) |archive-url=https://web.archive.org/web/20230829090140/https://www.irena.org/News/pressreleases/2023/Aug/Renewables-Competitiveness-Accelerates-Despite-Cost-Inflation |archive-date=29 August 2023 |date=29 August 2023 |url-status=live }}</ref>

{| class="wikitable sortable"
!
!Installed<ref name="RCS">{{Harvnb|IRENA RE Capacity|2020}}</ref><br />TWp
!Growth<br />TW/yr<ref name="RCS" />
!Production<br />per installed<br />capacity<sup>*</sup><ref name="RES">{{Harvnb|IRENA RE Statistics|2020}} PROD(GWh)/(CAP(GW)*8760h)</ref>
!Energy<br />TWh/yr<sup>*</sup><ref name="RES" />
!Growth<br />TWh/yr<sup>*</sup><ref name="RES" />
![[Levelized cost of energy|Levelized cost]]<br />US¢/kWh<ref name="IRENA RE Costs 2020 13">{{Harvnb|IRENA RE Costs|2020|p=13}}</ref>
!Av. auction prices<br />US¢/kWh<ref>{{Harvnb|IRENA RE Costs|2020|p=14}}</ref>
!Cost development<br />2010–2019<ref name="IRENA RE Costs 2020 13" />
|-
|Solar PV||0.580||0.098||13%||549||123||6.8||3.9||−82%
|-
|Solar CSP||0.006||0.0006||13%||6.3||0.5||18.2||7.5||−47%
|-
|Wind Offshore||0.028||0.0045||33%||68||11.5||11.5||8.2||−30%
|-
|Wind Onshore||0.594||0.05||25%||1194||118||5.3||4.3||−38%
|-
|Hydro||1.310||0.013||38%||4267||90||4.7|| ||+27%
|-
|Bioenergy||0.12||0.006||51%||522||27||6.6|| ||−13%
|-
|Geothermal||0.014||0.00007||74%||13.9||0.7||7.3|| ||+49%
|}

<sup>*</sup> = 2018. All other values for 2019.

=== Growth of renewables ===
{{multiple image
| align             = center
| total_width       = 600
| header            = Investment and sources
| image1            = 20210119 Renewable energy investment - 2004- BloombergNEF.svg
| caption1          = Investment: Companies, governments and households have committed increasing amounts to decarbonization, including renewable energy (solar, wind), electric vehicles and associated charging infrastructure, energy storage, energy-efficient heating systems, carbon capture and storage, and hydrogen.<ref name=BloombergNEF_20210119>{{cite news |title=Energy Transition Investment Hit $500 Billion in 2020 – For First Time |url=https://about.bnef.com/blog/energy-transition-investment-hit-500-billion-in-2020-for-first-time/ |work=BloombergNEF |publisher=(Bloomberg New Energy Finance) |date=19 January 2021 |archive-url=https://web.archive.org/web/20210119134344/https://about.bnef.com/blog/energy-transition-investment-hit-500-billion-in-2020-for-first-time/ |archive-date=19 January 2021 |url-status=live}}</ref><ref name=BloombergNEF_20230126/><ref name=BNEF_20240130>{{cite web |title=Global Clean Energy Investment Jumps 17%, Hits $1.8 Trillion in 2023, According to BloombergNEF Report |url=https://about.bnef.com/blog/global-clean-energy-investment-jumps-17-hits-1-8-trillion-in-2023-according-to-bloombergnef-report/ |website=BNEF.com |publisher=Bloomberg NEF |archive-url=https://web.archive.org/web/20240628232137/https://about.bnef.com/blog/global-clean-energy-investment-jumps-17-hits-1-8-trillion-in-2023-according-to-bloombergnef-report/ |archive-date=June 28, 2024 |date=30 January 2024 |quote=Start years differ by sector but all sectors are present from 2020 onwards. |url-status=live}}</ref><ref name=BloombergNEF_20250131>''2024 data:'' {{cite web |title=Energy Transition Investment Trends 2025 / Abridged report |url=https://assets.bbhub.io/professional/sites/24/951623_BNEF-Energy-Transition-Trends-2025-Abridged.pdf |publisher=BloombergNEF |archive-url=https://web.archive.org/web/20250202002640/https://assets.bbhub.io/professional/sites/24/951623_BNEF-Energy-Transition-Trends-2025-Abridged.pdf |archive-date=2 February 2025 |page=9 |date=30 January 2025 |url-status=live}}</ref>
| image2            = 2015- Investment in clean energy - IEA.svg
| caption2          = By 2025, investment in the energy transition had grown to about twice that for [[fossil fuel]]s (oil, natural gas and coal).<ref name=IEAworldEnergyInvestment_2025>{{cite web |title=World Energy Investment 2025 / Executive summary |url=https://www.iea.org/reports/world-energy-investment-2025/executive-summary |publisher=International Energy Agency |archive-url=https://archive.today/20250607172138/https://www.iea.org/reports/world-energy-investment-2025/executive-summary |archive-date=7 June 2025 |date=2025 |quote=IEA. Licence: CC BY 4.0 |url-status=live}}</ref>
| image3            = 20211104 Percentage of electricity from fossil fuels, nuclear, renewables - biggest fossil fuel emitters.svg
| caption3          = The countries most reliant on fossil fuels for electricity vary widely on how great a portion 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>
}}

{{multiple image
| align             = center
| total_width       = 600
| header            = Costs
| image4            = 20201019 Levelized Cost of Energy (LCOE, Lazard) - renewable energy.svg
| caption4          = '''Levelized cost:''' With increasingly widespread implementation of renewable energy sources, costs have declined, most notably for energy generated by solar panels.<ref name=LazardPopSci_costs>{{cite news |last1=Chrobak |first1=Ula |others=Infographics by Sara Chodosh |title=Solar power got cheap. So why aren't we using it more? |work=Popular Science |date=28 January 2021 |url=https://www.popsci.com/story/environment/cheap-renewable-energy-vs-fossil-fuels/ |url-status=live |archive-date=29 January 2021 |archive-url=https://web.archive.org/web/20210129144621/https://www.popsci.com/story/environment/cheap-renewable-energy-vs-fossil-fuels/}} Chodosh's graphic is derived from data in {{cite web |title=Lazard's Levelized Cost of Energy Version 14.0 |website=Lazard.com |publisher=Lazard |url=https://www.lazard.com/media/451419/lazards-levelized-cost-of-energy-version-140.pdf |archive-url=https://web.archive.org/web/20210128105700/https://www.lazard.com/media/451419/lazards-levelized-cost-of-energy-version-140.pdf |archive-date=28 January 2021 |date=19 October 2020 |url-status=live}}</ref><ref name=LazardLCOE_2024>{{cite web |title=Lazard LCOE Levelized Cost Of Energy+ |url=https://www.lazard.com/media/xemfey0k/lazards-lcoeplus-june-2024-_vf.pdf |publisher=Lazard |archive-url=https://web.archive.org/web/20240828224744/https://www.lazard.com/media/xemfey0k/lazards-lcoeplus-june-2024-_vf.pdf |archive-date=28 August 2024 |page=16 |date=June 2024 |url-status=live}}</ref>
<br/>[[Levelized cost of energy]] (LCOE) is a measure of the average net present cost of electricity generation for a generating plant over its lifetime.
| image5            = 2010- Cost of renewable energy - IRENA.svg
| caption5          = '''Past costs''' of producing renewable energy declined significantly,<ref name=IRENArenewableCostsFor_2022>{{cite web |title=Renewable Power Costs in 2022 |url=https://www.irena.org/News/articles/2023/Aug/Infographic-Renewable-Power-Generation-Costs-in-2022 |website=IRENA.org |publisher=International Renewable Energy Agency |archive-url=https://web.archive.org/web/20230829234136/https://www.irena.org/News/articles/2023/Aug/Infographic-Renewable-Power-Generation-Costs-in-2022 |archive-date=29 August 2023 |date=August 2023 |url-status=live }}</ref> with 62% of total renewable power generation added in 2020 having lower costs than the cheapest new fossil fuel option.<ref name=IRENA_20210622>{{cite web |title=Majority of New Renewables Undercut Cheapest Fossil Fuel on Cost |url=https://www.irena.org/newsroom/pressreleases/2021/Jun/Majority-of-New-Renewables-Undercut-Cheapest-Fossil-Fuel-on-Cost |website=IRENA.org |publisher=International Renewable Energy Agency |archive-url=https://web.archive.org/web/20210622210639/https://www.irena.org/newsroom/pressreleases/2021/Jun/Majority-of-New-Renewables-Undercut-Cheapest-Fossil-Fuel-on-Cost |archive-date=22 June 2021 |date=22 June 2021 |url-status=live}} ● [https://www.irena.org/newsroom/articles/2021/Jun/Low-Renewable-Costs-Allow-To-Power-Past-Coal Infographic] (with numerical data) and [https://web.archive.org/web/20210624184715/https://www.irena.org/newsroom/articles/2021/Jun/Low-Renewable-Costs-Allow-To-Power-Past-Coal archive thereof]</ref>
| image6            = 2010- Decreasing renewable energy costs versus deployment.svg
| caption6          = "'''Learning curves'''": Trend of costs and deployment over time, with steeper lines showing greater cost reductions as deployment progresses.<ref>{{cite book |title=Renewable Energy Generation Costs in 2022 |url=https://mc-cd8320d4-36a1-40ac-83cc-3389-cdn-endpoint.azureedge.net/-/media/Files/IRENA/Agency/Publication/2023/Aug/IRENA_Renewable_power_generation_costs_in_2022.pdf |publisher=International Renewable Energy Agency (IRENA) |archive-url=https://web.archive.org/web/20230830041356/https://mc-cd8320d4-36a1-40ac-83cc-3389-cdn-endpoint.azureedge.net/-/media/Files/IRENA/Agency/Publication/2023/Aug/IRENA_Renewable_power_generation_costs_in_2022.pdf |archive-date=30 August 2023 |page=57 |date=2023 |url-status=live |isbn=978-92-9260-544-5 }} Fig. 1.11</ref> With increased deployment, renewables benefit from [[learning curves]] and [[economies of scale]].<ref>{{Cite web |title=Why did renewables become so cheap so fast? |url=https://ourworldindata.org/cheap-renewables-growth |access-date=2022-06-04 |website=Our World in Data|date=December 2020 |last1=Roser |first1=Max }}</ref>
}}

{{clear}}
The results of a recent review of the literature concluded that as [[greenhouse gas]] (GHG) emitters begin to be held liable for damages resulting from GHG emissions resulting in climate change, a high value for liability mitigation would provide powerful incentives for deployment of renewable energy technologies.<ref>{{cite journal |last1=Heidari |first1=Negin |last2=Pearce |first2=Joshua M. |year=2016 |title=A Review of Greenhouse Gas Emission Liabilities as the Value of Renewable Energy for Mitigating Lawsuits for Climate Change Related Damages |url=https://www.academia.edu/19418589 |journal=Renewable and Sustainable Energy Reviews |volume=55C |pages=899–908 |doi=10.1016/j.rser.2015.11.025 |bibcode=2016RSERv..55..899H |s2cid=111165822 |access-date=26 February 2016 |archive-date=28 July 2020 |archive-url=https://web.archive.org/web/20200728123316/https://www.academia.edu/19418589/A_Review_of_Greenhouse_Gas_Emission_Liabilities_as_the_Value_of_Renewable_Energy_for_Mitigating_Lawsuits_for_Climate_Change_Related_Damages |url-status=live}}</ref>

In the decade of 2010–2019, worldwide investment in renewable energy capacity excluding large hydropower amounted to US$2.7 trillion, of which the top countries China contributed US$818 billion, the United States contributed US$392.3 billion, Japan contributed US$210.9 billion, Germany contributed US$183.4 billion, and the United Kingdom contributed US$126.5 billion.<ref name="2020gt-c4d" /> This was an increase of over three and possibly four times the equivalent amount invested in the decade of 2000–2009 (no data is available for 2000–2003).<ref name="2020gt-c4d">{{cite web |title=Global Trends in Renewable Energy Investment 2020 |url=https://europa.eu/capacity4dev/unep/documents/global-trends-renewable-energy-investment-2020 |website=Capacity4dev / European Commission |publisher=Frankfurt School-UNEP Collaborating Centre for Climate & Sustainable Energy Finance; BloombergNEF |date=2020 |access-date=16 February 2021 |archive-date=11 May 2021 |archive-url=https://web.archive.org/web/20210511103204/https://europa.eu/capacity4dev/unep/documents/global-trends-renewable-energy-investment-2020 |url-status=live }}</ref>

As of 2022, an estimated 28% of the world's electricity was generated by renewables. This is up from 19% in 1990.<ref>{{Cite journal |last1=Ritchie |first1=Hannah |last2=Roser |first2=Max |last3=Rosado |first3=Pablo |date=2022-10-27 |title=Energy |url=https://ourworldindata.org/renewable-energy |journal=Our World in Data}}</ref> By the end of 2024, global renewable power capacity reached 4,300 gigawatts (GW), with solar photovoltaics accounting for over 60% of annual additions.<ref>{{Cite web |date=2025-03-26 |title=Renewable capacity statistics 2025 |url=https://www.irena.org/Publications/2025/Mar/Renewable-capacity-statistics-2025?spm=a2ty_o01.29997173.0.0.2968c921WRcUD3 |access-date=2025-09-13 |website=www.irena.org |language=en}}</ref>

==== Future projections ====
{{See also|Energy transition}}
[[File:2010- Fossil fuels vs Wind + Solar - electricity generation.svg|thumb|In 2023, electricity generation from wind and solar sources was projected to exceed 30% by 2030.<ref name=RMI_20230613>{{cite web |last1=Bond |first1=Kingsmill |last2=Butler-Sloss |first2=Sam |last3=Lovins |first3=Amory |last4=Speelman |first4=Laurens |last5=Topping |first5=Nigel |title=Report / 2023 / X-Change: Electricity / On track for disruption |publisher=Rocky Mountain Institute |url=https://rmi.org/insight/x-change-electricity/ |archive-url=https://web.archive.org/web/20230713171138/https://rmi.org/insight/x-change-electricity/ |archive-date=13 July 2023 |date=13 June 2023 |url-status=live }}</ref>]]
A December 2022 report by the IEA forecasts that over 2022-2027, renewables are seen growing by almost 2,400 GW in its main forecast, equal to the entire installed power capacity of China in 2021. This is an 85% acceleration from the previous five years, and almost 30% higher than what the IEA forecast in its 2021 report, making its largest ever upward revision. Renewables are set to account for over 90% of global electricity capacity expansion over the forecast period.<ref name="IEA-3">IEA (2022), Renewables 2022, IEA, Paris https://www.iea.org/reports/renewables-2022, License: CC BY 4.0</ref> To achieve net zero emissions by 2050, IEA believes that 90% of global electricity generation will need to be produced from renewable sources.<ref name=":0" />

In June 2022, IEA Executive Director [[Fatih Birol]] said that countries should invest more in renewables to "ease the pressure on consumers from high fossil fuel prices, make our energy systems more secure, and get the world on track to reach our climate goals."<ref>{{Cite web |title=Record clean energy spending is set to help global energy investment grow by 8% in 2022 - News |url=https://www.iea.org/news/record-clean-energy-spending-is-set-to-help-global-energy-investment-grow-by-8-in-2022 |access-date=2022-06-27 |website=IEA |date=22 June 2022 |language=en-GB}}</ref>

China's [[Five-year plans of China#Fourteenth Plan (2021–2025)|five year plan to 2025]] includes increasing direct heating by renewables such as geothermal and solar thermal.<ref>{{Cite web |title=China's New Plan for Renewable Energy Development Focuses on Consumption |url=https://www.fitchratings.com/research/corporate-finance/chinas-new-plan-for-renewable-energy-development-focuses-on-consumption-19-06-2022 |access-date=2022-06-27 |website=www.fitchratings.com}}</ref>

[[REPowerEU]], the EU plan to escape [[Russia in the European energy sector|dependence on fossil Russian gas]], is expected to call for much more [[green hydrogen]].<ref>{{Cite web |last1=Claeys |first1=Bram |last2=Rosenow |first2=Jan |last3=Anderson |first3=Megan |date=2022-06-27 |title=Is REPowerEU the right energy policy recipe to move away from Russian gas? |website=www.euractiv.com |url=https://www.euractiv.com/section/energy/opinion/is-repowereu-the-right-energy-policy-recipe-to-move-away-from-russian-gas/ |access-date=2022-06-27 |language=en-GB}}</ref>

After a transitional period,<ref>{{Cite journal |last1=Gan |first1=Kai Ernn |last2=Taikan |first2=Oki |last3=Gan |first3=Thian Y |last4=Weis |first4=Tim |last5=Yamazaki |first5=D. |last6=Schüttrumpf |first6=Holger |date=2023-07-04 |title=Enhancing Renewable Energy Systems, Contributing to Sustainable Development Goals of United Nation and Building Resilience against Climate Change Impacts |journal=Energy Technology |volume=11 |issue=11 |article-number=2300275 |language=en |doi=10.1002/ente.202300275 |s2cid=259654837 |issn=2194-4288|doi-access=free }}</ref> renewable energy production is expected to make up most of the world's energy production. In 2018, the risk management firm, [[DNV GL]], forecasts that the world's primary [[energy mix]] will be split equally between fossil and non-fossil sources by 2050.<ref>{{Cite web |title=DNV GL's Energy Transition Outlook 2018 |url=http://eto.dnvgl.com/ |url-status=live |archive-url=https://web.archive.org/web/20211123224838/https://eto.dnv.com/2021 |archive-date=23 November 2021 |access-date=16 October 2018 |website=eto.dnvgl.com |language=en}}</ref>

Middle eastern nations are also planning on reducing their reliance fossil fuel. Many planned green projects will contribute in 26% of energy supply for the region by 2050 achieving emission reductions equal to 1.1 Gt CO<sub>2</sub>/year.<ref name=":14">{{Cite web |title=Top 5 renewable energy projects in the Middle East |date=17 February 2023 |url=https://www.progressiverecruitment.com/en-ae/knowledge-hub/industry-insights/top-5-renewable-energy-projects-in-the-middle-east/}}</ref>

Massive Renewable Energy Projects in the Middle East:<ref name=":14" />

* Mohammed bin Rashid Al Maktoum Solar Park in Dubai, UAE
* Shuaibah Two (2) Solar Facility in Mecca Province, Saudi Arabia
* NEOM Green Hydrogen Project in NEOM, Saudi Arabia
* Gulf of Suez Wind Power Project in Suez, Egypt
* Al-Ajban Solar Park in Abu Dhabi, UAE

===Demand===
In July 2014, [[World Wide Fund for Nature|WWF]] and the [[World Resources Institute]] convened a discussion among a number of major US companies who had declared their intention to increase their use of renewable energy. These discussions identified a number of "principles" which companies seeking greater access to renewable energy considered important market deliverables. These principles included choice (between suppliers and between products), cost competitiveness, longer term fixed price supplies, access to third-party financing vehicles, and collaboration.<ref>{{cite web|publisher=WWF and World Resources Institute |url=http://assets.worldwildlife.org/publications/705/files/original/Corporate_RE_buyers_guide-v6.pdf |title=Corporate Renewable Energy Buyers Principles|url-status=live|archive-url=https://web.archive.org/web/20210711232709/http://assets.worldwildlife.org/publications/705/files/original/Corporate_RE_buyers_guide-v6.pdf |archive-date=11 July 2021 |date=July 2014 |access-date=12 July 2021}}</ref>

UK statistics released in September 2020 noted that "the proportion of demand met from renewables varies from a low of 3.4 per cent (for transport, mainly from biofuels) to highs of over 20 per cent for 'other final users', which is largely the service and commercial sectors that consume relatively large quantities of electricity, and industry".<ref>{{OGL-attribution|Department for Business, Energy and Industrial Strategy, [https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/920631/Aggregated_Energy_Balances__of_which_renewables_.pdf Aggregated energy balances showing proportion of renewables in supply and demand], published 24 September 2020, accessed 12 July 2021}}</ref>

In some locations, individual households can opt to purchase renewable energy through a [[consumer green energy program]].

=== Developing countries ===
{{Excerpt|Renewable energy in developing countries|paragraphs=1-2}}

In Kenya, the [[Olkaria V Geothermal Power Station]] is one of the largest in the world.<ref>{{Cite web |last=Kabintie |first=Winnie |date=2023-09-05 |title=Africa Climate Summit - opportunities for harnessing renewable energy |url=https://www.kenyaforum.net/latest-articles/africa-climate-summit-opportunities-for-harnessing-renewable-energy/ |access-date=2023-09-05 |website=The Kenya Forum |language=en}}</ref> The [[Grand Ethiopian Renaissance Dam|Grand Ethiopia Renaissance Dam project]] incorporates wind turbines.<ref>{{Cite web |title=Ethiopia's GERD dam: A potential boon for all, experts say – DW – 04/08/2023 |url=https://www.dw.com/en/ethiopias-gerd-dam-a-potential-boon-for-all-experts-say/a-65254058 |access-date=2023-09-05 |website=dw.com |language=en}}</ref> Once completed, Morocco's [[Ouarzazate Solar Power Station]] is projected to provide power to over a million people.<ref>{{Cite web |last=Wanjala |first=Peter |date=2022-04-22 |title=Noor Ouarzazate Solar Complex in Morocco, World's Largest Concentrated Solar Power Plant |url=https://constructionreviewonline.com/projects/noor-ouarzazate-solar-complex-worlds-largest-concentrated-solar-power-plant/ |access-date=2023-09-05 |website=Constructionreview |language=en-us}}</ref>

== Policy ==
<!-- Deleted image removed: [[File:Share of electricity production (from renewables).png|thumb|upright=1.6|Share of electricity production from renewables, 2024<ref>{{cite web |title=Share of electricity production from renewables |url=https://ourworldindata.org/grapher/share-electricity-renewables |website=Our World in Data |access-date=27 June 2025}}</ref>]] -->
[[File:2021 Death rates, by energy source.svg|upright=1.6|thumb|Deaths caused as a result of [[fossil fuel]] use (areas of rectangles in chart) greatly exceed those resulting from production of renewable energy (rectangles barely visible in chart).<ref name=OWID_SafestEnergy_2021>{{cite journal |last1=Ritchie |first1=Hannah |last2=Roser |first2=Max |title=What are the safest and cleanest sources of energy? |url=https://ourworldindata.org/safest-sources-of-energy |journal=Our World in Data |archive-url=https://web.archive.org/web/20240115112316/https://ourworldindata.org/safest-sources-of-energy |archive-date=15 January 2024 |date=2021 |url-status=live }} Data sources: Markandya & Wilkinson (2007); UNSCEAR (2008; 2018); Sovacool et al. (2016); IPCC AR5 (2014); Pehl et al. (2017); Ember Energy (2021).</ref>]]
Policies to support renewable energy have been vital in their expansion. Where Europe dominated in establishing [[energy policy]] in the early 2000s, most countries around the world now have some form of energy policy.<ref name="IEA-2019">{{Cite web |title=Policies |url=https://www.iea.org/topics/renewables/policies/ |website=www.iea.org|access-date=8 April 2019|archive-date=8 April 2019|archive-url=https://web.archive.org/web/20190408094137/https://www.iea.org/topics/renewables/policies/|url-status=live}}</ref>

The [[International Renewable Energy Agency]] (IRENA) is an [[intergovernmental organization]] for promoting the adoption of renewable energy worldwide. It aims to provide concrete policy advice and facilitate [[capacity building]] and technology transfer. IRENA was formed in 2009, with 75&nbsp;countries signing the charter of IRENA.<ref>{{Cite web|url=https://www.irena.org/|archive-url=https://web.archive.org/web/20101226062317/http://irena.org/downloads/Founconf/Signatory_States_20090126.pdf|title=IRENA – International Renewable Energy Agency|date=2 August 2023|archive-date=26 December 2010|website=www.irena.org}}</ref> As of April 2019, IRENA has 160&nbsp;member states.<ref>{{Cite web |url=https://www.irena.org/irenamembership|title=IRENA Membership|website=/irenamembership|access-date=8 April 2019|archive-url=https://web.archive.org/web/20190406075718/https://irena.org/irenamembership|archive-date=6 April 2019}}</ref> The then United Nations Secretary-General [[Ban Ki-moon]] has said that renewable energy can lift the poorest nations to new levels of prosperity,<ref name="renewableenergyworld1">{{cite web |last=Leone |first=Steve |date=25 August 2011 |title=U.N. Secretary-General: Renewables Can End Energy Poverty |url=http://www.renewableenergyworld.com/rea/news/article/2011/08/u-n-secretary-general-renewables-can-end-energy-poverty |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 |access-date=27 August 2011 |work=Renewable Energy World}}</ref> and in September 2011 he launched the UN [[Sustainable Energy for All]] initiative to improve energy access, efficiency and the deployment of renewable energy.<ref>{{cite news|url=https://www.theguardian.com/global-development/2011/nov/02/human-development-report-renewable-energy|title=UN calls for universal access to renewable energy|last=Tran|first=Mark|date=2 November 2011|work=[[The Guardian]]|location=London|access-date=13 December 2016|archive-date=8 April 2016|archive-url=https://web.archive.org/web/20160408214820/http://www.theguardian.com/global-development/2011/nov/02/human-development-report-renewable-energy|url-status=live}}</ref>

The 2015 [[Paris Agreement]] on climate change motivated many countries to develop or improve renewable energy policies.{{sfn|REN21 Renewables Global Futures Report|2017}} In 2017, a total of 121 countries adopted some form of renewable energy policy.<ref name="IEA-2019" /> National targets that year existed in 176 countries.{{sfn|REN21 Renewables Global Futures Report|2017}} In addition, there is also a wide range of policies at the state/provincial, and local levels.{{sfn|REN21 Renewables Global Status Report|2011|pp=13-14}} Some [[Public utility|public utilities]] help plan or install [[Home energy upgrades from public utilities|residential energy upgrades]].

Many national, state and local governments have created [[Green bank (financial institution)|green banks]]. A green bank is a quasi-public financial institution that uses public capital to leverage private investment in clean energy technologies.<ref>Ken Berlin, Reed Hundt, Marko Muro, and Devashree Saha. "State Clean Energy Banks: New Investment Facilities for Clean Energy Deployment"</ref> Green banks use a variety of financial tools to bridge market gaps that hinder the deployment of clean energy.

Global and national policies related to renewable energy can be divided based on sectors, such as agriculture, transport, buildings, industry:

''Climate neutrality'' ([[net zero emissions]]) by the year 2050 is the main goal of the [[European Green Deal]].<ref>{{cite news |title=Putin promises gas to a Europe struggling with soaring prices |url=https://www.politico.eu/article/russia-president-vladimir-putin-gas-price-europe/ |work=[[Politico]] |date=13 October 2021 |access-date=23 October 2021 |archive-date=23 October 2021 |archive-url=https://web.archive.org/web/20211023031033/https://www.politico.eu/article/russia-president-vladimir-putin-gas-price-europe/ |url-status=live }}</ref> For the European Union to reach their target of climate neutrality, one goal is to decarbonise its energy system by aiming to achieve "net-zero [[greenhouse gas emissions]] by 2050."<ref>{{Cite web|title=The EU releases its Green Deal. Here are the key points|url=https://www.climatechangenews.com/2019/12/12/eu-releases-green-deal-key-points/|last=Simon|first=Frédéric|date=12 December 2019|website=Climate Home News|access-date=23 October 2021|archive-date=23 October 2021|archive-url=https://web.archive.org/web/20211023065758/https://www.climatechangenews.com/2019/12/12/eu-releases-green-deal-key-points/|url-status=live}}</ref>

== Finance ==
{{multiple image
| total_width       = 450
| image1            = 20210119 Renewable energy investment - 2004- BloombergNEF.svg
| caption1          = [[Electrification|Electrified]] transport and renewable energy are key areas of investment for climate change mitigation via an [[energy transition]].<ref name=BloombergNEF_20230126>{{cite news |last1=Catsaros |first1=Oktavia |title=Global Low-Carbon Energy Technology Investment Surges Past $1 Trillion for the First Time |url=https://about.bnef.com/blog/global-low-carbon-energy-technology-investment-surges-past-1-trillion-for-the-first-time/ |publisher=Bloomberg NEF (New Energy Finance) |date=26 January 2023 |archive-url=https://web.archive.org/web/20230522001857/https://about.bnef.com/blog/global-low-carbon-energy-technology-investment-surges-past-1-trillion-for-the-first-time/ |archive-date=22 May 2023 |at=Figure 1 |quote=Defying supply chain disruptions and macroeconomic headwinds, 2022 energy transition investment jumped 31% to draw level with fossil fuels |url-status=live}}</ref><ref name=BNEF_20240130>{{cite web |title=Global Clean Energy Investment Jumps 17%, Hits $1.8 Trillion in 2023, According to BloombergNEF Report |url=https://about.bnef.com/blog/global-clean-energy-investment-jumps-17-hits-1-8-trillion-in-2023-according-to-bloombergnef-report/ |website=BNEF.com |publisher=Bloomberg NEF |archive-url=https://web.archive.org/web/20240628232137/https://about.bnef.com/blog/global-clean-energy-investment-jumps-17-hits-1-8-trillion-in-2023-according-to-bloombergnef-report/ |archive-date=June 28, 2024 |date=30 January 2024 |quote=Start years differ by sector but all sectors are present from 2020 onwards. |url-status=live}}</ref><ref name=BloombergNEF_20250131>''2024 data:'' {{cite web |title=Energy Transition Investment Trends 2025 / Abridged report |url=https://assets.bbhub.io/professional/sites/24/951623_BNEF-Energy-Transition-Trends-2025-Abridged.pdf |publisher=BloombergNEF |archive-url=https://web.archive.org/web/20250202002640/https://assets.bbhub.io/professional/sites/24/951623_BNEF-Energy-Transition-Trends-2025-Abridged.pdf |archive-date=2 February 2025 |page=9 |date=30 January 2025 |url-status=live}}</ref>
| image2            = 2000- Clean energy patent filings - by country.svg
| caption2          = China's count of multi-country patent filings has surged since the mid-2010s, leading in batteries and solar, though Europe still dominates in wind energy and smart grids.<ref name=NYTimes_20250814/> China also leads in highly cited publications in global peer-reviewed journals.<ref name=NYTimes_20250814>{{cite news |last1=Bearak |first1=Max |last2=Rojanasakul |first2=Mira |title=How China Went From Clean Energy Copycat to Global Innovator |url=https://www.nytimes.com/interactive/2025/08/14/climate/china-clean-energy-patents.html |newspaper=The New York Times |date=14 August 2025 |archive-url=https://web.archive.org/web/20250815002927/https://www.nytimes.com/interactive/2025/08/14/climate/china-clean-energy-patents.html |archive-date=15 August 2025 |url-status=live }}</ref>
}}

The [[International Renewable Energy Agency]]'s (IRENA) 2023 report on renewable energy finance highlights steady investment growth since 2018: USD 348 billion in 2020 (a 5.6% increase from 2019), USD 430 billion in 2021 (24% up from 2020), and USD 499 billion in 2022 (16% higher). This trend is driven by increasing recognition of renewable energy's role in mitigating climate change and enhancing [[energy security]], along with investor interest in alternatives to fossil fuels. Policies such as [[feed-in tariff]]s in China and Vietnam have significantly increased renewable adoption. Furthermore, from 2013 to 2022, installation costs for solar photovoltaic (PV), onshore wind, and offshore wind fell by 69%, 33%, and 45%, respectively, making renewables more cost-effective.<ref>{{Cite web |date=2023-02-22 |title=Global landscape of renewable energy finance 2023 |url=https://www.irena.org/Publications/2023/Feb/Global-landscape-of-renewable-energy-finance-2023 |access-date=2024-03-21 |website=www.irena.org |language=en}}</ref><ref name=":1">{{Cite web |date=February 2023 |title=Global landscape of renewable energy finance 2023 |url=https://mc-cd8320d4-36a1-40ac-83cc-3389-cdn-endpoint.azureedge.net/-/media/Files/IRENA/Agency/Publication/2023/Feb/IRENA_CPI_Global_RE_finance_2023.pdf?rev=8668440314f34e588647d3994d94a785 |website=International Renewable Energy Agency (IRENA) |access-date=21 March 2024 |archive-date=21 March 2024 |archive-url=https://web.archive.org/web/20240321092402/https://mc-cd8320d4-36a1-40ac-83cc-3389-cdn-endpoint.azureedge.net/-/media/Files/IRENA/Agency/Publication/2023/Feb/IRENA_CPI_Global_RE_finance_2023.pdf?rev=8668440314f34e588647d3994d94a785 }}</ref>

Between 2013 and 2022, the renewable energy sector underwent a significant realignment of investment priorities. Investment in solar and wind energy technologies markedly increased. In contrast, other renewable technologies such as hydropower (including [[Pumped-storage hydropower|pumped storage hydropower]]), [[Biomass (energy)|biomass]], [[biofuel]]s, [[Geothermal energy|geothermal]], and [[marine energy]] experienced a substantial decrease in financial investment. Notably, from 2017 to 2022, investment in these alternative renewable technologies declined by 45%, falling from USD 35 billion to USD 17 billion.<ref name=":1" />

In 2023, the renewable energy sector experienced a significant surge in investments, particularly in solar and wind technologies, totaling approximately USD 200 billion—a 75% increase from the previous year. The increased investments in 2023 contributed between 1% and 4% to the GDP in key regions including the United States, China, the European Union, and India.<ref>{{Cite web |date=2024-04-18 |title=Clean energy is boosting economic growth – Analysis |url=https://www.iea.org/commentaries/clean-energy-is-boosting-economic-growth |access-date=2024-04-30 |website=IEA |language=en-GB}}</ref>

The energy sector receives investments of approximately USD 3 trillion each year, with USD 1.9 trillion directed towards [[Sustainable energy|clean energy]] technologies and infrastructure. To meet the targets set in the [[Net zero emissions|Net Zero Emissions]] (NZE) Scenario by 2035, this investment must increase to USD 5.3 trillion per year.<ref>{{Cite web |last=International Energy Agency |first=IEA |date=May 2024 |title=Strategies for Affordable and Fair Clean Energy Transitions |url=https://iea.blob.core.windows.net/assets/d3a68a4e-7f55-4c6a-8f4f-ce2e55475701/StrategiesforAffordableandFairCleanEnergyTransitions.pdf |access-date=30 May 2024 |website=www.iea.org}}</ref>{{Rp|page=15}}

== Debates ==
{{Main|Renewable energy debate||Green job|Intermittent power source}}

{{Further|Climate change mitigation#Overviews, strategies and comparisons of measures}}
=== Nuclear power proposed as renewable energy ===
[[File:2011-05-10 18-57-46 Switzerland - Wil crop.jpg|thumb|The [[Leibstadt Nuclear Power Plant]] in Switzerland]]
{{Excerpt|Nuclear power proposed as renewable energy}}

=== Geopolitics ===
{{See also|Russia in the European energy sector}}
[[File:TREC-Map-en.jpg|thumb|A concept of a [[super grid]]]]
The [[Geopolitics|geopolitical]] impact of the growing use of renewable energy is a subject of ongoing debate and research.<ref>{{Cite web|url=https://www.researchgate.net/publication/317954274|title=The Geopolitics of Renewable Energy|website=ResearchGate|access-date=26 June 2019|archive-date=28 July 2020|archive-url=https://web.archive.org/web/20200728123315/https://www.researchgate.net/publication/317954274_The_Geopolitics_of_Renewable_Energy|url-status=live}}</ref> Many fossil-fuel producing countries, such as [[Qatar]], [[Russia]], [[Saudi Arabia]] and [[Norway]], are currently able to exert diplomatic or geopolitical influence as a result of their oil wealth. Most of these countries are expected to be among the geopolitical "losers" of the energy transition, although some, like Norway, are also significant producers and exporters of renewable energy. Fossil fuels and the infrastructure to extract them may, in the long term, become [[stranded asset]]s.<ref>{{Cite journal |last1=Overland |first1=Indra |last2=Bazilian |first2=Morgan |last3=Ilimbek Uulu |first3=Talgat |last4=Vakulchuk |first4=Roman |last5=Westphal |first5=Kirsten |date=2019 |title=The GeGaLo index: Geopolitical gains and losses after energy transition |journal=Energy Strategy Reviews |volume=26 |article-number=100406 |bibcode=2019EneSR..2600406O |doi=10.1016/j.esr.2019.100406 |doi-access=free |hdl-access=free |hdl=11250/2634876}}</ref> It has been speculated that countries dependent on fossil fuel revenue may one day find it in their interests to quickly [[Fire sale|sell off]] their remaining fossil fuels.<ref>{{cite journal |last1=Mercure |first1=J.-F. |last2=Salas |first2=P. |last3=Vercoulen |first3=P. |last4=Semieniuk |first4=G. |last5=Lam |first5=A. |last6=Pollitt |first6=H. |last7=Holden |first7=P. B. |last8=Vakilifard |first8=N. |last9=Chewpreecha |first9=U. |last10=Edwards |first10=N. R. |last11=Vinuales |first11=J. E. |title=Reframing incentives for climate policy action |journal=Nature Energy |date=4 November 2021 |volume=6 |issue=12 |pages=1133–1143 |doi=10.1038/s41560-021-00934-2 |bibcode=2021NatEn...6.1133M |s2cid=243792305 |issn=2058-7546|doi-access=free |hdl=10871/127743 |hdl-access=free }}</ref>

Conversely, nations abundant in renewable resources, and the minerals required for renewables technology, are expected to gain influence.<ref>{{Cite journal|last=Overland|first=Indra|date=1 March 2019|title=The geopolitics of renewable energy: Debunking four emerging myths|journal=Energy Research & Social Science|volume=49|pages=36–40|doi=10.1016/j.erss.2018.10.018|issn=2214-6296|doi-access=free|bibcode=2019ERSS...49...36O |hdl=11250/2579292|hdl-access=free}}</ref><ref>{{Cite news |title=The transition to clean energy will mint new commodity superpowers |newspaper=[[The Economist]]|url=https://www.economist.com/finance-and-economics/2022/03/26/the-transition-to-clean-energy-will-mint-new-commodity-superpowers |access-date=2022-05-02 |issn=0013-0613}}</ref> In particular, [[China]] has become the world's dominant manufacturer of the technology needed to produce or store renewable energy, especially [[solar panel]]s, [[wind turbine]]s, and [[Lithium-ion battery|lithium-ion batteries]].<ref>{{Cite news |last=Shepherd |first=Christian |date=March 29, 2024 |title=China is all in on green tech. The U.S. and Europe fear unfair competition. |url=https://www.washingtonpost.com/world/2024/03/29/china-clean-green-energy-technology-trade/ |access-date=April 10, 2024 |newspaper=The Washington Post}}</ref> Nations rich in solar and wind energy could become major energy exporters.<ref name="cb1" /> Some may produce and export [[green hydrogen]],<ref>{{cite journal |last1=Van de Graaf |first1=Thijs |last2=Overland |first2=Indra |last3=Scholten |first3=Daniel |last4=Westphal |first4=Kirsten |title=The new oil? The geopolitics and international governance of hydrogen |journal=Energy Research & Social Science |date=1 December 2020 |volume=70 |article-number=101667 |doi=10.1016/j.erss.2020.101667 |pmid=32835007 |pmc=7326412 |bibcode=2020ERSS...7001667V |issn=2214-6296}}</ref><ref name="cb1">{{cite web |title=In-depth Q&A: Does the world need hydrogen to solve climate change? |url=https://www.carbonbrief.org/in-depth-qa-does-the-world-need-hydrogen-to-solve-climate-change |website=Carbon Brief |access-date=10 November 2021 |date=30 November 2020 |archive-date=1 December 2020 |archive-url=https://web.archive.org/web/20201201155033/https://www.carbonbrief.org/in-depth-qa-does-the-world-need-hydrogen-to-solve-climate-change |url-status=live}}</ref> although electricity is projected to be the dominant [[energy carrier]] in 2050, accounting for almost 50% of total energy consumption (up from 22% in 2015).<ref>{{Cite book |url=https://www.irena.org/publications/2021/Jun/World-Energy-Transitions-Outlook |title=World Energy Transitions Outlook: 1.5°C Pathway |publisher=[[International Renewable Energy Agency]] |year=2021 |isbn=978-92-9260-334-2 |location=Abu Dhabi |page=24 |language=en}}</ref> Countries with large uninhabited areas such as Australia, China, and many African and Middle Eastern countries have a potential for huge installations of renewable energy. The production of renewable energy technologies requires [[rare-earth element]]s with new supply chains.<ref>{{cite web |title=The Geopolitics Of Renewable Energy |url=https://energypolicy.columbia.edu/sites/default/files/CGEPTheGeopoliticsOfRenewables.pdf |year=2017|access-date=26 January 2020|archive-url=https://web.archive.org/web/20200204083012/https://energypolicy.columbia.edu/sites/default/files/CGEPTheGeopoliticsOfRenewables.pdf|archive-date=4 February 2020 |publisher=Center on Global Energy Policy Columbia University SIPA / Belfer Center for Science and International Affairs Harvard Kennedy School}}</ref>

Countries with already weak governments that rely on fossil fuel revenue may face even higher political instability or popular unrest. Analysts consider [[Nigeria]], [[Angola]], [[Chad]], [[Gabon]], and [[Sudan]], all countries with a history of [[Coup d'état|military coups]], to be at risk of instability due to dwindling oil income.<ref>{{Cite web |last1=Ince |first1=Matt |last2=Sikorsky |first2=Erin |date=December 13, 2023 |title=The Uncomfortable Geopolitics of the Clean Energy Transition |url=https://www.lawfaremedia.org/article/the-uncomfortable-geopolitics-of-the-clean-energy-transition |access-date=2024-04-10 |website=[[Lawfare (website)|Lawfare]] |language=en}}</ref>

A study found that transition from fossil fuels to renewable energy systems reduces risks from mining, trade and political dependence because renewable energy systems don't need fuel – they depend on trade only for the acquisition of materials and components during construction.<ref>{{cite journal |last1=Krane |first1=Jim |last2=Idel |first2=Robert |title=More transitions, less risk: How renewable energy reduces risks from mining, trade and political dependence |journal=Energy Research & Social Science |date=1 December 2021 |volume=82 |article-number=102311 |doi=10.1016/j.erss.2021.102311 |bibcode=2021ERSS...8202311K |s2cid=244187364 |issn=2214-6296}}</ref>

In October 2021, European Commissioner for Climate Action [[Frans Timmermans]] suggested "the best answer" to the [[2021 global energy crisis]] is "to reduce our reliance on fossil fuels."<ref name="Timmermans">{{cite news |date=6 October 2021 |title=EU countries look to Brussels for help with 'unprecedented' energy crisis |work=[[Politico]]|url=https://www.politico.eu/article/eu-countries-look-to-brussels-for-help-with-unprecedented-energy-crisis/ |url-status=live |access-date=23 October 2021 |archive-url=https://web.archive.org/web/20211021121838/https://www.politico.eu/article/eu-countries-look-to-brussels-for-help-with-unprecedented-energy-crisis/ |archive-date=21 October 2021}}</ref> He said those blaming the [[European Green Deal]] were doing so "for perhaps ideological reasons or sometimes economic reasons in protecting their vested interests."<ref name="Timmermans" /> Some critics blamed the [[European Union Emissions Trading System]] (EU ETS) and [[Nuclear power phase-out|closure of nuclear plants]] for contributing to the energy crisis.<ref>{{cite news |date=6 October 2021 |title=European Energy Crisis Fuels Carbon Trading Expansion Concerns |work=[[Bloomberg News|Bloomberg]]|url=https://www.bloomberg.com/news/articles/2021-10-06/european-energy-crisis-fuels-carbon-trading-expansion-concerns |url-status=live |access-date=23 October 2021 |archive-url=https://web.archive.org/web/20211022084826/https://www.bloomberg.com/news/articles/2021-10-06/european-energy-crisis-fuels-carbon-trading-expansion-concerns |archive-date=22 October 2021}}</ref><ref>{{cite news |date=20 October 2021 |title=The Green Brief: East-West EU split again over climate |work=[[Euractiv]] |url=https://www.euractiv.com/section/energy-environment/news/the-green-brief-east-west-eu-split-again-over-climate/ |url-status=live |access-date=23 October 2021 |archive-url=https://web.archive.org/web/20211020225129/https://www.euractiv.com/section/energy-environment/news/the-green-brief-east-west-eu-split-again-over-climate/ |archive-date=20 October 2021}}</ref><ref>{{cite news |date=8 October 2021 |title=In Global Energy Crisis, Anti-Nuclear Chickens Come Home to Roost |work=[[Foreign Policy]] |url=https://foreignpolicy.com/2021/10/08/energy-crisis-nuclear-natural-gas-renewable-climate/ |url-status=live |access-date=23 October 2021 |archive-url=https://web.archive.org/web/20211022084834/https://foreignpolicy.com/2021/10/08/energy-crisis-nuclear-natural-gas-renewable-climate/ |archive-date=22 October 2021}}</ref> European Commission President [[Ursula von der Leyen]] said that Europe is "too reliant" on [[natural gas]] and too [[List of countries by natural gas imports|dependent on natural gas imports]]. According to Von der Leyen, "The answer has to do with diversifying our suppliers ... and, crucially, with speeding up the transition to clean energy."<ref>{{cite news |date=20 October 2021 |title=Europe's energy crisis: Continent 'too reliant on gas,' says von der Leyen |work=Euronews |url=https://www.euronews.com/2021/10/20/europe-s-energy-crisis-continent-too-reliant-on-gas-says-von-der-leyen |url-status=live |access-date=23 October 2021 |archive-url=https://web.archive.org/web/20211024152313/https://www.euronews.com/2021/10/20/europe-s-energy-crisis-continent-too-reliant-on-gas-says-von-der-leyen |archive-date=24 October 2021}}</ref>

=== Metal and mineral extraction ===
{{See also|Environmental footprint of electric cars|Rare-earth element#Environmental considerations}}

The [[Energy transition|transition]] to renewable energy requires increased extraction of certain metals and minerals. Like all mining, this impacts the environment<ref>{{cite news |last1=Thomas |first1=Tobi |title=Mining needed for renewable energy 'could harm biodiversity' |url=https://www.theguardian.com/environment/2020/sep/01/mining-needed-for-renewable-energy-could-harm-biodiversity |access-date=18 October 2020 |agency=[[The Guardian]] |publisher=Nature Communications |date=1 September 2020 |archive-date=6 October 2020 |archive-url=https://web.archive.org/web/20201006002803/https://www.theguardian.com/environment/2020/sep/01/mining-needed-for-renewable-energy-could-harm-biodiversity |url-status=live }}</ref> and can lead to [[environmental conflict]].<ref>{{Cite journal |last1=Marín |first1=Anabel |last2=Goya |first2=Daniel |date=2021-12-01 |title=Mining—The dark side of the energy transition |url=https://www.sciencedirect.com/science/article/pii/S221042242100071X |journal=Environmental Innovation and Societal Transitions |series=Celebrating a decade of EIST: What's next for transition studies? |language=en |volume=41 |pages=86–88 |doi=10.1016/j.eist.2021.09.011 |bibcode=2021EIST...41...86M |s2cid=239975201 |issn=2210-4224|url-access=subscription }}</ref> For example, lithium mining uses around 65% of the water in the Salar de Atamaca desert forcing farmers and llama herders to abandon their ancestral settlements and creating environment degradation,<ref>{{cite web |title=UN highlights urgent need to tackle impact of likely electric car battery production boom |url=https://news.un.org/en/story/2020/06/1067272 |website=United Nations |date=28 June 2020 |access-date=26 March 2025}}</ref> in several African countries, the green energy transition has created a mining boom, causing deforestation, and threatening already endangered species.<ref>{{cite news |last1=Hemingway Jaynes |first1=Cristen |title=Africa's 'Mining Boom' Threatens More Than a Third of Its Great Apes |url=https://www.ecowatch.com/africa-mining-great-apes-threatened.html |access-date=10 April 2024 |agency=Ecowatch |publisher=the German Centre for Integrative Biodiversity Research (iDiv). |date=4 April 2024}}</ref>  Wind power requires large amounts of copper and zinc, as well as smaller amounts of the rarer metal [[neodymium]]. Solar power is less resource-intensive, but still requires significant amounts of aluminum. The expansion of electrical grids requires both copper and aluminum. Batteries, which are critical to enable storage of renewable energy, use large quantities of copper, nickel, aluminum and graphite. Demand for lithium is expected to grow 42-fold from 2020 to 2040. Demand for nickel, cobalt and graphite is expected to grow by a factor of about 20–25.<ref name="IEA minerals">{{Cite web |date=2021-05-05 |title=The Role of Critical Minerals in Clean Energy Transitions (presentation and full report) |url=https://www.iea.org/reports/the-role-of-critical-minerals-in-clean-energy-transitions |access-date=2022-11-14 |publisher=IEA |language=en}}</ref> For each of the most relevant minerals and metals, its mining is dominated by a single country: [[Copper mining in Chile|copper in Chile]], [[Nickel mining in Indonesia|nickel in Indonesia]], [[Rare earth industry in China|rare earths in China]], [[Mining in the Democratic Republic of the Congo|cobalt in the Democratic Republic of the Congo (DRC)]], and [[Lithium mining in Australia|lithium in Australia]]. China dominates [[Mineral processing|processing]] of all of these.<ref name="IEA minerals" />

Recycling these metals after the devices they are embedded in are spent is essential to create a [[circular economy]] and ensure renewable energy is sustainable. By 2040, recycled [[copper]], [[lithium]], cobalt, and [[nickel]] from spent batteries could reduce combined primary supply requirements for these minerals by around 10%.<ref name="IEA minerals" />

A controversial approach is [[deep sea mining]]. Minerals can be collected from new sources like [[polymetallic nodules]] lying on the [[seabed]].<ref>{{cite web |last1=Ali |first1=Saleem |date=2 June 2020 |title=Deep sea mining: the potential convergence of science, industry and sustainable development? |url=https://sustainabilitycommunity.springernature.com/posts/deep-sea-mining-the-potential-convergence-of-science-industry-and-sustainable-development |access-date=20 January 2021 |website=Springer Nature Sustainability Community |language=en}}</ref> This would damage local biodiversity,<ref>{{Cite web |title=Deep Sea Mining May Start in 2023, but Environmental Questions Persist |url=https://www.maritime-executive.com/article/deep-sea-mining-may-start-in-2023-but-environmental-questions-persist |access-date=2022-05-23 |website=The Maritime Executive |language=en}}</ref> but proponents point out that biomass on resource-rich seabeds is much scarcer than in the mining regions on land, which are often found in vulnerable habitats like rainforests.<ref>{{Cite news |title=The world needs more battery metals. Time to mine the seabed |url=https://www.economist.com/leaders/2023/07/06/the-world-needs-more-battery-metals-time-to-mine-the-seabed |access-date=2024-05-31 |newspaper=The Economist |issn=0013-0613}}</ref>

Due to co-occurrence of rare-earth and radioactive elements ([[thorium]], [[uranium]] and [[radium]]), rare-earth mining results in production of low-level [[radioactive waste]].<ref>{{Cite web|url=https://www.science.org/content/article/radioactive-waste-standoff-could-slash-high-tech-s-supply-rare-earth-elements|title=Radioactive waste standoff could slash high tech's supply of rare earth elements|last1=Law|first1=Yao-Hua|date=1 April 2019|website=Science {{!}} AAAS|access-date=23 April 2020|archive-date=1 April 2020|archive-url=https://web.archive.org/web/20200401184123/https://www.sciencemag.org/news/2019/04/radioactive-waste-standoff-could-slash-high-tech-s-supply-rare-earth-elements|url-status=live}}</ref>

=== Conservation areas ===
Installations used to produce wind, solar and hydropower are an increasing threat to key conservation areas, with facilities built in areas set aside for nature conservation and other environmentally sensitive areas. They are often much larger than fossil fuel power plants, needing areas of land up to 10 times greater than coal or gas to produce equivalent energy amounts.<ref>{{cite news |last1=McGrath |first1=Matt |date=25 March 2020 |title=Climate change: Green energy plant threat to wilderness areas |url=https://www.bbc.com/news/science-environment-52023881 |url-status=live |archive-url=https://web.archive.org/web/20200530170444/https://www.bbc.com/news/science-environment-52023881 |archive-date=30 May 2020 |access-date=27 March 2020 |publisher=[[BBC News]]}}</ref> More than 2000 renewable energy facilities are built, and more are under construction, in areas of environmental importance and threaten the habitats of plant and animal species across the globe. The authors' team emphasized that their work should not be interpreted as anti-renewables because renewable energy is crucial for reducing carbon emissions. The key is ensuring that renewable energy facilities are built in places where they do not damage biodiversity.<ref>{{cite news |date=27 March 2020 |title=Habitats Under Threat From Renewable Energy Development |url=https://www.technologynetworks.com/applied-sciences/news/habitats-under-threat-from-renewable-energy-developments-332651 |url-status=live |archive-url=https://web.archive.org/web/20200327094241/https://www.technologynetworks.com/applied-sciences/news/habitats-under-threat-from-renewable-energy-developments-332651 |archive-date=27 March 2020 |access-date=27 March 2020 |website=technologynetworks.com}}</ref>

In 2020 scientists published a [[world map]] of areas that contain renewable energy materials as well as estimations of their overlaps with "Key Biodiversity Areas", "Remaining Wilderness" and "[[protected area|Protected Areas]]". The authors assessed that careful [[strategic planning]] is needed.<ref>{{cite news |date=1 September 2020 |title=Mining needed for renewable energy 'could harm biodiversity' |url=https://www.theguardian.com/environment/2020/sep/01/mining-needed-for-renewable-energy-could-harm-biodiversity |url-status=live |archive-url=https://web.archive.org/web/20201006002803/https://www.theguardian.com/environment/2020/sep/01/mining-needed-for-renewable-energy-could-harm-biodiversity |archive-date=6 October 2020 |access-date=8 October 2020 |work=[[The Guardian]]}}</ref><ref>{{cite news |title=Mining for renewable energy could be another threat to the environment |url=https://phys.org/news/2020-09-renewable-energy-threat-environment.html |url-status=live |archive-url=https://web.archive.org/web/20201003033243/https://phys.org/news/2020-09-renewable-energy-threat-environment.html |archive-date=3 October 2020 |access-date=8 October 2020 |work=phys.org}}</ref><ref>{{cite journal |last1=Sonter |first1=Laura J. |last2=Dade |first2=Marie C. |last3=Watson |first3=James E. M. |last4=Valenta |first4=Rick K. |date=1 September 2020 |title=Renewable energy production will exacerbate mining threats to biodiversity |journal=Nature Communications |volume=11 |issue=1 |page=4174 |bibcode=2020NatCo..11.4174S |doi=10.1038/s41467-020-17928-5 |issn=2041-1723 |pmc=7463236 |pmid=32873789 |s2cid=221467922}} [[File:CC-BY icon.svg|class=noviewer|50x50px]] Text and images are available under a [[creativecommons:by/4.0/|Creative Commons Attribution 4.0 International License]] {{Cite web |url=https://creativecommons.org/licenses/by/4.0/ |title=CC BY 4.0 Deed &#124; Attribution 4.0 International &#124; Creative Commons |access-date=21 October 2020 |archive-date=16 October 2017 |archive-url=https://web.archive.org/web/20171016050101/https://creativecommons.org/licenses/by/4.0/ |url-status=bot: unknown }}.</ref>

=== Impact of climate change on renewable energy production ===
Climate change is making weather patterns less predictable. This can seriously hamper the use of renewable energy. For example, in the year 2023, in Sudan and Namibia, hydropower production dropped by more than half due to drastic reduction in rainfall, in China, India and some regions in Africa unusual weather phenomena reduced the amount of produced wind energy, heatwaves and clouds reduce the effectiveness of solar panels, melting glaciers create problems to hydropower. Nuclear energy is also affected as drought creates water shortage, so nuclear power plants sometimes do not have enough water for cooling.<ref>{{cite web |last1=Quinones |first1=Laura |title=Can renewable energy survive climate change? |url=https://news.un.org/en/story/2025/03/1161526 |website=United Nations |date=26 March 2025 |access-date=26 March 2025}}</ref>

== Society and culture ==

=== Public support ===
{{multiple image
| total_width       = 400
| image1            = Most_people_say_countries_should_back_renewable_energy_to_fight_climate_change.jpg
| caption1          = Most respondents to a climate survey conducted in 2021-2022 by the [[European Investment Bank]] say countries should back renewable energy to fight climate change.<ref>{{Cite book |last=Bank |first=European Investment |url=https://www.eib.org/en/publications/the-eib-climate-survey-2021-2022 |title=The EIB Climate Survey 2021-2022 - Citizens call for green recovery |date=2022-04-20 |publisher=European Investment Bank |isbn=978-92-861-5223-8 |language=EN}}</ref>
| image2            = Renewable_energies_are_considered_an_investment_priority_in_the_European_Union,_China_and,_to_a_lesser_extent,_the_United_States.png
| caption2          = The same survey a year later shows that renewable energy is considered an investment priority in the European Union, China and the United States.<ref>{{Cite book |last=Bank |first=European Investment |url=https://www.eib.org/en/publications/20230098-eib-climate-survey-europe |title=The EIB Climate Survey: Government action, personal choices and the green transition |date=2023-06-05 |publisher=European Investment Bank |isbn=978-92-861-5535-2 |language=EN}}</ref>
}}

[[File:202307 Survey - comfortable with solar wind nuclear in my community.svg|thumb|Acceptance of wind and solar facilities in one's community is stronger among U.S. Democrats (blue), while acceptance of nuclear power plants is stronger among U.S. Republicans (red).<ref name="WashPost_20231003">{{cite news |last1=Chiu |first1=Allyson |last2=Guskin |first2=Emily |last3=Clement |first3=Scott |date=3 October 2023 |title=Americans don't hate living near solar and wind farms as much as you might think |url=https://www.washingtonpost.com/climate-solutions/2023/10/03/solar-panels-wind-turbines-nimby/ |url-status=live |archive-url=https://web.archive.org/web/20231003211732/https://www.washingtonpost.com/climate-solutions/2023/10/03/solar-panels-wind-turbines-nimby/ |archive-date=3 October 2023 |newspaper=The Washington Post}}</ref>]]
Solar power plants may compete with [[arable land]],<ref name="van Zalk Behrens">{{Cite journal |last1=van Zalk |first1=John |last2=Behrens |first2=Paul |date=1 December 2018 |title=The spatial extent of renewable and non-renewable power generation: A review and meta-analysis of power densities and their application in the U.S. |journal=Energy Policy |volume=123 |pages=83–91 |bibcode=2018EnPol.123...83V |doi=10.1016/j.enpol.2018.08.023 |issn=0301-4215 |doi-access=free |hdl-access=free |hdl=1887/64883}}</ref><ref>{{Cite news |last=Leake |first=Jonathan |title=UK's largest solar farm 'will destroy north Kent landscape' |url=https://www.thetimes.com/uk/environment/article/uks-largest-solar-farm-will-destroy-north-kent-landscape-w95fxwjj5 |url-status=live |archive-url=https://web.archive.org/web/20200620144215/https://www.thetimes.co.uk/article/uks-largest-solar-farm-will-destroy-north-kent-landscape-w95fxwjj5 |archive-date=20 June 2020 |access-date=21 June 2020 |newspaper=[[The Times]] |issn=0140-0460}}</ref> while on-shore [[wind farm]]s often face opposition due to aesthetic concerns and noise.<ref>{{Cite news |last=McGwin |first=Kevin |date=20 April 2018 |title=Sámi mount new challenge to legality of Norway's largest wind farm |url=https://www.arctictoday.com/sami-mount-new-challenge-legality-norways-largest-wind-farm/ |url-status=live |archive-url=https://web.archive.org/web/20200728123316/https://www.arctictoday.com/sami-mount-new-challenge-legality-norways-largest-wind-farm/ |archive-date=28 July 2020 |access-date=21 June 2020 |website=ArcticToday}}</ref><ref>{{cite news |author=<!--Staff writer(s)/no by-line.--> |date=7 August 2018 |title=Why do so many people in France hate wind farms? |url=https://www.thelocal.fr/20180807/why-do-some-people-in-france-hate-wind-farms-so-much/ |url-status=live |archive-url=https://web.archive.org/web/20210725182107/https://www.thelocal.fr/20180807/why-do-some-people-in-france-hate-wind-farms-so-much/ |archive-date=25 July 2021 |access-date=25 July 2021 |work=The Local |location=France}}</ref> Such opponents are often described as [[NIMBY]]s ("not in my back yard").<ref>{{Cite news |title=America needs a new environmentalism |url=https://www.economist.com/united-states/2023/01/29/america-needs-a-new-environmentalism |archive-url=https://web.archive.org/web/20240429133920/https://www.economist.com/united-states/2023/01/29/america-needs-a-new-environmentalism |archive-date=2024-04-29 |access-date=2024-05-31 |newspaper=The Economist |issn=0013-0613}}</ref> Some environmentalists are concerned about fatal collisions of birds and bats with wind turbines.<ref>{{Cite news |last=Hogan |first=Brianne |date=2020-03-03 |title=Is it possible to build wildlife-friendly windfarms? |url=https://www.bbc.com/future/article/20200302-how-do-wind-farms-affect-bats-birds-and-other-wildlife |work=BBC}}</ref> Although protests against new wind farms occasionally occur around the world, regional and national surveys generally find broad support for both solar and wind power.<ref>{{Cite web |last=Spencer |first=Brian Kennedy and Alison |date=2021-06-08 |title=Most Americans support expanding solar and wind energy, but Republican support has dropped |url=https://www.pewresearch.org/short-reads/2021/06/08/most-americans-support-expanding-solar-and-wind-energy-but-republican-support-has-dropped/ |access-date=2024-05-31 |website=Pew Research Center |language=en-US}}</ref><ref>{{Cite journal |last1=Witkowska-Dabrowska |first1=Mirosława |last2=Świdyńska |first2=Natalia |last3=Napiórkowska-Baryła |first3=Agnieszka |date=2021-12-01 |title=Attitudes of Communities in Rural Areas towards the Development of Wind Energy |journal=Energies |language=en |volume=14 |issue=23 |page=8052 |doi=10.3390/en14238052 |doi-access=free |issn=1996-1073}}</ref><ref>{{Cite web |date=2017-06-12 |title=Limits to growth: Resistance against wind power in Germany |url=https://www.cleanenergywire.org/factsheets/fighting-windmills-when-growth-hits-resistance |access-date=2024-05-31 |website=Clean Energy Wire |language=en}}</ref>

[[Community wind energy|Community-owned wind energy]] is sometimes proposed as a way to increase local support for wind farms.<ref name=":6">{{Cite journal |last1=Hogan |first1=Jessica L. |last2=Warren |first2=Charles R. |last3=Simpson |first3=Michael |last4=McCauley |first4=Darren |date=December 2022 |title=What makes local energy projects acceptable? Probing the connection between ownership structures and community acceptance |url=https://linkinghub.elsevier.com/retrieve/pii/S0301421522004761 |journal=Energy Policy |language=en |volume=171 |article-number=113257 |doi=10.1016/j.enpol.2022.113257|bibcode=2022EnPol.17113257H |hdl=10023/26074 |hdl-access=free }}</ref> A 2011 UK Government document stated that "projects are generally more likely to succeed if they have broad public support and the consent of local communities. This means giving communities both a say and a stake."<ref>Department of Energy & Climate Change (2011). [https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48128/2167-uk-renewable-energy-roadmap.pdf UK Renewable Energy Roadmap (PDF)] {{Webarchive|url=https://web.archive.org/web/20171010110439/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48128/2167-uk-renewable-energy-roadmap.pdf|date=10 October 2017}} p. 35.</ref> In the 2000s and early 2010s, many renewable projects in Germany, Sweden and Denmark were owned by local communities, particularly through [[cooperative]] structures.<ref>DTI, [http://www.uk.coop/sites/default/files/36247mr_0_0.pdf Co-operative Energy: Lessons from Denmark and Sweden]{{Dead link|date=July 2018|bot=InternetArchiveBot|fix-attempted=yes}}, Report of a DTI Global Watch Mission, October 2004</ref><ref>Morris C & Pehnt M, [http://energytransition.de/wp-content/themes/boell/pdf/German-Energy-Transition.pdf German Energy Transition: Arguments for a Renewable Energy Future] {{Webarchive|url=https://web.archive.org/web/20130403005225/http://energytransition.de/wp-content/themes/boell/pdf/German-Energy-Transition.pdf|date=3 April 2013}}, Heinrich Böll Foundation, November 2012</ref> In the years since, more installations in Germany have been undertaken by large companies,<ref name=":6" /> but community ownership remains strong in Denmark.<ref>{{Cite web |title=Energy Communities |url=https://pub.norden.org/nordicenergyresearch2023-03/denmark.html |access-date=2024-05-31 |website=Nordic Cooperation |language=en}}</ref>

== History ==
{{See also|History of climate change policy and politics}}
Prior to the development of coal in the mid 19th century, nearly all energy used was renewable. The oldest known use of renewable energy, in the form of traditional [[biomass (energy)|biomass]] to [[Control of fire by early humans|fuel fires]], dates from more than a million years ago. The use of biomass for fire did not become commonplace until many hundreds of thousands of years later.<ref name="Fire">{{cite web |author=K. Kris Hirst |title=The Discovery of Fire |url=http://archaeology.about.com/od/ancientdailylife/qt/fire_control.htm |url-status=live |archive-url=https://web.archive.org/web/20130112213352/http://archaeology.about.com/od/ancientdailylife/qt/fire_control.htm |archive-date=12 January 2013 |access-date=15 January 2013 |publisher=[[About.com]]}}</ref> The second oldest usage of renewable energy was probably harnessing the wind in order to drive ships over water. This practice can be traced back some 7000 years, to ships in the [[Persian Gulf]] and on the [[Nile]].<ref>{{cite encyclopedia |title=wind energy |encyclopedia=[[The Encyclopedia of Alternative Energy and Sustainable Living]] |url=http://www.daviddarling.info/encyclopedia/W/AE_wind_energy.html |access-date=15 January 2013 |archive-url=https://web.archive.org/web/20130126061929/http://www.daviddarling.info/encyclopedia/W/AE_wind_energy.html |archive-date=26 January 2013 |url-status=live}}</ref> Geothermal energy from [[hot spring]]s has been used for bathing since [[Paleolithic]] times and space heating since ancient Roman times.<ref>{{cite web |title=Geothermal Energy |url=http://faculty.fairfield.edu/mediacenter/nm_webdesign/s_zandan/sz_alt_energy/geothermal_energy.html |url-status=live |archive-url=https://web.archive.org/web/20170325214438/http://faculty.fairfield.edu/mediacenter/nm_webdesign/s_zandan/sz_alt_energy/geothermal_energy.html |archive-date=25 March 2017 |access-date=17 January 2017 |website=faculty.fairfield.edu}}</ref> Moving into the time of recorded history, the primary sources of traditional renewable energy were [[Manual labour|human labor]], [[animal power]], [[water power]], wind, in grain crushing [[windmill]]s, and [[firewood]], a traditional biomass.

In 1885, [[Werner Siemens]], commenting on the discovery of the [[photovoltaic effect]] in the solid state, wrote:

{{blockquote|
text=In conclusion, I would say that however great the scientific importance of this discovery may be, its practical value will be no less obvious when we reflect that the supply of solar energy is both without limit and without cost, and that it will continue to pour down upon us for countless ages after all the coal deposits of the earth have been exhausted and forgotten.<ref>{{Cite journal|last=Siemens|first=Werner|date=June 1885|title=On the electro motive action of illuminated selenium, discovered by Mr. Fritts, of New York|journal=Journal of the Franklin Institute|volume=119|issue=6|pages=453–IN6|doi=10.1016/0016-0032(85)90176-0|bibcode=1885FrInJ.11953IN3S |url=https://zenodo.org/record/1779030|access-date=26 February 2021|archive-date=6 May 2021|archive-url=https://web.archive.org/web/20210506135319/https://zenodo.org/record/1779030|url-status=live}}</ref>}}

[[Max Weber]] mentioned the end of fossil fuel in the concluding paragraphs of his [[Die protestantische Ethik und der Geist des Kapitalismus]] (The Protestant Ethic and the Spirit of Capitalism), published in 1905.<ref>Weber suggests that the modern economic world will determine the lifestyle of everyone born into it "until the last [[hundredweight]] of fossil fuel is burned" (''[http://www.zeno.org/Soziologie/M/Weber,+Max/Schriften+zur+Religionssoziologie/Die+protestantische+Ethik+und+der+Geist+des+Kapitalismus/II.+Die+Berufsethik+des+asketischen+Protestantismus/2.+Askese+und+kapitalistischer+Geist bis der letzte Zentner fossilen Brennstoffs verglüht ist] {{Webarchive|url=https://web.archive.org/web/20180825212624/http://www.zeno.org/Soziologie/M/Weber,+Max/Schriften+zur+Religionssoziologie/Die+protestantische+Ethik+und+der+Geist+des+Kapitalismus/II.+Die+Berufsethik+des+asketischen+Protestantismus/2.+Askese+und+kapitalistischer+Geist|date=25 August 2018}}'').</ref> Development of solar engines continued until the outbreak of World War I. The importance of solar energy was recognized in a 1911 ''[[Scientific American]]'' article: "in the far distant future, [[Fossil fuel|natural fuels]] having been exhausted [solar power] will remain as the only means of existence of the human race".<ref>[http://www.hbs.edu/research/pdf/12-105.pdf "Power from Sunshine": A Business History of Solar Energy] {{Webarchive|url=https://web.archive.org/web/20121010213555/http://www.hbs.edu/research/pdf/12-105.pdf|date=10 October 2012}} 25 May 2012</ref>

The theory of [[peak oil]] was published in 1956.<ref>{{cite web |author=Hubbert, M. King |author-link=M. King Hubbert |date=June 1956 |title=Nuclear Energy and the Fossil Fuels |url=http://www.hubbertpeak.com/hubbert/1956/1956.pdf |archive-url=https://web.archive.org/web/20080527233843/http://www.hubbertpeak.com/hubbert/1956/1956.pdf |archive-date=27 May 2008 |access-date=10 November 2014 |publisher=[[Shell Oil Company]]/[[American Petroleum Institute]]}}</ref> In the 1970s environmentalists promoted the development of renewable energy both as a replacement for the eventual [[depletion of oil]], as well as for an escape from dependence on oil, and the first electricity-generating [[wind turbine]]s appeared. Solar had long been used for heating and cooling, but solar panels were too costly to build solar farms until 1980.<ref>{{cite web |title=History of PV Solar |url=http://www.solarstartechnologies.com/id69.html |archive-url=https://web.archive.org/web/20131206133548/http://solarstartechnologies.com/id69.html |archive-date=6 December 2013 |access-date=1 November 2012 |publisher=Solarstartechnologies.com}}</ref>

New government spending, regulation and policies helped the renewables industry weather the [[2008 financial crisis]] and the [[Great Recession]] better than many other sectors.<ref name="obama">[[Clean Edge]] (2009). [http://www.cleanedge.com/reports/pdf/Trends2009.pdf Clean Energy Trends 2009] {{Webarchive|url=https://web.archive.org/web/20090318040043/http://www.cleanedge.com/reports/pdf/Trends2009.pdf|date=18 March 2009}} pp. 1–4.</ref> In 2022, renewables accounted for 30% of global electricity generation, up from 21% in 1985.<ref name=":3">{{cite web |date=2023 |title=Share of electricity production from renewables |url=https://ourworldindata.org/grapher/share-electricity-renewables |access-date=15 August 2023 |website=Our World in Data}}</ref>

=== Ancient Historical Examples ===
Among the most notable historical uses of renewable energy (in the form of ancient and traditional methods), the following examples can be highlighted:
# Windmills in [[Europe]] and [[Asia]] (such as the [[Windmill|windmills]] of the [[Netherlands]] and [[Nashtifan]] in Iran).<ref>{{Cite journal |last=Reynolds |first=Terry S. |date=1994-05-06 |title=Aerial Technology: Power from Wind . A History of Windmill Technology. Richard L. Hills. Cambridge University Press, New York, 1994. x, 324 pp., illus. $59.95 or £45. |url=https://www.science.org/doi/10.1126/science.264.5160.855 |journal=Science |language=en |volume=264 |issue=5160 |pages=855–856 |doi=10.1126/science.264.5160.855 |pmid=17794729 |issn=0036-8075|url-access=subscription }}</ref> The earliest discovered verified designs of windmills date back to Iran, between 700 and 900 CE.<ref>Eldridge, Frank R. ''Wind machines: report''. Vol. 75, no. 51. The Foundation, 1975.</ref><ref>{{Cite book |last1=Shepherd |first1=William |title=Electricity Generation Using Wind Power |last2=Zhang |first2=Li |date=2016-06-28 |publisher=WORLD SCIENTIFIC |doi=10.1142/9978 |isbn=978-981-314-865-9}}</ref><ref>{{Cite web |title=ĀSĪĀ (or āsīāb, Mill) |url=https://www.iranicaonline.org/articles/asia-or-asiab-mill/ |access-date=2025-04-07 |website=Encyclopaedia Iranica |language=en-US}}</ref>
# Water mills ([[History of China|Ancient China]] and [[History of Iran|Ancient Persia]]).<ref>{{Cite journal |last1=Burke |first1=John G. |last2=Reynolds |first2=Terry S. |date=February 1984 |title=Stronger than a Hundred Men: A History of the Vertical Water Wheel |journal=The History Teacher |volume=17 |issue=2 |page=302 |doi=10.2307/492785 |jstor=492785 |issn=0018-2745}}</ref>
# [[Archimedes]]' [[Burning glass|burning lens]].
# Traditional cooling and ventilation systems based on [[Windcatcher|windcatchers]] and [[Solar updraft tower]] (or [[Solar chimney]]).
# Traditional architecture aware of natural [[heat transfer]] and natural [[energy transformation]] processes.
# Gravity-based [[Fountain|fountains]].
# Using animal [[Biomass (energy)|biomass]] in ancient fuel bricks.
# Solar ovens and furnaces in ancient China, India, Egypt, and Persia.
# Solar energy applications for traditional agricultural processing (drying), engineering material properties (solar curing of [[pottery]] and [[Ceramic|ceramics]]), and ancient health practices (natural disinfection by [[Sunlight|solar radiation]]).
# Long-distance gravitational water flow control in ancient [[Qanat|qanat technology]] for water transport and supply.
# Cargo and passenger transportation using [[Sail|sails]] on rivers, seas, and oceans.
# Cargo and passenger transportation based on understanding water currents in rivers, seas, and oceans.
# Using renewable vegetation (such as desert shrubs, agricultural waste, and pruned branches) for producing [[light]] and [[heat]].
# Using renewable oils (vegetable or animal-based) for producing light and heat.
# Maximizing use of natural sunlight during the day and moonlight at night in building architecture for purposes such as lighting, decorative applications (e.g., reflective tilework, mirror work, and surface polishing on stone or brick), timekeeping ([[Sundial|sundials]], noon markers, [[Prayer times|prayer time]] indicators, seasonal change markers), etc.<ref>Tabibian, S. H., F. Habib, and S. A. Garakani. "An analytical approach to the quality of natural light within the vault of Sepahsalar Mosque (Shahid Motahari School)." ''Naqshejahan-Basic studies and New Technologies of Architecture and Planning'' 9, no. 4 (2020): 245-256.</ref>

== See also ==
{{Portal|Climate change|Environment|Renewable energy|Society|Water|Wind power}}

* {{annotated link|Distributed generation}}
* {{annotated link|Efficient energy use}}
* {{annotated link|Fossil fuel phase-out}}
* {{annotated link|Thermal energy storage}} 
* {{annotated link|List of countries by renewable electricity production}}
* {{annotated link|List of renewable energy topics by country and territory}}
* {{annotated link|Renewable heat}}


{{Clear}}

== References ==
{{Reflist}}<ref>{{Cite web |title=Agrivoltaics: Producing Solar Energy While Protecting Farmland |url=https://cbey.yale.edu/research/agrivoltaics-producing-solar-energy-while-protecting-farmland |access-date=2025-03-30 |website=Yale Center for Business and the Environment |language=en}}</ref>

===Sources ===
{{refbegin|30em}}
* {{cite web |date=2021 |title=2021 Electricity Annual Technology Baseline (ATB) Technologies |publisher=United States National Renewable Energy Laboratory |url=https://atb.nrel.gov/electricity/2021/technologies |ref={{harvid|NREL ATB|2021}} |access-date=18 July 2021 |archive-date=18 July 2021 |archive-url=https://web.archive.org/web/20210718183006/https://atb.nrel.gov/electricity/2021/technologies |url-status=live }}
* {{cite book |date=March 2024 |title=Renewable Capacity Statistics 2024 |publisher=International Renewable Energy Agency (IRENA) |location=Abu Dhabi |isbn=978-92-9260-587-2 |url=https://www.irena.org/Publications/2024/Mar/Renewable-capacity-statistics-2024 |ref={{harvid|IRENA|2024}} |access-date=28 March 2023 }}
* {{cite book |date=2010 |title=Renewables 2010 Global Status Report |publisher=REN21 Secretariat |location=Paris |url=https://www.ren21.net/wp-content/uploads/2019/05/GSR2010_Full-Report_English.pdf |ref={{harvid|REN21 Renewables Global Status Report|2010}} |access-date=18 July 2021 |archive-date=10 July 2021 |archive-url=https://web.archive.org/web/20210710065216/https://www.ren21.net/wp-content/uploads/2019/05/GSR2010_Full-Report_English.pdf |url-status=live }}
* {{cite book |date=2011 |title=Renewables 2011 Global Status Report |publisher=REN21 Secretariat |location=Paris |url=https://www.ren21.net/wp-content/uploads/2019/05/GSR2011_Full-Report_English.pdf |ref={{harvid|REN21 Renewables Global Status Report|2011}} |access-date=18 July 2021 |archive-date=10 July 2021 |archive-url=https://web.archive.org/web/20210710065352/https://www.ren21.net/wp-content/uploads/2019/05/GSR2011_Full-Report_English.pdf |url-status=live }}
* {{cite book |date=2021 |title=Renewables 2021 Global Status Report |publisher=REN21 Secretariat |location=Paris |isbn=978-3-948393-03-8 |url=https://www.ren21.net/wp-content/uploads/2019/05/GSR2021_Full_Report.pdf |ref={{harvid|REN21 Renewables Global Status Report|2021}} |access-date=25 July 2021 |archive-date=15 June 2021 |archive-url=https://web.archive.org/web/20210615172702/https://www.ren21.net/wp-content/uploads/2019/05/GSR2021_Full_Report.pdf |url-status=live }}
* {{cite book |date=2017 |title=Renewables Global Futures Report: Great debates towards 100% renewable energy |publisher=REN21 Secretariat |location=Paris |isbn=978-3-9818107-4-5 |url=https://www.ren21.net/wp-content/uploads/2019/06/GFR-Full-Report-2017_webversion_3.pdf |ref={{harvid|REN21 Renewables Global Futures Report|2017}} |access-date=25 July 2021 |archive-date=12 June 2021 |archive-url=https://web.archive.org/web/20210612113808/https://www.ren21.net/wp-content/uploads/2019/06/GFR-Full-Report-2017_webversion_3.pdf |url-status=live }}
{{refend}}
* {{cite web |ref={{Harvid|IRENA RE Costs|2020}}
| title=Renewable Power Generation Costs in 2019
| publisher=IRENA
| url=https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Jun/IRENA_Power_Generation_Costs_2019.pdf
| date=2020
}}
* {{cite web|ref={{Harvid|IRENA RE Capacity|2020}}|url=https://www.irena.org/publications/2020/Mar/Renewable-Capacity-Statistics-2020|publisher=IRENA|title=Renewable Capacity Statistics 2020|year=2020}}
* {{cite web|ref={{Harvid|IRENA RE Statistics|2020}}|url=https://www.irena.org/publications/2020/Mar/Renewable-Capacity-Statistics-2020|publisher=IRENA|title=Renewable Energy Statistics 2020|year=2020}}

===Further reading===
* {{cite book |editor1-last=Sher |editor1-first=Farooq |title=Renewable Energy Technologies |date=2025 |publisher=Elsevier |isbn=9780443337710 |language=en}}

== External links ==
{{sister project links|d=Q12705|n=category:Renewable energy|q=renewable energy|wikt=renewable energy|c=Category:Renewable energy|voy=no|m=no|mw=no|species=no|b=Renewable Energy|v=Renewable energy|s=Category:Renewable energy}}

*[https://energypedia.info/wiki/Energypedia Energypedia] – a wiki platform for collaborative knowledge exchange on renewable energy in developing countries
*[https://www.renewableenergyconference.org Renewable Energy Conference] – a global platform for industry professionals, academics, and policymakers to exchange knowledge and discuss advancements in renewable energy technologies, with a focus on innovation, sustainability, and future energy solutions.

{{Renewable energy lists}}
{{Renewable energy by country}}
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[[Category:Renewable energy technology]]
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