19 ms·

Return of incandescent light bulbs as MIT makes them more efficient than LEDs

• protomyth 10y ago
  So, if this works and is 40% efficient compared to LED or florescent bulb's manage ~14% efficiency, do we ban all LED purchases in the US?
  • clarkmoody 10y ago
    No. Just let consumers choose. If I could have super-efficient incandescent bulbs, I would prefer them precisely because of the better colors and instant-on startup. (This assumes production ramp-up has kept these new incandescent prices well below that of LEDs)
    • protomyth 10y ago
      "No. Just let consumers choose." That wasn't the previous solution and I'm wondering if people who were fine with the demise of incandescent bulbs would be fine with a ban on LEDs because of the same efficiency concerns? I get the feeling the answer is no which makes me wonder about the original reason.
      • Retric 10y ago
        Traditional incandescent lights have terrible efficiency 2.5% or so. The benefit from Old Incandescent vs LED's is huge (5x to 10+x), but there is just not much room from the best LED's to 100% efficiency making the remaining gains less important. https://en.wikipedia.org/wiki/Luminous_efficacy https://en.wikipedia.org/wiki/Luminous_efficacy EX: 303lm/w vs maximum possible 683 lumens/w. http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/March/300LPW-LED-barrier http://www.cree.com/News-and-Events/Cree-News/Press-Releases... PS: Power is kind of an odd thing. Direct costs are so cheap most people ignore it, but the external costs are high enough to push efficiency gains. Taxes would be the best solution, but politics is odd.
        • cmurf 10y ago
          There you go. Set the "sales" tax rate on a luminous efficacy sliding scale. The lower the efficacy, the higher the tax %. It'd have to be some kind of wholesale/manufacturer tax, at least in the U.S., so that it's reflected in the sticker price before checkout.
      • maxerickson 10y ago
        Wouldn't big LED be happy to license the new tech and push that? Especially with LED sales waning as more and more people have 15 year bulbs.
      • GFK_of_xmaspast 10y ago
        I was and am perfectly fine with the old incandescents going away, and I'll be perfectly happy when LEDs are legally phased out in favor of something better.
      • cmurf 10y ago
        It would not surprise me one bit if it were discovered the lobbying effort for such laws were pushed by the very lighting industry that needed a way to compel people to buy much more expensive light bulbs with a higher profit margin. It reeks to me of the same reasons why we have ethanol mandated fuel in some cities.
      • dragonwriter 10y ago
        > That wasn't the previous solution and I'm wondering if people who were fine with the demise of incandescent bulbs would be fine with a ban on LEDs because of the same efficiency concerns? Yes, it was: the so-called "ban on incandescent bulbs" was actually an efficiency requirement which no existing incandescent bulbs met. Much of the research into high-efficiency incandescent bulbs (which IIRC actually had produced some bulbs that met it prior to the requirement going into effect, but which were not cost competitive with CFL or even LED bulbs) was directly spurred by the requirement. > I'm wondering if people who were fine with the demise of incandescent bulbs would be fine with a ban on LEDs because of the same efficiency concerns? I'm pretty sure that most the people in the public that were fine with the government setting efficiency targets that could be met by a variety of technologies on the market (but not, at the time, cost effectively by incandescent bulbs) would be just fine with moving the efficiency requirements up as new technologies become available. At any given time, which particular industry players would support and oppose such a move would, of course, vary based on the relative efficiency of what each particular industry player was invested in.
  • deleted 10y ago
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  • 3JPLW 10y ago
    It is interesting to think about how this commercial product might have to fight the anti-incandescent laws. Would this bulb be illegal in many states/countries right now?
    • Brakenshire 10y ago
      In the EU, there are no incandescent laws, there are only limits on efficiency.
  • haikuginger 10y ago
    LEDs themselves won't likely be banned, but we'll likely see a continuing ramp up of required efficiency standards, just as we do now.
  • cmurf 10y ago
    No, the bans were stupid to begin with and should be unwound. Instead, there should be highly granular electrical billing, if the electric company cares to really bill people properly for necessary overcapacity for that ~1 hour a day when demand spikes. I'd let them charge 1000% surge pricing if they wanted. People will absolutely alter their behavior to no negative effect for people who can't afford it, so long as the typical cost per kW is affordable.
• Fej 10y ago
  What are the chances of seeing this at retail in the next decade?
  • deleted 10y ago
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• colanderman 10y ago
  > Traditional incandescent bulbs have a ‘colour rendering index’ rating of 100, because they match the hue of objects seen in natural daylight. > Previously researchers have warned that the blue light emitted by modern bulbs could be stopping people from getting to sleep at night These two sentences do not go together. Daylight contains LOTS of blue light. 5 seconds of research into CRI says that the first sentence is false. CRI compares a light source to an ideal black body, not necessarily daylight.
  • flubert 10y ago
    >CRI compares a light source to an ideal black body, not necessarily daylight. Isn't the sun a pretty-close-to-ideal black body emitter? Is there something specific you are thinking of that makes daylight deviate significantly from black-body radiation? (Rayleigh scattering in the upper atmosphere?)
    • aardvark179 10y ago
      The sun provides a spectrum with a temperature of roughly 6500K, domestic lightbulbs produce something more like 2700K up to 3000K. The biggest difference between incandescent and CF/LED lights is that the spectrum from an incandescent bulb is quite smooth, whereas other lights tend to have a much spikier spectrum meaning you may see some odd colour effects from them and certain materials.
    • lutorm 10y ago
      Indeed it is, but that doesn't mean anything illuminated by a blackbody "match the hue of objects seen in natural daylight." CRI has much more to do with the ability to discriminate colors. The absolute hue is a strong function of the color temperature of the illumination, but the eye/brain is also very good at normalizing that away. This is precisely why I don't think people complaining about "nasty cool light" are based in fact. The color of the environment around you will quickly be normalized to be neutral by your brain, and it will be impossible for you to tell whether you are illuminated by a 3000K or 5500K light. You can really only tell color differences accurately.
  • 10y ago
• jandrese 10y ago
  This article read an awful lot like a marketing puff piece and failed to answer some obvious questions. There is way too much "those evil fluorescent bulbs are making your life miserable" in the article. 1. How long are the bulbs going to last? 2. How expensive would they be to manufacture? 3. When could we see these in stores? Often times there is a long road from laboratory prototype to production, and the supposed cost savings in electricity won't matter if they only last 1,000 hours and cost $100/bulb.
  • deleted 10y ago
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  • ams6110 10y ago
    Anecdote time. Those evil flourescent bulbs have made my life miserable. They don't last substantially longer in the real world. I am routinely replacing them within 12 months. They cost an order of magnitude more. They are considered toxic waste with special clean-up and disposal considerations. The amount of energy they save as a fraction of my total electric bill is inconsequential.
    • cmurf 10y ago
      Their aging properties are different than incandescent. Incandescent tends to just fail when the filament breaks. There isn't much change in the spectral power distribution, and hence the overall stability of the light source is quite good. Whereas with fluorescent and even LED, there's a decaying of the phosphors, so while it'll produce light for a longer time (probably) the quality of the light will suffer immensely to the point that I think the longevity claims are approximately useless crap unless of course you don't care at all about the quality of light.
    • ars 10y ago
      > They don't last substantially longer in the real world. Yes they do, I have a lot of them and I write the installation date on the bulb - they have failed more or less inline with what the package said. > They cost an order of magnitude more. They cost $1. There is no reason they need to cost more than that. > They are considered toxic waste with special clean-up and disposal considerations. That isn't true, it's one of those urban myths that spread by email. > The amount of energy they save as a fraction of my total electric bill is inconsequential. What are you spending so much on electricity on?
• kefka 10y ago
  Grrr! Incandescent lights, when heating would be used, are 100% efficient. They provide 3% light output, and 97% heat output. A single one on provides a great amount of heat and can easily provide spot-heat where humans are. Instead there's CFLs and LEDs. And CFLs are a great way to spread mercury pollution across a great area. Snopes has a decent article about hazards and response: http://www.snopes.com/medical/toxins/cfl.asp http://www.snopes.com/medical/toxins/cfl.asp
  • soperj 10y ago
    Not really that useful in places that are already hot, or heating while you want to sleep.
    • kefka 10y ago
      Of course, the bulbs would add 97% waste heat if heat isn't wanted. But most places here in the US have some soft of heating system for the winter. That would pretty much require changing out the bulbs for the winter. During sleeping? Scraping the bottom of the bucket much? I never said that incandescents would eliminate heating, only that it is 100% efficient when used appropriately.
      • nkozyra 10y ago
        I think it's a fair point; these bulbs are not used for heating because that's not their primary function (despite being more efficient at it than lighting). The inverse would apply to, say, a fireplace. Light is an acceptable (even desired) side effect of the primary function, but it would not be convenient to rely on it for that side effect.
  • venomsnake 10y ago
    Need a warmish proofing/fermentation chamber - just turn the lightbulbs (2x25W) in your oven on.
  • kazinator 10y ago
    Doesn't work out when heating wouldn't be used, or AC would be. Heating isn't always electric. Using electricity for heating is an egregious waste of a high quality energy source which can do all sorts of useful things besides generating heat.
• degenerate 10y ago
  People complaining about LEDs being too "bright" or "clinical/sterile" were too bothered to look into the different color temperature options. The annoyingly bright bulbs are around 5000K brightness which would make a home at night feel like a fully-lit classroom. I have 2700K bulbs which give off a much cozier incandescent glow: http://blog.batteriesplus.com/2013/seeing-things-in-a-different-light http://blog.batteriesplus.com/2013/seeing-things-in-a-differ... Sure, the bulbs take about 1/5 of a second to turn on, which is not instant, but the cheaper LEDs can take up to 2 seconds to reach full brightness. You have to buy a better made bulb to get the quicker "on", which means spending more money. People only trying the cheapest LEDs available are the ones complaining the most about them, I'd assume.
  • manmal 10y ago
    I have two different brands of 2,7k led bulbs, and they are like night and day. The ones that were shipped with a lamp are actually quite bluish. Haven't bothered to measure them though..
    • zamalek 10y ago
      > night and day Tsk tsk. We're do you source the bulbs? I've recently tried f.lux and I definitely get better sleep - I'd like to upgrade my home lighting story.
      • toomuchtodo 10y ago
        Philips Hue + Amazon Echo + Custom Integration = Glorious "Alexa, I'm ready for bed." is like I live in the future (warms up the lamp colors like flux on my mac). Still working on tying the coffee pot into the morning wakeup alarm though.
        • cgriswald 10y ago
          I'm in the process of figuring out how to talk to my color changing LEDs so I can change them over time like flux, but for now I'm just turning them a dim, dull red at bedtime and I am sleeping better than I have in years.
• kazinator 10y ago
  > The clinical white beam of LEDs and frustrating time-delay of ‘green’ lighting has left many hankering after the instant, bright warm glow of traditional filament bulbs. Sheer garbage. LEDs come on instantly, and are available in various color temperatures, thanks to filtering: you can have then in 2700K. If your LED isn't coming on instantly, it has some problem with the power supply, probably because you bought the lowest bargain-bin crap you could get your hands on. I've had Phillips flood lights (3000K) in my kitchen and living room for several years. They come on instantly and put out a warmly colored light that is consistent from the center of the spot to the fringes.
  • tacos 10y ago
    And your apples and oranges are the wrong color because the color rendition on them is so poor that Philips doesn't even publish the number. The only downlight I could find on their site has a CRI of 80 -- basically garbage. CRI is imperfect but things glow green until you get to the low 90s.
• nkozyra 10y ago
  > The clinical white beam of LEDs and frustrating time-delay of ‘green’ lighting I hear a lot about the "delays" in incandescent alternatives, but all of mine are barely perceptible. My Flux bulb has like 400ms; it's palpable but how could it ever annoy me? How often were you trying to illuminate something with a light bulb within 400ms and missed it? And of course, many of the adjustable/smart LEDs can mimic incandescent light temperature with ease. They cost more, but not necessarily over their lifetime. As mentioned, this article was fluff.
  • thescriptkiddie 10y ago
    "Green" and "energy saving" are often used to refer to florescent lighting in the UK. Florescent bulbs take some time to warm up before they reach full brightness, which is what they are complaining about. LED bulbs like your Flux don't have a delay.
    • nkozyra 10y ago
      Ah, thanks. The article does a poor job here, too, since it uses LED/CFL interchangeably. But if that's a known euphemism it gets a pass on this one :)
    • ars 10y ago
      > Florescent bulbs take some time to warm up before they reach full brightness They've had instant on fluorescent bulbs for a decade now, and they don't cost more. If yours are slow switch to a different supplier.
      • jrockway 10y ago
        Instant start is not what the comment you're replying refers to. Instant start is about how an arc is struck to get the gas to glow initially. The comment above is referring to how the light gets brighter as it runs longer, well after the gas begins to fluoresce. https://en.wikipedia.org/wiki/Fluorescent_lamp#Instant_start https://en.wikipedia.org/wiki/Fluorescent_lamp#Instant_start
• dkbrk 10y ago
  This news article doesn't even mention the article's name, the authors, or when it was published. It was actually published in January, and has just now been picked up by the Telegraph. Here is the citation: Ognjen Ilic, Peter Bermel, Gang Chen, John D. Joannopoulos, Ivan Celanovic, Marin Soljačić. Tailoring high-temperature radiation and the resurrection of the incandescent source. Nature Nanotechnology, 2016; DOI: 10.1038/nnano.2015.309 And here is the actual paper, via Sci-Hub: http://sci-hub.cc/10.1038/nnano.2015.309 http://sci-hub.cc/10.1038/nnano.2015.309 The Telegraph's explanation is terrible: "with a special crystal structure in the glass they can bounce back the energy which is usually lost in heat, while still allowing the light through." The tungsten filament is sandwiched between two plates made up of layers of oxides, designed to selectively reflect infrared radiation and transmit visible light. They used a numerical model to design and evaluate various candidate compositions for these plates. For a proof-of-concept, they chose one which uses layers of silicon oxide and tantalum oxide, with 90 layers in total per plate. This reflected about 90% of infrared radiation, producing a luminous efficiency of about 6.6%. This is comparable to commercial LEDs and compact fluorescents, though far from state-of-the-art. However, the results closely matched their numerical model, and a more complex structure comprised of layers of silicon dioxide, aluminium oxide, tantalum oxide and titanium dioxide, with 300 layers in total, should produce a luminous efficiency of 40%. This is significantly better than the state-of-the-art in LEDs (about 15-30%). They did not, however, actually build that one. I have no idea how expensive this would be to commercialise. It doesn't sound like the physics is particularly complex, but manufacturing costs could be prohibitive. I think it's safe to say we won't be seeing it outside the laboratory any time soon.
  • ohitsdom 10y ago
    Thank you, this was so much more informative than the article.
  • exhilaration 10y ago
    Also previously discussed on HN at least twice before: https://news.ycombinator.com/item?id=10916846 https://news.ycombinator.com/item?id=10916846 https://news.ycombinator.com/item?id=10889822 https://news.ycombinator.com/item?id=10889822
• TelAviv_1 10y ago
  Too bad incandescent bulbs are illegal here! We'll have to change the laws.
• known 10y ago
  https://en.wikipedia.org/wiki/Lumen_%28unit%29 https://en.wikipedia.org/wiki/Lumen_%28unit%29
• gherkin0 10y ago
  It's ironic that the factories that make incandescent bulbs are being shut down.
• bronz 10y ago
  wow. that is so fantastic. i wonder how they came to the 40% figure.
• gaius 10y ago
  Good - no more toxic chemicals from so-called eco-friendly bulbs in our homes.
• nostromo 10y ago
  We switched to LEDs about two years ago and have switched back to halogen bulbs recently for few reasons. 1) It didn't actually make much difference on our electricity bill. I believe this is because we use most of our lighting during the winter, and the wasted heat from the traditional bulbs isn't really wasted at all -- we just shifted more work to our electric heating system. 2) Many of the bulbs had burnt out. I am now very skeptical of all the "20 year lifetime" claims since we lost many expensive bulbs in two years. 3) The light quality just isn't great. People will argue this point, and I can't point to any evidence to support my claim, but our perception was that the light was either too blue, or too yellow, and just "looked weird." I wonder if it's related to the strobing of the LEDs. LED slow motion: https://www.youtube.com/watch?v=zAfWKcg8Bq0 https://www.youtube.com/watch?v=zAfWKcg8Bq0 Halogen slow motion: https://www.youtube.com/watch?v=sCD5BMr6LsA https://www.youtube.com/watch?v=sCD5BMr6LsA
  • djsumdog 10y ago
    I have to agree. Every few years I'll try again with LEDs and energy efficient bulbs. I'll look online, buy a few different brands and specifically look for the ones with a "cool" colour temperature that should look natural. In every instance the lighting was terrible. I really haven't yet found an energy efficient bulb that didn't make my place look like a jail cell. My current place has halogen track lighting and I really like it.
    • colonelxc 10y ago
      If you are looking for "natural" indoor lighting (like for a bedroom or living room), you probably want a "warm"er color, on the range of 2400k to 2600k. http://go/wiki/Color_temperature#Categorizing_different_lighting http://go/wiki/Color_temperature#Categorizing_different_ligh...
    • lutorm 10y ago
      You don't want "natural" lighting if you want it to look like an incandescent. "Natural", ie "day" light is very blue. You specifically want a non-natural, warm color temperature.
• ris 10y ago
  I love the first paragraph's insertion of a little EU-paranoia in the run up to the referendum. Vintage Telegraph.
• ck2 10y ago
  Philips has already had car headlight bulbs that do this "radiate heat back as light" trick. They are VERY VERY bright. In fact the brightest headlights before you go to real xeon. But they are not much more power efficient. 9011 HIR and 9012 HIR models http://store.candlepower.com/hirlighting.html http://store.candlepower.com/hirlighting.html
• NicoJuicy 10y ago
  The most interesting thing I ever read about light bulbs is that they used to last 100 years. But manufacturerers limited this due to sales : http://spectrum.ieee.org/geek-life/history/the-great-lightbulb-conspiracy http://spectrum.ieee.org/geek-life/history/the-great-lightbu... There is still one active for over 114 years and it has a 'live' feed http://www.centennialbulb.org/photos.htm http://www.centennialbulb.org/photos.htm ( 1 million hours and it's not that efficient anymore )
• kup0 10y ago
  This was posted a while back and picked apart by the comments, as it has been here too. This is all just "potential" improvements, just like we've been hearing about "crazy new battery technologies" for the past few years and have seen next-to-nothing come of it. Always good to see new tech and ideas, but let's not kid ourselves into thinking this will make it's way back into homes anytime soon. "Return of incandescent light bulbs" is an incredibly misleading headline that implies that due to this new tech, we're already starting to use these great new efficient bulbs- um, no. Not to mention, the prototype/initial version is nowhere near the "potential" level of efficiency they are claiming.
• Animats 10y ago
  From the paper: "This experimental device is a proof-of-concept, at the low end of performance that could be ultimately achieved by this approach." Somebody really needs to get MIT's PR department under control. The hype level is so high it's embarrassing to a good school. Especially in materials science articles. It's like reading the National Enquirer of science.
  • Faaak 10y ago
    Publish or Perish… Publish at all costs without going the extra mile.. A pity.
• ourmandave 10y ago
  Thank goodness! My LED Easy Bake Oven takes forever.
• brandon272 10y ago
  I built a house a couple years ago where the lighting used is predominately LED bulbs and I absolutely hate it. The pre-determined lighting plan for the home was presumably based on the brightness given off by certain incandescent bulbs and placing LED bulbs in those locations that are supposed to be wattage equivalent has resulted in a fairly dark house with what I would consider to be low quality of light. Many of the bulbs used in certain fixtures also emit a noticeable high pitched noise when on.
  • stephen_g 10y ago
    Sounds like pretty rubbish bulbs. Have you not tried replacing even one with a good quality brand? Of course, it might also just be that the lighting design wasn't very good in the first place...
    • brandon272 10y ago
      I have no idea what a good quality brand is. And if I did find better bulbs it would cost a fortune to replace all of the bulbs I just bought two years ago.
      • CamperBob2 10y ago
        Sounds like somebody spent a lot of money without doing any research. I must have tried samples of a half-dozen different brands before buying enough LED bulbs to retrofit all of my ceiling cans. Actually I sort of wasted my time, because the (subsidized) $2.99 65w replacements from the hardware store on the corner proved to be as good as any of them. No failures a year later (N = about 36) so they seem to be working out OK.
        • stephen_g 10y ago
          Similar story here, I found my favourite LED bulbs at the supermarket!
  • HNaTTY 10y ago
    If they're on dimmer circuits, they could just be cheap LED bulbs. Even if the dimmer is all the way up, and even if the LED bulb is marketed as dimmable.
• pcunite 10y ago
  Here is an interesting thread about color quality (something rarely brought up when LED gets mentioned). http://www.dpreview.com/forums/thread/3757505 http://www.dpreview.com/forums/thread/3757505
• sdx23 10y ago
  "However even ‘warm’ finish LED or florescent bulbs can only manage an index rating of 80 and most are far less." This is simply not true. Current state of the art is >80. If you search a little you'll find LEDs with CRI 95.
• slowmovintarget 10y ago
  This article also doesn't mention the current U.S. law which says it is now illegal to sell incandescent bulbs across state lines. The law should have been written to mandate efficiency, not implementation. Now there must be a legal fight to allow incandescent bulbs again (for the U.S., at least).
  • dalke 10y ago
    Why should a UK newspaper cover domestic US laws? And in the US, the law described at https://en.wikipedia.org/wiki/Energy_Independence_and_Security_Act_of_2007#B._Lighting_Energy_Efficiency https://en.wikipedia.org/wiki/Energy_Independence_and_Securi... suggests that the ban is not on technology choice but on efficiency, such that a more efficient incandescent bulb would be fine.
    • slowmovintarget 10y ago
      From the legislation: (C) Candelabra incandescent lamps and intermediate base incandescent lamps.-- ``(i) Candelabra base incandescent lamps.--A candelabra base incandescent lamp shall not exceed 60 rated watts. ``(ii) Intermediate base incandescent lamps.-- An intermediate base incandescent lamp shall not exceed 40 rated watts. Anything over 60 watts was to become unavailable by 2012, with a schedule to retire the 40 and 60 watt bulbs. Ironically, this meant that to get the same lighting levels, you were permitted to buy more 40w bulbs, but not a single 100w bulb. As to the "why cover US law?" question, I thought it relevant because the discovery was made by a US team at MIT and for there to be a "return" of incandescent bulbs would require both US and UK/European markets to be opened back up. Even if only as an irony juxtaposed with the location of the discovery, it was related. Now the law as stated would seemingly permit incandescent bulbs of equivalent brightness to old 100w bulbs, but only if they are 27w or less. Or, you know, you could just buy a gaggle of 27 watt bulbs.
      • dalke 10y ago
        What is your point about a candelabra incandescent lamp? That concerns only lamps which use a "candelabra screw base as described in ANSI C81.61–2006, Specifications for Electric Bases, common designations E11 and E12." Moreover, that is from a section which specifically allows them to be incandescent, so long as they don't exceed a given power limit. You also seem to have missed the part where it says: > The rulemaking— (I) shall not be limited to incandescent lamp technologies; and (II) shall include consideration of a minimum efficacy standard of 45 lumens per watt. or the "Backstop requirement": > If the Secretary fails to complete a rulemaking in accordance with clauses (i) through (iv) or if the final rule does not produce savings that are greater than or equal to the savings from a minimum efficacy standard of 45 lumens per watt, effective beginning January 1, 2020, the Secretary shall prohibit the sale of any general service lamp that emits less than 300 percent of the average lumens per watt emitted by a 100-watt incandescent general service lamp that is commercially available on the date of enactment of this clause. This allows incandescent bulbs so long as they are significantly more efficient than those sold before 2007. As to why UK newspapers writers are supposed to understand the details of domestic US law, and why UK newspaper readers are supposed to care, in order to get an extra moment of irony - well, that seems like a lot of work for very little gain. Especially when the EU has very similar laws, so UK readers may default to think that the US is already in the same boat, so there's little to no irony available.
• callesgg 10y ago
  When you live in a cold climate some light-bulbs become more efficient due to the fact that the heat is not waste heat. As it helps to heat up the room they are in.
  • imaginenore 10y ago
    Heating your home with electricity is probably the most expensive and the most wasteful way.
    • mnw21cam 10y ago
      Depends. If your electricity comes from coal/gas fired power stations, yes it is wasteful - just burn the fossils locally instead. If it comes from hydroelectricity, solar, nuclear, or wind, then no it is sensible.
• jrapdx3 10y ago
  Didn't see it mentioned in other comments, but a particular failing of LED lamps is their unsuitability for critical color matching applications. Fluorescents and CFLs are available for that use, but to date haven't seen LEDs that are satisfactory. This is important in art studios, museums and other venues. For many years I've used specialized 48" T12 fluorescents with good results. Incandescent/halogen lamps are also essential because color selection can depend on the target environment, there's a world of difference between indoor illumination and daylight in this respect. The high-efficiency lamps described in the article will likely be very useful and a welcome refresh of a light source that's so far been hard to emulate with LEDs. With IR energy being pumped back into the filament, maybe it's an option to run a hotter filament emitting a higher color temperature. More likely the input energy is just decreased so the resulting filament temp remains in conventional range. There still might be an issue re: time to filament burnout not differing from conventional lamps unless the filament is modified in some way. In the long run I imagine LEDs will be improved, curbing the disproportionate blue output, while enhancing and smoothing the long end of the spectrum. LED dominance will probably be complete when color rendering is optimized, they work properly with electronic dimmer switches, and lamp envelopes produce illumination as diffuse as classic sources, e.g., like "frosted" incandescents.
• Egidius 10y ago
  I'm suprised noone brought this documentary up: https://www.youtube.com/watch?v=-1j0XDGIsUg https://www.youtube.com/watch?v=-1j0XDGIsUg
• jrockway 10y ago
  Am I the only person that doesn't like "warm" light? I wish I could have all the lights in my apartment be D65 like my monitor. It makes everything look like a calm, cloudy day. At least with my monitor calibrated to that temperature, anyway.
  • cels 10y ago
    They should rename "warm" to "nasty dingy yellow".
• bwilliams18 10y ago
  This will find enormous success in the theatrical market. Nobody is willing to give up the CRI of tungsten filament fixtures.
• supergirl 10y ago
  I know the article is fluff when I see MIT in the title
• tsomctl 10y ago
  So, if I understand dkbrk correctly, this is a glass that transmits light but reflects infrared. This seems to have a huge number of other applications (assuming it is practical). Make windows out of it, so that your house stays cooler in the summer and warmer in the winter. Keep your car cooler in the summer. Better face shields for fire fighters. Put a window in your refrigerator. Let people get closer to metal foundries/casting metal.
• GigabyteCoin 10y ago
  >Researchers at MIT have shown that by surrounding the filament with a special crystal structure in the glass they can bounce back the energy which is usually lost in heat, while still allowing the light through. Why can't/don't they use those same crystals on LED lights?
  • fanf2 10y ago
    The crystals reflect back heat in order to improve efficiency by keeping the filament hot. LEDs don't work by being hot.
    • GigabyteCoin 10y ago
      They do lose energy in the form of heat, though. Ever seen the massive heatsinks required for a high wattage LED to work?
• nikolay 10y ago
  So happy as they are the healthiest night lighting anyway.
• ricksplat 10y ago
  Is there anything to be said for their durability and versatility though?
• hackney 10y ago
  Add a solar panel and one of those newfangled forever batteries and I'm sold.