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back to article Boffins: Ordinary lightbulbs can be made efficient, cheaply

Just as authorities in much of the Western world have moved to phase out the incandescent lightbulb, American boffins believe they have developed a process which can make the oldschool lights more efficient than energy-saving lamps. Optics boffins at the Rochester Uni in New York state say they've developed a process in which an …

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Anonymous Coward

@ Jan

Thanks for the heads up re. the GU10s - mine have only been in place for three weeks and all functioning happily so far.

What brand are yours, in case others may need the same warning? I'm using the ones from homewatt.co.uk with the yellow surface mount LEDs, £9.99 each.

I trialled a few each of the 'daylight' (white/blueish) and 'incandescent' (yellow tinge) and actually prefer the bluey ones, I find it a much nicer light to work under once you get used to it.

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Stocked up

I stocked up on filament bulbs long ago. Can't get the 100W anymore, but the attic is full of them, and R80 spots. I wouldn't mind the fluorescent substitutes if they would make a bright one, say equivalent to a 150 watt or even 250 watt tungsten. I found some 130 watt equivalent ones designed for SAD sufferers, but they are quite expensive (5 to 8 quid) and during the dim period at startup they are very dim indeed.

And why can't you get those two-bulb-into-one-socket adapters anymore? Ikea used to have them in Edison screw, but they have disappeared.

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@AC 12:24 GMT

"When all my my incandscent bulbs are gone, if there's no better lighting technology available, I'll revert to using candles and oil lamps"

There, there. Halogens are all right, so just switch to Solux or something similar.

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get the low-voltage LED fixtures

The LED replacements for your current incandescent sockets are having to adjust the voltage at each socket. It's those electronics that are failing, because the manufacturers are trying to make the bulbs inexpensive despite their relative complexity. If you want to use LEDs, get a room-sized low-voltage kit and use multiple individual LED elements that are just wires, an LED, and a reflector. You'll be much happier with the reliability that way.

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@The truth about CFLs

CFL's do indeed use more energy to manufacture - about 4Kw/h compared to 1Kw/h for an incandescent - not 1000x, 4x. What a pity for your argument that 1 CFL replaces an average 8 incandescents, 4Kw/h vs 8Kw/h. What an even bigger pity for you the lifetime energy use for *each* 100W incandescent is ~100Kw/h, arguing about the manufacturing cost is the sign of someone with no credible argument to make!

BTW: installing 125W Daylight CFL's nailed my Seasonal Affective Disorder where countless feeble incandescents failed. Buy cheap crap and you'll get crap light - so its nice of the CFL haters to keep sweeping the bad bulbs out of the market.

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I doubt it is useful

The microscopic surface texture of material does affect the way it emits radiation so I can believe zapping tungsten with lasers improves visible light emission efficiency.

Trouble is tungsten filaments slowly evaporate (which is how they wear out) and the surface is obviously the first to go so I doubt the efficiency improvements will last for more than a few hours.

And yes CFLS are generally crap, the rapid loss of output with age quickly renders them less efficient than halogen lamps. Combined with slow warm up, poor light quality, dangerous failure modes, toxic chemicals and about half of all existing light fittings being unsuitable for them they are just not a universally good idea. Sadly that doesn't stop technically illiterate politicians forcing them on us.

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Jan
Thumb Up

LED GU10s

@ac 14:10 GMT

> Thanks for the heads up re. the GU10s - mine have only been in place for three weeks

> and all functioning happily so far.

> What brand are yours, in case others may need the same warning? I'm using the ones

> from homewatt.co.uk with the yellow surface mount LEDs, £9.99 each.

I mostly have 3W GU10s from Ryness, bought in their shops, but they also have a web site http://www.ryness.co.uk/

I'm also impressed with a 5W GU10 bought from TLC http://www.tlc-direct.co.uk/

Less impressed with the service from Initial Lights.

> I trialled a few each of the 'daylight' (white/blueish) and 'incandescent' (yellow tinge) and

> actually prefer the bluey ones, I find it a much nicer light to work under once you get used to it.

Yes, as long as you don't turn on any low colour temperature bulbs as well, then the cool white

LEDs are really good to work under, read and illuminate artworks. I like their directionality.

If you take time to set them up then one person can read in a pool of white light while the person

next to them on the sofa can view video in an essentially dark room.

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Linux

There is no energy differnce

@Charlie Clark

Heat is IR

But the only energy changes that would be is that more light would be made instead of heat.

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RW
Alert

Pet Peeves

Peeve #1: El Reg spake "the Rochester Uni in New York state". Dear writers and editors, it's correctly called "the University of Rochester". Yes, it's in New York state and incredible as it may seem, it's in a city named Rochester, but it's not "Rochester University".

Nomenclatural precision re American institutions of higher education is difficult to attain, but if you just wing it, you can confuse your readers. In this case, Rochester (the city) is also home to the Rochester Institute of Technology, and your ever so kewl "Rochester Uni" is ambiguous enough to leave readers wondering just which institution is actually meant.

So dear beloved El Reg writers and editors, please take the time to ascertain the exact and correct name. You _will_ have to look these things up as they follow no particular pattern. Most decent American dictionaries have an appendix devoted to just this detail.

Peeve #1a: I'm surprised NuLab hasn't passed a flurry of regulations on this topic, it being just the kind of piss-ant triviality that engages their tiny minds to the utmost and gives them the thrill of being able to say "lookee us, we is governing the masses, wheee!"

Peeve #2: CFLs. Tried a pack. They wouldn't fit into my light fixtures, they aren't compatible with the wired-in touch dimmers I have in some rooms, the light quality was abysmal, and they impressed me as extremely fragile. Since I knock over a floor or table light a couple of times a year and break the bulb, considering the mercury in these things, no way I'm using them. Seeing conventional incandescents moving into the sights of the earth mother brigade as something to outlaw for environmental sinfulness, I went out and bought a big stash of the 100w bulbs I prefer: a lifetime supply, almost certainly, at my advanced age. As another comment pointed out, who cares if they convert a lot of their energy consumption into heat? In northern climes, that's perfectly okay.

Took the CFLs back to Home Depot and got a refund.

Peeve #2a: the earth mother brigade, aided and abetted by equally thoughtless pols, who have never seen an environmental bandwagon they didn't want to hop on. Another comment lamented quangoistic failure to distinguish objectives from methodsL: a common failure of the e.m.b.

Footnote #1: I have nightmares of a horde of silly, ill-educated earth mothers, all vast women clad in muu-muus, clutching me to their ample bosoms and nurturing me until I give up my sinful p.o.v.

Footnote #2: I mentioned my lifetime stash of conventional incandescents elsewhere on the web and was promptly accused by an earth mother of being selfish. But why oh why is that particular e.m. not out picketing her nearest car dealer? At least in North America, car dealerships are invariably lit up brighter than day all night long.

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Much difference in CFLs

I have smaller CFLs in the house; most of which have lasted a VERY long time....some may be close to 10 years old now. they were all (and no, i don't own stock or work there) Phillips Earthlites (however they spelled it). I am currently experimenting with a 150W and 300W CFL in my garage/workshop (I HAVE to be able to see). So far, one of the 150W has lasted two months and died (at $10US that sucks and I have already contacted the company about getting my money back).

If big gubmint expects people to give up incancescent lamps, they MUST get some better quality on these CFL lamps or you'll go broke buying them.

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Boffin

Energy concerns

Given that the laser used "unleashes as much power as the entire grid of North America" during its "few quadrillionths of a second" bursts, that equates to (*very* roughly) 1.1 ^-10 kWh (based on 3.6 trillion kWh used in 2005 in the US alone - http://www04.abb.com/global/seitp/seitp202.nsf/c71c66c1f02e6575c125711f004660e6/64cee3203250d1b7c12572c8003b2b48/$FILE/Energy%20efficiency%20in%20the%20power%20grid.pdf).

Unless, of course, they are trying to imply that more than 3.6 mil MWh are being released in those femtosecond bursts?

... And that was only for a pinpoint area on the filament. Which means that it would have to be moved adn fired over, and over, and over to fully cover one filament of one bulb. Let's not forget that (in the US, at least), a GE 60W bulb has 4 filament sections (~1cm each). Each one is coiled again and again, like a spring made up of a long spring, that helps to keep the filament warm, increasing efficiency. If strung out, it is nearly 5 times the length of the coiled coils.

So, if we are to cover _all_ of the filament, then we need to fire at all points of this coiled filament. Let's be generous and assume that only 3 sides per .1 mm of the filament needs to be "treated" - it is a three dimensional cylinder, after all.

3 (times per .1 mm) x 500 (.1 mm sections) x 1.1 x 10^-10 KWh (estimated power usage per shot) = 1.65 x 10^-8 kWh per bulb for the laser.

Not bad... except we then have to allow for the precision robotics required to hold the bulb/laser in relation to each other in order to ensure that each spot is not missed.... and do this 1500 times... So, to fully treat one bulb would (at one shot per second for repositioning and laser capacity recharge - that's actually generous, mind you), would take 25 minutes.

Perhaps not the best way to usher in a new revolution?

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The Free Market At Work

Well, not really. You don't hear so much about the intelligence of the free market these days, but outlawing incandescent light bulbs and mandating the change to digital TV are currently my two favorite "no such thing as a free market" examples.

CFLs are just plain bad. You get your choice of murky brown or icy blue light. Fifty cents every 1000 hours for incandescent, or seven dollars every 10,000 hours. No savings there.

With the mercury content, I'm very surprised they're not yet treated as hazardous waste.

The only folks who really benefit from this move are CFL manufacturers and their retailers.

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Bah!

I can't figure out what the people in Europe and the UK do to their bulbs. I've been using the "Energy Efficient" flourescent type since they came out and have had precisely one blow. The slow start time people complain about I *have* seen, on exterior, high-output spot lights, but it is certainly no worse than the start to full-brightness time on a sodium vapour lamp (and if you want to talk dangerous, they are a better candidate methinks). New interior-use bulbs sold in the US do not suffer this problem.

My older fittings did take a few seconds to come up to full brightness, but the newer spiral "almost bulb-shaped" ones are bright from the moment I switch them on. As for hard wearing, I used one in my cooker extractor hood because no-one told me I shouldn't. It is the one that blew - after a couple of years as compared to about once every nine months for so-called "rough-duty" filament bulbs. The bulbs also give a nice white light, indistinguishable from incandescent fittings they replace.

The only place I don't use them is in the dimmer-equipped light fittings, because all my fittings use the universally sold cheapo thyristor dimmers that are incompatible with the electronics of the flourescent lamps, or work with a three-way switch circuit that works in the dumbest way I can think of.

If instead of the switch selectively switching on both of the two bulbs at half or full brightness, the dimming action worked by switching on one bulb, then the second, I could fit flourescents without a problem. Why half-bright bulbs is better than one bulb at full whack is a mystery to me. It has no actual effect on the spread of light, as is proved when one bulb inevitably blows.

As for LED fittings, why they cannot be manufactured to turn on fewer elements in a "dim" mode is something someone brighter than me (or those older flourescent bulbs) will have to explain. Three-level incandescents are common in the US, so the market for an off/half/full bright LED bulb is there.

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Happy

My new get rich quick scheme

"When all my my incandscent bulbs are gone, if there's no better lighting technology available, I'll revert to using candles and oil lamps"

I have a stockpile of incandescent bulbs put away when I switched to CFLs (which I find entirely satisfactory, not sure what bulbs the CFL naysayers are on about but they sure aren't the ones I've been using!)

Let me know when you need them, they're yours. A million quid each ought to cover my costs. :)

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LED replacements

On the odd occasion over the past few years I've gone into a large chain DIY store to get something I idly go and look at the light displays they've set up, curious to see if the LED lights they're selling are anywhere near the brightness of equivilant halogen/tungsten etc. bulbs - nope, they're all still shite in terms of brightness. But it has to be said they only show/sell the LED bulbs which have clusters of 5mm LEDs in them, no high power Luxeon or Cree LED lights so I can't fully rule out LED bulbs as replacements for CFL/filament/halogen.

However on the subject of LEDs replacing traditional bulbs, I'm in the process of making a LED bike light - sure you've all seen the Cateye etc. 3/5/7/9 standard LEDs (wow, nine whole LEDs!) or the expensive single/triple high power LED setups - but I've taken a slightly different route, an array of 300 tightly packed 3mm LEDs which at full brightness only draw 10.3 watts. When powered you can't look at them straight on, cyclling it's like having a personal piece of daylight in front of you, a lot of fun and dimmable so I don't piss off car drivers (apart from the ones that don't dip their headlights).

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@Tjalf Boris Prößdorf

I swap in my collection of incandescent bulbs in late autumn and don't run heating over winter (in Australia, so winters are coldish but not cold-cold (spent several years living in Northern China where -30degC is normal winter-night temp., so a mere 10degC is almost T-shirt weather by comparison). Also let my PC do heavy video processing which I am not game to do in the summer (no AC either). My power bills are well below the national average for a comparable dwelling here.

I've been using CFLs since the late 80's. The last of the first set I ever bought is still running in my bathroom.

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Boffin

@Tjalf Boris

"Maybe those light bulbs are not efficient if seen only by themselves, but if you look at the room they are lighting and heating at the same time, the efficiency problem pretty much vanishes."

Popular misconception that. Heating a room using an electric light bulb is a lot more inefficient that using gas for example due to the inefficiencies in the electricity generation process. Fossil fuel powered generating stations provide 20-50% efficiency (roughly), so burning fossil fuels directly for heating purposes is a lot more efficient.

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Boffin

@Dave and Ed

Hang on - aren't green laser pointers done with an IR laser blasting its energy into a crystal which then glows green (and apparently *equally coherent* green, too - cool stuff)? Sounds as though the field of IR-to-visual energy conversion already exists, and if there is a mass market to be had I'm sure the cash would turn up for a bit of further research into different coloured / more efficient materials.

Meanwhile, I want one of those zappers, just to see what a "femtosecond-long pulse of extremely high-energy laser light" might do to a CCTV ...

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Longevity of the treatment

As a previous poster noted, the surface structure produced by this treatment might disappear as the bulb ages and the filament evaporates. Halogen bulbs have an additional problem. As the bulb ages, evaporated tungsten would be redeposited on the filament, destroying the treatment's remaining surface structure.

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Dead Vulture

Well done El Reg

Hmm...

Reg said: "American boffins believe they have developed a process which can make the oldschool lights more efficient than energy-saving lamps."

Press release says: "The process could make a light as bright as a 100-watt bulb consume less electricity than a 60-watt bulb"

So that's not more efficient than an energy efficient bulb is it? The equivalent flourescent uses only 18 watts IIRC.

Correct me if I'm wrong please.

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Bronze badge

Really?

Given that the article says :-

"American boffins believe they have developed a process which can make the oldschool lights more efficient than energy-saving lamps."

And that the claim is that these bulbs will use less power than a 60W incadescent light bulb yet produce the light output of a 100W then I think that this is not compatible with the view that they are as efficient as (florescent) energy saving bulbs. The latter have something like a 75% reduction in power usage.

In raw numbers a 100W GLS (incandescent) bulb produces about 17.5 lm/w (at best). This proposal (if it worked on a whole filament - yet to be proved) would get it to about 28 lm/w. However, we can already get to 24 lm/W using quartz-halogen bulbs (which are, of course, still incandescent) so that isn't so much better than proven, working technology. Both compare unfavourably with compact florescent bulbs at 60-70 lm/w. Even then, there is scope for new technology as yet to be developed to considerably exceed the efficiency of compact flourescents as they are still less than 15% efficient.

There are good theoretical grounds for incandescents being unable to compete in the low energy consumption area. Essentially this comes down to a simple matter of physics - the light output from an incandescent source is governed by the black-body radiation curve. In the case of incandescent light bulbs, the vast majority of that is emitted in the infra-red area. The only way to get more of the curve into the visible light part of the spectrum is to increase the operating temperature. Theoretically you might increase the efficiency of such a bulb by a factor of 4 or more over a tungsten GLS bulb, but you are then faced with the problem that no know material will stay solid at the required temperature and such a device would emit a great deal of damaging UV unless filtered.

So, in summary, we can pretty well match these claims already with tungsten-halogen bulbs at, I suspect, a lower cost than developing some new technology, and neither gets anywhere near a compact florescent despite what the article implies.

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Anonymous Coward

@ Ed Blackshaw

Actually, you have the conversions the wrong way around - IR is a longer wavelength than visible light, which in turn is longer than UV.

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@jan & joe & others ...

I'm aware that heating by electricity is inefficient (why not outlaw electric heaters?).

However the "inefficiency" of a lightbulb is - at least in colder climes - not quite as horrid if taken as part of the system "heated living quarters" as it is when you look at it just by comparing input of electrical energy with output of visible light.

Let me guess: instead of those 98% of energy which go to waste as we are told to believe, the real number might be closer to 50% waste. That is obviously not true for streetlights, but then I haven't ever seen incandescent bulbs in streetlights ...

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Happy

Science outwits politicians again?

Science outwits politicians again :)

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@Let's apply Occam's razor..

Thinning would make it radiate more, but perhaps more likely is that the change to the surface of the wire has changed the spectrum the wire radiates at.

Instead of radiating lots of IR (which we don't see), it radiates less IR and more visible radiation.

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Boffin

@jan, joe, tjalf re gas

And where pray would I get the gas from? Try thinking a little more globally. Not every country has a well developed network to supply domestic gas. And not every country uses coal or oil to generate electricity.

For example: here in Norway (about 40km south of Oslo) the sixty watt bulb in my lavatory is on 24 hours a day and as the peak daytime temperature this year was under fifteen celsius until this week I think I can justifiably count it as a space heater. Replacing it with a CFL would save perhaps 40W but the slack would have to be taken up by thermostatic electric heaters. And as the house is heated almost exclusively by electricity this would exactly balance until the outside temperature was such that the 40W was more than necessary and the panel heaters turn off completely (in the coldest months I supplement it with paraffin which of course is even more expensive than electricity). I use the cheapest bulbs obtainable and they last between six months and a year, that is between 4000 and 8000 hours. The reason for this, presumably, is that they are never subjected to thermal shock by being switched on and off.

And of course 98% of the electricity is generated by hydro so gas would not be as competitive as you say anyway (yes I know there are substantial losses in the HV lines).

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Unhappy

Incandescent bulbs don't waste energy...

Incandescent bulbs don't waste energy - they help to heat your home. If you change to low energy ones the central heating has to take up the slack. Result in CO2 - little difference!

Now factor in that fluorescents use toxic metals and probably have more embodied CO2 from manufacturing than old simple bulbs - I think the old ones are more green!

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Boffin

Heating nonsense

Offsetting the supposedly beneficial home heating effects of incandescent lightbulbs is the fact that in lots of places, people run air-conditioners at least part of the year to get excess heat OUT of their homes or offices. In such cases heat-generating light bulbs double the wastage: Use energy to generate waste heat, then more energy to pump it out of the building.

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When we can't afford the gas bill...

...we love a nice family evening sitting around the warmth of a good old-fashioned light bulb. Sadly we've only got one left.

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It heats my house argument

There is, of course, some value in the argument that the incandescent light bulbs heat you house which reduces the load on the central heating system. However, firstly there are times of the year (and climates) where you don't need the heat - indeed you might have air conditioning.

However, the second point is that this is only true if your house is heated using electricity (and premium rate, not off-peak storage heating). If the electricity comes from fossil fuels (and in most countries, most electricity is) then you have to look at the thermodynamic efficiency of the entire cycle. A good gas central heating boiler is perhaps 85% efficient. A typical generating station with transmission losses is going to be less than 30%. So yes, there is some offsetting, but even under the most favourable of conditions it is nothing like as much when comparing fossil fuels to heat your house vs fossil fuels to provide the electricity.

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What I think is happening here

is that the HIGHLY compressed metalic powder that is what the tungsten fillament is made from

is being heated to its melting point so the electricity is flowing much more easily amd so giving the impresion that something strange and wonderful is happening as for the various Goverments being in knee jerk mode isn't that what all goverments are in perpetualy not just ours.

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Boffin

Speaking as a trained scientist ...

I've never heard of such a great steaming pile of fucking shite in all my life.

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Heart

Speaking as a TS

You may be right Greg, but if you don't specify which turd you object to you comment is worthless. As a TS you should know that.

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