A Super-Efficient Light Bulb

Chroniton writes with news of a Silicon Valley company, Luxim, that has developed a tiny, full-spectrum light bulb, based on a plasma of argon gas, that gives off as much light as a streetlight while using less power. The Tic Tac-sized bulb operates at temperatures up to 6000K and produces 140 lumens/watt, almost ten times as efficient as standard incandescent lamps, and twice the efficiency of high-end LEDs. The new bulbs also have a lifetime of 20,000 hours. There's no mention of mercury or other heavy metals, which pose a problem for compact fluorescents.

That's all well and good...

but can I use it in a grow-op?

Beware - Parent post links to a virus

The "nasty police helicopters" link is no bueno. No clicking!

Light pollution

gives off as much light as a streetlight while using less power.

Great, people lighting their properties with more bright lights is just what we need. Light pollution is already a serious probably (it's destroyed amateur astronmy, see Mizon's Light Pollution [amazon.com] ). Instead of showing people how they can make do with less lights, we're just making it cheaper for private individuals to duplicate the Las Vegas strip.

Re:Light pollution

gives off as much light as a streetlight while using less power.

Great, people lighting their properties with more bright lights is just what we need

I missed the part of TFA that said these bulbs were going to be available at prices low enough for home use.

What makes you think these aren't just going to be used to... replace streetlights? Halving the power usage of streetlights nationwide would reduce atmospheric pollution measurably. If the choice is between light pollution and atmospheric polution... ...light pollution is the more desirable of the two.

Re:Light pollution

I agree. The reason it hasn't killed professional ground based astronomy is that it is quite easy to subtract the very focused wavelength of sodium vapor streetlights from an image, as sodium vapor lamps are almost completely monochromatic. If we switched to these full spectrum lamps that would be much more difficult, probably meaning we would only be able to do astronomy in very remote areas or with orbiting observatories. That said, even as strong a proponent of astronomy as I am, the increased efficiency of these lights would probably make it worthwhile...

Re:Light pollution

It is also easy to use shields, and angles to limit the amount of light going up, and only light up the areas that you need to. Besides reflects let you use a lower wattage and still light up the same area.

Re:Light pollution

it also affects drivers, and pilots as well. In some regions airports have pushed for local laws to limit light pollution going up into the sky as it interferes with planes landing. Spot lights can temporary blind drivers causing accidents.

Light pollution isn't so much about astronomy but being able to see when it is dark out, because some idiot is lighting up his yard like fen way park. At night less is more. I can use 5 watt 12 volt bulbs and light up your house better than spotlights. more of the house will be lit with less random dark spaces, and more importantly less shadows in which people can hid.

Price?

So...how much does it cost compared to an incandescent? Or an LED?

Dan Aris

they tell you in the video

Sounds like the company has $40 million in funding. So one bulb costs $40 million.

Not as low energy as you think

I found it interesting that the tiny bulb - at least in the video - was still using 250 watts and internally generated a temperature of 6000K (no they weren't talking color temp; they were talking actual temp). Now that's certainly lower than the 400 watt conventional streetlight they compared it to; but there's no mention in the video about scalability or low-power use. So the submitter's comment about it having advantages over compact fluorescents may have no basis in fact.

Ok, sombody's got to say it.....

Thats a bright idea.

full spectrum?

Full spectrum with an Ar plasma at 6000K ~= 0.5 eV? Yes, you can get a lot of light out of it and it looks white, but I wouldn't call it a full spectrum. There are mostly peaks in the region 900-1500 (I don't have a spectra right in front of me right now, so from memory). But I could be wrong of course.

God this shit here is worse than digg

A few points, inspired by those "insightful" comments i read till up to now
a) Temperature=!heat=!"OMG IT WILL KILL US!!!". You dont really want to know the "temperature" of the electron beam in your old style TV... (yeah, i know its not in thermodynamical equilibrium, and thus temperature is not defined, thus the "")
b) This is nothing really new. It is based on the same principle like the old sulfure-plasma lamps in the early 90s.
c) It doesnt scale down well. It needs its power provided by microwaves, which is not efficiently possible in the lower power range.
d) Yeah, it uses 250W. But provides as much light as a 1500W halogen thrower. Wake up, moms basement (which you are most familiar with) isnt the world, there are plenty of things you would like to have 10ks of lumens for.
e) Reinforced from d: Yeah, a 250W bulb can be energy efficent. Because it puts out a fucking lot light, numbnut.
f) Doesnt compare at all with leds: Leds have low surface brightness, are effiecent and dont scale UP well. This things have a very high surface brightness, are efficient and dont scape DOWN well. Apple, meet orange.
g) A better comparison would be vs HID: there they are supperior (longer lifetime, less dangerous, not much more complex driver (HIDs need a high-voltage ballast, too).

What the Spec says

According to the product specifications available from Luxim, the actual operating temperature of the surface of the light bulb must be actively cooled to below 850C, and it is recommended that the temperature remain above 650C.

There must be two dozen posts here already blathering about 6000K and nobody bothered to go read the company's official documentation? Here's their website [luxim.com], here are a whole bunch of specs and videos [lifi.com], now go read something before speculating.

Minor information

Latest LEDs available (now) go as high as about 90 lumens/watt (Luxeon Rebel, at 350mA, if properly heat sinked). I read, somewhere, that Nichia has demoed an LED at 130 lumens/watt.

However, their light, much like the light of this light, looks an awful lot like the light from a welder. You have to be careful about the pursuit of the almighty lumen -- it's a human-tweaked measure, not a physical measure, and lights score best by dumping all of their light into green. We probably don't want our homes to be lit by exclusively green light.

One thing to note is that there is wide spectrum (true 6000K, this new light), wide spectrum (white LEDs, a relatively smooth blob in the optical frequencies), and wide spectrum (a strategically chosen selection single frequencies, in fluorescent lights). This new bulb should produce very nice looking like, but it might benefit from some of the same phosphors used in white LEDs to down-convert the higher frequencies.

Properly run LEDs are claimed to have lifetimes in the range of 70,000 to 100,000 hours of use, and are not affected by rapid cycling (in fact, the recommended method for dimming them is to switch them on and off very quickly).

Re:Commercial use

Temperature isn't the whole story. Regular tungsten-filament incandescent bulbs operate at about 3600K, but it's a tiny filament, and encased in glass, so it's not much of a hazard.

A 6000K plasma may even be safer, depending on the density of the plasma.

Internal Temperature Doesn't matter.

> Such high operating temperatures would not be acceptable for domestic use
> - the risk of fire would simply be too great.

Don't be silly. 6000K is the internal temperature of the gas. The filament in an incandescent lamp can reach 3000K. What matters is the external temperature, which is likely to be lower for a more efficient lamp.

Re:Commercial use

In the video, the inventors mention that the Argon gas at the centre of the bulb (size of a christmas tree bulb) reaches the temperature of the surface of the sun (6000C). Given the small size of the bulb, there is probably a very steep temperature gradient (otherwise the glass tube would melt). But the energy is dissipated by emitting light of all wavelengths, not just in the infra-red region of the spectrum. I'd be worried about getting sunburn or cataracts from something like this.

Re:Commercial use

Heat and temperature are not the same thing. If it produces 140 lumens per watt, I believe that makes it something like 50% efficient (which is insanely high for lighting). That means a 100 watt lightbulb of this technology would turn 50 watts or so into heat, and 50 watts or so into light. A 100 watt incandescant is turning 85 watts into heat and 15 watts into light. So even if it runs at a higher temperature, its confined to a very small space.

This isn't dangerous at all.

Re:Commercial use

Additionally, if it really generated that much heat, it couldn't possibly be as efficient as even the worst incandescents.

To the contrary. The eye's range of sensitivity is tuned to the solar spectrum, emitted at a blackbody temperature just a bit below 6000 K. A bulb is most efficient if it emits light in the spectrum that the eye is sensitive to, and not in, say the infrared spectrum. So a bulb emitting blackbody spectrum becomes more efficient as the emission temperature goes up, and peaks in efficiency at around 6000.

Incandescent bulbs are not inefficient because they are too hot-- they are inefficient because they are not hot enough. They run somewhere about 2500 or 3000, and hence most of the light is emitted in the infrared, not the visible.

Re:COLOR temperature, not thermal temp

WTFV (watch the .. video). The temperature they're talking about really is 6000K in heat.

As other shave pointed out, this is not too much of a problem for household use as ordinary incandescents reach 3600 at the filament. You just need to encase it in a glass bulb.

Re:COLOR temperature, not thermal temp

In light physics, temperature and color temperature are the same thing. Color temperature refers to the temperature at which an ideal black body radiator will emit such a spectrum. This unit is obviously a temperature.

Moreover, this lamp appears to be a high bandwidth lamp -- "full spectrum" as they said. This implies that it does not depend on the absorbsion and emission characteristics of specific atoms. Lamps like these -- fluorescents, high efficiency sodium lamps, and the like -- emit light at discrete wavelengths. High bandwidth lamps depend on incandescence to produce light. Indeed, color temperature doesn't make sense for these kinds of lamps -- no black body radiator will emit discrete spectra. (There's a "corrected" color temperature unit for these lamps used in the lighting trade)

The point is: these lamps get hot. They reach about 6000K.

Re:Somebody please correct my math...

Lights are not on all of the time. if less than 12 hours use which is likely than your calculations put the life at 5 years in a street light configuration.

Re:Okay, that was just too awesome!

6000K? Who cares? The thing is, this bulb is generating about 10 times the lumens per watt of input power as a standard incandescent. That means that it is dissipating more energy in the form of light and less in the form of heat. Regardless of the internal temperature of the plasma, how "hot" the bulb gets is really a function of the actual dissipated energy. For instance, a spark of static electricity has an extremely high "temperature" but it doesn't burn you. Granted, some of that energy might be occuring in the infra-red range, but I doubt it will be any hotter than a normal bulb.

Also, if you look at HPS (high-pressure sodium vapor) lamps, the orange ones they use for street lights, the vessel that produces the light is actually quite small. There is an internal tube (made of quartz, I think) that holds the sodium. For the first few minutes, the bulb appears blue because you are seeing an arc in the center of it. After the sodium boils and then turns into a plasma, it is in a higher energy state and starts throwing off photons.

The only difference in this bulb is they are eliminating the electrodes and using a different plasma. They use a high frequency RF that's tuned to the resonate frequency of the gas. Sort of like a microwave does for water, but this is more focused. The gas resonates and becomes a plasma. Then it starts throwing off photons. Your efficiency is limited by how efficiently you can make your RF circuit and amplifier and how focused you can place the RF. I imagine they are quoting the theoretical efficiency but they probably haven't achieved it yet.

Re:Things I want to know

1) It scales down a bit at least. I'm pretty they were marketing it last year for projector bulbs at around 150W. Not sure whether it scales further down than that.

2) 6000K is very close to sunlight so yeah it's a nice warm sunny light - should in theory be nicer than incandescent light anyway.

3) No - it's a noble gas (unreactive) and naturally present in the atmosphere, making up nearly 1% of it in fact.

4 and 5) Dunno. I was just searching for the projector bulb version and couldn't find any actually for sale, which given that it was announced half a year ago isn't great going :(