Editing Incandescent light bulb (section)

===Efforts to improve efficacy===
[[File:Wolfram-Halogenglühlampe.png|thumb|upright|Xenon [[halogen lamp]] with an E27 base, which can replace a non-halogen bulb]]
Some research has been carried out to improve the efficacy of commercial incandescent lamps. In 2007, [[General Electric]] announced a ''high efficiency incandescent'' (HEI) lamp project, which they claimed would ultimately be as much as four times more efficient than current incandescents, although their initial production goal was to be approximately twice as efficient.<ref name=notsodim>{{Cite web|last=Daley |first=Dan |date=27 February 2008 |title=Incandescent's Not-So-Dim Future |url=https://plsn.com/articles/the-biz/incandescents-not-so-dim-future/|url-status=live|work=Projection, Lights & Staging News |volume=09 |issue=1 |page=46 |publisher=Timeless Communications Corp|archive-url=https://web.archive.org/web/20140306230206/http://www.plsn.com/current-issue/31-the-biz/2520-incandescents-not-so-dim-future.html |archive-date=6 March 2014}}</ref><ref>{{cite press release |last=Freeman |first=Kim |date=23 February 2007 |title=GE Announces Advancement in Incandescent Technology; New High-Efficiency Lamps Targeted for Market by 2010 |url=http://www.businesswire.com/portal/site/ge/index.jsp?ndmViewId=news_view&newsId=20070223005120 |publisher=[[Business Wire]] |url-status=dead |archive-url=https://web.archive.org/web/20130516151220/http://www.businesswire.com/portal/site/ge/index.jsp?ndmViewId=news_view&newsId=20070223005120 |archive-date=16 May 2013}}</ref> The HEI program was terminated in 2008 due to slow progress.<ref>{{cite news |last=Hamilton |first=Tyler |title=Why the brightest idea needs tinkering |url=https://www.thestar.com/business/2009/04/22/why_the_brightest_idea_needs_tinkering.html|newspaper=[[Toronto Star]] |date=22 April 2009 |url-status=live |archive-url=https://web.archive.org/web/20130620083715/http://www.thestar.com/business/2009/04/22/why_the_brightest_idea_needs_tinkering.html|archive-date=20 June 2013}}</ref><ref>{{cite news |last=Rahim |first=Saqib |date=28 June 2010 |title=The Incandescent Bulb Heads Offstage After Century-Long Performance |url=https://www.nytimes.com/cwire/2010/06/28/28climatewire-the-incandescent-bulb-heads-offstage-after-c-11795.html |work=The New York Times |url-status=live |archive-url=https://web.archive.org/web/20130518150756/http://www.nytimes.com/cwire/2010/06/28/28climatewire-the-incandescent-bulb-heads-offstage-after-c-11795.html |archive-date=18 May 2013}}</ref>
US Department of Energy research at [[Sandia National Laboratories]] initially indicated the potential for dramatically improved efficiency from a [[photonic lattice]] filament.<ref name=notsodim/> However, later work indicated that initially promising results were in error.<ref>{{cite web |title=Revolutionary tungsten photonic crystal could provide more power for electrical devices |url=https://share.sandia.gov/news/resources/releases/2003/other/planck-lin.html |publisher=[[Sandia National Laboratories]] |date=7 July 2003 |url-status=live |archive-url=https://web.archive.org/web/20130221204348/https://share.sandia.gov/news/resources/releases/2003/other/planck-lin.html |archive-date=21 February 2013}}</ref>

Prompted by legislation in various countries mandating increased bulb efficiency, ''hybrid'' incandescent bulbs have been introduced by [[Philips]]. The ''Halogena Energy Saver'' incandescents can produce about 23&nbsp;lm/W; about 30 percent more efficient than traditional incandescents, by using a reflective capsule to reflect formerly wasted infrared radiation back to the filament from which some is re-emitted as visible light.<ref name=NYT/> This concept was pioneered by Duro-Test in 1980 with a commercial product that produced 29.8&nbsp;lm/W.<ref>{{Cite journal |url=http://americanhistory.si.edu/collections/search/object/nmah_995209 |title=Prototype Heat-Mirror Tungsten Lamp |journal=Smithsonian Museum of American History |url-status=live |archive-url=https://web.archive.org/web/20151223061442/http://americanhistory.si.edu/collections/search/object/nmah_995209 |archive-date=23 December 2015}}</ref><ref>{{cite report|title=Energy Efficient Incandescent Lamp: Final Report |publisher=Lawrence Berkeley National Laboratory |date=April 1982}}</ref> More advanced reflectors based on [[interference filter]]s or [[photonic crystal]]s can theoretically result in higher efficiency, up to a limit of about 270&nbsp;lm/W (40% of the maximum efficacy possible).<ref name=Ilic>{{cite journal |title=Tailoring high-temperature radiation and the resurrection of the incandescent source |first1=Ognjen |last1=Ilic |journal=Nature Nanotechnology |volume=11 |issue=4 |pages=320–4 |year=2016 |doi=10.1038/nnano.2015.309 |pmid=26751172 |bibcode=2016NatNa..11..320I |hdl=1721.1/109242 |osti=1371442 |url=https://dspace.mit.edu/bitstream/1721.1/109242/1/Chen_Tailoring%20high-temperature.pdf |hdl-access=free |access-date=23 September 2019 |archive-date=14 February 2022 |archive-url=https://web.archive.org/web/20220214220607/https://dspace.mit.edu/bitstream/handle/1721.1/109242/Chen_Tailoring |url-status=live }}</ref> Laboratory proof-of-concept experiments have produced as much as 45&nbsp;lm/W, approaching the efficacy of compact fluorescent bulbs.<ref name=Ilic/><ref>{{cite news |last=McGrath |first=Matt |date=12 January 2016 |url=https://www.bbc.com/news/science-environment-35284112 |title=New development could lead to more effective lightbulbs |work=BBC News |url-status=live |archive-url=https://web.archive.org/web/20160113031746/http://www.bbc.com/news/science-environment-35284112 |archive-date=13 January 2016}}</ref>