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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A lot of misinformation here.
I’ve been an early adopter of LED lighting, since I used it on a boat, where the power supply is very limited.
LEDs are now made with luminous efficacies well over 100 lumens/Watt, which far outstrips other low-power lighting technologies, including CFLs. The problem arises in that there are only a few small firms such as Cree and Nichia that can achieve this – they seem to hold the patents, so the majors like GE, Osram are following along with the best they can do, which is often just half this.
This causes a lot of disappointment when the lamps are marketed as “100 Watt” replacement, when they simply are not. I have also managed to buy fake Cree lamps, well below the stated performance, and on dismantling, they were not Cree LEDs inside but a Chinese generic component.
The lifetime of the LED itself is determined by temperature – they really do not like being hot,
and 70C is hot for them, the heat degrades the phosphors. Because of this, it’s not really feasible to manufacture a replacement light bulb in a standard outline, you really need an integral heatsink. To add to this, incorporating the ballast inside the lamp is a real challenge – this is what the article is really about. LEDs work on constant DC current, and low Voltage.
The way forward is to fit a new luminaire, but few people are prepared to pay the cost of a whole new luminaire, so that presents a real adoption problem.
meanwhile when its cold (20F or lower) my furnace runs more often due to no heat from the lights.
yay.
Under run an incandescent lamp and it will last a very long time.
I have had several that I installed as a low voltage back up system.
That acted as a night light for stairs and hall way,
Run on solar clock, on every night when sun goes down.
24 volt 10watt powered at 18volt ac. still running 37years later.
Installed 1969 still working when sold house 2006.
True they only had half brilliance but did the job.
Don’t tell me about “energy saving”, I want to know about money-saving. Meantime, I’ll stick with the tried-and-true incandescents.
I have also used carbon filament lamps to charge batteries.
Do you know why.
Sorry off topic 😉
50 watt low voltage tungsten filament lamps have burnt down many house.
As far as I know all fluorescent bulbs need a large jolt of power to ionise the gas, this results in a huge power draw (compared to running power) I have read 2 to 4 running hours! in the use we normally give our lamps (on when we enter a room off when we leave) the CFL is awful compared to the old filament lamp! there was a website 5 years back (before the LED was common) that gave real world, tested life and power consumption in homes, the best was halogen mains voltage lamps on a dimmer , next was incandescent and way down last was the CFL. The last place I worked in the UK got me to fit a power use monitor to their (shared) power, they had a fit as when the spray birth lights went on (30 4 foot natural light tubes not the skinny ones) the hourly power was astronomical, the next hour with all the lights on was way less, we disconnected the cut out that shut the lights off on the bake cycle and when they went on they sated on till 5. You who claim cost savings with CFLs might be tricking yourselves, my 2 stay on 24/7 except for outages! last about 3 years.
LEDs are what CFLs were promised to be: efficient, long-lasting, and effective.
My house is full of them….
We converted to LEDs throughout the house about 3 years ago. It was expensive, but we bit the bullet. For example, in our sitting room there are 14 lamps consuming 56 watts per hour in total.
Conventional 35 watt halogens would have consumed 490 watts per hour. Whilst the life of these bulbs can be measured in years, my life is unlikely to last so long & in any case LEDs will probably be superseded before they fail. Probably we’ll have voice activated glowing walls, so the maximum savings will only be achieved if one becomes old fashioned & retains LED downlighters & wall washers.
Here’s a possible new technology
http://www.lighttape.co.uk/
Does your heating bill go through the roof because of LEDs? Unlikely – if your heating is electrical, your heater is probably 100% efficient, and simply supplies any heat no longer generated by incandescent bulbs. If you use natural gas for heating, you should be much better off unless your country does not allow fracking. If you use coal or wood, you will hardly notice the increased consumption. For propane or oil heaters it is a mixed bag.
While the energy savings is constant, the associated $ aren’t. Depends on where you live specifically, and your income level. (The US west coast wants its own carbon tax program.) Some utilities provide low-income rebates.
Please provide a reference for your statement on various fuels.
Just a few inaccuracies in the original text (perhaps translation errors) (boldface added by me);
“During practical testing, the scientists found that the drivers developed using this NEW semiconductor material were extremely robust.”
GaN (Gallium Nitride) is hardly a “new” material. All of the blue LEDs and Laser Diodes available since the 1990’s use it. Yes it is “faster” than silicon and that is why it is also used in microwave amplifiers.
“To function properly, they need a driver that ensures a constant supply of POWER at all times.”
Nowhere near true, the light output of any LED is linearly proportional (to the first and second order) to the applied current. The voltage developed across the LED is a function of the semiconductor band-gap which differs between materials. Since the physical area of the semiconductor junction is relatively small any “spike” or “surge” of current can heat the junction beyond it’s damage or “kill” threshold and permanently reduce or eliminate the light output.
What LEDs really need is a “driver” that protects them from the voltage surges common on most AC house wiring (“Mains” in Europe). An incandescent bulb with a larger thermal mass can withstand these surges better since the thermal response of the filament is on the orders of seconds. A 25% over power condition on an incandescent filament for a second makes little difference. A 25% over power condition on an LED for a second is likely “terminal”.
What could cause these surges, well large electrical uses like central air, refrigerators, etc can “pull down” the voltage inside you home when they switch on. Ever notice that momentary light bulb “flicker” when your AC “kicks in” ? The voltage recovers quickly, but when the AC turns off you could easily see a 10 volt surge (for a few 1/10s of a second) on your AC lines. These voltage surges can become current surges with a poorly designed driver circuit and kill or “maim” an LED.
But there has been lots of attention in the semiconductor industry to designing low cost/size driver ICs that overcome these problems.
Back about 20 years ago I designed a device to exposure color photographic paper (before it went extinct) with an array of small Red/Green/Blue LEDs imaged onto the paper with “ball lenses” (they are just a finely ground ball of glass). I had to design multiple LED driver circuits for the task (50+).
Cheers, Kevin.
I have enough incandescent blubs in a plastic tub to last me to 1) LED lighting is perfected and cheap 2) I die 3) civilization as we know it ends.
Forgive me as I take a shot at crowd sourcing. I’m developing a dynamic (moving) range transmissometer. I’m using a DPSS 1064 laser for the beacon but that won’t work for my final application. I would like a 940nm or 970nm LED (not a diode laser) with radiant intensity higher than 1W/sr. That means it’s radiating more than a watt. I search for such once in a while and can’t find anything – the “5W” ebay stuff is around 135mw/sr even if they say “5W”. Sometimes someone just knows about some hidden thing…
Tested LED lamps in industrial setting (three years ago ) As several have noted, heat is a MAJOR problem.
Results : epic FAIL . Short life span ,ran WAY too hot.
Hopefully , better heat sinks and better design(s) will fix this .
Re 12vdc not needing an “earth” conductor…. only if you do not mind burning things down / up .How many automotive electrical fires do you know of ? And 40 years of industrial experience leaves me extremely adverse to leaving out ANY safety related practises or procedures.
Also read somewhere that some people develop insomnia under exposure to blue spectrum light.
Still , LEDS have many benefits , and they will surely get even better.
Good post.
John in Oz;
“Lighter and cheaper wiring would also reduce costs as the current is much lower”
Unfortunately the lower current draw will not allow the use of lighter wire. It becomes a voltage drop problem. Even though you may only draw 1/10 amp at 1.5 volts, if the wiring goes for tens of feet the voltage drop (as a percentage of the 1.5 volts) becomes problematic.
Low voltage (24 VAC) wiring for landscape lighting has been around for a long time, and the gauge (lightness) of the wiring is actually larger than that used for High Voltage loads of the same wattage.
I believe a Mr. Edison and a Mr. Tesla had this discussion a few years back.
Cheers, Kevin
In December I bought an LED bulb (shaped like a regular incandescent, labeled as 40 W equivalent) as a test. I got it at Wal Mart for under $10. I installed it in an overhead fan to see if it would stand up to the vibrations, as I’ve found that CFL bulbs had problems in overhead fans.
1. It’s still going strong (so are the incandescent bulbs in the other three sockets).
2. To my eye the color is identical to the incandescents.
3. So is the brightness, although the incandescents are 60 W bulbs.
Meanwhile, a CFL bulb I installed in our kitchen ceiling fixture at the same time has already failed (no fan, just a light fixture). I’ve had a lot of problems with CFLs. They don’t last nearly as long as promised, and sometimes generate a horrible smell when the failure is from the ballast burning out. Does anyone know if the ballast fumes are dangerous?
Perry,
Your lamps my consume 56 watt-hours of energy in and hour but they do not consume 56 watts in an hour. They consume 56 watts all of the time they are on at every instant they are on.
Don’t give a rat’s ass what they are called or how they are made. I hate dim bulbs. Hate them! And twisty bulbs are the worst! The lighting has gotten so dim I have threatened to use kerosene lamps!!!!
I was an early adopter of efficient lighting but still haven’t bought my first LED. Why? I got spoilled is the simplest answer. The first CFL I bought was a GE CircleLite. It lasted 12 years at 3 hours a day average (probably more). My second one is still going 10+ years later. The smaller ones all seemed to die on me but I kept the receipts and returned. The larger companies like Sylvannia and Philips just had me fax them a copy of the bill of sale and they sent me a coupon for the price. In the 2-3 years before the bulbs died the price dropped from $10 to less than $5 so I was getting 3 bulbs for $10. Fair enough and the last batch are still going strong.
I’m finally at the last of my bulbs and as they burn out over the next few years I’m looking to buy some LED ones. Less than $10 for a 800 Lumen is my buy in point. Anyone have any Consumer’s Reports on which ones last the best?
I recently picked up a whole bunch of LED 60 watt equivalent bulbs for $6 (US) at COSTCO. They work pretty well so far. I have been using them to replace any bulb that fails in the house.
I didn’t like the color of CFL’s and then found out they can be high UV emitters. I am now converted fully to LED bulbs and have paid for them in saved power … and they keep getting cheaper. After running into my first incadenscent in a few years, I would say full spectrum LED’s are better. A couple of places a soft white style might be better, but overall LED’s are superior.
Silverbear says:
Interesting that the US allow lighting and power sockets on the same circuit whereas in Oz we have separate power and lighting circuits so we would not be adding to the wiring runs, just making the lighting runs with cheaper cabling..
Brad – the reference for natural gas is here
http://shrinkthatfootprint.com/average-natural-gas-prices-compare
I only guessed coal and wood; when I used them for heating, they were not major items on my budget. It may be different in an industrial setting.
A word of caution, natural gas heaters have a wide range of efficiency – from 100% (in-room catalytic types) to as low as 50% (an old-style furnace emitting water vapor through the smokestack).
Someone explain what we’re doing wrong. We have no CFL’s no LED’s and no solar panels or wind turbines. Maybe years of my mother nagging us kids to turn off the lights, take short showers (actually we only had a bathtub, no shower), and generally not to be wasteful paid off. My wife seems to have had the same mean mother.
http://imgur.com/liLBa30
We tried CFL a number of years ago. Right on the box it said ‘7 year life’. None of them lasted more than 1 to 2 years, some 6 months. So, before it become illegal we went to Menards and bought as many Edison bulbs that would fit in the cart and replaced every one of those CFL’s (one actually blew up) with the politically incorrect bulbs. Unfortunately those once nice durable GE bulbs were made in China; complete garbage.
I fail to see how spending $15-30 for a light bulb is going to have a ROI in my lifetime based on our electric bills, although LED Christmas bulbs and flashlights LED are great, not to mention for the guns.
CFL bulbs suck; there’s no other way to describe them. LED bulbs, even if I wanted them, are still not practical in many instances, such as existing light fixtures they don’t fit in. The cost of lighting our twice-a-day-use in the barn would be astronomical. Sorry, I just don’t see the logic in spending $1000 for 1 hour a day of use.
Alas, the good old incandescent bulb is actually still legal, you just have to make sure they are branded “rough service” in various wattages and know where to find them. Hallelujah! Menards was carrying them, not sure if they still do or not; I bought a bunch of them for about $5 apiece. Oh, and they last a LOT longer.
Here’s a place that sells “rough service” bulbs. http://www.newcandescent.com/
Call me a rebel, old fashioned or whatever, They can have my Edison bulbs when they pry them from my cold dead hands.
Exactly right (and interesting account of the history of automotive headlight technology; go read it if you haven’t). I like incandescent bulbs. I like their warm color and the mild heat they give off (in our cold New England climate, a blessing). I don’t mind paying for the electricity.
I really do not like being told by government enviro-whackos and Climate Parasites that I have to switch to some other kind of lighting. If I decide to switch, I will, on my own time.
I hope I’ve sequestered enough incandescents to last me a few years, but maybe I should go out and find more. . .
/Mr Lynn
Question: how does anyone know LED’s are long lasting when they’ve only been on the market for a few years? CFL’s were promised to be the same, but we sure didn’t find them to have the advertised MTBF, plus they get dim over time and are horrible in cold weather.