MIT: Incandescent Bulbs Now more efficient than LEDs!

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Incandescent bulbs are making a come back. Only problem is they're banned from being sold in countries...

MIT: Incandescents Now More Efficient than LEDs

Researchers at the MIT are publicizing that they have fixed the incandescent lightbulb with a brilliant improvement. They have wrapped the interior filament in a crystal glass that both bounces light and contains heat. It recycles energy in a way that addresses the main complaint against Edison’s bulb: It burns far too much energy for the light that it produces.

Why is this interesting? About a decade ago, governments around the world developed a fetish for banning incandescents (through an efficiency rule) and replacing them with expensive LED technology and florescent bulbs. It happened in Europe first but eventually came to the United States. The last American factory to produce them closed in 2010, and they are ever harder to find in even the big-box hardware stores. (As with all such bans, there are exceptions for elites who desire specialty bulbs.)

The change has been seriously annoying for many consumers. It has even given rise to hoarding and gray markets (in Germany, such bulbs were repackaged as “heat balls”). It has produced something of a political backlash, too.

On a personal note, my own dear mother replaced all her incandescents with fluorescents several years ago. I was sitting in her house feeling vaguely irritated by the searing lights in the room — cold and dreary — and had to turn them off. Sitting in the dimly lit room, my thought was: this is what the government has done to us. A great invention from the dawn of modernity is being driven out of use. Do I have to bring my own candles next holiday season?

Why should governments be in the position of deciding what technologies can and cannot be used, as if consumers are too stupid to make such decisions for themselves? Who is to decide what is efficient, and what the proper trade off should be between the energy expended and the light produced?

Maybe some people don’t mind the “inefficiency” of incandescent bulbs relative to the warm and wonderful light they produce. Entrepreneurs need to be able to discern and serve their needs.

The bans have given rise to a vast debate about which bulb is best and what kind of light technology governments should and should not permit. But these are really the wrong questions. The real issue should be: Why should governments be in the business of picking right and wrong technologies at all?

As the MIT innovation in lighting suggests, there are possibilities yet undiscovered that regulators have not thought of. If you write detailed regulations about existing technologies, you are forestalling the possibilities that scientists and entrepreneurs will discover new ways of doing things in the future.

A vast regulatory apparatus on cell phone technology in 1990 could never have imagined something like a modern cellphone. Regulations on digital commerce in 2000 might have stopped the rise of peer-to-peer services like Uber. Indeed, one of the reasons that the digital world is so innovative is precisely because the regulators haven’t yet caught up with the pace of innovation.

Regulations on technology freeze the status quo in place and make it permanent. How, for example, will regulations respond to the news that a new and improved form of incandescent bulb is possible? Early tests show it to be more efficient than the replacements which the regulations favor. Will there be a new vote, a rewrite of the law, a governing body that evaluates new lightbulbs, the same way we approach prescription drugs? None of this can possibly match the efficiency of a market process of trial and error, of experimentation, rejection, and adoption.

In government, a ban is a ban, something to be enforced, not tweaked according to new discoveries and approaches.

Herein we see the problems with all attempts by government to tightly manage any technology. Bitcoin is a great example. As soon as the price began to rise and the crypto sector began to appear viable, government agencies got in the business of regulating them as if the sector was already taking a shape that would last forever. And because technology and industry are always on the move, there is never a rational time to intervene with the proclamation “this is how it shall always be.”

Regulatory interventions stop the progress of history by disabling the limitless possibilities of the human imagination.

By the time regulators get around to rethinking the incandescent, the industry will probably have moved on to something new and even better, something no one can imagine could exist today.

MIT: Incandescents Now More Efficient than LEDs | Foundation for Economic Education

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Original article explaining how it works

Traditional light bulbs, thought to be well on their way to oblivion, may receive a reprieve thanks to a technological breakthrough.

Incandescent lighting and its warm, familiar glow is well over a century old yet survives virtually unchanged in homes around the world. That is changing fast, however, as regulations aimed at improving energy efficiency are phasing out the old bulbs in favor of more efficient compact fluorescent bulbs (CFLs) and newer light-emitting diode bulbs (LEDs).

Incandescent bulbs, commercially developed by Thomas Edison (and still used by cartoonists as the symbol of inventive insight), work by heating a thin tungsten wire to temperatures of around 2,700 degrees Celsius. That hot wire emits what is known as black body radiation, a very broad spectrum of light that provides a warm look and a faithful rendering of all colors in a scene.

But these bulbs have always suffered from one major problem: More than 95 percent of the energy that goes into them is wasted, most of it as heat. That’s why country after country has banned or is phasing out the inefficient technology. Now, researchers at MIT and Purdue University may have found a way to change all that.

The new findings are reported in the journal Nature Nanotechnology by three MIT professors — Marin Soljačić, professor of physics; John Joannopoulos, the Francis Wright Davis Professor of physics; and Gang Chen, the Carl Richard Soderberg Professor in Power Engineering — as well as MIT principal research scientist Ivan Celanovic, postdoc Ognjen Ilic, and Purdue physics professor (and MIT alumnus) Peter Bermel PhD ’07.

Light recycling

The key is to create a two-stage process, the researchers report. The first stage involves a conventional heated metal filament, with all its attendant losses. But instead of allowing the waste heat to dissipate in the form of infrared radiation, secondary structures surrounding the filament capture this radiation and reflect it back to the filament to be re-absorbed and re-emitted as visible light. These structures, a form of photonic crystal, are made of Earth-abundant elements and can be made using conventional material-deposition technology.

That second step makes a dramatic difference in how efficiently the system converts electricity into light. One quantity that characterizes a lighting source is the so-called luminous efficiency, which takes into account the response of the human eye. Whereas the luminous efficiency of conventional incandescent lights is between 2 and 3 percent, that of fluorescents (including CFLs) is between 7 and 15 percent, and that of most commercial LEDs between 5 and 20 percent, the new two-stage incandescents could reach efficiencies as high as 40 percent, the team says.

The first proof-of-concept units made by the team do not yet reach that level, achieving about 6.6 percent efficiency. But even that preliminary result matches the efficiency of some of today’s CFLs and LEDs, they point out. And it is already a threefold improvement over the efficiency of today’s incandescents.

The team refers to their approach as “light recycling,” says Ilic, since their material takes in the unwanted, useless wavelengths of energy and converts them into the visible light wavelengths that are desired. “It recycles the energy that would otherwise be wasted,” says Soljačić.

Bulbs and beyond

One key to their success was designing a photonic crystal that works for a very wide range of wavelengths and angles. The photonic crystal itself is made as a stack of thin layers, deposited on a substrate. “When you put together layers, with the right thicknesses and sequence,” Ilic explains, you can get very efficient tuning of how the material interacts with light. In their system, the desired visible wavelengths pass right through the material and on out of the bulb, but the infrared wavelengths get reflected as if from a mirror. They then travel back to the filament, adding more heat that then gets converted to more light. Since only the visible ever gets out, the heat just keeps bouncing back in toward the filament until it finally ends up as visible light.

“The results are quite impressive, demonstrating luminosity and power efficiencies that rival those of conventional sources including fluorescent and LED bulbs,” says Alejandro Rodriguez, assistant professor of electrical engineering at Princeton University, who was not involved in this work. The findings, he says, “provide further evidence that application of novel photonic designs to old problems can lead to potentially new devices. I believe that this work will reinvigorate and set the stage for further studies of incandescence emitters, paving the way for the future design of commercially scalable structures.”

The technology involved has potential for many other applications besides light bulbs, Soljačić says. The same approach could “have dramatic implications” for the performance of energy-conversion schemes such as thermo-photovoltaics. In a thermo-photovoltaic device, heat from an external source (chemical, solar, etc.) makes a material glow, causing it to emit light that is converted into electricity by a photovoltaic absorber.

“LEDs are great things, and people should be buying them,” Soljačić says. “But understanding these basic properties” about the way light, heat, and matter interact and how the light’s energy can be more efficiently harnessed “is very important to a wide variety of things.”

He adds that “the ability to control thermal emissions is very important. That’s the real contribution of this work.” As for exactly which other practical applications are most likely to make use of this basic new technology, he says, “it’s too early to say.”

The work was supported by the Army Research Office through the MIT Institute for Soldier Nanotechnologies, and the S3TEC Energy Frontier Research Center funded by the U.S. Department of Energy.

A nanophotonic comeback for incandescent bulbs? | MIT News

[niky]

Potential, they say. The demo is at about 6.6% Around 40 or so lumens per watt.

The LEDs I'm using now are around 75 lumens per watt (used to use higher, but they were expensive). They would still have quite a ways to go.

Still... it would be freaking fantastic if they did make 75-100 lumen/watt fixtures that were incandescent... no more messing around with electronics that can get fried by power surges. Just good old fashioned robust, microwaveable bulbs.

[safeorigin]

well, it's a prototype...

LEDs started off with much worse efficiency than even incandescent bulbs...

[african888]

in our house we have no more incandescnt bulbs. i have some more cfls but eventually will be switching to leds. leds being reasonably priced for me now.

the question for me is, if incandescents make a return and are more efficient, how much will it be? will it be like before? or priced like when LEDs started at around 300-500 for a 9w bulb?

[niky]

in our house we have no more incandescnt bulbs. i have some more cfls but eventually will be switching to leds. leds being reasonably priced for me now.

the question for me is, if incandescents make a return and are more efficient, how much will it be? will it be like before? or priced like when LEDs started at around 300-500 for a 9w bulb?

Depends on how the new technologies lend themselves to mass production.

Other designs use special coatings... this uses crystals deposited on the filament itself... probably expensive at the moment, but once mass produced, and considering MIT says there are no rare elements in it, should be much cheaper than LEDs.

My only question is life-span... since you're still using a heated filament, which will eventually burn out.

[safeorigin]

hmmm... since the crystals are using thermal energy to convert into light, perhaps it might have lower operating temperature?

[niky]

hmmm... since the crystals are using thermal energy to convert into light, perhaps it might have lower operating temperature?

All the new tech, even this new crystal system, works by returning heat to the filament... basically bouncing it back until it comes out as visible light.

Maybe they could pour less energy into the filament for the same lumens output?

Which leads to another advantage of incandescents... dimmability...

[CVT]

All the new tech, even this new crystal system, works by returning heat to the filament... basically bouncing it back until it comes out as visible light.

Maybe they could pour less energy into the filament for the same lumens output?

Which leads to another advantage of incandescents... dimmability...

Aside from dimmability,- they're de-facto electrical fuse...

Hmmm,- the development is interesting... Edison is right all along!

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