Copper in renewable energy: Difference between revisions
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{{Short description|The use of copper in renewable energy}} |
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{{Original research|date=May 2018}}{{Notability|date=May 2018}}{{POV|date=May 2018}} |
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[[Renewable energy]] sources such as [[solar energy|solar]], [[wind energy|wind]], [[tidal power|tidal]], [[hydroelectric power|hydro]], [[biomass energy|biomass]], and [[geothermal energy|geothermal]] have become significant sectors of the energy market.<ref> |
[[Renewable energy]] sources such as [[solar energy|solar]], [[wind energy|wind]], [[tidal power|tidal]], [[hydroelectric power|hydro]], [[biomass energy|biomass]], and [[geothermal energy|geothermal]] have become significant sectors of the energy market.<ref>{{Cite web |title=Renewables 2022 – Analysis |url=https://www.iea.org/reports/renewables-2022 |access-date=2023-08-16 |website=IEA |language=en-GB}}</ref><ref>{{Cite web |last= |first= |date=2019-06-14 |title=REN21 Renewables Global Status Report |url=https://www.ren21.net/reports/global-status-report/ |access-date=2023-08-16 |website=REN21 |language=en-US}}</ref> The rapid growth of these sources in the 21st century has been prompted by increasing costs of [[fossil fuel]]s as well as their [[environmental impact]] issues that [[Fossil fuel phase-out|significantly lowered]] their use. |
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[[Copper]] plays an important role in these renewable energy systems.<ref>Will the Transition to Renewable Energy Be Paved in Copper?, ''Renewable Energy World''; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html</ref><ref>García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. A global renewable mix with proven technologies and common materials, Energy Policy, 41 (2012): 561-57, http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf</ref><ref>A kilo more of copper increases environmental performance by 100 to 1,000 times |
[[Copper]] plays an important role in these renewable energy systems.<ref>Will the Transition to Renewable Energy Be Paved in Copper?, ''Renewable Energy World''; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html {{Webarchive|url=https://web.archive.org/web/20180622060455/https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html |date=2018-06-22 }}</ref><ref>García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. A global renewable mix with proven technologies and common materials, Energy Policy, 41 (2012): 561-57, http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf</ref><ref>{{Cite web |last= |date=2011-04-14 |title=Energy saving - A kilo more of copper increases environmental performance by 100 to 1,000 times |url=https://www.renewableenergymagazine.com/energy_saving/a-kilo-more-of-copper-increases-environmental |access-date=2023-08-16 |website=Renewable Energy Magazine, at the heart of clean energy journalism |language=en}}</ref><ref>Copper at the core of renewable energies; European Copper Institute; European Copper Institute; 18 pages; http://www.eurocopper.org/files/presskit/press_kit_copper_in_renewables_final_29_10_2008.pdf {{Webarchive|url=https://web.archive.org/web/20120523052432/http://eurocopper.org/files/presskit/press_kit_copper_in_renewables_final_29_10_2008.pdf |date=2012-05-23 }}</ref><ref>Copper in energy systems; Copper Development Association Inc.; http://www.copper.org/environment/green/energy.html {{Webarchive|url=https://web.archive.org/web/20200801021845/https://www.copper.org/environment/green/energy.html |date=2020-08-01 }}</ref> Copper usage averages up to five times more in renewable energy systems than in traditional power generation, such as fossil fuel and [[Nuclear power|nuclear]] power plants.<ref name="issues.solarindustrymag.com">The Rise Of Solar: A Unique Opportunity For Copper; Solar Industry Magazine; April 2017; Zolaika Strong; https://issues.solarindustrymag.com/article/rise-solar-unique-opportunity-copper {{Webarchive|url=https://web.archive.org/web/20221030093858/https://issues.solarindustrymag.com/article/rise-solar-unique-opportunity-copper |date=2022-10-30 }}</ref> Since copper is an excellent [[thermal conductor|thermal]] and [[electrical conductor]] among engineering metals (second only to silver),<ref>Pops, Horace, 1995. Physical Metallurgy of Electrical Conductors, in Nonferrous Wire Handbook, Volume 3: Principles and Practice, The Wire Association International</ref> electrical systems that utilize copper generate and transmit energy with high efficiency and with minimum environmental impacts. |
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When choosing electrical conductors, facility planners and engineers factor capital investment costs of |
When choosing electrical conductors, facility planners and engineers factor capital investment costs of materials against operational savings due to their electrical energy efficiencies over their useful lives, plus maintenance costs. Copper often fares well in these calculations. A factor called "copper usage intensity,” is a measure of the quantity of copper necessary to install one megawatt of new power-generating capacity. |
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[[File:Residuo electronico colombia cobre reciclaje metales 2.jpg|thumb|270x270px|Copper wires for recycling]] |
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When planning for a new renewable power facility, engineers and product specifiers seek to avoid supply shortages of selected materials. According to the [[United States Geological Survey]], in-ground copper [[Mineral resource classification|reserves]] have increased more than 700% since 1950, from almost 100 million tonnes to 720 million tonnes in 2017, despite the fact that world refined usage has more than tripled in the last 50 years.<ref>The World Copper Factbook, 2017; http://www.icsg.org/index.php/component/jdownloads/finish/170/2462</ref> Copper resources are estimated to exceed 5,000 million tonnes.<ref>Copper Mineral Commodity Summary (USGS, 2017) https://minerals.usgs.gov/minerals/pubs/commodity/copper/ mcs-2017-coppe.pdf</ref><ref>Global Mineral Resource Assessment (USGS, 2014) http://pubs.usgs.gov/fs/2014/3004/pdf/fs2014-3004.pdf</ref> |
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Bolstering the supply from [[copper extraction]] is the more than 30 percent of copper installed from 2007 to 2017 that came from recycled sources.<ref>Long-Term Availability of Copper; International Copper Association; http://copperalliance.org/wordpress/wp-content/uploads/2018/02/ICA-long-term-availability-201802-A4-HR.pdf {{Webarchive|url=https://web.archive.org/web/20180629050642/http://copperalliance.org/wordpress/wp-content/uploads/2018/02/ICA-long-term-availability-201802-A4-HR.pdf |date=2018-06-29 }}</ref> Its [[Recycling by material|recycling rate]] is higher than any other metal.<ref>Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; by Zolaikha Strong; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html {{Webarchive|url=https://web.archive.org/web/20180622060455/https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html |date=2018-06-22 }}</ref> |
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This article discusses the role of copper in various renewable energy generation systems. |
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==Overview |
== Overview == |
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The majority of copper usage, worldwide, is for electrical wiring, including the coils of generators and motors. |
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Copper plays a larger role in renewable energy generation than in conventional [[thermal power plants]] in terms of tonnage of copper per unit of installed power.<ref> Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies; Edgar G. Hertwich, Thomas Gibon, Evert A. Bouman, Anders Arvesen, Sangwon Suh, Garvin A. Heath, Joseph D. Bergesen, Andrea Ramirez, Mabel I. Vega, and Lei Shi; Proceedings of the National Academy of Sciences of the USA; May 19, 2015. 112 (20) 6277-6282; https://doi.org/10.1073/pnas.1312753111</ref> The copper usage intensity of renewable energy systems is four to six times higher than in fossil fuel or nuclear plants. So for example, while conventional power requires approximately 1 [[tonne]] of copper per installed [[megawatt]] (MW), renewable technologies such as wind and solar require four to six times more copper per installed MW. This is because copper is spread over much larger land areas, particularly in solar and wind energy power plants<ref>Winds of Trade Toward Copper; Energy & Infrastructure, http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper</ref> and there is a need for long runs of power and grounding cables to connect components that are widely dispersed.<ref>Current and Projected Wind and Solar Renewable Electric Generating Capacity and Resulting Copper Demand; BBF Associates and Konrad J.A. Kundig, July 20, 2011; http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf</ref> |
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Copper plays a larger role in renewable energy generation than in conventional [[thermal power plants]] in terms of tonnage of copper per unit of installed power.<ref>Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies; Edgar G. Hertwich, Thomas Gibon, Evert A. Bouman, Anders Arvesen, Sangwon Suh, Garvin A. Heath, Joseph D. Bergesen, Andrea Ramirez, Mabel I. Vega, and Lei Shi; Proceedings of the National Academy of Sciences of the USA; May 19, 2015. 112 (20) 6277-6282; https://doi.org/10.1073/pnas.1312753111</ref> The copper usage intensity of renewable energy systems is four to six times higher than in fossil fuel or nuclear plants. So for example, while conventional power requires approximately 1 [[tonne]] of copper per installed [[megawatt]] (MW), renewable technologies such as wind and solar require four to six times more copper per installed MW. This is because copper is spread over much larger land areas, particularly in solar and wind energy power plants.<ref>Winds of Trade Toward Copper; Energy & Infrastructure, http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper {{Webarchive|url=https://web.archive.org/web/20180622060429/http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper |date=2018-06-22 }}</ref> Power and grounding cables must run far to connect components that are widely dispersed, including to energy storage systems and to the main electrical grid.<ref>Current and Projected Wind and Solar Renewable Electric Generating Capacity and Resulting Copper Demand; BBF Associates and Konrad J.A. Kundig, July 20, 2011; http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf {{Webarchive|url=https://web.archive.org/web/20170624103919/http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf |date=2017-06-24 }}</ref><ref name="issues.solarindustrymag.com"/> |
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Wind and solar [[photovoltaic]] energy systems have the highest copper content of all renewable energy technologies. A single wind farm can contain between 4 million and 15 million pounds of copper. A photovoltaic solar power plant contains approximately 5.5 tons of copper per megawatt of power generation.<ref>Will the Transition to Renewable Energy Be Paved in Copper?; Renewable Energy World; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html</ref> A single 660-kW turbine is estimated to contain some 800 pounds of copper.<ref>Growing Renewable Energy Needs More Copper, Windpower Engineering, November 21, 2012; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/</ref> |
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Wind and solar [[photovoltaic]] energy systems have the highest copper content of all renewable energy technologies. A single wind farm can contain between 2000 and 7000 tons of copper. A photovoltaic solar power plant contains approximately 5.5 tons of copper per megawatt of power generation.<ref name =rew>{{cite web|title =Will the Transition to Renewable Energy Be Paved in Copper?|website =Renewable Energy World|date =15 January 2016|url =https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html|access-date =22 June 2018|archive-date =22 June 2018|archive-url =https://web.archive.org/web/20180622060455/https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html|url-status =dead}}</ref> A single 660-kW turbine is estimated to contain some 800 pounds (350 kg) of copper.<ref>Growing Renewable Energy Needs More Copper, Windpower Engineering, November 21, 2012; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ {{Webarchive|url=https://web.archive.org/web/20180622061901/https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ |date=2018-06-22 }}</ref> |
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The total amount of copper used in renewable-based and distributed electricity generation in 2011 was estimated to be 272 kilotonnes (kt). Cumulative copper use through 2011 was estimated to be 1,071 kt. |
The total amount of copper used in renewable-based and distributed electricity generation in 2011 was estimated to be 272 kilotonnes (kt). Cumulative copper use through 2011 was estimated to be 1,071 kt. |
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!Installed power in 2011<ref name=report>REN 21 2012 report</ref> |
!Installed power in 2011<ref name=report>REN 21 2012 report</ref> |
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!Cumulative installed power to 2011<ref name=report /> |
!Cumulative installed power to 2011<ref name=report /> |
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!Copper use in 2011<ref name="leonardo-energy4">Copper content assessment of solar thermal electric power plants (2010), Presentation by Protermosolar <http://www.protermosolar.com> for the European Copper Institute; Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title= |
!Copper use in 2011<ref name="leonardo-energy4">Copper content assessment of solar thermal electric power plants (2010), Presentation by Protermosolar <http://www.protermosolar.com> for the European Copper Institute; Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Ask an expert | Leonardo ENERGY |accessdate=2012-12-12 |url-status=dead |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 }}</ref><ref name="leonardo-energy2">Maximization of use of copper in photovoltaics. Presentation by Generalia Group to ECI, 2012; Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Ask an expert | Leonardo ENERGY |accessdate=2012-12-12 |url-status=dead |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 }}</ref><ref name="leonardo-energy3">Wind Generator Technology, by Eclareon S.L., Madrid, May 2012; http://www.eclareon.com; Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Ask an expert | Leonardo ENERGY |accessdate=2012-12-12 |url-status=dead |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 }}</ref> |
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!Cumulative copper use to 2011<ref name="leonardo-energy2"/><ref name="leonardo-energy3"/><ref name="leonardo-energy4"/> |
!Cumulative copper use to 2011<ref name="leonardo-energy2"/><ref name="leonardo-energy3"/><ref name="leonardo-energy4"/> |
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[[Solar thermal heating|Solar thermal heating and cooling energy systems]] rely on copper for their thermal energy efficiency benefits. Copper is also used as a special [[corrosion resistance|corrosion-resistant]] material in renewable energy systems in wet, [[humidity|humid]], and [[saline water|saline corrosive]] environments. |
[[Solar thermal heating|Solar thermal heating and cooling energy systems]] rely on copper for their thermal energy efficiency benefits. Copper is also used as a special [[corrosion resistance|corrosion-resistant]] material in renewable energy systems in wet, [[humidity|humid]], and [[saline water|saline corrosive]] environments. |
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Copper is a sustainable material that is 100% recyclable |
Copper is a sustainable material that is 100% recyclable and has a higher recycling rate than any other metal.<ref name =rew/> At the end of the useful life of equipment, its copper can be recycled with no loss of its beneficial properties. |
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==Solar photovoltaic power generation== |
==Solar photovoltaic power generation== |
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There is eleven to forty times more copper per unit of generation in [[photovoltaic system]]s than in conventional fossil fuel plants.<ref>Renewables Are as Green as You'd Expect; ''Scientific American''; October 8, 2014; https://www.scientificamerican.com/article/renewables-are-as-green-as-you-d-expect/; citing, Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies; by Edgar G. Hertwich et al.; ''Proceedings of the National Academy of Sciences of the USA''; May 19, 2015. 112 (20) 6277-6282; https://doi.org/10.1073/pnas.1312753111</ref> The usage of copper in photovoltaic systems averages around 4-5 tonnes per MW<ref name="renewableenergyworld.com">Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html {{Webarchive|url=https://web.archive.org/web/20180622060455/https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html |date=2018-06-22 }}</ref><ref name="issues.solarindustrymag.com"/> or higher if conductive ribbon strips that connect individual PV cells are considered.<ref name="leonardo-energy2" /> |
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Of the 20,000 TWh of power consumed globally in a single year,<ref>World Energy Outlook 2012, International Energy Agency; {{cite web |url=http://www.worldenergyoutlook.org/ |title=Archived copy |accessdate=2011-06-19 |deadurl=no |archiveurl=https://www.webcitation.org/5Qcwo3frA?url=http://www.worldenergyoutlook.org/ |archivedate=July 26, 2007 |df= }} </ref> approximately 90 TWh are generated from solar PV systems. While this is only a very small percentage of global energy consumption (0.6% of total installed electricity generating capacity worldwide),<ref name="leonardo-energy1">The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010; Independent research study available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Archived copy |accessdate=2012-12-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 |df= }}</ref> it is nevertheless sufficient to power the needs of more than 10 million people living at the standard of living in a developed country. |
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Copper is used in: |
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Various overlapping statistics regarding the growth of solar PVs have been cited. Solar PVs have been cited to have a 40% annual growth rate, which may grow even faster as the cost of the technology continues to decline.<ref name="leonardo-energy1"/> Another source cites operating capacity to have increased by an average of 58% annually from year end-2006 through 2011.<ref name="ren1">Renewables 2012: Global status report; REN 21 (Renewable Energy Policy Network for the 21st Century; {{cite web |url=http://new.ren21.net/REN21Activities/GlobalStatusReport.aspx |title=Archived copy |accessdate=2013-02-19 |deadurl=yes |archiveurl=https://archive.is/20130128084825/http://new.ren21.net/REN21Activities/GlobalStatusReport.aspx |archivedate=2013-01-28 |df= }}</ref> Installed capacity estimates to 2020 suggest a rapid rise in solar PV generation, growing by a factor of five between 2010 and 2020.<ref name="leonardo-energy1"/> |
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* small wires that interconnect [[photovoltaic modules]] |
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* earthing grids in [[electrode]] earth pegs, horizontal plates, naked cables, and wires |
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Household PV systems are smaller and losses in transmission and distribution are lower than in large-scaled PV power stations. Households are able to generate their own electricity and use the [[electrical grid]] for support and reliability. |
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* [[Direct current|DC]] cables that connect photovoltaic modules to [[inverters]] |
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* low-voltage [[Alternating current|AC]] cables that connect inverters to metering systems and protection cabinets |
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For these reasons, policy initiatives are taking place to enhance the deployment of solar photovoltaic energy installations. This would boost the steady expansion of PV markets by reducing the competitiveness gap of PVs compared to fossil fuel technologies.<ref>PV Parity; http://www.pvparity.eu</ref> The goal at this point is to reach grid parity,<ref>Photovoltaic Grid Parity Monitor, Leonardo Energy; http://www.leonardo-energy.org/photovoltaic-grid-parity-monitor</ref> where the cost of producing energy from rooftop panels over the course of their 25-year lifetime equates to the cost of retail electricity generated by conventional sources. This achievement has already been accomplished in some regions.<ref>Parkinson, Giles; 2011. Solar PV at grid parity! Now what? Climate Spectator, http://www.climatespectator.com.au/commentary/solar-pv-grid-parity-now-what?</ref><ref>Trabish, Herman K; 2011. Solar grid parity is here today; GreentechSolar; http://www.greentechmedia.com/articles/read/New-Study-Solar-Grid-Parity-Is-Here-Today</ref> |
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* high-voltage AC cables |
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* communication cables |
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===Copper in photovoltaic power systems=== |
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* inverters/power electronics |
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There is eleven to forty times more copper per unit of generation in photovoltaic systems than in conventional fossil fuel plants.<ref>Renewables Are as Green as You'd Expect; ''Scientific American''; October 8, 2014; https://www.scientificamerican.com/article/renewables-are-as-green-as-you-d-expect/; citing, Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies; by Edgar G. Hertwich et. al; ''Proceedings of the National Academy of Sciences of the USA''; May 19, 2015. 112 (20) 6277-6282; https://doi.org/10.1073/pnas.1312753111</ref> The usage of copper in photovoltaic systems averages around 4-5 tonnes per MW<ref>Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html</ref> or higher if conductive ribbon strips that connect individual PV cells are considered.<ref name="leonardo-energy2"/> |
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* ribbons |
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* transformer windings. |
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The copper usage intensity averages around 4-5 tonnes per MW or higher if ribbons (conductive strips to connect individual PV cells) are considered.<ref name="leonardo-energy2"/> |
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Copper is used in: 1) small wires that interconnect [[photovoltaic modules]]; 2) earthing grids in [[electrode]] earth pegs, horizontal plates, naked cables, and wires; 3) [[Direct current|DC]] cables that connect photovoltaic modules to [[inverters]]; 4) low-voltage [[Alternating current|AC]] cables that connect inverters to metering systems and protection cabinets; 5) high-voltage AC cables; 6) communication cables; 7) inverters/power electronics; 8) ribbons; and 9) transformer windings. |
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Copper used in photovoltaic systems in 2011 was estimated to be 150 kt. Cumulative copper usage in photovoltaic systems through 2011 was estimated to be 350 kt.<ref name="leonardo-energy2"/> |
Copper used in photovoltaic systems in 2011 was estimated to be 150 kt. Cumulative copper usage in photovoltaic systems through 2011 was estimated to be 350 kt.<ref name="leonardo-energy2"/> |
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=== Photovoltaic system configurations === |
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[[PV system|Solar photovoltaic (PV) systems]] are highly scalable, ranging from small [[rooftop photovoltaic power station|rooftop systems]] to large [[photovoltaic power station]] with capacities of hundreds of [[megawatt]]s. Residential and community-based systems generally range in capacity from 10 kW to 1 MW. |
[[PV system|Solar photovoltaic (PV) systems]] are highly scalable, ranging from small [[rooftop photovoltaic power station|rooftop systems]] to large [[photovoltaic power station]] with capacities of hundreds of [[megawatt]]s. In residential systems, copper intensity appears to be linearly scalable with the capacity of the electrical generation system.<ref>Current and projected wind and solar renewable electric generating capacity and resulting copper demand; Copper Development Association Sustainable Electrical Energy Program; July 20, 2011, by BFF Associates and Konrad J.A. Kundig; http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf {{Webarchive|url=https://web.archive.org/web/20170624103919/http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf |date=2017-06-24 }}</ref> Residential and community-based systems generally range in capacity from 10 kW to 1 MW. |
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PV cells are grouped together in [[solar modules]]. These modules are connected to panels and then into PV arrays. In [[grid-connected photovoltaic power system]], arrays can form sub-fields from which electricity is collected and transported towards the grid connection. |
PV cells are grouped together in [[solar modules]]. These modules are connected to panels and then into PV arrays. In [[grid-connected photovoltaic power system]], arrays can form sub-fields from which electricity is collected and transported towards the grid connection. |
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Copper [[solar cable]]s connect modules (module cable), arrays (array cable), and sub-fields (field cable). Whether a system is connected to the grid or not, electricity collected from the PV cells needs to be converted from [[Direct current|DC]] to [[Alternating current|AC]] and stepped up in voltage. This is done by [[solar inverter]]s which contain copper windings, as well as with copper-containing power electronics. |
Copper [[solar cable]]s connect modules (module cable), arrays (array cable), and sub-fields (field cable). Whether a system is connected to the grid or not, electricity collected from the PV cells needs to be converted from [[Direct current|DC]] to [[Alternating current|AC]] and stepped up in voltage. This is done by [[solar inverter]]s which contain copper windings, as well as with copper-containing power electronics. |
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=== Solar cells === |
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The [[photovoltaic]] industry uses several different [[semiconducting material]]s for the production of [[solar cells]] and often groups them into first and second generation technologies, while the third generation includes a number of emerging technologies that are still in the research and development phase. Solar cells typically convert 20% of incident sunlight into electricity, allowing the generation of 100 - 150 kWh per square meter of panel per year.<ref name="leonardo-energy1"/> |
The [[photovoltaic]] industry uses several different [[semiconducting material]]s for the production of [[solar cells]] and often groups them into first and second generation technologies, while the third generation includes a number of emerging technologies that are still in the research and development phase. Solar cells typically convert 20% of incident sunlight into electricity, allowing the generation of 100 - 150 kWh per square meter of panel per year.<ref name="leonardo-energy1">The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010; Independent research study available at Leonardo Energy - Ask an Expert; {{cite web|url=http://www.leonardo-energy.org/ask-expert|title=Ask an expert | Leonardo ENERGY|url-status=dead|archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert|archivedate=2012-11-26|accessdate=2012-12-12}}</ref> |
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Conventional first-generation [[crystalline silicon]] (c-Si) technology includes [[monocrystalline silicon]] and [[polycrystalline silicon]]. In order to reduce costs of this wafer-based technology, copper-contacted silicon solar cells are emerging as an important alternative to [[silver]] as the preferred conductor material. Challenges with solar cell metallization lie in the creation of a homogenous and qualitatively high-value layer between silicon and copper to serves as a barrier against copper diffusion into the [[semiconductor]]. Copper-based front-side metallization in silicon solar cells is a significant step towards lower cost.<ref>PV Technology: Swapping Silver for Copper, 2012. Renewable Energy World International; July 2, 2012; http://www.renewableenergyworld.com/rea/news/article/2012/07/pv-technology-swapping-silver-for-copper</ref> |
Conventional first-generation [[crystalline silicon]] (c-Si) technology includes [[monocrystalline silicon]] and [[polycrystalline silicon]]. In order to reduce costs of this wafer-based technology, copper-contacted silicon solar cells are emerging as an important alternative to [[silver]] as the preferred conductor material. Challenges with solar cell metallization lie in the creation of a homogenous and qualitatively high-value layer between silicon and copper to serves as a barrier against copper diffusion into the [[semiconductor]]. Copper-based front-side metallization in silicon solar cells is a significant step towards lower cost.<ref>PV Technology: Swapping Silver for Copper, 2012. Renewable Energy World International; July 2, 2012; http://www.renewableenergyworld.com/rea/news/article/2012/07/pv-technology-swapping-silver-for-copper</ref> |
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The second-generation technology includes [[thin film solar cell]]s. Despite having a slightly lower [[Solar cell efficiency|conversion efficiency]] than conventional PV technology, the overall [[cost-per-watt]] is still lower. Commercially significant thin film technologies include [[copper indium gallium selenide solar cell]]s (CIGS) and [[cadmium telluride photovoltaics]] (CdTe), while [[amorphous silicon]] (a-Si) and [[micromorphous silicon]] (m-Si) tandem cells are slowly being outcompeted in recent years. |
The second-generation technology includes [[thin film solar cell]]s. Despite having a slightly lower [[Solar cell efficiency|conversion efficiency]] than conventional PV technology, the overall [[cost-per-watt]] is still lower. Commercially significant thin film technologies include [[copper indium gallium selenide solar cell]]s (CIGS) and [[cadmium telluride photovoltaics]] (CdTe), while [[amorphous silicon]] (a-Si) and [[micromorphous silicon]] (m-Si) tandem cells are slowly being outcompeted in recent years. |
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CIGS, which is actually copper (indium-gallium) diselenide, or Cu(InGa)Se<sub>2</sub>, differs from silicon in that it is a [[heterojunction]] [[semiconductor]]. It has the highest solar energy conversion efficiency (~20%) among thin film materials.<ref>Characterization of 19.9%-Efficient CIGS Absorbers; National Renewable Energy Laboratory, May 2008; http://www.nrel.gov/docs/fy08osti/42539.pdf. Retrieved 10 February 2011</ref> Because CIGS strongly absorbs sunlight, a much thinner film is required than with other semiconductor materials. |
CIGS, which is actually copper (indium-gallium) diselenide, or Cu(InGa)Se<sub>2</sub>, differs from silicon in that it is a [[heterojunction]] [[semiconductor]]. It has the highest solar [[energy conversion efficiency]] (~20%) among thin film materials.<ref>Characterization of 19.9%-Efficient CIGS Absorbers; National Renewable Energy Laboratory, May 2008; http://www.nrel.gov/docs/fy08osti/42539.pdf. Retrieved 10 February 2011</ref> Because CIGS strongly absorbs sunlight, a much thinner film is required than with other semiconductor materials. |
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A photovoltaic cell manufacturing process has been developed that makes it possible to print CIGS semi-conductors. This technology has the potential to reduce the price per solar watt delivered. |
A photovoltaic cell manufacturing process has been developed that makes it possible to print CIGS semi-conductors. This technology has the potential to reduce the price per solar watt delivered. |
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Mono-dispersed [[copper sulfide]] [[nanocrystals]] are being researched as alternatives to conventional single crystals and thin films for photovoltaic devices. This technology, which is still in its infancy, has potential for [[dye-sensitized solar cells]], all-inorganic solar cells, and hybrid [[nanocrystal solar cell|nano-crystal]]-polymer composite solar cells.<ref>Wadia, C. et al., 2008. Synthesis of copper (I) sulfide nanocrystals for photovoltaic application; Nanotech 2008 Conference Program Abstract; http://www.nsti.org/Nanotech2008/showabstract.html?absno=70355 {{Webarchive|url=https://web.archive.org/web/20131104021523/http://www.nsti.org/Nanotech2008/showabstract.html?absno=70355 |date=2013-11-04 }}</ref> |
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While copper is one of the components in CIGS solar cells, the copper content of the cell is actually small: about 50 kg of copper per MW of capacity.<ref>Global Solar; http://www.globalsolar.com, as cited in The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010; page 59. Independent research study available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Archived copy |accessdate=2012-12-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 |df= }}</ref> |
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=== Cables === |
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Mono-dispersed [[copper sulfide]] [[nanocrystals]] are being researched as alternatives to conventional single crystals and thin films for photovoltaic devices. This technology, which is still in its infancy, has potential for [[dye-sensitized solar cells]], all-inorganic solar cells, and hybrid [[nanocrystal solar cell|nano-crystal]]-polymer composite solar cells.<ref>Wadia, C. et. al, 2008. Synthesis of copper (I) sulfide nanocrystals for photovoltaic application; Nanotech 2008 Conference Program Abstract; http://www.nsti.org/Nanotech2008/showabstract.html?absno=70355</ref> |
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Solar generation systems cover large areas. There are many connections among modules and arrays, and connections among arrays in sub-fields and linkages to the network. Solar cables are used for wiring solar power plants.<ref>Solar First Source; {{cite web |url=http://solarfirstsource.com/solar-cable.html |title=Solar cable photovoltaic equipment |accessdate=2013-01-03 |url-status=dead |archiveurl=https://web.archive.org/web/20110325102653/http://www.solarfirstsource.com/solar-cable.html |archivedate=2011-03-25 }}</ref> The amount of cabling involved can be substantial. Typical sizes of copper cables used are 4–6 mm<sup>2</sup> for module cable, 6–10 mm<sup>2</sup> for array cable, and 30–50 mm<sup>2</sup> for field cable.<ref name="leonardo-energy1"/> |
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=== Energy efficiency and system design === |
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====Cables==== |
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Energy efficiency and renewable energy are twin pillars of a sustainable energy future. However, there is little linking of these pillars despite their potential synergies. The more efficiently energy services are delivered, the faster renewable energy can become an effective and significant contributor of primary energy. The more energy is obtained from renewable sources, the less fossil fuel energy is required to provide that same energy demand.<ref name="ren1">Renewables 2012: Global status report; REN 21 (Renewable Energy Policy Network for the 21st Century; {{cite web|url=http://new.ren21.net/REN21Activities/GlobalStatusReport.aspx|title=REN21 - Renewables Global Status Report|url-status=dead|archiveurl=https://archive.today/20130128084825/http://new.ren21.net/REN21Activities/GlobalStatusReport.aspx|archivedate=2013-01-28|accessdate=2013-02-19}}</ref> This linkage of renewable energy with energy efficiency relies in part on the electrical energy efficiency benefits of copper. |
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Solar generation systems cover large areas. There are many connections among modules and arrays, and connections among arrays in sub-fields and linkages to the network. Solar cables are used for wiring solar power plants.<ref>Solar First Source; {{cite web |url=http://solarfirstsource.com/solar-cable.html |title=Archived copy |accessdate=2013-01-03 |deadurl=yes |archiveurl=https://web.archive.org/web/20110325102653/http://www.solarfirstsource.com/solar-cable.html |archivedate=2011-03-25 |df= }}</ref> The amount of cabling involved can be substantial. Typical diameters of copper cables used are 4–6 mm<sup>2</sup> for module cable, 6–10 mm<sup>2</sup> for array cable, and 30–50 mm<sup>2</sup> for field cable.<ref name="leonardo-energy1"/> |
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====Energy efficiency and system design considerations==== |
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Energy efficiency and renewable energy are twin pillars of a sustainable energy future. However, there is little linking of these pillars despite their potential synergies. The more efficiently energy services are delivered, the faster renewable energy can become an effective and significant contributor of primary energy. The more energy is obtained from renewable sources, the less fossil fuel energy is required to provide that same energy demand.<ref name="ren1"/> This linkage of renewable energy with energy efficiency relies in part on the electrical energy efficiency benefits of copper. |
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Increasing the [[diameter]] of a copper cable increases its electrical [[efficient energy use|energy efficiency]] ''(see: [[Copper wire and cable]])''. Thicker cables reduce [[Copper loss|resistive (I<sup>2</sup>R) loss]], which affects lifetime profitability of PV system investments. Complex cost evaluations, factoring extra costs for materials, the amount of solar radiation directed towards solar modules per year (accounting for diurnal and seasonal variations, subsidies, tariffs, payback periods, etc.) are necessary to determine whether higher initial investments for thicker cables are justified. |
Increasing the [[diameter]] of a copper cable increases its electrical [[efficient energy use|energy efficiency]] ''(see: [[Copper wire and cable]])''. Thicker cables reduce [[Copper loss|resistive (I<sup>2</sup>R) loss]], which affects lifetime profitability of PV system investments. Complex cost evaluations, factoring extra costs for materials, the amount of solar radiation directed towards solar modules per year (accounting for diurnal and seasonal variations, subsidies, tariffs, payback periods, etc.) are necessary to determine whether higher initial investments for thicker cables are justified. |
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Depending upon circumstances, some conductors in PV systems can be specified with either copper or [[ |
Depending upon circumstances, some conductors in PV systems can be specified with either copper or [[aluminium]]. As with other electrical conducting systems, there are advantages to each ''(see: [[Copper wire and cable]])''. Copper is the preferred material when high electrical conductivity characteristics and flexibility of the cable are of paramount importance. Also, copper is more suitable for small roof facilities, in smaller cable trays, and when ducting in [[steel]] or [[plastic]] pipes.<ref name="leonardo-energy2"/> |
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Cable ducting is not needed in smaller power facilities where copper cables are less than 25mm<sup>2</sup>. Without duct work, installation costs are lower with copper than with |
Cable ducting is not needed in smaller power facilities where copper cables are less than 25mm<sup>2</sup>. Without duct work, installation costs are lower with copper than with aluminium.<ref name="leonardo-energy2"/> |
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[[Data communications]] networks rely on copper, [[optical fiber]], and/or [[radio frequency|radio]] links. Each material has its advantages and disadvantages. Copper is more reliable than radio links. Signal attenuation with copper wires and cables can be resolved with [[signal amplifiers]].<ref name="leonardo-energy2"/> |
[[Data communications]] networks rely on copper, [[optical fiber]], and/or [[radio frequency|radio]] links. Each material has its advantages and disadvantages. Copper is more reliable than radio links. Signal attenuation with copper wires and cables can be resolved with [[signal amplifiers]].<ref name="leonardo-energy2"/> |
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==Concentrating solar thermal power== |
==Concentrating solar thermal power== |
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[[Concentrating solar power]] (CSP), also known as [[solar thermal electricity]] (STE), uses arrays of [[mirror]]s that concentrate the sun's rays to temperatures between 400<sup>0</sup>C and 1000<sup>0</sup>C.<ref name="leonardo-energy1" /> Electrical power is produced when the concentrated light is converted to heat, which drives a heat engine (usually a [[steam turbine]]) connected to an electrical power generator. |
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The Sun’s solar energy can also be harnessed for its heat. When the Sun’s energy heats a [[Coolant|fluid]] in a closed system, its pressure and temperature rise. When introduced to a [[turbine]], the fluid expands, turning the turbine and producing [[electrical power]].<ref name="leonardo-energy1"/> |
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[[Concentrating solar power]] (CSP), also known as [[solar thermal electricity]] (STE), uses arrays of [[mirror]]s that concentrate the sun’s rays to temperatures between 400<sup>0</sup>C -1000<sup>0</sup>C.<ref name="leonardo-energy1"/> Electrical power is produced when the concentrated light is converted to heat, which drives a heat engine (usually a [[steam turbine]]) connected to an electrical power generator. |
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CSP facilities can produce large-scale power and hold much promise in areas with plenty of sunshine and clear skies. Poised to make Sun-powered grids a reality,<ref>Hutchinson, Alex, 2008. Solar thermal power may make sun-powered grid a reality; Popular Mechanics; November 1, 2008</ref> CSP is currently capable of providing power and dispatchability on a scale similar to that of fossil fuel or nuclear electrical power plants. |
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The electrical output of CSP facilities match shifting daily demand for electricity in places where air conditioning systems are spreading. When backed by thermal storage facilities and combustible fuel, CSP offers utilities electricity that can be dispatched when required, enabling it to be used for base, shoulder and peak loads.<ref>Technology Roadmap: Concentrating Solar Power; IEA, http://www.iea.org/publications/freepublications/publication/csp_roadmap.pdf</ref> |
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Industry groups have estimated that the technology could generate a quarter of the world’s electricity needs by 2050.<ref>Jha, Alok, 2009. Concentrated solar power could generate 'quarter of world's energy,' The Guardian; May 26, 2009; https://www.theguardian.com/environment/2009/may/26/solarpower-renewableenergy</ref> For this reason, plans for future CSP facilities are ambitious. A timeline of CSP deployment around the world is available.<ref>4 CSP facts and figures; Timeline of CSP deployment around the world; CSP World; {{cite web |url=http://www.csp-world.com/resources/4-csp-facts-figures |title=Archived copy |accessdate=2013-04-22 |deadurl=yes |archiveurl=https://web.archive.org/web/20130429051148/http://www.csp-world.com/resources/4-csp-facts-figures |archivedate=2013-04-29 |df= }}</ref> Total installed power is forecasted to increase exponentially through 2025,<ref name="autogenerated1">Global Concentrated Solar Power Markets and Strategies: 2010-2025, IHS Emerging Energy Research, April 2010</ref><ref name="autogenerated2">2011 global status report by Renewable Energy Policy Network for the 21st Century (REN21)</ref> creating as much as 130,000 jobs.<ref name="researchandmarkets1">Solar thermal power market guide; Energy Business Reports; October 2011; 153 pps. {{cite web |url=http://www.energybusinessreports.com/Solar-Thermal-Power.html |title=Archived copy |accessdate=2013-02-19 |deadurl=yes |archiveurl=https://web.archive.org/web/20131103150555/http://www.energybusinessreports.com/Solar-Thermal-Power.html |archivedate=2013-11-03 |df= }}</ref> |
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In 2010, [[Spain]], the world leader of CSP technology, was constructing or planning to build some 50 large CSP plants. That nation has a total installed base of 1581 MW of power plus an additional 774 MW nearing completion for installation.<ref name="leonardo-energy4"/> Other countries in southern [[Europe]] also have CSP facilities, as do countries in emerging markets, such as [[Chile]], [[India]], [[Morocco]], [[Saudi Arabia]], [[South Africa]], and the [[United Arab Emirates]].<ref name="autogenerated1"/><ref name="researchandmarkets1"/><ref>CSP Markets Report 2012-2013; CSP Today; http://www.csptoday.com/csp-markets-report/conference-event-brochure.php</ref> |
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Unlike wind energy, photovoltaics, and most distributed power, the main advantage of CSP is its [[thermal storage]] capability<ref>Dessau, Kathy Li 2010. Concentrating solar thermal: Sun power even in the dark; Solar Novus Today; July 26; http://www.solarnovus.com/index.php?option=com_content&view=article&id=1073:concentrating-solar-thermal-sun-power-even-in-the-dark&catid=38:application-tech-features&Itemid=246</ref> and hybridization possibilities.<ref name="leonardo-energy1"/> Storage systems range from 4 hours in the most typical plants to more than 20 hours when base load is required. This can complement variable generation of other renewable power sources. |
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CSP systems are sometimes combined with fossil fueled steam turbine generation, but interest is growing in pure CSP technology.<ref name="leonardo-energy1"/> Further information on concentrating solar power is available from the Global Solar Thermal Energy Council.<ref>Global Solar Thermal Energy Council, http://www.solarthermalworld.com</ref> |
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===Copper in concentrating solar thermal power facilities=== |
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A CSP system consists of: 1) a concentrator or collector containing [[mirror]]s that reflect [[solar radiation]] and deliver it to the receiver; 2) a receiver that absorbs concentrated sunlight and transfers heat energy to a working fluid (usually a [[mineral oil]], or more rarely, molten [[salts]], [[metals]], [[steam]] or [[air]]); 3) a transport and storage system that passes the fluid from the receiver to the power conversion system; and 4) a [[steam turbine]] that converts thermal power to electricity on demand. |
A CSP system consists of: 1) a concentrator or collector containing [[mirror]]s that reflect [[solar radiation]] and deliver it to the receiver; 2) a receiver that absorbs concentrated sunlight and transfers heat energy to a working fluid (usually a [[mineral oil]], or more rarely, molten [[salts]], [[metals]], [[steam]] or [[air]]); 3) a transport and storage system that passes the fluid from the receiver to the power conversion system; and 4) a [[steam turbine]] that converts thermal power to electricity on demand. |
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Copper is used in field power [[Copper wire and cable|cables]], grounding networks, and [[ |
Copper is used in field power [[Copper wire and cable|cables]], grounding networks, and [[Electric motor|motors]] for tracking and pumping fluids, as well as in the main generator and [[high voltage]] [[transformer]]s. Typically, there is about 200 tonnes copper for a 50 MW power plant.<ref name="leonardo-energy4"/> |
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It has been estimated that copper usage in concentrated solar thermal power plants was 2 kt in 2011. Cumulative copper usage in these plants through 2011 was estimated to be 7 kt.<ref name="leonardo-energy4"/> |
It has been estimated that copper usage in concentrated solar thermal power plants was 2 kt in 2011. Cumulative copper usage in these plants through 2011 was estimated to be 7 kt.<ref name="leonardo-energy4"/> |
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There are four main types of CSP technologies, each containing a different amount of copper: parabolic trough plants, tower plants, distributed linear absorber systems including linear Fresnel plants, and dish Stirling plants.<ref name="leonardo-energy4"/> The use of copper in these plants is described here. |
There are four main types of CSP technologies, each containing a different amount of copper: parabolic trough plants, tower plants, distributed linear absorber systems including linear Fresnel plants, and dish Stirling plants.<ref name="leonardo-energy4"/> The use of copper in these plants is described here. |
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=== Parabolic trough plants === |
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[[Parabolic trough]] plants are the most common CSP technology, representing about 94% of power installed in Spain. These plants collect solar energy in parabolic trough concentrators with linear collector tubes. The heat transfer fluids are typically synthetic oil that circulates through tubes at inlet outlet/temperatures of 300 °C to 400 °C. The typical storage capacity of a 50 MW facility is 7 hours at nominal power. A plant of this size and storage capacity can generate 160 GWh/year in a region like Spain. |
[[Parabolic trough]] plants are the most common CSP technology, representing about 94% of power installed in Spain. These plants collect solar energy in parabolic trough concentrators with linear collector tubes. The heat transfer fluids are typically synthetic oil that circulates through tubes at inlet outlet/temperatures of 300 °C to 400 °C. The typical storage capacity of a 50 MW facility is 7 hours at nominal power. A plant of this size and storage capacity can generate 160 GWh/year in a region like Spain. |
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Copper quantities also vary according to design. The solar field of a typical 50 MW power plant with 7 hours of storage capacity consists of 150 loops and 600 motors, while a similar plant without storage uses 100 loops and 400 motors. Motorized valves for mass flow control in the loops rely on more copper. Mirrors use a small amount of copper to provide [[galvanic corrosion]] protection to the reflective silver layer. Changes in the size of the plants, size of collectors, efficiencies of heat transfer fluids will also affect material volumes.<ref name="leonardo-energy4"/> |
Copper quantities also vary according to design. The solar field of a typical 50 MW power plant with 7 hours of storage capacity consists of 150 loops and 600 motors, while a similar plant without storage uses 100 loops and 400 motors. Motorized valves for mass flow control in the loops rely on more copper. Mirrors use a small amount of copper to provide [[galvanic corrosion]] protection to the reflective silver layer. Changes in the size of the plants, size of collectors, efficiencies of heat transfer fluids will also affect material volumes.<ref name="leonardo-energy4"/> |
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=== Tower plants === |
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[[Solar power tower|Tower plants]], also called central tower power plants, may become the preferred CSP technology in the future. They collect solar energy concentrated by the [[heliostat]] field in a central receiver mounted at the top of the tower. Each heliostat tracks the Sun along two axes (azimuth and elevation). Therefore, two motors per unit are required. |
[[Solar power tower|Tower plants]], also called central tower power plants, may become the preferred CSP technology in the future. They collect solar energy concentrated by the [[heliostat]] field in a central receiver mounted at the top of the tower. Each heliostat tracks the Sun along two axes (azimuth and elevation). Therefore, two motors per unit are required. |
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A 50 MW solar tower facility with 7.5 hours of storage uses about 219 tonnes of copper. This translates to 4.4 tonnes of copper/MW, or, in other terms, 1.4 tonnes/GWh/year. Of this amount, cables account for approximately 154,720 kg. Electronic equipment, such as generators, transformers, and motors, account for approximately 64,620 kg of copper. A 100 MW plant has slightly more copper per MW in the solar field because the efficiency of the heliostat field diminishes with the size. A 100 MW plant will have somewhat less copper per MW in process equipment.<ref name="leonardo-energy4"/> |
A 50 MW solar tower facility with 7.5 hours of storage uses about 219 tonnes of copper. This translates to 4.4 tonnes of copper/MW, or, in other terms, 1.4 tonnes/GWh/year. Of this amount, cables account for approximately 154,720 kg. Electronic equipment, such as generators, transformers, and motors, account for approximately 64,620 kg of copper. A 100 MW plant has slightly more copper per MW in the solar field because the efficiency of the heliostat field diminishes with the size. A 100 MW plant will have somewhat less copper per MW in process equipment.<ref name="leonardo-energy4"/> |
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=== Linear Fresnel plants === |
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[[Compact linear Fresnel reflector|Linear Fresnel]] plants use linear reflectors to concentrate the |
[[Compact linear Fresnel reflector|Linear Fresnel]] plants use linear reflectors to concentrate the Sun's rays in an absorber tube similar to parabolic trough plants. Since the concentration factor is less than in parabolic trough plants, the temperature of the [[Coolant|heat transfer fluid]] is lower. This is why most plants use [[saturated steam]] as the working fluid in both the solar field and the turbine. |
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A 50 MW linear Fresnel power plant requires about 1,960 tracking motors. The power required for each motor is much lower than the parabolic trough plant. A 50 MW lineal Fresnel plant without storage will contain about 127 tonnes of copper. This translates to 2.6 tonnes of copper/MW, or in other terms, 1.3 tonnes of copper/GWh/year. Of this amount, 69,960 kg of copper are in cables from process area, solar field, earthing and lightning protection and controls. Another 57,300 kg of copper is in equipment (transformers, generators, motors, mirrors, pumps, fans).<ref name="leonardo-energy4"/> |
A 50 MW linear Fresnel power plant requires about 1,960 tracking motors. The power required for each motor is much lower than the parabolic trough plant. A 50 MW lineal Fresnel plant without storage will contain about 127 tonnes of copper. This translates to 2.6 tonnes of copper/MW, or in other terms, 1.3 tonnes of copper/GWh/year. Of this amount, 69,960 kg of copper are in cables from process area, solar field, earthing and lightning protection and controls. Another 57,300 kg of copper is in equipment (transformers, generators, motors, mirrors, pumps, fans).<ref name="leonardo-energy4"/> |
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=== Dish Stirling plants === |
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These plants are an emerging technology that has potential as a solution for decentralized applications. The technology does not require water for cooling in the conversion cycle. These plants are non-dispatchable. Energy production ceases when clouds pass overhead. Research is being conducted on advanced storage and hybridization systems. |
These plants are an emerging technology that has potential as a solution for decentralized applications. The technology does not require water for cooling in the conversion cycle. These plants are non-dispatchable. Energy production ceases when clouds pass overhead. Research is being conducted on advanced storage and hybridization systems. |
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==Solar water heaters (solar domestic hot water systems)== |
==Solar water heaters (solar domestic hot water systems)== |
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[[Solar water heating|Solar water heaters]] can be a cost-effective way to generate hot water for homes. They can be used in any climate. The fuel they use, sunshine, is free.<ref name="energysavers1">Solar water heaters; Energy Savers; Energy Efficiency and Renewable Energy; U.S. Department of Energy; http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850/</ref> |
[[Solar water heating|Solar water heaters]] can be a cost-effective way to generate hot water for homes. They can be used in any climate. The fuel they use, sunshine, is free.<ref name="energysavers1">Solar water heaters; Energy Savers; Energy Efficiency and Renewable Energy; U.S. Department of Energy; http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850/ {{Webarchive|url=https://web.archive.org/web/20120825233625/http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850 |date=2012-08-25 }}</ref> |
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Solar hot water collectors are used by more than 200 million households as well as many public and commercial buildings worldwide.<ref name="ren1"/> The total installed capacity of solar thermal heating and cooling units in 2010 was 185 GW-thermal.<ref name="autogenerated2"/> |
Solar hot water collectors are used by more than 200 million households as well as many public and commercial buildings worldwide.<ref name="ren1"/> The total installed capacity of solar thermal heating and cooling units in 2010 was 185 GW-thermal.<ref name="autogenerated2">2011 global status report by Renewable Energy Policy Network for the 21st Century (REN21)</ref> |
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Solar heating capacity increased by an estimated 27% in 2011 to reach approximately 232 GWth, excluding unglazed swimming pool heating. Most solar thermal is used for water heating, but solar space heating and cooling are gaining ground, particularly in Europe.<ref name="ren1"/> |
Solar heating capacity increased by an estimated 27% in 2011 to reach approximately 232 GWth, excluding unglazed swimming pool heating. Most solar thermal is used for [[water heating]], but solar space heating and cooling are gaining ground, particularly in Europe.<ref name="ren1"/> |
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There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. Passive solar techniques do not require working electrical or mechanical elements. They include the selection of materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun.<ref name="leonardo-energy1"/> |
There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. Passive solar techniques do not require working electrical or mechanical elements. They include the selection of materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun.<ref name="leonardo-energy1"/> |
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Copper is an important component of solar thermal heating and cooling systems because of its high [[List of thermal conductivities|heat conductivity]], resistance to atmospheric and water corrosion, sealing and joining by soldering, and mechanical strength. Copper is used both in receivers and primary circuits (pipes and heat exchangers for water tanks).<ref name="autogenerated2"/> For the [[Solar thermal collector|absorber plate]], |
Copper is an important component of solar thermal heating and cooling systems because of its high [[List of thermal conductivities|heat conductivity]], resistance to atmospheric and water corrosion, sealing and joining by soldering, and mechanical strength. Copper is used both in receivers and primary circuits (pipes and heat exchangers for water tanks).<ref name="autogenerated2"/> For the [[Solar thermal collector|absorber plate]], aluminium is sometimes used as it is cheaper, yet when combined with copper piping, there may be problems in regards to allow the absorber plate to transfer its heat to the piping suitably. An alternative material that is currently used is [[Cross-linked polyethylene#PEX-AL-PEX|PEX-AL-PEX]]<ref>[http://www.builditsolar.com/Experimental/PEXCollector/SmallPanelTests.htm PEX-AL-PEX used frequently for solar thermal collector construction]</ref> but there may be similar problems with the heat transfer between the absorber plate and the pipes as well. One way around this is to simply use the same material for both the piping and the absorber plate. This material can be copper off course but also aluminium or PEX-AL-PEX. |
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Three types of [[solar thermal collector]]s are used for residential applications: [[Solar thermal collector#Flat plate collectors|flat plate collectors]], integral collector-storage, and [[Solar thermal collector#Evacuated tube collectors|solar thermal collector: Evacuated tube collectors]]; They can be direct circulation (i.e., heats water and brings it directly to the home for use) or indirect circulation (i.e., pumps heat a transfer fluid through a heat exchanger, which then heats water that flows into the home) systems.<ref name="energysavers1"/> |
Three types of [[solar thermal collector]]s are used for residential applications: [[Solar thermal collector#Flat plate collectors|flat plate collectors]], integral collector-storage, and [[Solar thermal collector#Evacuated tube collectors|solar thermal collector: Evacuated tube collectors]]; They can be direct circulation (i.e., heats water and brings it directly to the home for use) or indirect circulation (i.e., pumps heat a transfer fluid through a heat exchanger, which then heats water that flows into the home) systems.<ref name="energysavers1"/> |
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In an evacuated tube solar hot water heater with an indirect circulation system, evacuated tubes contain a glass outer tube and metal absorber tube attached to a fin. Solar thermal energy is absorbed within the evacuated tubes and is converted into usable concentrated heat. Copper heat pipes transfer thermal energy from within the solar tube into a copper header. A thermal transfer fluid (water or [[glycol]] mixture) is pumped through the copper header. As the solution circulates through the copper header, the temperature rises. The evacuated glass tubes have a double layer. The outer layer is fully transparent to allow solar energy to pass through unimpeded. The inner layer is treated with a selective [[optical coating]] that absorbs energy without reflection. The inner and outer layers are fused at the end, leaving an empty space between the inner and outer layers. All air is pumped out of the space between the two layers (evacuation process), thereby creating the thermos effect which stops conductive and convective transfer of heat that might otherwise escape into the atmosphere. Heat loss is further reduced by the low-emissivity of the glass that is used. Inside the glass tube is the copper heat pipe. It is a sealed hollow copper tube that contains a small amount of proprietary liquid, which under low pressure boils at a very low temperature. Other components include a solar heat exchanger tank and a solar pumping station, with pumps and controllers.<ref>Solar hot water; B&R Service Inc.; http://www.bandrservice.com/solar.htm</ref><ref>How solar hot water system works; SolarPlusGreen.com; http://www.solarplusgreen.com/solar-know-how.htm</ref><ref>Mirasol Solar Energy Systems; http://www.mirasolenergysystems.com/pdf/et-technology.pdf</ref><ref>How solar heaters work; Mayca Solar Energy; {{cite web |url=http://www.maycasolar.com/techinfo.asp |title= |
In an evacuated tube solar hot water heater with an indirect circulation system, evacuated tubes contain a glass outer tube and metal absorber tube attached to a fin. Solar thermal energy is absorbed within the evacuated tubes and is converted into usable concentrated heat. Copper heat pipes transfer thermal energy from within the solar tube into a copper header. A thermal transfer fluid (water or [[glycol]] mixture) is pumped through the copper header. As the solution circulates through the copper header, the temperature rises. The evacuated glass tubes have a double layer. The outer layer is fully transparent to allow solar energy to pass through unimpeded. The inner layer is treated with a selective [[optical coating]] that absorbs energy without reflection. The inner and outer layers are fused at the end, leaving an empty space between the inner and outer layers. All air is pumped out of the space between the two layers (evacuation process), thereby creating the thermos effect which stops conductive and convective transfer of heat that might otherwise escape into the atmosphere. Heat loss is further reduced by the low-emissivity of the glass that is used. Inside the glass tube is the copper heat pipe. It is a sealed hollow copper tube that contains a small amount of proprietary liquid, which under low pressure boils at a very low temperature. Other components include a solar heat exchanger tank and a solar pumping station, with pumps and controllers.<ref>Solar hot water; B&R Service Inc.; http://www.bandrservice.com/solar.htm</ref><ref>How solar hot water system works; SolarPlusGreen.com; http://www.solarplusgreen.com/solar-know-how.htm {{Webarchive|url=https://web.archive.org/web/20120904220147/http://www.solarplusgreen.com/solar-know-how.htm |date=2012-09-04 }}</ref><ref>Mirasol Solar Energy Systems; http://www.mirasolenergysystems.com/pdf/et-technology.pdf {{Webarchive|url=https://web.archive.org/web/20131104014440/http://www.mirasolenergysystems.com/pdf/et-technology.pdf |date=2013-11-04 }}</ref><ref>How solar heaters work; Mayca Solar Energy; {{cite web |url=http://www.maycasolar.com/techinfo.asp |title=Technical Info, Haining Mayca Solar Energy Technology Co., Ltd. |accessdate=2012-11-26 |url-status=dead |archiveurl=https://web.archive.org/web/20121028203532/http://www.maycasolar.com/techinfo.asp |archivedate=2012-10-28 }}</ref><ref>Bayat Energy: solar water heaters; http://www.bayatenergy.co.uk/Solar%20Water%20Heaters%20Catalogue.pdf {{Webarchive|url=https://web.archive.org/web/20131103191342/http://www.bayatenergy.co.uk/Solar%20Water%20Heaters%20Catalogue.pdf |date=2013-11-03 }}</ref> |
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==Wind== |
==Wind== |
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In a [[wind turbine]], the wind's [[kinetic energy]] is converted into [[mechanical energy]] to drive a [[Electric generator|generator]], which in turn generates [[electricity]]. The basic components of a wind power system consist of a tower with rotating blades containing an electricity generator and a transformer to step up voltage for electricity transmission to a substation on the grid. Cabling and electronics are also important components.<ref name="leonardo-energy1" /><ref>Distributed generation and renewables – wind power; Power Quality and Utilisation Guide; Leonardo Energy; {{cite web|url=http://www.copperinfo.co.uk/power-quality/downloads/pqug/832-wind-power.pdf|title=Archived copy|url-status=dead|archiveurl=https://web.archive.org/web/20121101181406/http://www.copperinfo.co.uk/power-quality/downloads/pqug/832-wind-power.pdf|archivedate=2012-11-01|accessdate=2012-12-12}}</ref> |
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[[Wind power]] is the conversion of wind energy into a useful form of energy, such as using [[wind turbines]] to make electricity, [[windmills]] for mechanical power, [[windpump]]s for water pumping or drainage, or [[sail]]s to propel ships. In a [[wind turbine]], the wind's [[kinetic energy]] is converted into [[mechanical energy]] to drive a [[Electric generator|generator]], which in turn generates [[electricity]]. |
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The harsh environment [[Offshore wind power|offshore wind]] farms means that the individual components need to be more rugged and corrosion protected than their onshore components. Increasingly long connections to shore with subsea MV and HV cables are required at this time. The need for [[corrosion resistance|corrosion protection]] favors [[copper nickel]] cladding as the preferred alloy for the towers. |
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Wind energy is one of the fastest growing energy technologies. Wind power capacity increased from a very small base of around 0.6 GW in 1996 to around 160 GW in 2009.<ref name="leonardo-energy1"/> It has also been reported that wind power capacity increased by 20% in 2011 to approximately 238 GW by 2012. This was the largest addition in capacity of any of the renewable energy technologies.<ref name="ren1"/> It is anticipated that the growth of wind energy will continue to rise dramatically. Moderate estimates for global capacity by 2020 are 711 GW.<ref>Wind Energy – The Facts, European Wind Energy Association (EWEA), as cited in The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010</ref> |
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Copper is an important conductor in wind power generation.<ref>Miles of copper make it possible, Copper and Wind Energy: Partners for a Clean Environment; Copper Development Association Inc., http://www.copper.org/applications/electrical/energy/casestudy/wind_energy_a6101.html#top {{Webarchive|url=https://web.archive.org/web/20121018110937/http://www.copper.org/applications/electrical/energy/casestudy/wind_energy_a6101.html#top |date=2012-10-18 }}</ref><ref name="copper2">Wind energy basics – how copper helps make wind energy possible; http://www.copper.org/environment/green/casestudies/wind_energy/wind_energy.html</ref> Wind farms can contain several hundred-thousand feet of copper<ref>Tatakis, Jim 2011. Copper truly is the green metal; Granite's Edge – Investment insight from Granite Investment Advisors; http://www.granitesedge.com/2011/02/01/copper-truly-is-the-green-metal {{Webarchive|url=https://web.archive.org/web/20130602182832/http://www.granitesedge.com/2011/02/01/copper-truly-is-the-green-metal/ |date=2013-06-02 }}</ref> weighing between 4 million to 15 million pounds, mostly in wiring, cable, tubing, generators and step-up transformers.<ref name="renewableenergyworld.com"/><ref name="ReferenceA">The Rise Of Solar: A Unique Opportunity For Copper; Solar Industry Magazine; April 2017; by Zolaika Strong; https://issues.solarindustrymag.com/article/rise-solar-unique-opportunity-copper {{Webarchive|url=https://web.archive.org/web/20221030093858/https://issues.solarindustrymag.com/article/rise-solar-unique-opportunity-copper |date=2022-10-30 }}</ref> |
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Some 50 countries operated wind power facilities in 2010.<ref name="ren1"/> |
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Copper usage intensity is high because turbines in wind generation farms are spread over large areas.<ref name="windpowerengineering.com">Growing renewable energy needs more copper; by Nic Sharpley; November 21, 2012; ''Windpower Engineering''; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ {{Webarchive|url=https://web.archive.org/web/20180622061901/https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ |date=2018-06-22 }}</ref> In land-based wind farms, copper intensity can range between 5,600 and 14,900 pounds per MW, depending on whether the step-up transformers have copper or aluminium conductors. In the off-shore environment, copper intensity is much higher: approximately 21,000 pounds per MW, which includes submarine cables to shore.<ref>Growing renewable energy needs more copper; by Nic Sharpley; November 21, 2012; ''Windpower Engineering''; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ {{Webarchive|url=https://web.archive.org/web/20180622061901/https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ |date=2018-06-22 }}; citing the study: Current and projected wind and solar renewable electric generating capacity and resulting copper demand; by BFF Associates and Konrad J.A. Kundig; published at: http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf {{Webarchive|url=https://web.archive.org/web/20170624103919/http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf |date=2017-06-24 }}</ref> In both onshore and offshore environments, additional copper cabling is used to connect wind farms to main electrical grids.<ref name="ReferenceA"/> |
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Traditionally, wind power has been generated on land. But higher wind speeds are available offshore compared to land.<ref>Offshore Wind Power 2010 BTM Consult, Madsen & Krogsgaard; 22 November 2010. {{cite web |url=http://btm.dk/news/offshore+wind+power+2010/?s%3D9%26p%3D%26n%3D39 |title=Archived copy |accessdate=2010-11-22 |deadurl=yes |archiveurl=https://web.archive.org/web/20110630030725/http://btm.dk/news/offshore%2Bwind%2Bpower%2B2010/?s=9&p=&n=39 |archivedate=2011-06-30 |df= }}</ref> Technologies are being improved to exploit the potential of wind power in offshore environments. The offshore wind power market is expanding with the use of larger turbines and installations farther from shore.<ref name="ren1"/> |
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The amount of copper used for wind energy systems in 2011 was estimated to be 120 kt. The cumulative amount of copper installed through 2011 was estimated to be 714 kt.<ref name="leonardo-energy3"/> {{as of|2018}}, global production of wind turbines use 450,000 tonnes of copper per year.<ref name=owj2019>{{cite web |title=Fast pace of growth in wind energy driving demand for copper |url=https://www.rivieramm.com/editors-choice-brand/fast-pace-of-growth-in-wind-energy-driving-demand-for-copper-56058 |website=Riviera Maritime Media |language=En}}</ref> |
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Offshore installation, as yet, is a comparatively small market, probably accounting for little more than 10% of installation globally. The location of new [[wind farms]] increasingly will be offshore, especially in Europe. Offshore wind farms are normally much larger, often with over 100 turbines with ratings up to 3 MW and above per turbine. The harsh environment means that the individual components need to be more rugged and corrosion protected than their onshore components. Increasingly long connections to shore with subsea MV and HV cables are required at this time. The need for [[corrosion resistance|corrosion protection]] favors [[copper nickel]] cladding as the preferred alloy for the towers. |
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For wind farms with three-stage gearbox doubly fed 3 MW induction generators, approximately 2.7 t per MW is needed with standard wind turbines. For wind turbines with LV/MV transformers in the nacelle, 1.85 t per MW is needed.<ref name="imedea.uib-csic.es">García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. A global renewable mix with proven technologies and common materials, Energy Policy 41 (2012): 561-57, http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf</ref> |
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Wind power installations vary in scale and type. Large wind farm installations linked to the [[electrical grid]] are at one end of the spectrum. These may be located either onshore or offshore. At the other end of the spectrum are small individual [[turbines]] that provide electricity to individual premises or electricity-using installations. These are often in rural and grid-isolated sites.<ref name="leonardo-energy1"/> |
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Copper is primarily used in coil windings in the [[stator]] and [[Rotor (electric)|rotor]] portions of [[Electric generator|generators]] (which convert mechanical energy into electrical energy), in [[high voltage]] and [[low voltage]] cable conductors including the vertical electrical cable that connects the [[nacelle]] to the base of the [[wind turbine]], in the coils of transformers (which steps up low voltage AC to high voltage AC compatible with the grid), in [[gearboxes]] (which convert the slow revolutions per minute of the rotor blades to faster rpms) and in wind farm electrical grounding systems.<ref name="windpowerengineering.com"/> Copper may also be used in the nacelle (the housing of the wind turbine that rests on the tower containing all the main components), auxiliary motors (motors used to rotate the nacelle as well as control the angle of the rotor blades), cooling circuits (cooling configuration for the entire [[drive train]]), and [[power electronics]] (which enable the wind turbine systems to perform like a power plant).<ref>Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI on July 12, 2010. Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Ask an expert | Leonardo ENERGY |accessdate=2012-12-12 |url-status=dead |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 }}</ref> |
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The basic components of a wind power system consist of a tower with rotating blades containing an electricity generator and a transformer to step up voltage for electricity transmission to a substation on the grid. Cabling and electronics are also important components.<ref name="leonardo-energy1"/><ref>Distributed generation and renewables – wind power; Power Quality and Utilisation Guide; Leonardo Energy; {{cite web |url=http://www.copperinfo.co.uk/power-quality/downloads/pqug/832-wind-power.pdf |title=Archived copy |accessdate=2012-12-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20121101181406/http://www.copperinfo.co.uk/power-quality/downloads/pqug/832-wind-power.pdf |archivedate=2012-11-01 |df= }}</ref> |
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In the coils of wind generators, electric current suffers from losses that are proportional to the resistance of the wire that carries the current. This resistance, called [[copper loss]]es, causes energy to be lost by heating up the wire. In wind power systems, this resistance can be reduced with thicker copper wire and with a cooling system for the generator, if required.<ref>Meyers, C. Bracken, 2009. Energy loss of a wind turbine; Centurion Energy; July 31, 2009; http://centurionenergy.net/energy-loss-of-a-wind-turbine {{Webarchive|url=https://web.archive.org/web/20121030051645/http://centurionenergy.net/energy-loss-of-a-wind-turbine |date=2012-10-30 }}</ref> |
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===Copper in wind power generation=== |
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Copper is an important conductor in wind power generation.<ref>Miles of copper make it possible, Copper and Wind Energy: Partners for a Clean Environment; Copper Development Association Inc., http://www.copper.org/applications/electrical/energy/casestudy/wind_energy_a6101.html#top</ref><ref name="copper2">Wind energy basics – how copper helps make wind energy possible; http://www.copper.org/environment/green/casestudies/wind_energy/wind_energy.html</ref> Wind farms can contain several hundred-thousand feet of copper<ref>Tatakis, Jim 2011. Copper truly is the green metal; Granite’s Edge – Investment insight from Granite Investment Advisors; http://www.granitesedge.com/2011/02/01/copper-truly-is-the-green-metal</ref> weighing between 4 million to 15 million pounds.<ref>Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html</ref> The amount of copper used for wind energy systems in 2011 was estimated to be 120 kt. The cumulative amount of copper installed through 2011 was estimated to be 714 kt.<ref name="leonardo-energy3"/> |
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=== Copper in generators === |
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For wind farms with three-stage gearbox doubly fed 3 MW induction generators, approximately 2.7 t per MW is needed with standard windmills. For windmills with LV/MV transformers in the nacelle, 1.85 t per MW is needed.<ref>García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. A global renewable mix with proven technologies and common materials, Energy Policy 41 (2012): 561-57, http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf</ref> |
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Either copper or aluminium conductors can be specified for generator cables.<ref>Critical Component — Cables: Choosing the right cable for specific turbine applications is essential for wind farm success; Wind Systems; Uwe Schenk; http://www.windsystemsmag.com/article/detail/538/critical-componentcables {{Webarchive|url=https://web.archive.org/web/20180720225626/http://www.windsystemsmag.com/article/detail/538/critical-componentcables |date=2018-07-20 }}</ref> Copper has the higher electrical conductivity and therefore the higher electrical energy efficiency. It is also selected for its safety and reliability. The main consideration for specifying aluminium is its lower capital cost. Over time, this benefit is offset by higher energy losses over years of power transmission. Deciding which conductor to use is determined during a project's planning phase when utility teams discuss these matters with turbine and cable manufacturers. |
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Regarding copper, its weight in a generator will vary according to the type of generator, [[power rating]], and configuration. Its weight has an almost linear relationship to the power rating. |
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Copper is primarily used in coil windings in the [[stator]] and [[Rotor (electric)|rotor]] portions of [[Electric generator|generators]] (which convert mechanical energy into electrical energy), in [[low voltage]] cable conductors including the vertical electrical cable that connects the [[nacelle]] to the base of the [[wind turbine]], in the coils of transformers (which steps up low voltage AC to high voltage AC compatible with the grid), and in [[gearboxes]] (which convert the slow revolutions per minute of the rotor blades to faster rpms). Copper may also be used in the nacelle (the housing of the wind turbine that rests on the tower containing all the main components), auxiliary motors (motors used to rotate the nacelle as well as control the angle of the rotor blades), cooling circuits (cooling configuration for the entire [[drive train]]), and [[power electronics]] (which enable the wind turbine systems to perform like a power plant).<ref>Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI on July 12, 2010. Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Archived copy |accessdate=2012-12-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 |df= }}</ref> |
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Generators in [[Wind turbine design|direct-drive wind turbines]] usually contain more copper, as the generator itself is bigger due to the absence of a gearbox.<ref name="leonardo-energy5">Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI; July 12, 2010. Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Ask an expert | Leonardo ENERGY |accessdate=2012-12-12 |url-status=dead |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 }}</ref> |
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In the coils of wind generators, electric current suffers from losses that are proportional to the resistance of the wire that carries the current. This resistance, called [[copper loss]]es, causes energy to be lost by heating up the wire. In wind power systems, this resistance can be reduced with thicker copper wire and with a cooling system for the generator, if required.<ref>Meyers, C. Bracken, 2009. Energy loss of a wind turbine; Centurion Energy; July 31, 2009; http://centurionenergy.net/energy-loss-of-a-wind-turbine</ref> |
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====Copper in generators==== |
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The amount of copper in a generator will vary according to the type of generator, its [[power rating]], and its configuration. The weight of copper has an almost linear relationship to the power rating of the generator. |
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Generators in [[Wind turbine design|direct-drive wind turbines]] contain more copper, as the generator itself is bigger due to the absence of a gearbox.<ref name="leonardo-energy5">Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI; July 12, 2010. Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Archived copy |accessdate=2012-12-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 |df= }}</ref> |
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A generator in a direct drive configuration could be 3.5 times to 6 times heavier than in a geared configuration, depending on the type of generator.<ref name="leonardo-energy5"/> |
A generator in a direct drive configuration could be 3.5 times to 6 times heavier than in a geared configuration, depending on the type of generator.<ref name="leonardo-energy5"/> |
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|[[Induction generator|Conventional asynchronous generators]] (CAG) ||390 || Geared; neutral demand until 2015; will become negligible by 2020. |
|[[Induction generator|Conventional asynchronous generators]] (CAG) ||390 || Geared; neutral demand until 2015; will become negligible by 2020. |
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|[[Alternator|Conventional synchronous generators]] (CSG) ||330–4000 || Geared and direct; |
|[[Alternator|Conventional synchronous generators]] (CSG) ||330–4000 || Geared and direct; may become more popular by 2020. |
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|[[Permanent magnet synchronous generator]]s (PMSG) ||600–2150 || Market expected to develop by 2015. |
|[[Permanent magnet synchronous generator]]s (PMSG) ||600–2150 || Market expected to develop by 2015. |
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Direct-drive configurations of the synchronous type machines contain the most copper. Conventional synchronous generators (CSG) direct-drive machines have the highest per-unit copper content. The share of CSGs will increase from 2009 to 2020, especially for direct drive machines. DFAGs accounted for the most unit sales in 2009.<ref name="leonardo-energy5"/> |
Direct-drive configurations of the synchronous type machines usually contain the most copper, but some use aluminium.<ref name=owj2019/> Conventional synchronous generators (CSG) direct-drive machines have the highest per-unit copper content. The share of CSGs will increase from 2009 to 2020, especially for direct drive machines. DFAGs accounted for the most unit sales in 2009.<ref name="leonardo-energy5"/> |
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The variation in the copper content of CSG generators depends upon whether they are coupled with single-stage (heavier) or three-stage (lighter) gearboxes. Similarly, the difference in copper content in PMSG generators depends on whether the turbines are medium speed, which are heavier, or high-speed turbines, which are lighter.<ref name="leonardo-energy5"/> |
The variation in the copper content of CSG generators depends upon whether they are coupled with single-stage (heavier) or three-stage (lighter) gearboxes. Similarly, the difference in copper content in PMSG generators depends on whether the turbines are medium speed, which are heavier, or high-speed turbines, which are lighter.<ref name="leonardo-energy5"/> |
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There is increasing demand for synchronous machines and direct-drive configurations. CSG direct and geared DFAGs will lead the demand for copper. The highest growth in demand is expected to be the direct PMSGs, which is forecast to account for 7.7% of the total demand for copper in wind power systems in 2015. However, since permanent magnets that contain the rare earth element neodymium may not be able to escalate globally, direct drive synchronous magnet (DDSM) designs may be more promising.<ref |
There is increasing demand for synchronous machines and direct-drive configurations. CSG direct and geared DFAGs will lead the demand for copper. The highest growth in demand is expected to be the direct PMSGs, which is forecast to account for 7.7% of the total demand for copper in wind power systems in 2015. However, since permanent magnets that contain the rare earth element neodymium may not be able to escalate globally, direct drive synchronous magnet (DDSM) designs may be more promising.<ref name="imedea.uib-csic.es"/> The amount of copper required for a 3 MW DDSM generator is 12.6 t.<ref>Bang, D., Polinder, H. Shrestha, G. and Ferreira, J.A., 2009. Possible solutions to overcome drawbacks of direct-drive generator for large wind turbines; In: Ewc 2009 Proceedings, CT3 session, available at http://www.ewec2009proceedings.info.</ref> |
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Locations with high-speed turbulent winds are better suited for variable-speed wind turbine generators with full-scale power converters due to the greater reliability and availability they offer in such conditions. Of the variable-speed wind turbine options, PMSGs could be preferred over DFAGs in such locations. In conditions with low wind speed and turbulence, DFAGs could be preferred to PMSGs.<ref name="leonardo-energy3"/> |
Locations with high-speed turbulent winds are better suited for variable-speed wind turbine generators with full-scale power converters due to the greater reliability and availability they offer in such conditions. Of the variable-speed wind turbine options, PMSGs could be preferred over DFAGs in such locations. In conditions with low wind speed and turbulence, DFAGs could be preferred to PMSGs.<ref name="leonardo-energy3"/> |
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High-temperature superconductors (HTSG) technology is currently under development. It is expected that these machines will be able to attain more power than other wind turbine generators. If the offshore market follows the trend of larger unit machines, offshore could be the most suitable niche for HTSGs.<ref name="leonardo-energy3"/> |
High-temperature superconductors (HTSG) technology is currently under development. It is expected that these machines will be able to attain more power than other wind turbine generators. If the offshore market follows the trend of larger unit machines, offshore could be the most suitable niche for HTSGs.<ref name="leonardo-energy3"/> |
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=== Copper in other components === |
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For a 2 MW turbine system, the following amounts of copper were estimated for components other than the generator: |
For a 2 MW turbine system, the following amounts of copper were estimated for components other than the generator: |
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{| class="wikitable" |
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Copper Content by other Component Types, 2 MW turbine<ref>Frost and Sullivan, 2009, cited in Wind Generator Technology, by Eclareon S.L., Madrid, May 2012; www.eclareon.com; Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title= |
Copper Content by other Component Types, 2 MW turbine<ref>Frost and Sullivan, 2009, cited in Wind Generator Technology, by Eclareon S.L., Madrid, May 2012; http://www.eclareon.com; Available at Leonardo Energy - Ask an Expert; {{cite web |url=http://www.leonardo-energy.org/ask-expert |title=Ask an expert | Leonardo ENERGY |accessdate=2012-12-12 |url-status=dead |archiveurl=https://web.archive.org/web/20121126131037/http://www.leonardo-energy.org/ask-expert |archivedate=2012-11-26 }}</ref> |
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Cabling is the second largest copper-containing component after the generator. A wind tower system with the transformer next to the generator will have medium-voltage (MV) power cables running from the top to the bottom of the tower, then to a collection point for a number of wind towers and on to the grid substation, or direct to the substation. The tower assembly will incorporate wire harnesses and control/signal cables, while low-voltage (LV) power cables are required to power the working parts throughout the system.<ref name="leonardo-energy1"/> |
Cabling is the second largest copper-containing component after the generator. A wind tower system with the transformer next to the generator will have medium-voltage (MV) power cables running from the top to the bottom of the tower, then to a collection point for a number of wind towers and on to the grid substation, or direct to the substation. The tower assembly will incorporate wire harnesses and control/signal cables, while low-voltage (LV) power cables are required to power the working parts throughout the system.<ref name="leonardo-energy1"/> |
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For a 2 MW wind turbine, the vertical cable could range from 1,000 |
For a 2 MW wind turbine, the vertical cable could range from 1,000 to 1,500 kg of copper, depending upon its type. Copper is the dominant material in underground cables.<ref name="leonardo-energy5"/> |
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=== Copper in grounding systems === |
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Copper is vital to the [[electrical grounding]] system for wind turbine farms. Grounding systems can either be all-copper (solid or stranded copper wires and copper bus bars) often with an American gauge rating of 4/0 but perhaps as large as 250 thousands of circular mils<ref>Winds of Trade Toward Copper; Energy & Infrastructure; http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper {{Webarchive|url=https://web.archive.org/web/20180622060429/http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper |date=2018-06-22 }}</ref> or copper-clad steel, a lower cost alternative.<ref>Introduction to wind turbine cables: Cables 101: by Kathie Zipp, January 17, 2012; https://www.windpowerengineering.com/mechanical/cables-connectors/cables-101/</ref> |
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Turbine masts attract [[lightning]] strikes, so they require [[lightning protection]] systems. When lightning strikes a turbine blade, current passes along the blade, through the blade hub in the [[nacelle]] ([[gearbox]]/ generator enclosure) and down the mast to a grounding system. The blade incorporates a large cross-section copper conductor that runs along its length and allows current to pass along the blade without deleterious heating effects. The nacelle is protected by a lightning conductor, often copper. The grounding system, at the base of the mast, consists of a thick copper ring conductor bonded to the base or located within a meter of the base. The ring is attached to two diametrically opposed points on the mast base. Copper leads extend outward from the ring and connect to copper grounding electrodes. The grounding rings at turbines on wind farms are inter-connected, providing a networked system with an extremely small aggregate resistance.<ref name="copper2"/> |
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Solid [[Copper wire and cable|copper wire]] has been traditionally deployed for grounding and lightning equipment due to its excellent [[electrical conductivity]]. However, manufacturers are moving towards less expensive bi-metal copper clad or aluminium grounding wires and cables.<ref>Mattera, Michael; 2010. An alternative to copper-based grounding; Windpoweer Engineering & Development; August 4, 2010; http://www.windpowerengineering.com/tag/copper-clad-steel/</ref> Copper-plating wire is being explored. Current disadvantages of copper plated wire include lower conductivity, size, weight, flexibility and current carrying capability. |
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====Copper in grounding systems==== |
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Copper is vital to the [[electrical grounding]] system for wind turbine farms. Turbine masts attract [[lightning]] strikes, so they require [[lightning protection]] systems. When lightning strikes a turbine blade, current passes along the blade, through the blade hub in the [[nacelle]] ([[gearbox]]/ generator enclosure) and down the mast to a grounding system. The blade incorporates a large cross-section copper conductor that runs along its length and allows current to pass along the blade without deleterious heating effects. The nacelle is protected by a lightning conductor, often copper. The grounding system, at the base of the mast, consists of a thick copper ring conductor bonded to the base or located within a meter of the base. The ring is attached to two diametrically opposed points on the mast base. Copper leads extend outward from the ring and connect to copper grounding electrodes. The grounding rings at turbines on wind farms are inter-connected, providing a networked system with an extremely small aggregate resistance.<ref name="copper2"/> |
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=== Copper in other equipment === |
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Solid [[Copper wire and cable|copper wire]] has been traditionally deployed for grounding and lightning equipment due to its excellent [[electrical conductivity]]. However, manufacturers are moving towards less expensive bi-metal copper clad or aluminum grounding wires and cables.<ref>Mattera, Michael; 2010. An alternative to copper-based grounding; Windpoweer Engineering & Development; August 4, 2010; http://www.windpowerengineering.com/tag/copper-clad-steel/</ref> Copper-plating wire is being explored. Current disadvantages of copper plated wire include lower conductivity, size, weight, flexibility and current carrying capability. |
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After generators and cable, minor amounts of copper are used in the remaining equipment. In yaw and pitch auxiliary motors, the [[Yaw system|yaw drive]] uses a combination of [[induction motors]] and multi-stage [[Epicyclic gearing|planetary gearboxes]] with minor amounts of copper. [[Power electronics]] have minimal amounts of copper compared to other equipment. As turbine capacities increase, converter ratings also increase from low voltage (<1 kV) to medium voltage (1–5 kV). Most wind turbines have full [[Electric power conversion|power converters]], which have the same [[power rating]] as the [[Electric generator|generator]], except the DFAG that has a power converter that is 30% of the rating of the generator. Finally, minor amounts of copper are used in air/oil and water cooled circuits on gearboxes or generators.<ref name="leonardo-energy5"/> |
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Class 5 copper power cabling is exclusively used from the generator through the loop and tower interior wall. This is due to its ability to withstand the stress from 15,000 torsion cycles for 20 years of service life.<ref>Critical Component—Cables: Choosing the right cable for specific turbine applications is essential for wind farm success; Wind Systems; Uwe Schenk; http://www.windsystemsmag.com/article/detail/538/critical-componentcables {{Webarchive|url=https://web.archive.org/web/20180720225626/http://www.windsystemsmag.com/article/detail/538/critical-componentcables |date=2018-07-20 }}</ref> |
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====Copper in other equipment==== |
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After generators and cable, minor amounts of copper are used in the remaining equipment. In yaw and pitch auxiliary motors, the [[Yaw system|yaw drive]] uses a combination of [[induction motors]] and multi-stage [[Epicyclic gearing|planetary gearboxes]] with minor amounts of copper. [[Power electronics]] have minimal amounts of copper compared to other equipment. As turbine capacities increase, converter ratings also increase from low voltage (<1kV) to medium voltage (1kV-5kV). Most wind turbines have full [[Electric power conversion|power converters]], which have the same [[power rating]] as the [[Electric generator|generator]], except the DFAG that has a power converter that is 30% of the rating of the generator. Finally, minor amounts of copper are used in air/oil and water cooled circuits on gearboxes or generators.<ref name="leonardo-energy5"/> |
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[[Superconductivity|Superconducting]] materials are being tested within and outside of wind turbines. They offer higher electrical efficiencies, the ability to carry higher currents, and lighter weights. These materials are, however, much more expensive than copper at this time.<ref name="leonardo-energy5"/> |
[[Superconductivity|Superconducting]] materials are being tested within and outside of wind turbines. They offer higher electrical efficiencies, the ability to carry higher currents, and lighter weights. These materials are, however, much more expensive than copper at this time.<ref name="leonardo-energy5"/> |
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=== Copper in offshore wind farms === |
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The amount of copper in offshore wind farms increases with the distance to the coast. Copper usage in offshore |
The amount of copper in offshore wind farms increases with the distance to the coast. Copper usage in offshore wind turbines is on the order of 10.5 t per MW.<ref>Growing renewable energy needs more copper; by Nic Sharpley; November 21, 2012; ''Windpower Engineering''; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ {{Webarchive|url=https://web.archive.org/web/20180622061901/https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ |date=2018-06-22 }}; citing the study: Current and projected wind and solar renewable electric generating capacity and resulting copper demand; by BFF Associates and Konrad J.A. Kundig; published at: http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf {{Webarchive|url=https://web.archive.org/web/20170624103919/http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf |date=2017-06-24 }}</ref> The [[List of offshore wind farms in Germany|Borkum 2 offshore wind farm]] uses 5,800 t for a 400 MW, 200 kilometer connection to the external grid, or approximately 14.5 t of copper per MW. The [[Horns Rev Offshore Wind Farm]] uses 8.75 tons of copper per MW to transmit 160 MW 21 kilometers to the grid.<ref>García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. "A global renewable mix with proven technologies and common materials." Energy Policy 41 (2012): 561-574. http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf</ref> |
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==References== |
==References== |
Latest revision as of 17:33, 20 January 2024
Renewable energy sources such as solar, wind, tidal, hydro, biomass, and geothermal have become significant sectors of the energy market.[1][2] The rapid growth of these sources in the 21st century has been prompted by increasing costs of fossil fuels as well as their environmental impact issues that significantly lowered their use.
Copper plays an important role in these renewable energy systems.[3][4][5][6][7] Copper usage averages up to five times more in renewable energy systems than in traditional power generation, such as fossil fuel and nuclear power plants.[8] Since copper is an excellent thermal and electrical conductor among engineering metals (second only to silver),[9] electrical systems that utilize copper generate and transmit energy with high efficiency and with minimum environmental impacts.
When choosing electrical conductors, facility planners and engineers factor capital investment costs of materials against operational savings due to their electrical energy efficiencies over their useful lives, plus maintenance costs. Copper often fares well in these calculations. A factor called "copper usage intensity,” is a measure of the quantity of copper necessary to install one megawatt of new power-generating capacity.
When planning for a new renewable power facility, engineers and product specifiers seek to avoid supply shortages of selected materials. According to the United States Geological Survey, in-ground copper reserves have increased more than 700% since 1950, from almost 100 million tonnes to 720 million tonnes in 2017, despite the fact that world refined usage has more than tripled in the last 50 years.[10] Copper resources are estimated to exceed 5,000 million tonnes.[11][12]
Bolstering the supply from copper extraction is the more than 30 percent of copper installed from 2007 to 2017 that came from recycled sources.[13] Its recycling rate is higher than any other metal.[14]
Overview
[edit]The majority of copper usage, worldwide, is for electrical wiring, including the coils of generators and motors.
Copper plays a larger role in renewable energy generation than in conventional thermal power plants in terms of tonnage of copper per unit of installed power.[15] The copper usage intensity of renewable energy systems is four to six times higher than in fossil fuel or nuclear plants. So for example, while conventional power requires approximately 1 tonne of copper per installed megawatt (MW), renewable technologies such as wind and solar require four to six times more copper per installed MW. This is because copper is spread over much larger land areas, particularly in solar and wind energy power plants.[16] Power and grounding cables must run far to connect components that are widely dispersed, including to energy storage systems and to the main electrical grid.[17][8]
Wind and solar photovoltaic energy systems have the highest copper content of all renewable energy technologies. A single wind farm can contain between 2000 and 7000 tons of copper. A photovoltaic solar power plant contains approximately 5.5 tons of copper per megawatt of power generation.[18] A single 660-kW turbine is estimated to contain some 800 pounds (350 kg) of copper.[19]
The total amount of copper used in renewable-based and distributed electricity generation in 2011 was estimated to be 272 kilotonnes (kt). Cumulative copper use through 2011 was estimated to be 1,071 kt.
Installed power in 2011[20] | Cumulative installed power to 2011[20] | Copper use in 2011[21][22][23] | Cumulative copper use to 2011[22][23][21] | |
---|---|---|---|---|
Gigawatts (GW) | Gigawatts (GW) | Kilotons (kt) | Kilotons (kt) | |
Photovoltaics | 30 | 70 | 150 | 350 |
Solar thermal electricity | 0.46 | 1.76 | 2 | 7 |
Wind | 40 | 238 | 120 | 714 |
Total for all three technologies | 272 | 1071 |
Copper conductors are used in major electrical renewable energy components, such as turbines, generators, transformers, inverters, electrical cables, power electronics, and information cable. Copper usage is approximately the same in turbines/generators, transformers/inverters, and cables. Much less copper is used in power electronics.
Solar thermal heating and cooling energy systems rely on copper for their thermal energy efficiency benefits. Copper is also used as a special corrosion-resistant material in renewable energy systems in wet, humid, and saline corrosive environments.
Copper is a sustainable material that is 100% recyclable and has a higher recycling rate than any other metal.[18] At the end of the useful life of equipment, its copper can be recycled with no loss of its beneficial properties.
Solar photovoltaic power generation
[edit]There is eleven to forty times more copper per unit of generation in photovoltaic systems than in conventional fossil fuel plants.[24] The usage of copper in photovoltaic systems averages around 4-5 tonnes per MW[25][8] or higher if conductive ribbon strips that connect individual PV cells are considered.[22]
Copper is used in:
- small wires that interconnect photovoltaic modules
- earthing grids in electrode earth pegs, horizontal plates, naked cables, and wires
- DC cables that connect photovoltaic modules to inverters
- low-voltage AC cables that connect inverters to metering systems and protection cabinets
- high-voltage AC cables
- communication cables
- inverters/power electronics
- ribbons
- transformer windings.
Copper used in photovoltaic systems in 2011 was estimated to be 150 kt. Cumulative copper usage in photovoltaic systems through 2011 was estimated to be 350 kt.[22]
Photovoltaic system configurations
[edit]Solar photovoltaic (PV) systems are highly scalable, ranging from small rooftop systems to large photovoltaic power station with capacities of hundreds of megawatts. In residential systems, copper intensity appears to be linearly scalable with the capacity of the electrical generation system.[26] Residential and community-based systems generally range in capacity from 10 kW to 1 MW.
PV cells are grouped together in solar modules. These modules are connected to panels and then into PV arrays. In grid-connected photovoltaic power system, arrays can form sub-fields from which electricity is collected and transported towards the grid connection.
Copper solar cables connect modules (module cable), arrays (array cable), and sub-fields (field cable). Whether a system is connected to the grid or not, electricity collected from the PV cells needs to be converted from DC to AC and stepped up in voltage. This is done by solar inverters which contain copper windings, as well as with copper-containing power electronics.
Solar cells
[edit]The photovoltaic industry uses several different semiconducting materials for the production of solar cells and often groups them into first and second generation technologies, while the third generation includes a number of emerging technologies that are still in the research and development phase. Solar cells typically convert 20% of incident sunlight into electricity, allowing the generation of 100 - 150 kWh per square meter of panel per year.[27]
Conventional first-generation crystalline silicon (c-Si) technology includes monocrystalline silicon and polycrystalline silicon. In order to reduce costs of this wafer-based technology, copper-contacted silicon solar cells are emerging as an important alternative to silver as the preferred conductor material. Challenges with solar cell metallization lie in the creation of a homogenous and qualitatively high-value layer between silicon and copper to serves as a barrier against copper diffusion into the semiconductor. Copper-based front-side metallization in silicon solar cells is a significant step towards lower cost.[28]
The second-generation technology includes thin film solar cells. Despite having a slightly lower conversion efficiency than conventional PV technology, the overall cost-per-watt is still lower. Commercially significant thin film technologies include copper indium gallium selenide solar cells (CIGS) and cadmium telluride photovoltaics (CdTe), while amorphous silicon (a-Si) and micromorphous silicon (m-Si) tandem cells are slowly being outcompeted in recent years.
CIGS, which is actually copper (indium-gallium) diselenide, or Cu(InGa)Se2, differs from silicon in that it is a heterojunction semiconductor. It has the highest solar energy conversion efficiency (~20%) among thin film materials.[29] Because CIGS strongly absorbs sunlight, a much thinner film is required than with other semiconductor materials.
A photovoltaic cell manufacturing process has been developed that makes it possible to print CIGS semi-conductors. This technology has the potential to reduce the price per solar watt delivered.
Mono-dispersed copper sulfide nanocrystals are being researched as alternatives to conventional single crystals and thin films for photovoltaic devices. This technology, which is still in its infancy, has potential for dye-sensitized solar cells, all-inorganic solar cells, and hybrid nano-crystal-polymer composite solar cells.[30]
Cables
[edit]Solar generation systems cover large areas. There are many connections among modules and arrays, and connections among arrays in sub-fields and linkages to the network. Solar cables are used for wiring solar power plants.[31] The amount of cabling involved can be substantial. Typical sizes of copper cables used are 4–6 mm2 for module cable, 6–10 mm2 for array cable, and 30–50 mm2 for field cable.[27]
Energy efficiency and system design
[edit]Energy efficiency and renewable energy are twin pillars of a sustainable energy future. However, there is little linking of these pillars despite their potential synergies. The more efficiently energy services are delivered, the faster renewable energy can become an effective and significant contributor of primary energy. The more energy is obtained from renewable sources, the less fossil fuel energy is required to provide that same energy demand.[32] This linkage of renewable energy with energy efficiency relies in part on the electrical energy efficiency benefits of copper.
Increasing the diameter of a copper cable increases its electrical energy efficiency (see: Copper wire and cable). Thicker cables reduce resistive (I2R) loss, which affects lifetime profitability of PV system investments. Complex cost evaluations, factoring extra costs for materials, the amount of solar radiation directed towards solar modules per year (accounting for diurnal and seasonal variations, subsidies, tariffs, payback periods, etc.) are necessary to determine whether higher initial investments for thicker cables are justified.
Depending upon circumstances, some conductors in PV systems can be specified with either copper or aluminium. As with other electrical conducting systems, there are advantages to each (see: Copper wire and cable). Copper is the preferred material when high electrical conductivity characteristics and flexibility of the cable are of paramount importance. Also, copper is more suitable for small roof facilities, in smaller cable trays, and when ducting in steel or plastic pipes.[22]
Cable ducting is not needed in smaller power facilities where copper cables are less than 25mm2. Without duct work, installation costs are lower with copper than with aluminium.[22]
Data communications networks rely on copper, optical fiber, and/or radio links. Each material has its advantages and disadvantages. Copper is more reliable than radio links. Signal attenuation with copper wires and cables can be resolved with signal amplifiers.[22]
Concentrating solar thermal power
[edit]Concentrating solar power (CSP), also known as solar thermal electricity (STE), uses arrays of mirrors that concentrate the sun's rays to temperatures between 4000C and 10000C.[27] Electrical power is produced when the concentrated light is converted to heat, which drives a heat engine (usually a steam turbine) connected to an electrical power generator.
A CSP system consists of: 1) a concentrator or collector containing mirrors that reflect solar radiation and deliver it to the receiver; 2) a receiver that absorbs concentrated sunlight and transfers heat energy to a working fluid (usually a mineral oil, or more rarely, molten salts, metals, steam or air); 3) a transport and storage system that passes the fluid from the receiver to the power conversion system; and 4) a steam turbine that converts thermal power to electricity on demand.
Copper is used in field power cables, grounding networks, and motors for tracking and pumping fluids, as well as in the main generator and high voltage transformers. Typically, there is about 200 tonnes copper for a 50 MW power plant.[21]
It has been estimated that copper usage in concentrated solar thermal power plants was 2 kt in 2011. Cumulative copper usage in these plants through 2011 was estimated to be 7 kt.[21]
There are four main types of CSP technologies, each containing a different amount of copper: parabolic trough plants, tower plants, distributed linear absorber systems including linear Fresnel plants, and dish Stirling plants.[21] The use of copper in these plants is described here.
Parabolic trough plants
[edit]Parabolic trough plants are the most common CSP technology, representing about 94% of power installed in Spain. These plants collect solar energy in parabolic trough concentrators with linear collector tubes. The heat transfer fluids are typically synthetic oil that circulates through tubes at inlet outlet/temperatures of 300 °C to 400 °C. The typical storage capacity of a 50 MW facility is 7 hours at nominal power. A plant of this size and storage capacity can generate 160 GWh/year in a region like Spain.
In parabolic trough plants, copper is specified in the solar collector field (power cables, signals, earthing, electrical motors); steam cycle (water pumps, condenser fans, cabling to consumption points, control signal and sensors, motors), electricity generators (alternator, transformer), and storage systems (circulating pumps, cabling to consumption points). A 50 MW plant with 7.5 hours of storage contains approximately 196 tonnes of copper, of which 131,500 kg are in cables and 64,700 kg are in various equipment (generators, transformers, mirrors, and motors). This translates to about 3.9 tonnes/MW, or, in other terms, 1.2 tonnes/GWh/year. A plant of the same size without storage can have 20% less copper in the solar field and 10% less in the electronic equipment. A 100 MW plant will have 30% less relative copper content per MW in the solar field and 10% less in electronic equipment.[21]
Copper quantities also vary according to design. The solar field of a typical 50 MW power plant with 7 hours of storage capacity consists of 150 loops and 600 motors, while a similar plant without storage uses 100 loops and 400 motors. Motorized valves for mass flow control in the loops rely on more copper. Mirrors use a small amount of copper to provide galvanic corrosion protection to the reflective silver layer. Changes in the size of the plants, size of collectors, efficiencies of heat transfer fluids will also affect material volumes.[21]
Tower plants
[edit]Tower plants, also called central tower power plants, may become the preferred CSP technology in the future. They collect solar energy concentrated by the heliostat field in a central receiver mounted at the top of the tower. Each heliostat tracks the Sun along two axes (azimuth and elevation). Therefore, two motors per unit are required.
Copper is required in the heliostat field (power cables, signal, earthing, motors), receiver (trace heating, signal cables), storage system (circulating pumps, cabling to consumption points), electricity generation (alternator, transformer), steam cycle (water pumps, condenser fans), cabling to consumption points, control signal and sensors, and motors.
A 50 MW solar tower facility with 7.5 hours of storage uses about 219 tonnes of copper. This translates to 4.4 tonnes of copper/MW, or, in other terms, 1.4 tonnes/GWh/year. Of this amount, cables account for approximately 154,720 kg. Electronic equipment, such as generators, transformers, and motors, account for approximately 64,620 kg of copper. A 100 MW plant has slightly more copper per MW in the solar field because the efficiency of the heliostat field diminishes with the size. A 100 MW plant will have somewhat less copper per MW in process equipment.[21]
Linear Fresnel plants
[edit]Linear Fresnel plants use linear reflectors to concentrate the Sun's rays in an absorber tube similar to parabolic trough plants. Since the concentration factor is less than in parabolic trough plants, the temperature of the heat transfer fluid is lower. This is why most plants use saturated steam as the working fluid in both the solar field and the turbine.
A 50 MW linear Fresnel power plant requires about 1,960 tracking motors. The power required for each motor is much lower than the parabolic trough plant. A 50 MW lineal Fresnel plant without storage will contain about 127 tonnes of copper. This translates to 2.6 tonnes of copper/MW, or in other terms, 1.3 tonnes of copper/GWh/year. Of this amount, 69,960 kg of copper are in cables from process area, solar field, earthing and lightning protection and controls. Another 57,300 kg of copper is in equipment (transformers, generators, motors, mirrors, pumps, fans).[21]
Dish Stirling plants
[edit]These plants are an emerging technology that has potential as a solution for decentralized applications. The technology does not require water for cooling in the conversion cycle. These plants are non-dispatchable. Energy production ceases when clouds pass overhead. Research is being conducted on advanced storage and hybridization systems.
The largest dish Sterling installation has a total power of 1.5 MW. Relatively more copper is needed in the solar field than other CSP technologies because electricity is actually generated there. Based on existing 1.5 MW plants, the copper content is 4 tonnes/MW, or, in other terms, 2.2 tonnes of copper/GWh/year. A 1.5 MW power plant has some 6,060 kg of copper in cables, induction generators, drives, field and grid transformers, earthing and lightning protection.[21]
Solar water heaters (solar domestic hot water systems)
[edit]Solar water heaters can be a cost-effective way to generate hot water for homes. They can be used in any climate. The fuel they use, sunshine, is free.[33]
Solar hot water collectors are used by more than 200 million households as well as many public and commercial buildings worldwide.[32] The total installed capacity of solar thermal heating and cooling units in 2010 was 185 GW-thermal.[34]
Solar heating capacity increased by an estimated 27% in 2011 to reach approximately 232 GWth, excluding unglazed swimming pool heating. Most solar thermal is used for water heating, but solar space heating and cooling are gaining ground, particularly in Europe.[32]
There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. Passive solar techniques do not require working electrical or mechanical elements. They include the selection of materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun.[27]
Copper is an important component of solar thermal heating and cooling systems because of its high heat conductivity, resistance to atmospheric and water corrosion, sealing and joining by soldering, and mechanical strength. Copper is used both in receivers and primary circuits (pipes and heat exchangers for water tanks).[34] For the absorber plate, aluminium is sometimes used as it is cheaper, yet when combined with copper piping, there may be problems in regards to allow the absorber plate to transfer its heat to the piping suitably. An alternative material that is currently used is PEX-AL-PEX[35] but there may be similar problems with the heat transfer between the absorber plate and the pipes as well. One way around this is to simply use the same material for both the piping and the absorber plate. This material can be copper off course but also aluminium or PEX-AL-PEX.
Three types of solar thermal collectors are used for residential applications: flat plate collectors, integral collector-storage, and solar thermal collector: Evacuated tube collectors; They can be direct circulation (i.e., heats water and brings it directly to the home for use) or indirect circulation (i.e., pumps heat a transfer fluid through a heat exchanger, which then heats water that flows into the home) systems.[33]
In an evacuated tube solar hot water heater with an indirect circulation system, evacuated tubes contain a glass outer tube and metal absorber tube attached to a fin. Solar thermal energy is absorbed within the evacuated tubes and is converted into usable concentrated heat. Copper heat pipes transfer thermal energy from within the solar tube into a copper header. A thermal transfer fluid (water or glycol mixture) is pumped through the copper header. As the solution circulates through the copper header, the temperature rises. The evacuated glass tubes have a double layer. The outer layer is fully transparent to allow solar energy to pass through unimpeded. The inner layer is treated with a selective optical coating that absorbs energy without reflection. The inner and outer layers are fused at the end, leaving an empty space between the inner and outer layers. All air is pumped out of the space between the two layers (evacuation process), thereby creating the thermos effect which stops conductive and convective transfer of heat that might otherwise escape into the atmosphere. Heat loss is further reduced by the low-emissivity of the glass that is used. Inside the glass tube is the copper heat pipe. It is a sealed hollow copper tube that contains a small amount of proprietary liquid, which under low pressure boils at a very low temperature. Other components include a solar heat exchanger tank and a solar pumping station, with pumps and controllers.[36][37][38][39][40]
Wind
[edit]In a wind turbine, the wind's kinetic energy is converted into mechanical energy to drive a generator, which in turn generates electricity. The basic components of a wind power system consist of a tower with rotating blades containing an electricity generator and a transformer to step up voltage for electricity transmission to a substation on the grid. Cabling and electronics are also important components.[27][41]
The harsh environment offshore wind farms means that the individual components need to be more rugged and corrosion protected than their onshore components. Increasingly long connections to shore with subsea MV and HV cables are required at this time. The need for corrosion protection favors copper nickel cladding as the preferred alloy for the towers.
Copper is an important conductor in wind power generation.[42][43] Wind farms can contain several hundred-thousand feet of copper[44] weighing between 4 million to 15 million pounds, mostly in wiring, cable, tubing, generators and step-up transformers.[25][45]
Copper usage intensity is high because turbines in wind generation farms are spread over large areas.[46] In land-based wind farms, copper intensity can range between 5,600 and 14,900 pounds per MW, depending on whether the step-up transformers have copper or aluminium conductors. In the off-shore environment, copper intensity is much higher: approximately 21,000 pounds per MW, which includes submarine cables to shore.[47] In both onshore and offshore environments, additional copper cabling is used to connect wind farms to main electrical grids.[45]
The amount of copper used for wind energy systems in 2011 was estimated to be 120 kt. The cumulative amount of copper installed through 2011 was estimated to be 714 kt.[23] As of 2018[update], global production of wind turbines use 450,000 tonnes of copper per year.[48]
For wind farms with three-stage gearbox doubly fed 3 MW induction generators, approximately 2.7 t per MW is needed with standard wind turbines. For wind turbines with LV/MV transformers in the nacelle, 1.85 t per MW is needed.[49]
Copper is primarily used in coil windings in the stator and rotor portions of generators (which convert mechanical energy into electrical energy), in high voltage and low voltage cable conductors including the vertical electrical cable that connects the nacelle to the base of the wind turbine, in the coils of transformers (which steps up low voltage AC to high voltage AC compatible with the grid), in gearboxes (which convert the slow revolutions per minute of the rotor blades to faster rpms) and in wind farm electrical grounding systems.[46] Copper may also be used in the nacelle (the housing of the wind turbine that rests on the tower containing all the main components), auxiliary motors (motors used to rotate the nacelle as well as control the angle of the rotor blades), cooling circuits (cooling configuration for the entire drive train), and power electronics (which enable the wind turbine systems to perform like a power plant).[50]
In the coils of wind generators, electric current suffers from losses that are proportional to the resistance of the wire that carries the current. This resistance, called copper losses, causes energy to be lost by heating up the wire. In wind power systems, this resistance can be reduced with thicker copper wire and with a cooling system for the generator, if required.[51]
Copper in generators
[edit]Either copper or aluminium conductors can be specified for generator cables.[52] Copper has the higher electrical conductivity and therefore the higher electrical energy efficiency. It is also selected for its safety and reliability. The main consideration for specifying aluminium is its lower capital cost. Over time, this benefit is offset by higher energy losses over years of power transmission. Deciding which conductor to use is determined during a project's planning phase when utility teams discuss these matters with turbine and cable manufacturers.
Regarding copper, its weight in a generator will vary according to the type of generator, power rating, and configuration. Its weight has an almost linear relationship to the power rating.
Generators in direct-drive wind turbines usually contain more copper, as the generator itself is bigger due to the absence of a gearbox.[53]
A generator in a direct drive configuration could be 3.5 times to 6 times heavier than in a geared configuration, depending on the type of generator.[53]
Five different types of generator technologies are used in wind generation:
- double-fed asynchronous generators (DFAG)
- conventional asynchronous generators (CAG)
- conventional synchronous generators (CSG)
- permanent magnet synchronous generators (PMSG)
- high-temperature superconductor generators (HTSG)
The amount of copper in each of these generator types is summarized here.
Technology | Average copper content (kg/MW) | Notes |
---|---|---|
Double-fed asynchronous generator (DFAG) | 650 | Geared; most common wind generator in Europe (70% in 2009; strong demand until 2015, then neutral as high cost of maintenance and servicing and need for power correction equipment for grid compliance will make these less popular in next ten years. |
Conventional asynchronous generators (CAG) | 390 | Geared; neutral demand until 2015; will become negligible by 2020. |
Conventional synchronous generators (CSG) | 330–4000 | Geared and direct; may become more popular by 2020. |
Permanent magnet synchronous generators (PMSG) | 600–2150 | Market expected to develop by 2015. |
High-temperature superconductor generators (HTSG) | 325 | Nascent stage of development. It is expected that these machines will attain more power than other WTGs. Offshore could be the most suitable niche application. |
Direct-drive configurations of the synchronous type machines usually contain the most copper, but some use aluminium.[48] Conventional synchronous generators (CSG) direct-drive machines have the highest per-unit copper content. The share of CSGs will increase from 2009 to 2020, especially for direct drive machines. DFAGs accounted for the most unit sales in 2009.[53]
The variation in the copper content of CSG generators depends upon whether they are coupled with single-stage (heavier) or three-stage (lighter) gearboxes. Similarly, the difference in copper content in PMSG generators depends on whether the turbines are medium speed, which are heavier, or high-speed turbines, which are lighter.[53]
There is increasing demand for synchronous machines and direct-drive configurations. CSG direct and geared DFAGs will lead the demand for copper. The highest growth in demand is expected to be the direct PMSGs, which is forecast to account for 7.7% of the total demand for copper in wind power systems in 2015. However, since permanent magnets that contain the rare earth element neodymium may not be able to escalate globally, direct drive synchronous magnet (DDSM) designs may be more promising.[49] The amount of copper required for a 3 MW DDSM generator is 12.6 t.[54]
Locations with high-speed turbulent winds are better suited for variable-speed wind turbine generators with full-scale power converters due to the greater reliability and availability they offer in such conditions. Of the variable-speed wind turbine options, PMSGs could be preferred over DFAGs in such locations. In conditions with low wind speed and turbulence, DFAGs could be preferred to PMSGs.[23]
Generally, PMSGs deal better with grid-related faults and they could eventually offer higher efficiency, reliability, and availability than geared counterparts. This could be achieved by reducing the number of mechanical components in their design. Currently, however, geared wind turbine generators have been more thoroughly field-tested and are less expensive due to the greater volumes produced.[23]
The current trend is for PMSG hybrid installations with a single-stage or two-stage gearbox. The most recent wind turbine generator by Vestas is geared drive. The most recent wind turbine generator by Siemens is a hybrid. Over the medium term, if the cost of power electronics continues to decrease, direct-drive PMSG are expected to become more attractive.[23] High-temperature superconductors (HTSG) technology is currently under development. It is expected that these machines will be able to attain more power than other wind turbine generators. If the offshore market follows the trend of larger unit machines, offshore could be the most suitable niche for HTSGs.[23]
Copper in other components
[edit]For a 2 MW turbine system, the following amounts of copper were estimated for components other than the generator:
Component | Average Cu content (kg) |
---|---|
Auxiliary motors (pitch and yaw drives) | 75 |
Other parts of the nacelle | <50 |
Vertical cables | 1500 |
Power electronics (converter) | 150 |
Cooling circuits | <10 |
Earthing and lightning protection | 750 |
Cabling is the second largest copper-containing component after the generator. A wind tower system with the transformer next to the generator will have medium-voltage (MV) power cables running from the top to the bottom of the tower, then to a collection point for a number of wind towers and on to the grid substation, or direct to the substation. The tower assembly will incorporate wire harnesses and control/signal cables, while low-voltage (LV) power cables are required to power the working parts throughout the system.[27]
For a 2 MW wind turbine, the vertical cable could range from 1,000 to 1,500 kg of copper, depending upon its type. Copper is the dominant material in underground cables.[53]
Copper in grounding systems
[edit]Copper is vital to the electrical grounding system for wind turbine farms. Grounding systems can either be all-copper (solid or stranded copper wires and copper bus bars) often with an American gauge rating of 4/0 but perhaps as large as 250 thousands of circular mils[56] or copper-clad steel, a lower cost alternative.[57]
Turbine masts attract lightning strikes, so they require lightning protection systems. When lightning strikes a turbine blade, current passes along the blade, through the blade hub in the nacelle (gearbox/ generator enclosure) and down the mast to a grounding system. The blade incorporates a large cross-section copper conductor that runs along its length and allows current to pass along the blade without deleterious heating effects. The nacelle is protected by a lightning conductor, often copper. The grounding system, at the base of the mast, consists of a thick copper ring conductor bonded to the base or located within a meter of the base. The ring is attached to two diametrically opposed points on the mast base. Copper leads extend outward from the ring and connect to copper grounding electrodes. The grounding rings at turbines on wind farms are inter-connected, providing a networked system with an extremely small aggregate resistance.[43]
Solid copper wire has been traditionally deployed for grounding and lightning equipment due to its excellent electrical conductivity. However, manufacturers are moving towards less expensive bi-metal copper clad or aluminium grounding wires and cables.[58] Copper-plating wire is being explored. Current disadvantages of copper plated wire include lower conductivity, size, weight, flexibility and current carrying capability.
Copper in other equipment
[edit]After generators and cable, minor amounts of copper are used in the remaining equipment. In yaw and pitch auxiliary motors, the yaw drive uses a combination of induction motors and multi-stage planetary gearboxes with minor amounts of copper. Power electronics have minimal amounts of copper compared to other equipment. As turbine capacities increase, converter ratings also increase from low voltage (<1 kV) to medium voltage (1–5 kV). Most wind turbines have full power converters, which have the same power rating as the generator, except the DFAG that has a power converter that is 30% of the rating of the generator. Finally, minor amounts of copper are used in air/oil and water cooled circuits on gearboxes or generators.[53]
Class 5 copper power cabling is exclusively used from the generator through the loop and tower interior wall. This is due to its ability to withstand the stress from 15,000 torsion cycles for 20 years of service life.[59]
Superconducting materials are being tested within and outside of wind turbines. They offer higher electrical efficiencies, the ability to carry higher currents, and lighter weights. These materials are, however, much more expensive than copper at this time.[53]
Copper in offshore wind farms
[edit]The amount of copper in offshore wind farms increases with the distance to the coast. Copper usage in offshore wind turbines is on the order of 10.5 t per MW.[60] The Borkum 2 offshore wind farm uses 5,800 t for a 400 MW, 200 kilometer connection to the external grid, or approximately 14.5 t of copper per MW. The Horns Rev Offshore Wind Farm uses 8.75 tons of copper per MW to transmit 160 MW 21 kilometers to the grid.[61]
References
[edit]- ^ "Renewables 2022 – Analysis". IEA. Retrieved 2023-08-16.
- ^ "REN21 Renewables Global Status Report". REN21. 2019-06-14. Retrieved 2023-08-16.
- ^ Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html Archived 2018-06-22 at the Wayback Machine
- ^ García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. A global renewable mix with proven technologies and common materials, Energy Policy, 41 (2012): 561-57, http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf
- ^ "Energy saving - A kilo more of copper increases environmental performance by 100 to 1,000 times". Renewable Energy Magazine, at the heart of clean energy journalism. 2011-04-14. Retrieved 2023-08-16.
- ^ Copper at the core of renewable energies; European Copper Institute; European Copper Institute; 18 pages; http://www.eurocopper.org/files/presskit/press_kit_copper_in_renewables_final_29_10_2008.pdf Archived 2012-05-23 at the Wayback Machine
- ^ Copper in energy systems; Copper Development Association Inc.; http://www.copper.org/environment/green/energy.html Archived 2020-08-01 at the Wayback Machine
- ^ a b c The Rise Of Solar: A Unique Opportunity For Copper; Solar Industry Magazine; April 2017; Zolaika Strong; https://issues.solarindustrymag.com/article/rise-solar-unique-opportunity-copper Archived 2022-10-30 at the Wayback Machine
- ^ Pops, Horace, 1995. Physical Metallurgy of Electrical Conductors, in Nonferrous Wire Handbook, Volume 3: Principles and Practice, The Wire Association International
- ^ The World Copper Factbook, 2017; http://www.icsg.org/index.php/component/jdownloads/finish/170/2462
- ^ Copper Mineral Commodity Summary (USGS, 2017) https://minerals.usgs.gov/minerals/pubs/commodity/copper/ mcs-2017-coppe.pdf
- ^ Global Mineral Resource Assessment (USGS, 2014) http://pubs.usgs.gov/fs/2014/3004/pdf/fs2014-3004.pdf
- ^ Long-Term Availability of Copper; International Copper Association; http://copperalliance.org/wordpress/wp-content/uploads/2018/02/ICA-long-term-availability-201802-A4-HR.pdf Archived 2018-06-29 at the Wayback Machine
- ^ Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; by Zolaikha Strong; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html Archived 2018-06-22 at the Wayback Machine
- ^ Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies; Edgar G. Hertwich, Thomas Gibon, Evert A. Bouman, Anders Arvesen, Sangwon Suh, Garvin A. Heath, Joseph D. Bergesen, Andrea Ramirez, Mabel I. Vega, and Lei Shi; Proceedings of the National Academy of Sciences of the USA; May 19, 2015. 112 (20) 6277-6282; https://doi.org/10.1073/pnas.1312753111
- ^ Winds of Trade Toward Copper; Energy & Infrastructure, http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper Archived 2018-06-22 at the Wayback Machine
- ^ Current and Projected Wind and Solar Renewable Electric Generating Capacity and Resulting Copper Demand; BBF Associates and Konrad J.A. Kundig, July 20, 2011; http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf Archived 2017-06-24 at the Wayback Machine
- ^ a b "Will the Transition to Renewable Energy Be Paved in Copper?". Renewable Energy World. 15 January 2016. Archived from the original on 22 June 2018. Retrieved 22 June 2018.
- ^ Growing Renewable Energy Needs More Copper, Windpower Engineering, November 21, 2012; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ Archived 2018-06-22 at the Wayback Machine
- ^ a b REN 21 2012 report
- ^ a b c d e f g h i j Copper content assessment of solar thermal electric power plants (2010), Presentation by Protermosolar <http://www.protermosolar.com> for the European Copper Institute; Available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ a b c d e f g Maximization of use of copper in photovoltaics. Presentation by Generalia Group to ECI, 2012; Available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ a b c d e f g Wind Generator Technology, by Eclareon S.L., Madrid, May 2012; http://www.eclareon.com; Available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ Renewables Are as Green as You'd Expect; Scientific American; October 8, 2014; https://www.scientificamerican.com/article/renewables-are-as-green-as-you-d-expect/; citing, Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies; by Edgar G. Hertwich et al.; Proceedings of the National Academy of Sciences of the USA; May 19, 2015. 112 (20) 6277-6282; https://doi.org/10.1073/pnas.1312753111
- ^ a b Will the Transition to Renewable Energy Be Paved in Copper?, Renewable Energy World; Jan 15, 2016; https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html Archived 2018-06-22 at the Wayback Machine
- ^ Current and projected wind and solar renewable electric generating capacity and resulting copper demand; Copper Development Association Sustainable Electrical Energy Program; July 20, 2011, by BFF Associates and Konrad J.A. Kundig; http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf Archived 2017-06-24 at the Wayback Machine
- ^ a b c d e f The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010; Independent research study available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ PV Technology: Swapping Silver for Copper, 2012. Renewable Energy World International; July 2, 2012; http://www.renewableenergyworld.com/rea/news/article/2012/07/pv-technology-swapping-silver-for-copper
- ^ Characterization of 19.9%-Efficient CIGS Absorbers; National Renewable Energy Laboratory, May 2008; http://www.nrel.gov/docs/fy08osti/42539.pdf. Retrieved 10 February 2011
- ^ Wadia, C. et al., 2008. Synthesis of copper (I) sulfide nanocrystals for photovoltaic application; Nanotech 2008 Conference Program Abstract; http://www.nsti.org/Nanotech2008/showabstract.html?absno=70355 Archived 2013-11-04 at the Wayback Machine
- ^ Solar First Source; "Solar cable photovoltaic equipment". Archived from the original on 2011-03-25. Retrieved 2013-01-03.
- ^ a b c Renewables 2012: Global status report; REN 21 (Renewable Energy Policy Network for the 21st Century; "REN21 - Renewables Global Status Report". Archived from the original on 2013-01-28. Retrieved 2013-02-19.
- ^ a b Solar water heaters; Energy Savers; Energy Efficiency and Renewable Energy; U.S. Department of Energy; http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850/ Archived 2012-08-25 at the Wayback Machine
- ^ a b 2011 global status report by Renewable Energy Policy Network for the 21st Century (REN21)
- ^ PEX-AL-PEX used frequently for solar thermal collector construction
- ^ Solar hot water; B&R Service Inc.; http://www.bandrservice.com/solar.htm
- ^ How solar hot water system works; SolarPlusGreen.com; http://www.solarplusgreen.com/solar-know-how.htm Archived 2012-09-04 at the Wayback Machine
- ^ Mirasol Solar Energy Systems; http://www.mirasolenergysystems.com/pdf/et-technology.pdf Archived 2013-11-04 at the Wayback Machine
- ^ How solar heaters work; Mayca Solar Energy; "Technical Info, Haining Mayca Solar Energy Technology Co., Ltd". Archived from the original on 2012-10-28. Retrieved 2012-11-26.
- ^ Bayat Energy: solar water heaters; http://www.bayatenergy.co.uk/Solar%20Water%20Heaters%20Catalogue.pdf Archived 2013-11-03 at the Wayback Machine
- ^ Distributed generation and renewables – wind power; Power Quality and Utilisation Guide; Leonardo Energy; "Archived copy" (PDF). Archived from the original (PDF) on 2012-11-01. Retrieved 2012-12-12.
{{cite web}}
: CS1 maint: archived copy as title (link) - ^ Miles of copper make it possible, Copper and Wind Energy: Partners for a Clean Environment; Copper Development Association Inc., http://www.copper.org/applications/electrical/energy/casestudy/wind_energy_a6101.html#top Archived 2012-10-18 at the Wayback Machine
- ^ a b Wind energy basics – how copper helps make wind energy possible; http://www.copper.org/environment/green/casestudies/wind_energy/wind_energy.html
- ^ Tatakis, Jim 2011. Copper truly is the green metal; Granite's Edge – Investment insight from Granite Investment Advisors; http://www.granitesedge.com/2011/02/01/copper-truly-is-the-green-metal Archived 2013-06-02 at the Wayback Machine
- ^ a b The Rise Of Solar: A Unique Opportunity For Copper; Solar Industry Magazine; April 2017; by Zolaika Strong; https://issues.solarindustrymag.com/article/rise-solar-unique-opportunity-copper Archived 2022-10-30 at the Wayback Machine
- ^ a b Growing renewable energy needs more copper; by Nic Sharpley; November 21, 2012; Windpower Engineering; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ Archived 2018-06-22 at the Wayback Machine
- ^ Growing renewable energy needs more copper; by Nic Sharpley; November 21, 2012; Windpower Engineering; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ Archived 2018-06-22 at the Wayback Machine; citing the study: Current and projected wind and solar renewable electric generating capacity and resulting copper demand; by BFF Associates and Konrad J.A. Kundig; published at: http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf Archived 2017-06-24 at the Wayback Machine
- ^ a b "Fast pace of growth in wind energy driving demand for copper". Riviera Maritime Media.
- ^ a b García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. A global renewable mix with proven technologies and common materials, Energy Policy 41 (2012): 561-57, http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf
- ^ Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI on July 12, 2010. Available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ Meyers, C. Bracken, 2009. Energy loss of a wind turbine; Centurion Energy; July 31, 2009; http://centurionenergy.net/energy-loss-of-a-wind-turbine Archived 2012-10-30 at the Wayback Machine
- ^ Critical Component — Cables: Choosing the right cable for specific turbine applications is essential for wind farm success; Wind Systems; Uwe Schenk; http://www.windsystemsmag.com/article/detail/538/critical-componentcables Archived 2018-07-20 at the Wayback Machine
- ^ a b c d e f g h Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI; July 12, 2010. Available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ Bang, D., Polinder, H. Shrestha, G. and Ferreira, J.A., 2009. Possible solutions to overcome drawbacks of direct-drive generator for large wind turbines; In: Ewc 2009 Proceedings, CT3 session, available at http://www.ewec2009proceedings.info.
- ^ Frost and Sullivan, 2009, cited in Wind Generator Technology, by Eclareon S.L., Madrid, May 2012; http://www.eclareon.com; Available at Leonardo Energy - Ask an Expert; "Ask an expert | Leonardo ENERGY". Archived from the original on 2012-11-26. Retrieved 2012-12-12.
- ^ Winds of Trade Toward Copper; Energy & Infrastructure; http://www.energyandinfrastructure.com/sections/columns1/469-winds-of-trade-toward-copper Archived 2018-06-22 at the Wayback Machine
- ^ Introduction to wind turbine cables: Cables 101: by Kathie Zipp, January 17, 2012; https://www.windpowerengineering.com/mechanical/cables-connectors/cables-101/
- ^ Mattera, Michael; 2010. An alternative to copper-based grounding; Windpoweer Engineering & Development; August 4, 2010; http://www.windpowerengineering.com/tag/copper-clad-steel/
- ^ Critical Component—Cables: Choosing the right cable for specific turbine applications is essential for wind farm success; Wind Systems; Uwe Schenk; http://www.windsystemsmag.com/article/detail/538/critical-componentcables Archived 2018-07-20 at the Wayback Machine
- ^ Growing renewable energy needs more copper; by Nic Sharpley; November 21, 2012; Windpower Engineering; https://www.windpowerengineering.com/business-news-projects/uncategorized/growing-renewable-energy-needs-more-copper/ Archived 2018-06-22 at the Wayback Machine; citing the study: Current and projected wind and solar renewable electric generating capacity and resulting copper demand; by BFF Associates and Konrad J.A. Kundig; published at: http://copperalliance.org/wordpress/wp-content/uploads/2017/03/Projected-wind-solar-copper-demand-1.pdf Archived 2017-06-24 at the Wayback Machine
- ^ García-Olivares, Antonio, Joaquim Ballabrera-Poy, Emili García-Ladona, and Antonio Turiel. "A global renewable mix with proven technologies and common materials." Energy Policy 41 (2012): 561-574. http://imedea.uib-csic.es/master/cambioglobal/Modulo_I_cod101601/Ballabrera_Diciembre_2011/Articulos/Garcia-Olivares.2011.pdf