Readers might recall I was an early adopter of LED lighting technology. Now it is getting even better.
New LED light design offers less energy, more light
LEDs are durable and save energy. Now researchers have found a way to make LED lamps even more compact while supplying more light than commercially available models. The key to success: transistors made of the semiconductor material gallium nitride.
Incandescent light bulbs are now banned in the EU, while energy-saving lamps remain a bone of contention. In 2016, it will be lights out for halogen bulbs over 10 watts as well. LEDs (light-emitting diodes) therefore have the best chance of becoming the light source of the future. Experts reckon that LED retrofit lamps for use in standard bulb fittings will overtake traditional energy-saving bulbs for the first time from 2015. By 2020 it is predicted that LEDs will have captured between 88 and 90 percent of the lighting market. The tiny diodes offer a whole host of advantages as the most environmentally friendly source of light – they contain no harmful substances, consume less energy and, with a lifetime of between 15,000 and 30,000 hours, last longer than conventional light sources. They also work at full brightness as soon as you flick the switch.
Coping with higher temperatures
LEDs do have one weakness, though – they are extremely sensitive to variations and spikes in power. To function properly, they need a driver that ensures a constant supply of power at all times. This driver, which takes the alternating current from the grid and converts it into direct current with a reduced voltage, has a profound influence on the light yield and lifetime of the LED lamp as a whole. The demands placed on the driver electronics are correspondingly high. This has prompted researchers at the Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg to focus their attention on voltage transformers featuring gallium nitride (GaN) transistors. During practical testing, the scientists found that the drivers developed using this new semiconductor material were extremely robust. Components made of GaN can operate at higher currents, voltages and temperatures than standard silicon transistors. “Heat plays a role both in the brightness and the service life of LED lamps,” says Dr. Michael Kunzer, group manager at Fraunhofer IAF.
Gallium nitride transistors switch at high speed
Gallium nitride transistors can also switch at high frequencies. The switching speed has a significant impact on the size of the coils and condensers built into the drivers for energy storage. In a GaN-based driver, the switch speed can be made as much as a factor of 10 faster than that of its silicon equivalent. “Applied to a smaller surface, this means it is possible to make switching cheaper. The whole LED lamp can be made lighter and more compact while delivering the same or even improved illumination,” explains Kunzer. Since the energy storage component plays a decisive role in manufacturing costs, this could have an extremely positive effect on the end price.
Thanks to the new semiconductor material’s useful properties, Kunzer and his team have been able to boost the efficiency of the GaN driver to 86 percent – between one and four percentage points better than its silicon equivalent. When compared with the silicon transistor LED lamps available on the market., the scientists were able to increase the light output: while the luminous flux of commercial LED retrofit lamps featuring silicon components is around 1000 lumen (the unit used to measure the light produced), researchers from the IAF have been successful in increasing this to 2090 lumen. “20 percent of energy consumption worldwide can be attributed to lighting, so it’s an area where savings are particularly worthwhile. One shouldn’t underestimate the role played by the efficiency of LED drivers, as this is key to saving energy. In principle, the higher the light yield and efficiency, the lower energy consumption is. If you think that by 2020 LEDs will have carved out a market share of almost 90 percent, then it is obvious that they play a significant role in protecting our environment,” says Kunzer. The researchers will be showcasing a demonstrator of their retrofit LED from April 7-11 at the Hannover Messe, where they can be found at the joint Fraunhofer booth in Hall 2, Booth D18.
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Alan Watt, Climate Denialist Level 7 says:
Technically speaking, LEDs will not have captured that larger percentage of the lighting market; it will have been awarded to them by virtue of regulatory bans on competing technologies.
Those regulations have helped and will help LED lighting and I wish they hadn’t been enacted. However, on the bright side:
1. I believe LED’s would have won anyway — just as solid state electronics beat out vacuum tubes. Ignoring all of the CO2 nonsense, LED technology is just plain superior to incandescent or CFL.
2. We haven’t sunk billions of taxpayer dollars into misguided lighting technologies.
otsar says:
March 11, 2014 at 2:39 pm
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They finally got blue light LEDs about 10 years ago, after decades of work.
UV LEDs are probably still several decades off.
Once they get them though, recorded movies will probably get close to theatre quality.
My new house has very high ceilings in the living room with in-ceiling can lights – the previous owners had horrible 200watt incandescents in them. I’ll soon replace them with 25watt LEDs saving nearly a kilowatt/hour — but my main concern is lifespan; I only want to have to climb a very high ladder ONCE.
I build custom LED light fixtures for various things and the least reliable component by far is any electrolytic capacitor in the circuit (as it is with most any other electronic switching power supplies).
For LEDs, the killer is heat. There is a direct relation between life expectancy and operating temperature. Mount an LED on a sufficient heat sink, keep the current within spec, and the rated life expectancy will be met. As for the power supply, keep out any cheap electrolytic caps and the power supply might last as long as the LED.
In Oz, Phillips introduced a new type of mains-voltage LED replacement bulb in 2013 – better output/watt and colour than 2012 model, and lower price. I can’t find any technical data, but the difference may be a fluorescent coating on the inside of the bulb (it glows for an instant after bulb turned off, like a fluorescent tube.) But still the limitation is intolerance of high temperature, a problem with the very high max. mid-summer temperatures we have. So don’t believe the life claimed on the packet. Also, I am busy upgrading my ceiling insulation, to compensate for the lost wattage, otherwise saving will be lost in gas usage for heating.
A reference site for quality and technical issues for the impending flood of LED lights would be very helpful.
We’ve used CFLs for 14 years because our new house had tons of can lights that would have cost us a fortune. The CFLs all lasted at least 8 years. The only issues we had were the warm up time and that they don’t work well, or at all, in the cold. We had them in the porch lights since we leave them on all night, but that doesn’t work in the winter and in really cold temps of around zero, they don’t work at all.
LEDs are way too expensive still.
I do have some heirloom lamps where only low-wattage incandescents work. I stocked up on 60 watts when I could.
We also switched all of our Christmas lights to LEDs. It was expensive but worth it after all the years of blown fuses, juggling wattage, and the wind breaking the bulbs. The colors are a bit different, but we can put almost all of them on one outlet.
While Anthony’s article is technically accurate (and like him I am installing LED lighting), he implies that changing to LED lighting will save a large amount of the electrical energy presently used by lighting. This is historically inaccurate. As the cost of operating lighting decreased (either due to less expensive electricity or more efficient bulbs) people installed more or higher wattage lighting and left the lighting on longer. A typical example is LED christmas lighting that is left on 24 hours a day rather than being switched off. The cost of operating LED lighting is now so low that there is less incentive to switch it off. Sigh….
John in Oz sez: —————————–
If low voltage LED lighting is going to be the norm, perhaps building codes should be changed such that a low voltage lighting circuit is built into our building power distribution boxes.
A single voltage converter supplying all lighting power would eliminate the need for converters in every LED lamp, lowering the unit cost even further. Lighter and cheaper wiring would also reduce costs as the current is much lower and an earth cable should not be necessary for 12V DC circuits.
—————-end quote ———————-
This sounds like it could be a good plan in new construction. But it would necessitate running “lights only” circuits to all rooms in addition to all the “appliances” wall-sockets. And for floor and table lamps, one would need either a separate “lighting” wall socket on each wall, or else. . .? But I like the idea! There is a lot about home/commercial wiring that could be improved over the next few years.
We live in an old [80-100 yrs] farmhouse (in the USA near the Great Lakes) whose wiring has been “updated” several times, in bits and runs, last time by me when we moved here 20 years ago. Ground floor wiring is great, next floor up is so-so and the top storey (finished room/attic) has EVERYTHING on ONE circuit contolled be a single light switch at the bottom of the stairs! We’d done limited use of CFLs earlier in the century, but in the last 18 months we’ve gone over almost 100% to LED light bulbs. The cost and quality have both improved (if you watch for sales!) There are limited coices in terms of color output, but lamp shades and glass can correct most problems one might have. Better than incandescent or CFLs, in my experience.
Very interesting article! Thanks, Anthony.
Forget about LEDS, OLEDS rule.
If alternatives to incandescents are (will be) as great as claimed, there is hardly any reason to legislate mandates for them. These mandates always seem to overlook crappy characteristics
of new technologies. The pubic pays for these things and has to live with them and should be the sole arbitor as to whether and when they ae considered good enough to be the new norm.
you got it.
As long as the little buggers don’t continue to burst into flames.
Had one do that in a fixture on the ceiling of my mobile home.
(Yes, mobile home dwellers are very concerned about light bulbs that burst into flames. Fire: It’s a hazard of the lifestyle.)
“The switching speed has a significant impact on the size of the coils and condensers built into the drivers for energy storage.”
Did anyone understand this (or any of the rest of the article)? Presumably higher switching speed could enable the transformer coils to be made smaller, but how does it reduce what’s needed to store a given amount of energy?
@Common Sense says:
March 11, 2014 at 3:18 pm
Hmm, well lucky you. My experience with CFL’s suggests they are basically a scam. I date the base of bulbs when I install them. None have lasted more than a year and a half, well under the touted 7year/22,000hr span. Everything from Philips to the cheapies, all reek. Oddly, for outdoor use they’ve been fine. My porch lights have gone on at down to 2F. They take about 5 minutes to get to full (or apparently full) brightness, but I’ve never had one not fire up.
The free market always, ALWAYS, produces better results and products than government mandates. If governments had left the light bulb market to it’s own creativity and didn’t force the dangerous, expensive and dim CFL bulbs onto the market LED bulbs would more than likely have an even larger market share at this point in time.
Barbee says:
March 11, 2014 at 3:39 pm
You will be pleased to know that UL considers this a normal and acceptable end-of-life failure mode for CFL’s.
In a temperate or cold climate any energy saving created by the increased in efficiciency in converting electrical energy to light energy is counteracted by the room thermostat which turns the heating on in a room more often if you put a more efficient light bulb in it.
The EU ban on moving incandescent bulbs around does not apply to online and mail-order, only to physical shops in the street. Also they were being smuggled in to the East of England by the lorry-load and sold at car-boot sales.
The legitimate Amazon prices look much higher than the illicit car-boot sale prices, especially with the postage and packing.
Where LEDs have caused a revolution is in stage lighting: one can now perform in dazzling light on stage without getting fried, and without the hazard of climbing a ladder to put colour filters in.
Happy with the science and technology, abhor the enforcement. If it is so good the market should fix it and leave me the choice.
Incandescent lamps were only banned for domestic use in the EU – in theory. When Christopher Booker requested the UK government provide him with the legislation that banned them in the UK it couldn’t – therefore they aren’t. They are not banned for industrial use so you can buy them and use them in the home. They are slightly less bright due to thicker filament to withstand rough handling – often labelled ‘rough service’ for use in inspection lamps etc. I use incandescent lamps on stage in 150w, 200w and 500w monsters and they can’t be changed due to the focussing of the reflectors.
CFLs are slow to light – especially in the cold. They don’t like being switched on and off frequently and are prone to overheating in unventilated fittings, both of which shorten their life to much below that claimed by greenies. They can also go bang and take out your whole lighting circuit, so are not recommended to be left on in empty properties. Also may catch fire. Incandescent lamps can have a much monger life if you use a dimmer switch as it reduced the stress on the filament.
LEDs are brilliant and I use a lot of them now. Great in my campervan for giving good light at low consumption and not draining the battery. Never yet had an LED fail.
A few months ago I bought a LED desk lamp from Costco. The lamp has touch controls in the base (on/off, brightness, colour temperature), and two rows of LEDs (warm, cool). The lamp worked well enough for a few months, then suddenly one of the banks of LEDs would not turn off. I had lost the store receipt, so I decided to open up the base and see if I could identify and replace a component which may have failed. The base housed a 1 1/4″ x 2 1/2″ circuit board (the “driver”) with a handful of components, resistors, capacitors, a tiny IC or two, etc. None of which showed any obvious damage.
To me, this highlights the fundamental problem with the current generation of LED lighting technology. While the LEDs themselves may be long-lived, you cannot simply plug a LED into the wall. Somewhere inside will have to be some basic electronic components and if any of those fail, that’s the end of the LED lamp itself.
It would definitely be an improvement if the new semiconductor driver described in the article can replace those cheap components.
Joe Born: I think that it is an awkward translation and it is referring to the size of the inductors and/or capacitors needed in the switching power supply. Higher frequency switchers require smaller inductors/capacitors — inductors and capacitors being devices that store energy.
Note. I am not criticizing the translator or the translation. I certainly couldn’t do any better.
They would be better instaling a robust voltage regulation system (V-phase) on the incoming power feed to the house, then a much simpler, cheaper and more robust DC power supply could be used in the light bulb. Of course this would mean that they would sell less replacements and lower the price of their high priced light bulb.
I adopted CFL globes fairly early, having lived in a place with extremely high electricity costs (remote island, diesel generators) and have gotten used to the colours, although my wife complains- I like the Warm White, she prefers Cool White. I also adopted LED globes for my cars, such as interior lighting, I can play with colour themes, and get whiter, brighter lights than the crappy incandescent yellow. Unfortunately, many cars have warning modules for areas like tail lights, so to change to LEDs, one needs to add ballast resistance, or warning lights come up, which rather defeats the purpose of changing to LED globes. For household use I’ll stick with CFL until LED globes get cheaper. I have great many CFL globes anyway, as I move every few years with work and take them with me. Given their dislike of fluctuating power, they’d be a liability in places I live in anyway- frequent power outages and spikes especially when there are storms about. It’s not unusual for the whole of my town to be blacked out due to a storm, or some idiot hitting a power pole.
If you can get the LED to give off the light (color) of the standard incandescent bulb, I’ll buy it:
http://www.purecolorartist.com/night–day.html
I have color pallets for incandescent, daylight, and fluorescent light sources. I haven’t yet done a painting for LED lighting, which is bluer than daylight. Florescent is the least pleasant light with which to view a painting. I have been experimenting with color since the mid sixties. Just sayin…
Throw the watermelons out and allow incandescents. I lived in a house built in the 30’s. The bulbs on the back of the house were the original Mazdas. For infrequent use or for applications where the color and heat-producing qualities of incandescents are deemed beneficial by the user, let the homeowner use what they bloody well want.
I read the other day.
That there are LED’s that now operate at over unity.
When they are in that state that they absorb thermal energy.
True that they are very low powered and narrow colour photon band.
But that they have only just been researched does look to cool bright future 🙂