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.
We’ve should replace all of those CFL bulbs eventually – mercury in every one, and they break sometimes as well as get improperly thrown into the trash when they go bad. The primary problem with LEDs is heat – they don’t work well in enclosed spaces.
We own houses in AZ and MN. We just switched out (450+) BR30 halogen floods plus dozens of normal incandescent lamp bulbs to led bulbs at the AZ house. Starting in July of this year, the local utility will be awarded a new monthly fee to compensate it for the fact that, in aggregate, the customers are not using enough electricity. (https://www.tep.com/customer/rates/new/). This is also true in MN (not fun but see riders http://www.xcelenergy.com/staticfiles/xe/Regulatory/Regulatory%20PDFs/rates/MN/Me_Section_5.pdf).
Not cynical, but the utilities’ need for return on infrastructure buildout means we pay if we conserve, and we pay if we use lotsa electricity.
I haven’t tried any LED’s that I know of (the wife could have sneaked one in on me) but did try the CFL’s and hated them. I have a lifetime supply in every wattage of incandescent and will probably even have a few to leave to someone in my will. Electricity is still pretty cheap where I am and I usually like the heat they put out.
My experience with LED lighting (in-ceiling down-lighting incl. power converter, purchased on-line from China, ~$14ea, 12W equiv. to ~70W incand.) is that the LEDs are bright and very reliable. Great alternative to traditional pot lighting. No failures after 1.5 years. My biggest complaint is that although the lamps were advertised as dimmable, the power converters DO NOT work with standard dimmer controls. I have purchased “LED friendly” dimmers and the result is the same: the LED power converters go insane (I know now why but I won’t go into the details here).
I’m almost resorting to designing and building my own converters. I’d prefer however to buy something off-the-shelf if it works and is not too pricy.
“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.”
Watts are a rate of energy per time. Watts per hour is meaningless. When the lamps are on they are consuming energy at a rate of 56 watts. The real issue is how much light for those watts and if the light is acceptable (color temp etc.)
I have been combining “older” fluorescent lights with LEDs. I put the LEDs where I need the light right away (at the bottom of the stairway, at the front door where i need to find the keyhole) and use the flours to come up to full brightness and balance out the spectrum a bit. (or make it worse, I am not sure sometimes.)
Still am a little peeved at the early sudden death on some of the LEDs; these are supposed to last for ages.
We live in an area that has power outages two or three times a year; I use a old car battery to power three of these LED lights though an inverter; I can always get 2 evenings out of one charge.
But I miss the incandescents…they were just the right heat to put in the pump box in the backyard to keep it from freezing in the winter cold spells.
Curious George says: “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.”
Natural gas has always been cheaper than heating with electricity, fracking or not.
And you are completely forgetting he AC season I guess? Where you pay twice for your refrigerator and lights, removing their heat from the house?
Great conversation! I’ve been holding back on LED bulbs until the price-point reduced, but that may be about now.
I’ve been a reluctant adopter of the CFL twisty-bulbs….however, the first one I ever bought (nicknamed “Hercules”) has operated without fail in an outside light fixture for at least four years. Since I live in Chicago, the Delta T can easily be 120º F! I’m fairly impressed with the old thing.
Everything works, it is just a question of if it works for you. The waste heat of the incandescent bulbs is an advantage in a cold house in the winter, and they sure were cheap. However, I don’t find that I miss them much, except for the bright 3-way bulbs. C’est la vie.
Just wonder what an EMP from a nearby lightning strike would do to a house full of LED light bulbs.
I like LED bulbs and have many in high-use fixtures. However I cannot justify the increased cost in a fixture that only operates 1 hour per month (guest bedrooms, etc). It simply is not cost effective at such low usage levels.
For that reason alone I have stockpiled incandescents for use into the foreseeable future.
In effect the cost of wind energy and fewer fossil power plants has been legislated down to the consumers via more “efficient” and costly bulbs. But I digress…
You want to save money on electrical lighting? Replace all the miserable outdoor lighting fixtures that wastefully illuminate the night sky and decrease safety because you get blinded by the direct view of bare bulbs with full cutoff fixtures that only illuminate the ground. These require lower wattage bulbs and increase safety because your night night vision is much less impacted. Recover our dark sky heritage. Astronomers will thank you.
I have found CFL bulbs are very green in color and I can detect a flicker. I am waiting to see what LEDs look like before blowing a bunch of money on something I don’t like. I have put in a large supply of bulbs and at the current rate of consumption, I suspect the bulbs will last longer than I will. At night most of the time I only have one 100 watt bulb on between dark and bed time but I do use other bulbs when I move around the house. Color is so important to me that the walls are painted with a very light brown paint to give that warm feeling to the house.
If I were truly worried about power consumption, I would do something about my computer as it draws over 200 watts or twice what my single light bulb draws. The big power draw in my house is the 4 ton heat pump which can suck almost $200 of power a month in the Arizona summer with the house temperature set to 78 degrees.
In addition I have a 25 year old fixture with 12 60 watt bulbs. I have never replaced a bulb in it because it’s not usable on high so it has a dimmer to reduce the output to livable levels and the lower filament temperature greatly extends the life of the bulb.
I am not against LEDs as I had a 7 segment alarm clock that lasted over 30 years and failed only because the power company spiked it and the control board for the furnace. Even after the failure, the LEDs were still good but the timer chip was fried.
Those buying all the LED lights, I have one simple question again. How do you know they are long lasting?
My guess is that we will only find out what is the best kind of lighting if all restrictions on marketing all types are lifted and all hidden taxes and subsidies eliminated and they can all compete with one another – i.e., a truly free market. I’m dreaming, of course.
My own experience with CFLs has been: (1) actually little more intensity for the wattage than with incandescents – an advertised 60 watt equivalent CFL for me has usually been more like 20 to 30 watts from incandescents; (2) the bulbs dim quite rapidly, down to half or less as intense within a month, and don’t last much longer than incandescents – say, three or four months vs. two or three months in the fixtures in my house; (3) there is a noticeable ozone smell around the fixtures where I have CFLs, but not around incandescents. It’s the same for all the brands I’ve tried.
The rapid dimming and the ozone smell make me wonder what sort of emissions are coming out of the CFLs. I suspect strongly that mercury is among them.
Makes me want to find a way to make the regulatory ciphers who come up with these things pay personally to fix it. How’s that for a law – if regulatories do damage, they pay?
Yep, done. All lights in my house are LEDs including standard sized globes and spots. You can get warm (slightly yellow) or cool (slightly blue). Either way my energy bills dropped by about 12% so it should take me quite some time to pay it off. Also, I am told, some of them now work with dimmers.
In terms of life, I have had to replace only one since I have done this about a year ago – I have something like 45 globes (bulbs) in the house.
A CFL bulb may be $2 or $3 for 800 lumens or more (especially if in a cheap pack) and last for several years or more depending on the light fixture usage. The LED equivalent usually costs such as $10 or more, while being no more than at best similar lumens/watt. Breaking even in gain from even longer lifespan would take a long time if ever.
But few people understand figures well in any context, and the media loves hype.
If going to run a light fixture 24 hours a day, that’d be the best bet for a LED bulb to pay off: not in all light fixtures, though, not unless/until they get cheaper.
Incandescents are much less efficient and shorter-lived by far than CFLs, but there are a few applications where waste heat is not a waste, while only the energy religion required not letting people choose. I’d put an incandescent in a closet with a light on only a few minutes a week, for example.
Randle Dewees says: March 11, 2014 at 5:47 pm
“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.”
Bad news dude. No. 3 is a lock in a very short time.
Latitude says:
March 11, 2014 at 2:45 pm
No, wind and solar will never achieve more than footnote status in terms of baseload power generation. EIA projected well below 1% for wind and solar through 2030 back when they were honest. Still no different, but now the EIA hide the reality by mixing wind and solar in with hydroelectric power, and change units to make comparisons more difficult.
Saw 2300 lumen LED ceiling can replacement units at COSTCO for $17 (23W).
Joe Born: “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?”
Double the frequency and you will double the number of intervals storing half the energy, so the total energy stored over time is the same. Doubling the frequency allows the use of smaller caps and coils which not only cost less, but take up less space.
I am a little disappointed that out of all the post so far, only one, KevinK, had any technical LED information. I have been using LEDs in products since the 60’s when they first became available and the recent advancements in power output have made them practical for lighting.
To get a white LED, a blue or UV LED is used and a glob of phosphor is put on top of the die to down convert some of the higher frequency (short wavelength) light into lower frequency longer wavelength light (red, yellow, green, etc.). The resultant mix of wavelengths gives warm white, cool white, etc. The first white LEDs were still experimenting with the phosphors, which is why the early white LEDs had a blue tinge to them, but that is largely a non issue now.
An LED is a current device with a compliance voltage (voltage drop across the LED) that is dependent upon the chemistry used. The white LEDs using a blue LED that has a compliance voltage around 3.5 volts. If the power source is a constant voltage device, like a battery, a dropping resistor is commonly used to limit the current. (Now you know why the cheap flashlights use 3 AAA cells, to get the voltage over 3.5 volts)
All of the power generated by the current flowing through the resistor is waste heat. The most efficient way to power an LED is with a switching power supply whose output is a current, typically from a switched inductor. The newer flashlights, like the new LED Maglight, now use this method.
The part about the GaN transistors appears to be mostly BS. The typical LED switching power supply will be a few ten to a few hundreds of KHz. The only reason someone would want to use a GaN tranistor is because they have lower parasitic capacitance compared to a Mosfet, but that only matters in the high Mhz to GHz range. Using a GaN transistor makes no sense, and it will have no effect on the efficiency of the LED. There is no way using GaN transistors can do anything significant, let alone double the power output of the LED.
CFL’s were (are) a scam. I put in a whole bunch (several dozen) expecting to lower my electric bill. To name just a few of their sins: They only last perhaps 1/4 to at most 1/2 the life advertised. They flicker and sometimes “pop” (bang!) when they die too soon. When mine are all gone, I will worry about where to discard the dead. And I now understand they aren’t supposed to be installed “base up” (the boxes do not tell you this). They dim significantly after a few months. And they do kill off switches (not a big issue if you are your own electrician, I suppose). “Fool me once, shame on you.” I am currently replacing back with incandescents, and I am old enough that “lifetime supply” is a meaningful notion.
As for LEDs, they too seem like a good idea. Probably are. But I wait and see this time. I had not thought about the “regulator” or ballast issue with LEDs. If the LEDs last, but the regulators burn, what do we gain? Seriously, what IS the long term reliability? I am hearing “fool me twice…..”
Anybody really know?
“environmentally friendly source of light … consume less energy …”
This site – of all places – should bring in a link to Jevons Paradox. Jevons pointed out that when you use an input to some process more efficiently, you will eventually use more of that input. By making the conversion of electricity into light cheaper, we will find more and more ways to use lights – and inevitably use more and more electricity for lighting. As computers have grown increasingly efficient in their use of electricity, we use more and more electricity to power them. People who own Priuses drive more.
I recently read that white LEDs surpassed a 200lm/W limit, and soon enough it turned a sort of wishful PR. Cree claims 80 CRI and 3,000K (ANSI) colour temperature and mass production in 2015 or so.
I don’t know about you, but I just can’t settle for flickering 80 CRI light produced by phosphors. Everyone, living and dead, look like a twilight saga banquet under that light. I can’t read for longer than 15 minutes or so, and their flicker makes things even worse. Because of the phosphors making their light “white” they are not too different from the ghastly CFLs, hence their abysmal CRI. And they are dying, with me in pain, forever.
I wouldn’t be this much disappointed with LEDs if I was not completely happy with halogens. I’ll need to have halogens indefinitely at least for reading and preparing food. In my country, although in EU, incandescents are still available. Halogens are not banned yet, so I’ll pile a stack for the time they get banned. Unless LEDs just suddenly start behaving.
As a sidenote, modern lightbulbs are exempt from every EM compatibility law … because they just can’t meet any.