One sickly sheep infects the flock - Isaac Watts
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Solar powered torches are now a reality
JUST AS PEOPLE are coming to terms with compact fluorescent lights (CFL), it is time to move to LEDs. Luckily, the good people at GlacialLight have a bunch of them for you, from standard products to toys.
You probably know Glacial from one of their other divisions, GlacialTech, maker of PC heatsinks and power supplies. The LED lighting side of the company is now its own division called GlacialLight. As is the norm, the idea is to ramp up volume and drive prices down. Since LED lights take up less power and are much more efficient than CFLs, this is a good thing.
New design on the left, old on right
The hot (or cool and bright, anyway) news of the show is the new GL-MR16 design from Glacial. OK, bulb designs are never 'hot', but these 12V DC bulbs use a standard GU5.3 socket (the little square one with two pins), and consume only 3W.
They are very bright, 20 of these would make a room almost painful with the same power usage as a single 60W bulb. A year ago, when I was looking to retrofit my house, similar bulbs cost $40-60, now Glacial has them for $8, and that will likely drop soon when the new design phases in. That is wholesale, so think a bit more after retail price gouging.
Glacial also has larger BR20/30/40 LEDs that run on 110/220v current for $30. These are large lights to flood a room, but only suck 6 or 9 W. They fit in E26/E27 sockets, the standard screw in bulbs for US and Europe.
Multiple tubes and shiny stuff
A little more common is the standard fluorescent tube. Glacial has a T8 tube that runs between 8-24W depending on the version, and uses standard 110/220V power. You can buy them as single tubes, or as a custom unit like the one pictured above. They can get quite bright for very little power.
More toward the fun side are products that ask questions like, "How much light could you get from the same power use?". The answer, a lot. Think streetlights, or one-upping the cops when they put that nasty spotlight on you when you are... oh look, out the window, a bird.
Want to blind a neighborhood?
Glacial has four spotlights ranging from 7W to 60W. Since 3W MR-16 bulbs are painful to stare at, imagine what you can do with 20 times that. Fun fun fun, and portable too, you could even run it off a car inverter. Some [expletive deleted] driving behind you with his high beams on? Bleach his retinas. No, don't do this, it is probably illegal, but you could if you are an antisocial twit.
Because LEDs are several times more efficient than CFLs, which are in turn several times more efficient than incandescent lights, you can pull all sorts of neat tricks with them. That leads to devices like the GlacialLight DynaSolar LED torch. Yes, really, they did it... a solar-powered torch. It also has a crank just in case you are caught out in the dark without a sun to power it with.
Given the cost drops, LEDs will be a lot more common in the near future. We hear Google is retrofitting its campus with them, so the ROI must be there. Once you have acceptance, experimentation will follow. That leads to things which make the solar powered flashlight seem tame.
Hang on, we are only at the beginning of this curve. µ
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LEDs yield about 40-60 Lumen/Watt whileas CLFs yield about 50-80 Lumen/Watt. Take into account that LEDs are much more expensive and need a current transformer (70% - 90% efficiency) if connected to 110V/230V power lines than you can imagine that they're less efficient than CFL.
Still, they're way more efficient than the classic light bulb and they're small and don't get hot which makes them suitable for certain temperature-sensitive environments.
Another major drawback is the volume/lumen ratio of the LEDs. They're really BIG in terms of size but yield little lumen. That means, if you want to have a LED light bulb as bright as a 60 Watt classic light bulb you have to STUFF this bulb like hell with many many many of these small LEDs. Something like 80 LEDs or more. This can be a big engineering problem which is the reason why there are not many E27 LED bulbs around.
There is a new generation of LEDS in the pipeline which should yield similar or slightly higher Lumen/Watt as CFLs but they're not on the shelfs yet and it can take some more time for them to appear.
LEDs are now reaching up to 161 lumens/watt - far better than CFLs.
See http://members.misty.com/don/led.html
for more information
Your article said LED's were many times more efficient than CFL's they are not they are less efficient for now.
As your reference says they have newer technology that will be more efficient. That at least means in a year or so we may get LED lights that will do more than night light applications. Some of these will do more now less efficiently but not replacing the bulb is an advantage.
For now they are a niche product great for flashlights, nightlights and places where bulb replacement is a real problem.
But it looks like in a few years they may make the CFL's obsolete.
They are Dimmable which is a huge advantage over CFL's.
I've seen a single 3W LED, and let me tell you it will make you blind. The only problem with LEDs is that they are uni-directional- a major problem that hasn't yet been tackled in an efficient manner. You can stuff a light bulb with 80 LEDs, but it's not practical. It will be several years before a -true- LED breakthrough surfaces the news. It will be another several years before we see the technology in production.
A very bright wind up torch would be great to have on a camping trip. I like it.
160 lumen/watt if we want a GREEN light and have 1,000 of them working at 3 mA?
LED's are getting there, not quite there yet. They're better in niche markets right now, where battery life is important etc.
Charlie bless you, always make my morning:
"Some [expletive deleted] driving behind you with his high beams on? Bleach his retinas. No, don't do this, it is probably illegal, but you could if you are an antisocial twit."
I have one and it's at least five years old.
Unfortunately saying a 2W LED is better than a 1W one only tells us one thing, that it's better at consuming power!
This fascination for rating LED's in terms of power used has to stop. Light output in Lumens, or better yet luminous efficiency in Lumens/Watt are far more rational choices if you want efficiency to improve.
So please can everyone stop using Watts when talking about these technologies!
That said I'm not convinced that we should be improving luminous efficiency in the UK anyway; most of the time we need space heating, and lightbulbs are usually turned off when you're not in the room. In some ways I'd actually rather they made them even less efficient for indoor use ;)
Obviously luminous efficiency does make a lot of sense for outdoors; but most people don't have a lot of lights outside anyway, so focus should be on the councils and their street lighting and traffic lights.
LED lighting is okay for low-light needs, but CFL are really the choice for regular indoor lighting. What I'm waiting for are the laser-based "LEDs" researchers at companies like Nichia are working on. The laser produces a far more intense source of blue/UV light to light up the phosphorous that is used to create white light from it. It's also more energy efficient than plain LEDs.
"most of the time we need space heating"
Yeah, in the middle of summer I really want my house even hotter.
Bulbs that get hot are even worse in hotter climates.
The 161L/W led is only a prototype, these are not commercially available. The best you can hope for is 100L at 1W and they come at a premium. Today's typical commercially available LED lighting array run at 70-80L/W at rated power.
LEDs are on par with CFLs' they're not several times more efficient - to do that they need to be approaching 100% efficient and we're a long way from that!
I've already bought some LED lights to replace some GU10 Halogen lights in one bathroom and in my kitchen.
The ones I bought were the brightest ones I could get (6W) from Lumia bulbs off of Ebay.
I have to say that they aren't quite ready for prime time.
They're a little noisy (though they quiet down after about 10 minutes) and the brightest you can get is the equivalent to a 30W Halogen (which is a 6W LED).
The noise issue isn't a problem in a bathroom or kitchen. But I wouldn't want them in my bedroom or living room.
If you have 50W halogen bulbs and you want the same brightness, you're out of luck.
Based on the research I've done, LEDs don't have any efficiency advantage over CFL bulbs.
The advantages they have is they come on instantly at full brightness (CFLs often don't reach full brightness until after a minute), they last much longer, they are more robust and there are no toxic materials in an LED bulb.
For LED bulbs to hit the mainstream and replace CFLs, the have to get brighter, cheaper, less noisy and be more widely available.
Why they use leds in flashlights and battery powered lights? CFL are much cheaper, and if they can render similar batery life, why go to the much more expensive LED? Something is wrong here.
The reason why CFL isn't used for torches is because of the size! CFL is more compact that a normal fluoro light, but is still singificantly bigger than what would be practical for a torch. The other problem is CFL's require a large amount of power to start up, which you can't get from 3V (2 AA batteries). The start up power, which is only for a second, is why many people think its better to leave a fluoro on for an hour than to turn it off and turn it back on when needed. This is of course nonsense, as the startup power may be 60W/hr, but since its only for a second the actual power used is 60/3600W. CFL's use more than their stated power for the first few moments when they're cold, but unless you're walking in and out of a room every 20 seconds its much more efficient to turn them off.
Following on from Mick: because LEDs are small, the light can be collimated quite well. A decent parabolic reflector for a CFL would have to be huge. For the same size torch, the LED version will be useably brighter.
@ Peter:
LEDs don't make any noise whatsoever. The drive circuitry for yours must not be very good.
I see all these talks about LED and that reminds me of a research that one of my classmate has done previously.
They measured the power usage of Fluorescent, halogen and LED light bulb. The strange thing is while halogen light bulb uses less wattage than stated on package, the Fluorescent actually uses more (e.g. 3W using up to 15W). Is the extra watt used for heating up the light bulb?