"Chunlei Guo, associate professor of optics at the University of Rochester, ... have been able to squeeze out fluorescent-like energy performance from an incandescent light bulb. The breakthrough boils down to a laser treatment of the bulb's tungsten filament, a processing step which could one day become a standard in the light bulb industry."
Too late. Incandescent bulbs will soon be illegal.
From that article: "The pulse lasts a mere femtosecond, and delivers as much power as the entire grid of North America into a needle point size spot."
Huh? I think they left out one of the units or something, and if they didn't I don't see how using that much energy to modify the filaments could save energy on a production scale.
ROn 6/2/2009 2:32 PM RicodJour spake thus:
Read the comments below the article: lots of sloppy "science" in the text.
I forwarded this article to my pointy-headed scientist friend. Curious to see what he has to say about this.
If I was interpreting the article correctly, I believe that what they were saying was that they were putting a massive amount of energy into the filament over a very short timescale. so quite possibly the total kWh used to "modify" a filament may be very reasonable, but the current drawn for that brief instant would be quite massive. nothing that couldn't be handled with a hugeass bank of capacitors.
Now whether, overall, it's worth it... or if it really works... remains to be seen. An interesting read, if nothing else. I'd certainly be inclined to buy a hotrodded incandescent bulb over a CFL given similar energy consumption (including the energy used in production)
nate
The upcoming USA Federal 2012/2014 incandescent ban has lots of exceptions and loopholes, including an exception for meeting or exceeding an energy efficiency standard that a few incandescents on the market using "HIR" technology already meet. The one in the above article exceeds that standard and would be allowed.
- Don Klipstein ( snipped-for-privacy@misty.com)
A femtosecond is 10 raised to the -15 power. So, while it's a lot of power, it lasts for such a short time, that it's not much energy at all. If it was any significant amount of energy, it would vaporize the entire filament, not just change it.
de quoted text -
The real problem here is that they didn't do anywhere what the headline claimed. According to the facts in the article, they can produce an incandescent bulb that produces the light of a 100W one while using only 60W. While a major improvement, that's still almost 3X the 23W of a CFL. MAybe they think they can get there with further refinement, but it isn't so yet.
quoted text -
True, but there are applications where an incandescent is more appropriate than a CFL (hallway lights, outdoor lighting, etc.) so improvements in incandescent technology combined with the use of CFLs where appropriate can only reduce our overall energy use.
Plus, an incandescent can be dimmed out of the box; only a few expensive CFLs can. More savings - why use more light than you need? Use bright bulbs in all your fixtures but dim them down to a comfortable level. Bulbs will last darn near forever, and you can adjust the light level from needing a little to make up for an overcast day to much brighter on a dark night.
I for one welcome our new energy-saving incandescent overlords :P
nate
I know what a femtosecond is, even though I've never actually measured one (I have a cheap watch). The article said that for that femtosecond the power output to convert the filament was as much power as the entire NA power grid puts out (assumedly for the same femtosecond). Multiply that femtosecond power requirement by how many bulbs produced in {insert time period here} and a lot of those decimal point zeros fall off and the energy spent to save energy might be quite large indeed.
It's a crappy article written about something very interesting.
R
Wasting 'light' or energy? I wonder if most people realize that the older dimmer switches used a resistor and the potentially-saved energy is just dissipated as heat - they don't save energy. The newer ones chop up the sine wave and do save energy, so if someone is trying to be energy efficient they will need to upgrade those old dimmers along with the bulbs.
R
They do actually save some energy, because power is V^2/R, so for constant voltage, if you increase the total circuit resistance, you decrease the power. But as you point out, of the total power reduction of the light bulb, some is wasted as heat in the dimmer.
Cheers, Wayne
There aren't many resistance based dimmers around that need to be replaced. The triac semiconductor type have been the only thing you find for the common switch replacement applications for at least several decade.
Even if you multiply somthing that is 15 zeros small by a hundred or a thousand, it still isn;t going to be a number that amounts to any extraordinary amount of energy.
Let's say you make 1000 bulbs a second, which would be a hell of a nice production rate. The total generating capacity of NA, which is certainly more than the actual grid usage, is about 1 tera watt. Now let's figure out how much energy in KWH it actually takes to hit each one of those 1000 bulbs with that laser pulse:
1.0 E12 total NA capacity in wattsConvert to Kwatts:
1.0 E9 KWWhich would be 1.0 E9 KWHours if the pulse lasted an hour, but it only lasts a femtosecond, divide that by 3600 to get to seconds
2.8 E5 KWHthen by 10 E15 to get to a femtosecond:
2.8 E-10then multiply by 1000 bulbs:
2.8 E-7 KWH is the energy it actually takes to hit those 1000 bulbs made in one second.In an hour it would use:
1.0 E-3 which is 1 thousandth of a KWH of energy, or 1 watt hour. Clearly an amount insignificant even compared to household usage.
So I'm going to have to get light fixtures that are non-standard halogens that suck up more energy, or deal with CFL's that give me a headache. Nice choice. :)
CFLs give you a headache...? Why? If it's the color of the light, they make different types. The flicker on fluorescent tubes bothers me, but I've never noticed a flicker on a CFL.
R
A CFL *IS* a fluorescent tube.
The "daylight" CFL's are the only ones that I can tolerate, and I generally find them far more fatiguing than regular incandescent bulbs. Do they make them with an incandescent-like glow? That might help.
Although, besides that, I admit I just don't really like the technology that much, beyond the wattage savings. Maybe its psychological. :)
I refuse to put them in anywhere that I need "quick" light, like in hallways, the kitchen, motion-activated yard lights, etc, because it takes :30-:60 to achieve full brightness. And that's under normal (60-80 degree) temperatures. The yard light (I have a two-light flood, one is incandescent, the other is a CFL) takes a good 2 minutes to warm up in the winter.
I will sometimes notice a flicker effect with standard fluorescent lamps that use magnetic ballasts but not those with electronic ballasts like CFL's. Here's a website with some information about the reasons for perceived flicker of fluorescent lights:
You know exactly what I meant, but thanks for the unnecessary clarification anyway.
R
We're all psycho to some degree, right? There are fluorescent lights that people generally find easier on their eyes.
If you have a problem with a quick light, it is actually _you_ that are moving too quickly. Flip the switch and take a couple of minutes to open the door and step outside. See? The fluorescent is shining brightly! ;)
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