Apologies, typo here
"For what we don't actually know is the electrical price of lumens?"
Should read "elasticity of demand for lumens with respect to price."
This year's Nobel Prize in Physics went to the three Japanese guys who worked on, and got right, the blue LED. It's an excellent piece of work, enabling a whole new ensemble of energy efficient lamps and colour LED screens, and fully deserving of the prize. And yes, it might well change society in wondrous and wonderful ways. …
"...enables blue LEDs to be produced, and once you've got those to add to red and green ones, white light is possible and the LED light bulb could become reality."
Is the above extract correct?
Although it is certainly possible to purchase an RGB LED, such RGB LED light bulbs or similar RGB LED lighting strips seem to be more commonly sold as a accent lighting or novelty items. Based on what I've seen, most (virtually all?) LED lighting is based on LEDs using UV or Blue plus White or Yellow phosphor. Available as Warm or Cool coloured white light.
Am I correct on this point?
That's correct. In practice, most white LEDs don't produce "white" light by mixing primaries. The do it by using a phosphor coating which "downshifts" much of the blue light to longer wavelengths and mixing this with the blue light that penetrates the phosphor layer.
Of course, none of these technologies produce the continuous (black-body) spectrum of an incandescent bulb, although many people seem to believe they do.
who says people believe LED's (or whatever) produce a blackbody spectrum, I'm sure they a) don't know what a blackbody spectrum is; b) don't care?
I remember switching to energy saving bulbs some years ago and the feel of my rooms being different from filament bulbs, somehow 'colder', but now I've got used to it and happy in the (presumed) energy saving costs, although I've not tried to isolate this from fluctuating electricity prices; I'm not sure many people check their actual consumption, only how much their bill is (which is the point of the article and the prize award).
R + G + B will ONLY EVER work for a colour display. It's absolutely rubbish even if correct Colour temperature for lighting as the colour rendition is about the worst possible. Perhaps R G & B laser light might be slightly worse.
"White" LED are worse even than CFL or Florescent lamps as the UV LED isn't short enough wavelength for decent phosphors.
Very efficient CCFL, CFL or Florescent lamps are poorer colour rendition than best ones as the best colour uses more phosphors and less efficient ones to get a smoother spectrum with less gaps, spikes, dips etc
Unless there is a new type of UV LED, the White LED will be always poorer rendition. The phosphors wear too. White LEDs also are not as energy efficient as suggested due to PSU losses and less wide angle light.
Halogen is still best colour artificial light, with some less efficient Florescent lamps and CFLs less good.
RGB LED is far better LCD backlight than "White LED", most cheaper "White LED" are a bit purple and CCFL backlight may yellow a little with age, but after a few years the CCFL backlights are superior as backlights to cheap "white" LED. Very few TVs and Notebooks now have good backlights. Built down to a cost.
The AMOLED phone displays are not traditional R , G, and B LEDs, Sony calls the true LEDs, Crystal displays.
Can we even accurately measure it given the signal is mixed with every other electrical device in the home? Sure, we can put meters on individual appliances and work it out but is there any simple way to say "X" is lighting. Does it get more complicated given the ambient light cast off by the myriad devices in our lives like computer and TV screens and the dozens of other devices with luminous displays even if it's just a green led on the router, a red one on the switch and a blue one on the modem? At some point we're just picking, err, nits.
> Does it get more complicated given the ambient light cast off by the myriad devices in our lives like computer and TV screens and the dozens of other devices with luminous displays even if it's just a green led on the router, a red one on the switch and a blue one on the modem?
Depends what you're measuring. If you're measuring the actual cost of bringing your home up to a certain level of litness, yes, that all complicated matters considerably. But if you're measuring the amount that humans spend on lighting, it doesn't. A router may throw a bit of light into a room, but that's a side-effect; when someone spends £50 on a router, they never think "And 30p of that comes out of my lighting budget."
Another factor that is often overlooked is that in a place like the UK where a lot of lighting is used in winter, indoors, and along with heating, then any increase in efficiency is going to be partly offset by the heating system making up for the reduction in waste heat.
Other than that point, I tend to agree with Tim that we will just use more of it if the running cost is reduced.
No, Colour Temperature isn't the problem, its Colour Rendition, which is rubbish. The directionality is an issue too. LED lighting is ghastly compared to CFL.
RF noise of badly designed SMPSU for LED or Electronic Ballast of CFL can be easily solved. Regulation and enforcement is too lax.
Labelling is misleading .
Since most UK heating is by gas, solid fuel or oil, turning off a 100W incandescent and increasing the output of the CH boiler reduces electricity demand (and hence generation load). Anybody heating their house with electricity who doesn't have a private wind turbine is either unfortunate (renting) or needs a serious rethink (owner), because electricity costs more per Joule than does gas.
Software or engineering, it is almost always better to have something with minimal side effects. An incandescent bulb is around 2-4% efficient as a visible light emitter and most of that light is down the long wave end. There are many situations - street lighting, shop lighting, lighting in summer - where that waste heat is a highly undesirable side effect.
"Anybody heating their house with electricity who doesn't have a private wind turbine is either unfortunate (renting) or needs a serious rethink (owner), because electricity costs more per Joule than does gas."
Gas isn't available to around one in eight of the UK population because they are off the gas grid, and it isn't available in high rise buildings for safety reasons (noting some use communal gas boilers, some use dry electric heat). The cost balance between electric and gas should also take account of the depreciation of a gas boiler (say £150 a year), interest on the capital tied up (say £100 a year), and an annual safety check and clean (say £100). That's £350 a year of hidden costs before you've done anything. And there's a further couple of grand tied up in a wet heating system (say £250 a year, maybe more if you pay for "heating cover"). Added together the standing costs of a wet, gas fired heating system are around £700-800 a year, which would buy around 5 GWh of heat. And that doesn't include the gas supply standing charge, typically a further £100-150 a year (in terms of figures above, the gas standing charge would pay the depreciation on a dry electric system).
Against that a dry electric system is cheap to install and lasts longer so has lower depreciation, and has virtually no maintenance costs. In a typical draughty, poorly insulated house I'd agree gas is a no brainer where available. But in a very well insulated modern house a dry electric system can start to look a credible option. Economy 7 tariffs and storage heaters (with peak top up) can be as cost effective in the longer term as gas in a typical house, even though you'd have higher electricity bills. If I were doing a self build or a self-specify, I'd be looking for passivhaus levels of insulation, and use underfloor dry electric heating, and do without gas at all (that's a pipe dream, or non-pipe dream, depending on how you look at it).
Industry insider hint for those currently on E7 tariffs: Switch supplier twice a year - outside of the heating season you need the cheapest normal non-E7 tariff, during the heating season the cheapest E7 or E10. When switching in spring you're looking for a supplier who will offer you single rate electricity on a dual rate meter, as not all do. Do the sums, see if it works for you. Also, if you've not got night storage heaters, and you're on E7, chances are that you're paying a lot more than you would on a single rate tariff (to be in the money you need 35-40% of all electricity used across the year to be used in the cheaper off peak period). If either the seasonal strategy or the 35% of all power off peak things are news to you, I may have just saved you £150-200 a year, so in lieu of my beer fund, contributions welcome to the RNLI.
Not that long ago in some more northern climes where incandescent traffic signals were replaced with LEDs one problem was that there wasn't enough "waste heat" in winter to remove the snow from in front of the light making them near impossible to see in the day time.
Not that long ago in some more northern climes where incandescent traffic signals were replaced with LEDs one problem was that there wasn't enough "waste heat" in winter to remove the snow from in front of the light making them near impossible to see in the day time.
A typical mark-one problem. They've retro-fitted LEDs into existing enclosures without giving enough thought to the design of the entire system. The mark-two LED traffic light will have a small heater on its front shield / lens connected to a controller that will maintain the lens temperature above freezing point.
It might also have a well-insulated enclosure so that the heat from the LEDs does not go to waste, just as long as that doesn't result in the LEDs overheating in summer! Or maybe an aluminium heatsink that is exposed to the elements, with the LEDs (and cold-weather heater) sealed into it in a suitably weatherproof manner. Maybe the traffic light of the future will look like discs on a pole, rather than boxes of lights on a pole.
+1 to Nigel. I was in Minsk, Belarus last week and most of their traffic lights are thin flat panels with LEDs. They get very cold weather in winter and I'm guessing the lights would not accumulate much snow or need much heat to melt it off.
Here in the UK you see what look like LED array traffic lights but still in a big square box with shrouds - but we don;t get much properly cold weather or snow (practically none last year - and my son got a sledge for Xmas :-(
We had one of our guys bring in his VCR to repair (not the type of thing we normally worked on), we plugged it into the only composite monitors we had there, monochrome green screens. It would serve the purpose well enough in any case.
However, the only tape that was available at that time to test it, was a porno.
In the middle of "testing" the boss looks over our shoulders, and said "As long as it's not a blue movie, that's allright".
I have to agree that a greater prevalence of LED lighting options will lead to more use of lighting. The same holds true in heating, where if you offer people an insulation package for their homes (draught proofing, new boiler, cavity wall and loft insulation), then according to some very good studies, in a third of households the heating bills rise. The term the industry use is "comfort taking", and it's a simple fact of human behaviour.
And that illustrates some of the problems in forecasting demand and energy use, and the partial delivery of claimed benefits. In the move from incandescent to CFL bulbs, the "waste" heat was anything but during the six month or so of the UK heating season. Admittedly using electric bulbs is an expensive way of heating your home compared to gas, but the planet-savers didn't factor in the lost benefits of incandescent filaments, that on a fully adjusted basis were probably around 15% of their energy use. And likewise they didn't allow for the poor light output, poor light quality, and often slow start up of CFLs that caused people to buy a bigger nominal replacement CFL, or to have additional lights on. The only real reason that CFLs have become as widespread as they have is the EU tree-hugger's ban on incandescent bulbs, along with the UK Department of Energy & Climate Change forcing energy suppliers to subsidies or hand out hundreds of millions of CFL's
subsidised from levies on your electricity bill.
Even with LEDs the "crap eco light" problem has not been fully addressed, with lots of low grade harsh bluey-white lights on the market, sometimes low output, and often low reliability at the cheap end of the market. For GU10 halogens, there's plenty of good, reasonably priced LED options with output as good as a halogen, but for other fittings there's a lot of variation, and indeed a lot of crap on the market. At present there's few 100W BC incandescent equivalents available - the CFL versions tend to disappoint, and there's no trustworthy 1600 lumen bulbs I can find.
Curiously enough, one of the biggest benefits of LEDs is in street lighting. The overall energy savings if every street light in the land were LED are modest at around 0.3 GW (cf 2GW for a decent size thermal power station), but the quality of the light is far better, the savings on replacing bulbs half as often add up, and the luminaires (the light fittings) are far better designed with less light spill and darker skies.
"Curiously enough, one of the biggest benefits of LEDs is in street lighting."
In desperate economic moves UK councils are already reducing street lighting almost back to the 18th century levels. My large town switches off all the street lights at midnight - leaving only a few high level clusters on major roads. LED lights would be seen as a source of further economy.
The pitch black result is that any late return from an event requires a torch. Possibly an employment opportunity for link boys - or footpads.
"The pitch black result is that any late return from an event requires a torch. Possibly an employment opportunity for link boys - or footpads."
And just as much of an employment opportunity for paramedics and fire &rescue services:
The curious thing is why local government think they are in such desperate economic times. Current public spending is only marginally down from the astronomical levels achieved by notorious traitor Gordon Brown, my council tax is higher than it has ever been, and nationally the public sector is still spending £100 billion a year more than it raises through taxes (and none of that includes billions of pounds of stealth taxes like all the levies on your energy bills, mandated private sector expenses like employee pensions, or the half a billion telly tax).
> The curious thing is why local government think they are in such desperate economic times.
They don't. They're pretending they do in order to blackmail the public. "Nice library you've got here. Be a terrible shame if something were to happen to it. Like, for instance, Westminster threatening my gravy train."
So, just in case you are out after dark a couple of times a month this justifies your local council wasting money on energy every night. What's wrong with a small LED torch in your pocket when you know you are going to be out after dark? for some of us who live in the country this is the only option.
City dwellers don't realise how much energy, and therefore money, is wasted in street lights, shops and offices and floodlights everywhere from the back garden to the local castle walls.
"So, just in case you are out after dark a couple of times a month this justifies your local council wasting money on energy every night. "
Well sod off and live somewhere where there are no street lights then. You may find IS-held Syria to your taste, so lacking in all forms of modern amenity that I'm sure it is doing wonders for the planet.
"My large town switches off all the street lights at midnight - leaving only a few high level clusters on major roads."
LED plus sensors means that they can be dialled back 90%, but still fire up as cars/people go under them (the lamps communicate to adjacent poles, so it's not just the one you're under which lights up). This technology has been around a few years now.
As for energy costs, the single most expensive part of any streetlamp's operation is getting a bloke to change the lamp. Traditional ones are rated in on/off cycles as well as hours, so switching 'em off early may not make them last any longer and does bugger-all to save money overall. That sounds more like someone with a fetish for dark skies (Any amateur astonomers on the council?)
The pitch black conditions and increased nighttime accident rate sounds like a perfect oppportunity for compensation lawyers to wipe out any savings made - and then some.
LED street lanterns tend to use more energy than the sodium ones they replaced. 35w sodium=35w+9w (ballast lossed)=44w. 60w LED +5w gear losses=65w. The main energy saving is the potential to dim them down yes, but unfortunately the GSM based control system is about the most unreliable system the human race has developed.
HPS street lamps use significantly more than 35 watts per bulb. Try multiplying that by ten.
As for me, I live where the initial UK trials for LED street lighting were carried out. Going from a HPS section to a LED section is an amazing difference. Yay for white not-piss-yellow street lamps.
Bus-stops are disconnecting from the grid. They harvest enough energy from a solar panel during the day, to run timetable illimination and an LED light in the roof of the shelter. I was surprised when I first encountered one, that the shelter light was bright enough to read a newspaper.
Street lights could do the same thing, if only rules would allow the illumination levels to be dropped. At present there seem to be regulations stating that where there is street-lighting at all, it has to be bright. So you get a ridiculous safety hazard on some main roads, where you get dazzled driving into a street-lit section, and then have lost your night-vision adaptation when you drive out of it. Maintaining the whole road lit to the brightness of a full moon (or maybe just a little brighter) would surely be safer.
"Admittedly using electric bulbs is an expensive way of heating your home compared to gas, but the planet-savers didn't factor in the lost benefits of incandescent filaments, that on a fully adjusted basis were probably around 15% of their energy use. "
Afraid that's simply not true. As a 'planet-saver' who's worked on the nuts and bolts of energy efficiency for nearly a decade, the heat replacement effect has been well understood and factored in to efficiency savings calculations from lighting to appliances and ITC for at least as long. It doesn't make a big difference but it's big enough to be worth factoring in to any saving calculation.
It doesn't make a big difference but it's big enough to be worth factoring in to any saving calculation.
I did the sums. Allowing for the much earlier sunset in Winter and the fact that I'm at work during the day, something like three-quarters of my light usage was at the same time as I'm heating my flat. Plus any heat from lights that doesn't warm me, goes to warm my upstairs neighbours. So I have mostly gone back to Halogen-incandescent bulbs.
True, there are greater inefficiencies in electrical generation and distribution, than in high-efficiency (condenser boiler) gas central heating. But there are a lot of old boilers that won't be replaced for decades(*), and a lot of electric-only residences, and a fair number of rural homes that have to use Calor gas or oil or -shock! - coal heating.
(*) [Rant] especially since there's a regulation that requires your existing 15mm gas supply pipe to be upgraded to 22mm as part of any installation of any new boiler, despite the fact that many boilers are designed to work without any problem on a 15mm pipe. So, to the cost of a new boiler, add the cost and hassle of ripping up carpets and floors to install a new pipe, and repairing the damage afterwards. Madness. Oh, and you're no longer allowed to DIY the electrical work. Neither can the gas fitter do it. One of Prescott's jobs-for-ther-lads policies, you are regally required to employ an electrician as well as a gas fitter and a carpet fitter and a plumber. (And a council bureaucrat to keep the records)
Which is why my boiler won't be replaced until I sell my flat. If the new owner can be bothered, that is. [/rant]
Seconded - I suspect the major eco benefit of LED will be the very long life - anyone seen an LCA?
Hopefully that will be as true when/if we get a decent 100W equivalent. CFL especially of the expenisve dimmable variety and halogen have very poor life expectancy - switch cycle limits seem the culprit.
Just bought some 60W equivalents for clusters and been very impressed - if they even come halfway close to the expected lifetime I'll be happy - very high ceilings!
>I suspect the major eco benefit of LED will be the very long life -
Both incandescent and compact fluorescent bulbs are available in long-life versions. The first CFL I bought in the 1980's is still going (outside lamp that requires a ladder to change), and I was buying 2000 hr and 5000 hr incandescents just out of laziness (so I didn't have to change as often).
I suspect that people will continue to buy lamps that require frequent replacement.
although I believe in your numbers about the stability of the amount of money spent, I don't think that comes from more light on our houses. You get more efficient lights, you use more energy on computers, tablets, smartphones, etc.
Our energy consumption is not going to fall, that's for sure, but due to new uses, not for brighter lights indoors.
I don't think that tablets and smartphones are even worth mentioning. With USB power, they'd peak at about 10 watts (5v x 2A max), and the actual average would be much less than that. Consider also that they spend much of their duty cycle on standby - best measured in milliwatts. If you own a cat, then it is almost certainly a larger heat source than your tablet.
The EnergyStar / EnerGuide lables tell the story. Year after year, the latest apppliances and TVs are off the low end of the scale as compares to the min-max range set by the previous year's models. Our new 50-inch TVs are anticipated to require just $14 worth of power per year.
My ongoing attempt to heat my house using consumer electronics is becoming more difficult with each appliance upgrade. I have achieved an annual baseload that is several times the winter hump for electric heating.
In live events, LED sources are already saving significant quantities of electricity. And, yes, at the same time, people are using more and more fixtures, but they use so much less electricity than the discharge / incandescent predecessors that a real decrease in energy usage is happening.
Even more so where it comes to outdoor temporary events. Using LED can mean a more impressive stage / better lit site, while needing a smaller generator, less diesel and smaller, lighter cabling.
And we're also seeing plenty of snake oil - "It's LED therefore it's green".
There are several LED luminaires that are actually considerably less efficacious than the 'equivalent' tungsten-halogen luminaire - in some cases less than a basic tungsten!
One LED fixture I've recently seen is only 9-10 lm/W - while the 'similar' tungsten-halogen is 13 lm/W
Won't name names but they're easy to spot - if the fixture spec only says how many watts of LEDs it has and doesn't give both the input power and beam lumens, you can be pretty sure it's better at heating than lighting.
What is the life cycle cost of the various forms of lighting?
Household tungsten lights were cheap to manufacture and presumably to recycle - but with poor energy efficiency over relatively short lives. The "spot light" form factors seemed to have much shorter lives than the traditional bulbs.
Excluding subsidies, CFL bulbs were expensive - and need specialised recycling. They have often failed quite quickly and the light output has never matched the claimed "equivalent" tungsten bulb.
LED lights are also expensive - and need specialised recycling. My current sample has not yet had a failure - even though it is a quick on/off light to save ignition wear on the fluorescent tubes. Electronic components, and tungsten bulbs, generally seem to fail from switching surges.
My quick on/off kitchen lighting was a decorative 1970s cluster of 6 x 25w tungsten bulbs - which gave rather dim lighting. CFL bulbs of that shape didn't create the same effect - and overall it was just as dim. The replacement LED light fitting takes a nominal 3 x 4 watts and is nice and bright.
I didn't have to economise on the electricity bills - but the original tungsten fitting was merely being pretty in an otherwise functional room. To give a bright even light the kitchen has 2 x 80 watt fluorescent tubes. They only needed new tubes after 30 years - and LED alternatives in that form factor were not available at that time.
"LED lights are also expensive - and need specialised recycling"
Not that specialised. You can either dispose of LED GU10 fittings and the like with large metal heat sinks into the mixed metals recycling, or other LEDs into electronics waste recycling, the rest of which which contains much the same sort of mix of diodes and electronics. What's more, the better quality LED's aren't going to need recycling for the fat end of two decades anyway.
The expense issue is a myth as well - the capital cost is higher, but the lifespan is much longer as well as fuel costs lower, and with most lights you'd be getting a cash payback of 18 months to two and half years from an LED. Try finding a financial investment offering you a safe 30% annual return!
"What's more, the better quality LED's aren't going to need recycling for the fat end of two decades anyway."
Not my experience on a very small sample. A work light with two GU10s in it had one fail in about a year. Nothing wrong with the LEDs but the associated electronics started switching on & off at about 1 Hz. And there's the problem, any LED run from a voltage source more than about 3v is going to need some sort of converter. Even if it were impossible to produce LEDs with a shorter life than the heat death of the universe you'll have no indication that the manufacturer sought to source the lowest possible quality converter components until it goes titsup.
"Not my experience on a very small sample."
I'd agree that there's a goodly helping of rubbish on the market, and even some well known brands may have produced duffers, and with your point that the driver electronics will be the bit most likely to die, but being a charitable sort (as poster 080 will confirm above) I attribute this to LED being an emerging technology. Our office buildings have all been refitted with trade LED luminaires and in buildings housing 1,200 employees I'm unaware of any problems, so I think it is possible to get
When I bought a shed load of Tesco-brand GU10's, I kept the receipt and one box (which promises 25,000 hours use), with the specific intention of taking any failures in the next decade back to the shop. 18 months into this plan there has not been a single failure amongst the 19 bulbs installed, most of them running for around 1,200 hours a year, only eight and a half years until I can throw the box and receipt away. Fingers crossed!
"Household tungsten lights were cheap to manufacture and presumably to recycle - but with poor energy efficiency over relatively short lives."
"The cartel’s grip on the lightbulb market lasted only into the 1930s. Its far more enduring legacy was to engineer a shorter life span for the incandescent lightbulb. By early 1925, this became codified at 1,000 hours for a pear-shaped household bulb, a marked reduction from the 1,500 to 2,000 hours that had previously been common. "
It's worth noting that if you run an incandescent lightbulb at 5% over its rated voltage, it gives 10% more light but only lasts half as long. You get that much variation in supply voltage along the street from a distribution transformer.
"But when is the inflexion point? When will we be satiated with light and thus energy efficiency, in its provision, will lead to less energy use? As this climate change policy blog puts it:..."
I'm afraid that climate change policy blog is simply wrong. We've already reached saturation of interior lighting levels in our homes (at least in the UK) and I'm sure there are very very good psycho/physiological reasons why we aren't going to have daylight levels of illumination indoors (does he really consider that to be a likely scenario??)
This is quite clearly demonstrated by looking at the trend in lighting demand over the past 40 years. UK residential lighting demand peaked in 2002, trended down slowly til 2007 when it fell off a cliff and in 2012 was now back to the level that we last saw in 1978 (see DECC publication Energy Consumption in the UK for the numbers). And over that period the number of households in the UK has increased by a third.
In spite of replacing the vast majority of our incandescent GLS bulbs with CFLs (which have a much lower total cost of ownership) we haven't seen a major uptick in demand for lighting services. And we won't see a major uptick when we replace those CFLs and, much more importantly, all of our halogens (which really are a phenomenal waste of money and energy and now account for half of residential lighting demand) with LEDs which will be well underway before the decade is out.
No, in the UK residential (and indeed all) lighting demand is going to continue to fall off a cliff thanks to LEDs and this is going to make a big impact on our electricity demand.
In the developing world we will see an increase in demand for lighting services which is great because LEDs are enabling the rapid growth of off grid, renewably sourced lighting which is to be welcomed.
Wrote :- "We've already reached saturation of interior lighting levels in our homes (at least in the UK)
So all homes have all their lights on all the time?
Offices, yes. At work there is a glass covered (roof and sides down to knee level) 50 yd link between two buildings. Every morning its continuous line of flourescent tube lights is still on from the previous night (presumably the night guard patrol turns it on in summer). I turn it off each morning, because it is as bright as daylight in there. If I do not, no-one else does. In fact if anyone else sees me turn it off they give me a very funny look - almost makes me ashamed to do it.
These people would not leave such lights on at home - yet. But even I now keep my hall light on all evening because it has a low energy bulb. I did not leave it on when it was incandescent, so I certainly use more electricity there now than before.
Oh I'm sure there'll be some rebound through people leaving lights on longer (another factor that should be, and is included in any forecasting of benefits from energy efficiency) but that's quite a different thing to adding lots more lighting to increase illumination levels within the home, something which that policy blog seems to imply is inevitable.
> I'm sure there'll be some rebound through people leaving lights on longer ... but that's quite a different thing to adding lots more lighting to increase illumination levels within the home
Leaving lights on longer is adding more lighting to increase illumination levels within the home.
@ Squander Two... Well it results in the same illumination levels for longer periods of time. The thrust of the article was that there would suddenly be a big increase in illumination levels (i.e. lots more lights or the same number of much brighter lights) which is what I was pushing back on because there is no evidence for it but it's always rolled out by people trying to diss energy efficiency in lighting.
> Well it results in the same illumination levels for longer periods of time.
I.e., more lighting.
> The thrust of the article was that there would suddenly be a big increase in illumination levels
I've just reread it in case I missed something, and nope, sorry, you've projected this onto it; it's just not in there. The article points out that, when light gets cheaper, we buy more of it. It doesn't go into specific details about exactly where that spending occurs.
> it's always rolled out by people trying to diss energy efficiency in lighting.
I don't see any of that here either. I don't think that pointing out that increased efficiency may not have the effects some people claim it will is the same as opposing efficiency.
I have two LED lights as hall lights, and what makes the difference is that they have a motion sensor, so there's no groping for the light switch. They also take account of ambient light level. The usual pattern for electronics is a long life, with an initial risk of early failure.
I was already on fluorescents, and colour rendition isn't critical. But this sort of control seems to be quite new, and for a pretty obvious reason. Once you have the voltage for the LEDs, you have to power for the control electronics. The extra expense turns out to be quite small, compared to an ordinary LED. And the end result knocks down the time-domain element of total power consumption.
"what makes the difference is that they have a motion sensor, so there's no groping for the light switch."
This is going to be the big trend in security lighting too.
CFL AND Halogen based lamps need to be on for longer periods, else the on/off cycling kills them in short order. LEDs can switch on and off as often as required (assuming there are no issues of thermal creep on the heatsink and substrate), which means that outdoor security lighting can move towards a "dark skies" model (which attracts more attention when the lights come on than constantly on lights do.)
Even if this is counteracted by reducing the spread of constantly-on floodlights mounted high to keep them out of missile range of spotty herberts and putting in more "spot" security lighting, the overall power consumption trend will be "downwards"
LEDs are pretty much invulnerable to shaking from a thrown stone, unlike a hot filament - and the local oiks regularly knock out "inconvenient" incandescent security lamps around here.
Yes, power consumption from heating is likely to rise long-term, but only a fool would install an electric radiator based system when heat pumps already give heating operational (and installation) costs comparable with gas-based systems.
"No, in the UK residential (and indeed all) lighting demand is going to continue to fall off a cliff thanks to LEDs and this is going to make a big impact on our electricity demand."
Between 2010 and 2012 the decline you note flattened out, and in three of four National Grid future scenarios lighting energy demand hovers around current levels for the next decade. And unfortunately DECC's other policies (like transport electrification, de-gassing heat), accompanied by a big expansion in house building will more than offset the benefits of more efficient lighting, leading to a near doubling of electricity use by 2050.
And in a world that uses much more electricity, DECC's ideas of building expensive, intermittent, low-load factor power sources like wind are pure idiocy. Almost as stupid as writing a blank cheque to EDF for Hinkley Point B.
"Between 2010 and 2012 the decline you note flattened out"
Not according to the numbers in Table 3.10 (units are ttoe):
2010 - 1,212
2011 - 1,179
2012 - 1,181
2013 - 1,145
We'll just have to wait and see what the Commission does regarding a halogen lighting phase out. My money is on them going for it (it's a no-brainer now with halogen replacements now being at the right quality and price point) so my money's on the Gone Green trend for lighting.
"Not according to the numbers in Table 3.10 (units are ttoe):"
You disingenuous toad (it could have been a lot ruder, but I thought better of it). Your original point was that lighting demand fell off a cliff in 2007, and my point was that that decline dramatically slowed down in the period 2010-13, so perhaps you'd better repost and include the numbers right through from 2002 through to 2007? We both know where it is in DUKES, but I'll let you find and post it because it confirms what I'm saying that the "falling off the cliff" trend has dramatically slowed.
And you happily quote Gone Green (1) without regard to the other three scenarios, or the distinct possibility that within five years the EU could have broken itself up, or we may be outside it. This disputette between you and I is a pity - we seem to agree on the central point that well designed modern LED lighting is a great boon, on a like for like basis reduces energy use, and can offer better light quality in a lot (if not all situations).
(1) For those not in the loop, Gone Green is one of National Grid's "Future Scenarios". These are not forecasts, just a range of possible futures. For those who are interested in such technical stuff the whole NG Future scenarios are fantastic pieces of work, and they're freely available here:
The full download is a PDF document of around 214 pages, and National Grid do a programme of rolling consultations with all stakeholders and partners to get their views and input.
"Disingenuous toad"? It sounds like you're straight out of the 1920s you insufferable cur.
I wasn't being in the slightest bit disingenuous. I merely provided some numbers to show that your claim that it had flattened out wasn't quite correct. It's still trending down, albeit a lot slower than previously. The reason for this is entirely clear when you look at the evolution of demand from the different lighting technologies:
Unsurprisingly the rate of reduction decreases as the incandescent GLS lamps fall out of the lighting stock very quickly. It only takes a few years to get rid of the vast majority of incandescents so their contribution to lighting demand has effectively dropped off to zero.
Now the focus will shift to the 50% of lighting demand that is consumed by halogen lamps. That tiny blue strip in the above graph represents LEDs and that strip will rapidly expand as the halogen strip disappears. How soon that starts is down to the European Union (or electricity price rises). The EU has already made a start, phasing out the most inefficient halogens but it's the directional halogens that need to go as they form the bulk of that demand. Thankfully halogens only last 1,000 hours also so they'll disappear just as quickly as GLS lamps once the transition starts.
It'll do wonders for reigning in the winter peak in electricity demand too so initiating the phase out of halogens really should be a top priority.
"Thankfully halogens only last 1,000 hours also so they'll disappear just as quickly as GLS lamps once the transition starts."
My last set of MR16 and GU10 incandescent purchases were 10,000 hour jobbies. They lasted about 5 years before I replaced them with CFLs and then LEDs (Tesco's leds/cfls have been reliable, ones from other sources (I'm looking at you B&Q!) have not been.)
I finally got irritated enough with the RF and infrared hash emitted from all the ES and BC CFLs around the place that I changed them this year.
16W "corncob" leds easily outperform 21W ("100W equivalent") CFLs and apart from not having that pesky 30 second warmup period have a better colour gamut too.
The externals will be replaced with leds when the CFLs in them start to die (which should be next year) and at the same time I'll be considering "upgrading" to the robot ones which track heat sources as the existing cheap fittings are starting to craze due to UV exposure. I've seen the robot ones in action and you'd be amazed how fast a prowler can run if the light swivels towards him- and stays pinned on him as he moves. The only current issue is the cost.
We'll just have to wait and see what the Commission does regarding a halogen lighting phase out. My money is on them going for it (it's a no-brainer now with halogen replacements now being at the right quality and price point) so my money's on the Gone Green trend for lighting.
And if they do that then they are the most stupid idiots in the history of bloody fools, and the entire lighting industry will fight them to the death.
Just because something is LED does not mean it's efficacious. Lots of them are utter shite, consuming more electricity to make less light than a halogen.
The last round of proposals set a Lumens/Watt minimum and said nothing whatsoever about the technology. This is the only sane thing to do - defining a particular technology is the act of a moron.
"And if they do that then they are the most stupid idiots in the history of bloody fools, and the entire lighting industry will fight them to the death. Just because something is LED does not mean it's efficacious. Lots of them are utter shite, consuming more electricity to make less light than a halogen."
Yer wot? Please point out an LED lamp with lower lumens per watt than the equivalent halogen lamp. 30W of LED lighting would be immensely bright and way too big for a standard fitting - you can get LED security floodlights that consume 30W but I wouldn't want one in my living room.
"The last round of proposals set a Lumens/Watt minimum and said nothing whatsoever about the technology. This is the only sane thing to do - defining a particular technology is the act of a moron."
I couldn't agree more! It's far and away the best metric and I don't care what technology achieves it. But it will have exactly the same effect - it'll phase out the halogens and replace them with LEDs.
Seeing as you insist - two 230V products you can buy now:
Coemar LEDko @ 26deg: under 9 lumens/Watt. (Source: LSI, ignoring power factor losses.)
ETC Source Four (750W Halogen) @ 26deg: 13 lumens/Watt. (The 375W lamp is about 11 lumens/Watt.)
- In reality the LEDko is worse due to power factor which again acts in the halogen's favour.
There are several worse LED fixtures, this is simply the first one I found with published figures that you can check. I've seen LED fixtures that barely reach 5 lumens/watt due to poor optics, diode overheating and (especially) power supply efficiency.
They're generally easy to spot - if it doesn't give both input power and field/beam lumens, it's probably terrible. (Converting lux to to lumens will overestimate as datasheets give peak lux, not average)
Quite a few domestic ones are really terrible, primarily due to cutting too many corners in the LED driver/power supply design. Aside from that, the optics need to match the purpose - I've seen a lot where the optics are so narrow that you can't even use it as a reading light, yet it's sold as room lighting.
That's before you even start considering the quality of the light - the CRI and CQS of most domestic LED are painfully low, even worse than cheap florry.
They can be good, but most aren't and some are truly terrible.
Am I missing something? I just checked those out and they seem to be for theatres, not residential lamps.
It's undoubtedly a mixed bag with a lot of cheap shite out there but the good quality ones are definitely there for the buying and getting cheaper all the time. And the existence of crap products is no reason not to tighten the legislation, just a reason for good quality information for consumers, choice editing from retailers or, even better, additional parameters to the labelling requirements such as CRI or PF (there is precedence for that as washing machines are rated for spin and wash performance as well as energy).
I would argue that LED halogen replacements are in a better place now than CFLs were at the same point in their deployment cycle and we want to avoid making the same mistakes that were made with the GLS phase out.
The vast majority of domestic LED retrofits give no published figures whatsoever, and many are nameless making them impossible to check.
In testing a lot of domestic are also worse than halogen - there are even capacitor-resistor dropper LED lamps out there!
Aside from that there is the problem of optics - most are tight spotlights so even those that do provide significantly more lumens/Watt often don't actually light the room.
Oddly CRI scores seem to be rarely given - odd, as these are usually well publicised for florry tubes.
The latest approach at the higher end of the quality range is RGB - this is more efficacious and repeatable than Blue + Phosphor, however CRI is misleading for narrowband emitters (it's easy to get a really high or low score despite being mediocre) and CQS is not a ratified standard yet making it very hard to compare.
UV + Phosphor is basically never done, because UV LEDs are low efficacy and rip themselves to pieces in a few thousand hours. (Philips did a near-UV + External phosphor for a while, but it's been discontinued for ages. Shame as it was quite a nice lamp)
I've already assumed that they are morons, and have purchased a lifetime's supply of halogen bulbs just in case they become unobtainium. In the process, I discovered the vast difference between wholesale and retail prices! Also (see my other posts) not all Lumens are equal. The spectrum matters. Especially if you suffer, even mildly, from SAD.
(I can imagine it now, circa 2040, someone trying to get his GP to prescribe GU10 halogen bulbs. "But Doc, they're prescription-only these days! ")
One thing this author seems to have ignored, is that energy, sooner or later is going to stop being from fossil fuels, and from cleaner sources.
Just last week, we got some info on what appears to be a cold fusion unit. Rather try to explain it my self, I will point you to the article I read.
Cold Fusion Reactor -- Andrea Rossi’s E-Cat -- http://www.extremetech.com/extreme/191754-cold-fusion-reactor-verified-by-third-party-researchers-seems-to-have-1-million-times-the-energy-density-of-gasoline
Now if that is what it appears to be, as described in that article, then oil and coal is going to end very soon. And like many other people, I hope this is the real thing.
I don't have many thoughts about the prizes so much, since they are often not contemporary when given (picking the winners after the fact...).
But 2 items in recent history got a NP. White (well blue) LEDs and Fluorescent proteins (green, yellow, cyan).
The former gives me a camping light that will stay illuminated for a month(!) , available 2003?(NP2014)
The latter is used to see the inner workings of cells (cancer and otherwise)...never before possible. available 1996?(NP2004)
I think we have been spoiled by the astonishing rise in technology, and how ubiquitous "new" is...
This was the Physics Prize, not the economics one, so the narrow understanding suggested by the article may not be the entire picture.
Also, take the context. In the 80s and 90s, companies like BP were producing vast amounts of simple 70w solar panels, which along with a lead acid battery, and a fluorescent light tube with built in inverter, were installed throughout Southern Africa in rural areas. Areas like these previously either did without light, or use paraffin lamps. Paraffin for cooking and lighting often spelt disaster. Flourescent lamps were better than nothing, but they buzz, are prone to failure, and the cost of the entire shebang is quite high, even discounting the PR for which undoubtedly the exercise was done.
Now take the potential of LEDs for enabling sight during the hours of darkness You can go to a tat store in the west and buy half a dozen "garden lights" for a fiver. These are mere trinkets to us, but in the rural third world are transformative, providing safety in flammable dwellings and general night-time safety too. A few offcuts of solar panel material, a few NiMH AA batteries, a few LEDs with diffusers are now all that's required, at hugely reduced cost, no high voltages to cause danger, no buzzing or flickering to cause headaches, no lead acid to cause more danger and much longer lasting.
Yes,I would say the prize is very well deserved, but maybe not so much from a narrow, western economic viewpoint.
"First Al Gore, now LEDS. "
You forgot Obama getting the Peace prize before he'd even had the chance to do nothing. Or the similar award a schoolgirl who had the misfortune to get herself shot in the head.
I think the problem with the Nobel awards over recent years is a severe case of liberal political correctness.
The highest load here is on hot summer afternoons when everyone is running the AC, and generally have few lights on, so the peak loads won't be helped by LED lighting. Assuming we don't use more light to offset the savings, it will only increase the day/night difference in load. Maybe electric cars will help make up the growth in that difference, as most would be charging them at night.
The load isn't the main problem! how many times have you changed a light bulb?? for me that would have been 2 or 3 times a year!
I put all CFL in 10 years ago, the first went bad only a couple of years ago... the only other changes I have done is upgrade one to 'fast switch on' type...
I am still waiting for a decent 1000lumen (similar to 75 watt filament) here in UK..
the best is 870 lumen, roughly like 50W... not worth me spending 20 quid on! :)
That really only matters for difficult to reach places. For a typical bulb in a lamp, or fixture in a normal height ceiling you'd have to be atrociously lazy to consider saving a few replacements a year to be worth it.
Until fairly recently it was pretty hard to argue that alternative bulbs saved money on the basis of having to replace incandescent more often. Maybe it was true for you, but I've not had the experience with CFLs you have! What did save money was power - but only on bulbs used frequently. As bulbs I frequently used burned out, I replaced them, first with CFLs (which had little or no improvement in lifetime for me, and an annoying delay in turning on) and now with LEDs. Knowing I'll save money on energy, and hoping that it lasts long enough to make up for at least some of the difference in cost.
When a bulb I almost never use burns out, like say the bulb in the hall closet, I replace it with an incandescent because they're cheapest. There's no energy savings on a bulb that's lit maybe 20 minutes a year, and I probably won't live long enough, let alone live at the same house long enough, to make up the difference in cost through avoiding future replacements.
"When a bulb I almost never use burns out, like say the bulb in the hall closet, I replace it with an incandescent because they're cheapest. "
60W incandescent - 1 quid at tesco
4W LED - 4 quid at tesco (less when they're on special)
The most annoying thing about a dead lamp is that they almost always happen at an inconvenient time.
So? expect a future Novel prize for something revolutionary in solar harvesting or (especially) electricity storage(*). Perovskite solar panels may be a candidate, if they can overtake Silicon (much like LEDs overtook CFLs) Note: Solar power and aircon usage are a perfect match. Peak demand pretty much equals peak sun. Unlike the UK, where peak heating demand equals minimum sun. We really do need that energy storage breakthrough.
(*) Or not. Sometimes there's no big breakthrough. Just lots and lots and lots of small ones.
Re: They are so efficient that if the UK switched over to LED lighting, the nation could save 10 per cent of its electricity bill and do without eight new power stations
I think Tim's assessment omits the decentralization of power generation that is inherent in 12V DC LED home lighting. I reckon a standard 90x165cm solar cell array connected to a 12V battery can run up to 80 LED light fixtures in the home - should be enough for most private homes. Great way to save that huge wad of dosh being sunk into the bottomless Hinckley Point pit.
"I reckon a standard 90x165cm solar cell array connected to a 12V battery can run up to 80 LED light fixtures in the home"
I reckon you're grossly overestimating the efficiency of LED lighting -- you'll still need 20-40 watts of lighting for general lighting of a moderate sized room. Also I reckon you're not considering that most of your lighting needs are during the times of day when your solar cell array isn't producing any electricity at all.
Lifestyle choice here. LEDs are very good at doing a small close-up light source (that's not a burn hazard, and that doesn't need a permanent mains connection). So you could light your living space only to the level of a full moon, and use small portable sources for reading and other tasks needing bright illumination.
I doubt many wealthy Westerners will make that choice, but in the Third World things are different.
...unlike the recent Nobel Prize in physics awarded for the discovery of graphene. That IMO was the least deserved prize in recent memory.
The method of generating single atomic layers of materials using adhesive tape has been known since at least the early 1960s and the much-vaunted potential for graphene itself is starting to resemble the hype surrounding that other form of carbon, the nanotube.
There is, indeed, some interesting physics associated with GaN (blue) LEDs. That's why the award, not for economics. What bothers me is that they never gave (or included this year) an award to the people who invented LEDs in the first place. (One of them, NIck Holonyak, had a lab just down the hall from mine at the University of Illinois).
There is also some interesting physics going on in a two dimensional sheet of graphene, where the conduction and valence bands have no curvature to them, as well as carbon nanotubes, which are just graphene rolled up into a tube.
However, you must remember, the Nobel prize for physics is only for EXPERIMENTAL physics. They can't give it solely for things like theoretical electron band calculations (for either LEDs or graphene). That's why Einstein's Nobel prize was for the Photoelectric Effect and not for Relativity.
Exactly - whole article was basically:
"Ohhh - Nobel Prize - I'm an economist, I don't really understand that Physics stuff, so what I'll do is have a stab at explaining it, get it wrong, then focus in on a small quote from a commentary surrounding the actual awarding of the prize, blow it out of proportion, bang on about a load of shit to do with potential issues - then, wait for it, the killer conclusion - "I don't know..."
Fucking brilliant... I genuinely envy people who can turn in work like that with a straight face, and then manage to get paid for it.
Back to the Physics - working GaN LEDs was a tremendous achievement, and not at all trivial scientifically. Thus prize well deserved in my book.
Economists can fuck off back to their own brand of astrological hocus pocus on their own time...
Ever so slightly unkind. You say:
"Back to the Physics - working GaN LEDs was a tremendous achievement, and not at all trivial scientifically. Thus prize well deserved in my book.
Economists can fuck off back to their own brand of astrological hocus pocus on their own time..."
My opening paragraph once again:
"This year's Nobel Prize in Physics went to the three Japanese guys who worked on, and got right, the blue LED. It's an excellent piece of work, enabling a whole new ensemble of energy efficient lamps and colour LED screens, and fully deserving of the prize. And yes, it might well change society in wondrous and wonderful ways."
@ Tim Worstall
I'm sorry Tim, I must have missed the full impact of that paragraph under the screaming banner headline proclaiming "LED lies" and appearing to cast aspersions on the awarding of the prize.
To be honest though, if that's the only point I raised that you have an issue with I must have been nearer the mark than I thought...
> I don't really understand that Physics stuff, so what I'll do is have a stab at explaining it, get it wrong
Whatever you may think of Tim's article, he has at least explained the economics he's presented. Unless you explain the bit Tim got wrong, you're not exactly outdoing him, are you?
> focus in on a small quote from a commentary surrounding the actual awarding of the prize
Hmm. A quote from an eminent physicist explaining the societal importance of the prize in a way that is both representative of what lots of other people are saying about it and is also illustrative of the basis of current legislation. It's hardly some obscure immaterial point, is it?
Apart from that, you seem to be angry that a writer has used something that is currently prominent in the news as a springboard to talk about something that is closely related to it. But surely that's a completely normal everyday event.
@ Squander Two
> Unless you explain the bit Tim got wrong, you're not exactly outdoing him, are you?
The first 4 or 5 commentards already did a neat job. There was no point in my repeating them.
> It's hardly some obscure immaterial point, is it?
It's an eminent physicist, who is nothing to do with the invention nor the Nobel Committee, talking about energy savings that LEDs produce in relation to other lighting methods. It's a back of a fag packet illustration of how much of a difference the technology has made in terms of power consumption. He's not an expert in National Power management. Its a "could fill 4 football stadiums" moment.
That then gets cherry picked by the Guardian, who push a pro-renewables editorial agenda. That article then gets snipped and picked again by Tim, who needs a hook for some copy he wants to submit.
By which point we are so far away from the fact that it's a Physics prize, awarded for some bloody good work that the Nobel itself is irrelevant to the meat of Tim's article.
"Worstall on the Weekend - Will the LED revolution be all it's cracked up to be?" would have been far more apt and pissed me off far less.
> The first 4 or 5 commentards already did a neat job.
Their explications were certainly very interesting, but they were writing in response to an error that was not in fact in the article.
> Its a "could fill 4 football stadiums" moment. ... That then gets cherry picked by the Guardian, who push a pro-renewables editorial agenda.
So... what? Therefore no-one must respond to it? I don't get it.
Like I said, that pro-renewables agenda is accepted by our governing classes and is the basis of legislation that affects us all. It doesn't seem that unreasonable to write about it.
> By which point we are so far away from the fact that it's a Physics prize, awarded for some bloody good work that the Nobel itself is irrelevant to the meat of Tim's article.
Again, so what? The Register had already covered the news of the prize here. So what's your point? The Register may publish one and only one article about each piece of news? When one piece of news brings a particular related issue to public attention, The Register may never write about that related issue? Again, I don't get it. Just how fucking boring do you want this website to be?
> "Worstall on the Weekend - Will the LED revolution be all it's cracked up to be?" would have been far more apt and pissed me off far less.
You do know writers don't write their own headlines, right?
Oh, and also, the Nobel Committee did write:
As about one fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth’s resources. Materials consumption is also diminished as LEDs last up to 100,000 hours, compared to 1,000 for incandescent bulbs and 10,000 hours for fluorescent lights.
> Their explications were certainly very interesting, but they were writing in response to an error that was not in fact in the article.
>Therefore no-one must respond to it? I don't get it.
You're right, you don't. If he's responding to a piece in the Guardian then fine, no problem with that - just write the article accordingly. But the article isn't written like that, instead it comes across as trying to downplay the significance of the Prize.
> Oh, and also, the Nobel Committee did write..
Yup - and what they wrote is correct. For any given light output, using LEDs for it will "save" resources compared to using incandescents. The Committee's missive does NOT say LEDs will ultimately lead to an absolute reduction in the amount of energy used for lighting. I would go so far as saying that it has been carefully worded to avoid saying it.
I have, twice. I can see why you might think that it says that you can only get white light by mixing red, green, and blue, but it really doesn't. One might even say that it has been carefully worded to avoid saying that. RTFA.
> instead it comes across as trying to downplay the significance of the Prize.
Oh, yes, I see what you mean:
It's an excellent piece of work, enabling a whole new ensemble of energy efficient lamps and colour LED screens, and fully deserving of the prize. And yes, it might well change society in wondrous and wonderful ways. ... whatever happens in the world of lighting, gallium nitride has already changed our world. It's the basis of the higher density we can now achieve in optical storage. ... this is a good example of basic research that got commercialised very quickly. Blue lasers are still (just about, depending upon which generation of them you want to talk about) in patent and that's why the portion of the research done at Nichia Corp was so valuable to the company.
Yeah, it's practically dripping with bile-laden derision.
"This enables blue LEDs to be produced, and once you've got those to add to red and green ones, white light is possible and the LED light bulb could become reality."
Pretty unequivocal in what it is saying. Add a blue LED to a Red one and a Green one and you can get a white "bulb". Not how it is done. Here's a simple textbook white LED structure diagram. http://www.thinkyusa.com/commentary/upload_images/image2-1%20LED-xsection_eng.jpg
So unequivocally wrong.
> practically dripping with bile-laden derision
Half your selective quotes don't refer to the LED work, but instead to other uses of GaN - not part of the Prize award. What was your point? If we are resorting to selectively quoting items of irrelevance out of context:
"might well change society... unlikely to happen... really not sure...Oops, upside your head...we will fight on the beaches..."
> Pretty unequivocal in what it is saying. Add a blue LED to a Red one and a Green one and you can get a white "bulb".
Really can't be arsed giving a point-by-point breakdown of the piece, but you maybe need to learn the difference between "and" and "therefore", and note that Tim was explicitly writing about both bulbs and screens.
> Half your selective quotes don't refer to the LED work, but instead to other uses of GaN - not part of the Prize award. What was your point?
So what's your point now? You claimed that the whole article was completely dismissive of the scientists' work -- because it cast doubt on points made which you also insist are nothing to do with their work. I point out that the article is full of praise for the work. Even if half the quotes are irrelevant (because they relate to some of the work's broader applications rather than just LED bulbs), so what? They're still praise. I can't see even a smidgen of this derisory contempt for the Nobel-winners' work that you claim saturates the article. You're reacting to something that isn't there.
> you maybe need to learn the difference between "and" and "therefore"
Nope, which is why I also used the word "and", not "therefore". Parsing is something I don't have a problem with. You and comprehension on the other hand...
> You're reacting to something that isn't there.
Fine, you think it's all fine and dandy, I don't. Happy days. As I suspect this will start to descend towards the levels of a slanging match if it continues, how about we draw stumps on an enjoyable exchange of views?
We did start to light up more stuff immedeately, and as soon as the technology was (cheaply) available :
Quite a lot of light produced by LED is not for interior lighting.. It's for lighting screens.. TV , any number of mobile gadget, billboards... It's all done by LED nowadays, and quite bright as well.
I think if you take all those lumens into your equations you'd get quite a different figure.
> We did start to light up more stuff immedeately
I don't think the article suggests at any point that we didn't.
> I think if you take all those lumens into your equations you'd get quite a different figure.
I think you're mistaken about what that figure is. It's not money spent on things that happen to emit light; it's money spent on lighting.
And even if you did take those things into account, the result would be that we're spending more resources on lighting, not less.
FTA: First, interior light levels are still well below the intensity of daylight, by as much as one or two orders of magnitude. There is no immediately apparent reason why people should have an intrinsic preference for lower light levels
Well, first of all, indoor light levels are 2-3 orders of magnitude below daylight: sunlight is about 100000 lux, a brightly lit office about 400 lux, and most homes about a quarter of that. That's why lighting a lamp outside when it's sunny doesn't contribute anything to brightness.
But empirically, it seems as if people do prefer lower light levels. People don't light their homes with metal halogen or fluorescent lamps, they use incandescents because the weaker, orange, light is "cosy".
To a degree I think that's because of tradition, and partly because fluorescent light is ugly (excepting a very few specialty bulbs such as the Bio Vital, fluorescents have poor color rendition, making colors and skintones unnatural) and metal halide expensive, but I do also think it's a real preference.
With LED it is possible to get within one order of magnitude of sunlight, and the quality of the light, while not as close to natural light as metal halide, is much better than that of fluorescents.
I suspect what we will eventually see, is that most choose to light most of their houses about as weakly as today, but with localized areas with much stronger illumination, especially utility areas (the kitchen, bathroom, garage).
You can make all the lux, lumen whatever calcs you want, but average people use a standard incandescent filament bulb wattage, as they have been used for ages...
A bright office is good so you can your work properly, but after work you need to rest your eyes...
Incandescents are all that have been used for ages...There is nothing 'traditional' or 'cosy' about it!! that is all the average person had!! >:(
... unless you are rich enough to have a large place with space for huge strip-lights...
CFL came out in 1985, and took about 5 years to become vaguely affordable to normal people!
It's not the brightness, it's the full spectrum. You can see far better with N lumens of light from an incandescent source, than the same N lumens from a fluorescent source.
The spectrum of a CFL is quite frightful. A white LED is considerably better, but there's still far too much blue in it. Our eyes are evolved to see best with an incandescent source (the sun, a flame) or smoothly filtered derivations (moonlight, the setting sun). An old-style lightbulb may well activate psychological / physiological responses associated with sunset - hence "cosy". (My opinion of LEDs is that they are "brighter" than daylight, and therefore quite unsuitable for night-time illumination).
There's also a gathering body of evidence that even very low levels of blue light can disrupt sleep patterns. If you have any sleep trouble and LED lighting I'd suggest getting some red- or amber-LED torches and nightlights, and avoiding ever turning on white LEDs between bed-time and morning. Also put black tape over any blue LEDs on electronics in your bedroom.
I suffer from mild SAD so I notice these things more than many. White LEDs are good for waking up on dark mornings!
The Goths are actually right on this one= ''there is no actual reason that night-time light levels need to be anywhere like daytime levels'... or for that matter 'why we even need electric lights'...
caveiat= during our numerous local power failures our 1800 sq/ft living area is lit by 4ea. Deitz no.7 kerosine lamps and 3ea. 9th century single 18hr. votive candle lamps... except for the 3-led emergency radio, that's it... the overall ambiance is quite pleasant a/la ca.1830 lighting and we usually spend the down time talking n playing games (something we do not seem to have time for when the power's on)...RS.
The design suggestion for using High Efficiency Fluorecent Tubes was to place only 2 tubes on a 3 tube fixture, and to disconnect some fixtures. It is common in shopping centres and government buildings around here.
It is sold as a power saving measure. Perhaps part of the reason they get away with it is that new tubes are always brighter than old tubes, so you don't get a fair comparison when you replace 3 old tubes with 2 new tubes: the new tubes are bright by design, but also bright by newness.
In any case, I would not place 2 bright tubes in a fixture built for 3 old-design tubes: given the choice, I would make my school, government and shopping buildings brighter, because I focus better in brighter light.
> It's not just about better light. The invention of usable blue LEDs, and the race for efficiency that followed, launched a broad range of new technologies.
From the article:
But, before we go there, we should point out that whatever happens in the world of lighting, gallium nitride has already changed our world. It's the basis of the higher density we can now achieve in optical storage.
> I would call it a world changing invention.
From the article:
And yes, it might well change society in wondrous and wonderful ways.
When LED bulbs became available for US $8.00, I snapped a few up to test them out.
I've since bought a bag of them an replace my aging incandescent bulbs with them, as well as my CFL bulbs.
While the energy savings seems a pittance of 10 watts vs 18 watts, the light is whiter, appears brighter and is a *lot* cooler running than the CFL bulbs. That heat adds up in my house, as I need more light now than I did in my younger days.
-There is one thing that sucks more than getting older. Not living long enough to be getting older.
Similar here. Our local supermarket have started doing a range of LED replacement bulbs.
Our kitchen had 10 50w 12v halogen downlighters. After trialling 3 LED bulbs (5w each, and claimed to be equivalent to a 35w incandescent bulb), I found that the light they produce is very similar to the halogens they've replaced. I've since replaced all 10 bulbs, and although the colour is very slightly cooler, they've still far exceeded my expectations.
They're certainly much better at getting people to notice the response vehicles I'm involved with than the old incandescent rotators or gas-discharge strobes, so there's a saving, although in a very different sense than in other comments.
There is some anecdotal evidence that when driving in a severe blizzard, the lack of heat from the lamp means that the lightbar doesn't "self clear", and I'm very much against dazzling other drivers with the high level spots, particularly at night, which could help with this, but overall I'm very pleased as are many of my colleagues.
We shouldn't ignore the fact that darkness also has a value.
For astronomers (even just those who gaze up at the Milky Way and go 'Wow!').
For those who prefer watching TV or using a computer/tablet/phone without trying to cope with several bright light sources bouncing off the screen.
For those who want to rest their eyes from the day's glare and those who like to sleep with no distractions.
Oh - and vampires.
Actually, we know four things about demand for LED light. Here's your two to start:
"We really only know two things about the demand for light. (1) Historically, when the price falls, we just use more of it. (2) Secondly, at some point, we expect satiation and thus increasing efficiency to lead to reduced energy consumption."
But there are four, not two, characteristics that contribute to the demand for artificial light: (1) price (of purchase and/or operation - you choose), (2) supply (availability), (3) quantity of light produced by a device (lumens), and (4) quality of light produced by a device (spectral emission of light).
Business/industry and government may be focused on the cost of energy consumed, the cost of the bulb in the first place, and the brightness of light produced, but the consumer has a larger concern: the quality of light produced by blue LEDs. The quality of light produced by LEDs is most often described as flat, harsh, eerie and unattractive. Until blue LEDs produce white light - real white light with a full spectrum of color emissions - public demand will be dampened. Nobody wants to sit down in their living room in the evening and look like an alien being in the greenish-yellow "warm" light of an LED "white light" bulb. It doesn't matter how much energy they could save...
Spot on - I live out of town, have to walk significant distances around fields at night, and use LED torches for their good battery life, but *damn* the world look awful when lit by an LED torch.
It really stuns me how if I turn the torch to my face it is utterly dazzling, but when I am looking for something out in the paddock it feels as if the light is a fraction of the brightness of the 14.4V tungsten filament torch that I got with my cordless drill. LEDs are great for glare, less so for *vision*.
I've had similar experiences with so-called 'warm white' CFLs from GE, so I just stick with Phillips CFLs as they seem to have decent taste in phosphors.
40 watt equivalent LED replacement bulbs are on sale at WalMart for 4 bucks each. Every Watt you save is that much Crude/Natural Gas that doesn't get burned with drives down the cost of energy and cleans the air. 40 Watt LEDs will be 2 bucks next year. 100 Watt Solar panels will be under 50 cents a watt in the next 24 months. Ultra Caps will be out in mass production in the next 24 months for your home and car. We are this close to being 100% solar powered in the home and car in the next 5 years. Air conditioning and heating is next. And folks wonder why the Saudi's have open the crude spigots. You folks worried about quality lite for growing pot are a hoot.
I'm sick of hearing how LED lights are cheaper and "better for the environment" but somehow the costs of making the things and the environmental impact of fabbing the semiconductors involved is never factored in. Isn't is a bit suspicious that the figures for that are "unknown" in the same way the true costs of ethanol production are "unknown" thirty years and more since it was introduced into gasoline? I mean, you'd think the people making them would have some sort of handle on how much it is going to cost them before they start the production line, wuncha?
I'm also sick of hearing how durable LED lights will be. Busses in my neck of the woods have had them for years and every day I see one with clusters out in its stop lights, and the red traffic light at the end of my road has been LED for three years and burns out once a year where the old style light never failed until a hurricane brought the bugger down hard onto the road.
FACT: At a local DIY superstore a domestic LED bulb costs about 3.5 times as much to buy as a heavy-duty incandescent one of the "equivalent" output does, and I don't have to run around the houses trying to get someone, anyone to tell me where I recycle the f*cking thing when against all reason it *does* fail (just like the "longer life" fluorescents do).
Said bulb will also work just fine in dimmers that employ thyristors because there are no electronics to get upset by the buggered-about waveform of the supply, and an actual example I owned ran for three years in an extractor hood whereas the fluorescent I replaced it with lasted six months. I'm not even tempted to spend ten bucks to try LED lighting there instead.
I wonder how much hazard these bloody sci-fi lamps add to a fireman's lot when they burn with the rest of the house. Old-fashioned incandescents typically just collapse in on themselves and drip a bit. No noxious gasses from frying semiconductor gubbins or plastic housings/envelopes to worry about.
I suppose the big question is: what does some shadowy industry need all the tungsten for?
To me the real effect of LED using less power is that designs using PV solar cells and a small battery becomes the obvious solution to powering the LED, rather than the cost of cabling to the mains.
So LEDs might well use more electricity. But not add to CO2 creation.
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