Why LEDs Don't Beat CFLs Even Though They Should 685
TaeKwonDood writes "LEDs don't beat CFLs in the home yet, but it's not simply because PG&E is getting rich making people feel like they are helping the environment buying CFLs made in China that are shipped to the US using a lot more fossil fuels than they save. It's a problem of indication versus illumination. However, some new discoveries are going to change all that."
Not just cost, but optics (Score:5, Informative)
LEDs are not traditionally used for illumination not only because of the costs of LEDs, but because of the complex optics required to distribute the light. it's rare to see LEDs used for illumination, though it is making an entrance for some applications, like flashlights [maglite.com] and even headlamps [motorauthority.com]. As LED prices continue to come down and LED optics technology improves and cost stabilize, conventional LED lamp retrofits will become commonplace. Take a look at LEDtronics [ledtronics.com] for some examples.
Re:Not just cost, but optics (Score:5, Informative)
Did you notice all the LED xmas lights this year?
CFLs still suck (Score:2, Informative)
They come in two color temps. "Cool White" is about the same as a white LED. Sterile and way too much blue/green. "Warm" is another name for sickly yellow and makes me think of those yellow incandescent bulbs used to keep moths away. Until they make a CFL that matches a normal incandescent I'm not switching.
Re:Riiight (Score:3, Informative)
Until earlier this year (when they stopped production in favor of CFLs), GE was still manufacturing their incandescent bubls in the US.
Re:Not just cost, but optics (Score:5, Informative)
Although I agree with some points of your post, most of your belief is not quite accurate. LEDs now make the best flash light illumination, and the power drain on batteries is minimal. I've been using LED headlamps for years, so this is nothing new, as your post implies.
The problem with them being used in homes is that they direct their illumination to a specific spot. This is not a bad thing though. I've recently seen them configured as spot lamps. Perfect for recessed lighting.
The optics in LED technology can easily be modified to diffuse light to make a great replacement for CFL & incandescent. Give it time.
Shipping Costs (Score:5, Informative)
If a shipping vessel can hold 35,000 tons of cargo and the shipping weight of a CFL is 1/2 pound, the vessel can hold 140 million bulbs. Of course there is not enough space for them all, but they can ship with heavier items, and I am assuming costs are allocated by weight.
If a 7,000 mile journey burns 875 tons of fuel, or 15.75 million gallons, then each bulb is allocated
Therefore, the shipping costs don't even come close to negating the energy savings.
Re:Buh-Bye CFLs (Score:2, Informative)
led's would be great if they weren't so direct and cold, and they didn't cost $30 a pop.
Re:As the tag says, lumen per watt (Score:4, Informative)
Re:Buh-Bye CFLs (Score:3, Informative)
what start up delay?
I have currently have 6 CFLs running in my studio. all but 1 start up instantly, the other one, being 5 years old, takes a second or so. the larger ones (2 40-watt bulbs) may take a few seconds to reach full brightness, but enough light is there the second I hit the switch. the 25 watt bulbs all start up instantly.
i have never had a CFL overheat or burn out. if you are running into all of these problems, i would suggest trying out higher quality bulbs. Sometimes, there is a reason for the difference in price between to brands.
I pay about $3.50 for each 25 watt bulb, and $10 for the 40 watt bulbs, and they work much better than the cheaper ones you find in dollar stores.
Re:LEDs == Frustration (Score:5, Informative)
Actually, I have never found a LED bulb nor any CFLs that with a confortable color spectrum.
Also, most inexpensive CFLs lose their brightness very quickly and need to be replaced far sooner than what the manufacturer would have you believe.
CFL are harmfull to artwork (Score:1, Informative)
Re:Riiight (Score:5, Informative)
You are either buying CFLs from a completely incompetent manufacturer, or simply have a bizarre situation where reality is bending around you.
I replaced all bulbs in my home with CFLs three years ago. None have burned out to date, and I saw a small but measureable decrease in home energy use, as my home energy costs are very stable. Everyone I know who has replaced all or some of their bulbs have had the same experience.
There's demonstrable energy savings to be had, and a measureable lifespan increase simply due to the physics of CFL versus incandescent.
Re:Mod parent up! (Score:5, Informative)
I've got a nice, tungesten-coloured LED right here that emits nearly omnidirectional light if I just remove the lens that comes with it. I don't think directionality is really any kind of inherent problem, just a manufacturing issue.
Re:LEDs == Frustration (Score:3, Informative)
There are LEDs with very tungsten-like spectra. They're just not very common yet.
15 years. (Score:5, Informative)
I have had the CFL in my hallway for 15 years.
I haven't changed a lightbulb in at least five, and even that was because somebody hit it with a broom handle. I don't remember much from when I was a kid but those other types of lights would die every now and then.
You're doing it wrong.
Commercial shipping (Score:5, Informative)
Except that commercial shipping is usually done by volume not weight. Only if the weight is extremely excessive does it matter for pricing. Shipping containers are usually charged by the container, not by the weight. They have a weight *limit*, but that is not the same thing. I can't imagine hitting the weight limit of a container with any kind of light bulb.
Trucks are the same way for large quantities.
Re:Riiight (Score:5, Informative)
Then there is something seriously wrong with your wiring or the bulbs you buy. The claims are sometimes overdone on the packaging, but it was much worse back in 2001 than now. Also, some manufacturers are more reliable than others (feit electric at Costco and Sylvania at lowes, other places, seem to be good for certain models). The Walmart brand Great Value seems to be horrible, at least in my experience.
I've had enclosed Par 38 CFLs (23w) die on me with some regularity although it has gotten a little better the last year. OTOH the enclosed Par 20 (13w CFL) have been absolutely solid since 2004, after a bad first run.
My longest lasting lights about 10 regular 13 watters --60w equivalent-- enclosed exterior ones. They started in all temps from (-5F to 100F). They used to be dusk to dawn for the first 3 years, so I guess 12 hours a day on average through the year, then the solar cell went bad on several 2 3-lamp posts and so 6 lights were running continuously for about a year (busy year). When I fixed that, put a timer in to start at dusk and turn off rougly midnight.
Through those 6 years, about 5 lights went bad. Keep in mind, they were running around probably 4,380 hrs a year. One year it was the max 8,760 with no breaks. And now, it's down to 2,190. This is probably due to them being on for extended periods and not constantly switched on and off which wears on a ballast and kills the shoddy ballasts fast.
CFLs are a type of fluorescents, and if the ballast is shoddy, you can forget it. Also had to replace every fluorescent ballast in a section of newly constructed office space once as one in an entire row (same manufacturer) went bad one at a time in a short period. Doesn't meant fluorescent tech is bad, means it was either a bad manufacturer or bad run. BTW, there can be bad fluorescent tubes as well, Philips seems to be good while the much cheaper Sylvania contractor packs are shit.
Just how it goes. Go to some CFL forums and learn. Have no experience with dimmers though. Don't have a one.
Re:Riiight (Score:3, Informative)
You can also dramatically reduce labor costs and accidents. I personally don't mind having an excuse to leave the ladder and the step-stool in the garage.
Re:Not just cost, but optics (Score:2, Informative)
Sorry, in this case optics is a huge deal. Companies are barely rolling out permanent LED fixtures (not bulbs, but something you install in the ceiling and replace years later) which have been engineered with partial reflective domes, heatsinking, and the right distribution of white (blue/yellow phosphor) LEDs. It's going to take a while before you can create a good LED bulb that will screw into a standard tap. I do research in this area.
Re:LEDs should last forever but apparently don't (Score:2, Informative)
I'm a lighting engineer that helps design LED systems...
Those failures are likely not the LEDs, but are the fault of the controller components. Like any electronic, cheap components become the weak link in the chain, and skimping money on the controller results in shoddy quality in the unit as a *whole*, even if the LEDs are perfectly fine (and I would bet that the LEDs are still perfectly fine.)
Re:LEDs == Frustration (Score:3, Informative)
Well, you nearly have that already. Sunlight is much closer to the bluish-white LED light than to tungsten. (Tungsten is around 3000K, sunlight is 6500K, white LEDs are around 8000K.)
Re:LEDs == Frustration (Score:4, Informative)
Re:CFL are harmfull to artwork (Score:3, Informative)
Not entirely. CFLs are fluorescent lamps. They produce ultraviolet light which a fluorescent layer of different phosphors on the inside of the tube converts into visible light. This conversion isn't 100%. Most CFLs do therefore emit a very small amount of UV light. (If, and only if, you leave the phosphors out, you get the kind of tubes which are used in tanning beds.)
Where this argument enters bullshit territory is that the problem is worse with CFLs than with incandescents. Incandescent lights are black body radiators. In order to create a "whiter" light, the temperature of the filament must be increased. This also increases the amount of UV light. If you use halogen lights, make sure you buy bulbs with UV filter fronts, because halogen bulbs really produce noteworthy amounts of UV lights.
Re:Acronym Overload... (Score:2, Informative)
Compact Florescent Light/Lamp (CFL)
Light Emitting Diode (LED)
Now Use Wikipedia Buddy (NUWB)
Re:Riiight (Score:3, Informative)
Thats funny because all the CFL's I have at home have lasted for YEARS. The only one that has ever burned out is the one in my fridge, after 4 years. They have lasted far far longer than any other bulb I have ever used, with a huge savings in electricity usage.
I don't know what kind of crap CFL's you buy but the ones I have work perfectly, with vast lifespans. I just bought them at home depot or wherever.
Re:Seriously? (Score:5, Informative)
A 20' container is approx 19' x 7' x 7' or 1.6M cubic inches (it's a bit bigger, but I left room for pallets, etc).
If a CFL + packaging is 3" x 4" x 6" = 72 in^3 then you can fit around 22,000 of them into a 20' container
This site [cypressindustries.com] claims you can ship a 20' container from China to the US for $3800 USD
Let's say that 75% of the shipping cost goes toward fuel, the rest goes to labor, paying off the ship, container rental, etc. Sounds reasonable.
I'm going to use Diesel for the energy calculations. I know that ships run off bunker fuel, not diesel, but I have to think that the cost per unit of energy for bunker fuel is cheaper than diesel since it's less refined, so by using Diesel I'm being conservative. Right now you can buy diesel for under $2/gal, so with 75% of $3800, we can buy 1425 gallons of diesel.
Diesel has 38 MJ [hypertextbook.com] of energy per liter (143 MJ/gal), or 40KWh according to the units command.
So, each light bulb uses 40KWh / 22,000 = 1.8 KWh (1800 Wh)of energy
A 29 Watt CFL can replace a 100 Watt incandescent bulb, so that's a 71 watt savings... 1800Wh / 71 W = 25 hours
Sooooo....a CFL will save the energy used to ship it in about 25 hours of operation. CFL's are supposed to last 5000 hours, so over its lifetime, it will save over 200 times more energy than used to ship it. (of course, this is only this shipping energy, and ignores the extra energy that it took to manufacture the CFL it as compared to an incadescent. I don't know how to do that math).
Re:Riiight (Score:5, Informative)
No, it's valid if they're both made extra-nationally, but in different places. Most incandescents are actually made in the United States by GE, but the vast bulk of the remainder are made in Mexico, and shipped up by rail, which is far more efficient than slow-boating them from China. It turns out that there are more than one country outside of America, and that those countries aren't actually all in the same location.
Of course, if anyone actually did the math, they'd find out that the energy cost of shipping is offset by the energy savings in usage in under three days; sometimes I wonder whether people have any idea how many lightbulbs fit on a large boat, or how little fuel a large boat actually needs.
But hey, made up math is great for making arguments, right?
Re:Riiight (Score:2, Informative)
I've used CFLs for many years. My experience is that NO, they don't last nearly as long as their marketing hype--but they generally last longer than incandescents. It's not 100% though--I've got a couple of the older bulbs still in places like crawl spaces and utility rooms that are the original bulbs, I think, and I've had a couple of CFLs that are NOT in on/off situations that died amazingly quick.
By the same token I have seen a decrease in electrical usage dedicated to lighting, however--not the magical numbers enthusiastically mentioned by the CFL faithful but solid enough.
Short version: They've been worth it for me, though they don't live anywhere near up to their hype.
Re:LEDs == Frustration (Score:4, Informative)
But typically LED-based "white" lighting is a series of discreet spectra between red and blue, rather than a continuous spectra from red to blue; color temperature by itself is not a sufficient metric for comparison.
Re:15 years. (Score:4, Informative)
>> couldn't figure out why CFLs were lasting months rather than years in the bathroom
You bought crappy CFLs. CFL's don't have a problem with on/off as long as you're not running a disco or something. My 5 round CFL bulbs in the bathroom are going strong after 2 years. Same for everyone else in the family.
I agree that CFLs aren't for every possible use, but they are great for almost everything. The only thing they're not great for is decorative lamps (although you can get different shapes of CFLs) and outdoor lamps that aren't always on in cold environments (takes too long to warm up and produce full light).
Speaking of caves... (Score:3, Informative)
Actually, caving (don't call it spelunking [wikipedia.org]) is one of the areas that modern LEDs have absolutely taken over: the combination of efficiency, durability, longetivity, and small package size have completely replaced incandescent options (e.g., http://www.stenlight.com/ [stenlight.com])
Old-time carbide lamps still have limited application, mostly in giant caves and/or extremely long & cold expeditions, but Fluorescent has always been far too fragile in terms of packaging to warrant consideration.
Re:Riiight (Score:4, Informative)
CFL bulbs will give you 10+ years of service if you leave them on for at least 30 minutes everytime you turn one on. Not good for use in bathrooms or inside refrigerators.
Re:"using a lot more fossil fuels than they save"? (Score:2, Informative)
It's actually more like two and a half days, according to GE. You need to take into account loading and unloading the boat, shipping from the factory, shipping to the store from the docks, the cost of fighting bad weather, packaging the devices, the cost of stores managing their inventory, et cetera. Which is, you know, not to suggest that 2.5 days is a problem or anything. Still, just so you know, someone who knows this process end to end has cooked up two days nine hours as an average to FooMart in middle america.
Still, thank you for being the first person to actually put effort into debunking this pathetically obvious myth.
Re:LEDs should last forever but apparently don't (Score:3, Informative)
They do better if they are not half assed. A cheap PAR60 LED flood should cost you about $45.00 anything less than that is trash and will die. problem is Americans in general are really cheap bastards and flip out when they see a $45.00 light bulb.
So what you can buy are really really low grade crap that has not been tested and probably are full of cold solder joints. your municipality is also being cheap bastards and buying the cheapies instead of the $225.00 lamps they SHOULD be buying for those stoplights.
They last when built right. you cant get them built right unless you pay for it.
Maybe GEOBulb, except the cost (Score:3, Informative)
C. Crane's GEOBulb [ccrane.com] looks very promising in terms of the future of LEDs, but the price is quite painful. I'm personally using some 120-130 lumen candelabra LED bulbs [theledlight.com], which delivers close to the light of a 25 watt incandescent.
The LED bulbs are now coming in different color temperatures, so things are progressing.
Re:Not just cost, but optics (Score:4, Informative)
Re:Seriously? (Score:2, Informative)
where I said 1.8KWh above, I should have said 1.8Wh, but this is wrong anyway.
It takes 1400 gallons of diesel to ship the container, so that means that each bulb is using 1400 * 40000 Wh / 22000 = 2500 Wh
So it takes 35 hours for the CFL to recoup the energy used in shipping.
I didn't take into account the fact that turning diesel into electricity is not 100% efficient, so you're not going to get 40KHw out of a gallon of diesel. In real life it's probably closer to 50% [power-technology.com]. So that makes my numbers even more conservative and it's probably closer to 17 hours to recoup the energy cost.
Re:Not just cost, but optics (Score:3, Informative)
I suspect it's easy to make uniform mono-chromatic light, but people want white LEDs which have phosphor to convert part of the blue to yellow. That needs to be uniform and likely complicates matters. Notice that most LED flash lights have a bluish center, even the pricey Maglites suffer from this. A good halogen bulb is still much more uniform, which makes it more useful when trying to find things in the dark (no patterns imprinted on the scene from your light.)
I got good results by drilling a hole in a ping pong ball and sticking an LED just in it up to the flange on the bottom of the LED. It was quite uniform for colored and/or RGB LEDs. Not so much for white.
Just some info. (Score:2, Informative)
Re:Not just cost, but optics (Score:1, Informative)
I've had 2 problems with LEDs for the home to-date. First is that the "Lumens" ratings tend to be in the beam-spot, which tends to be a small fraction of the total sphere that an incandescent light would be lumen rated on - so... when an LED manufacturer claims "light as bright as a 100W bulb" - yea, sure, in the illuminated spot, but overall output is still puny.
Second problem is that any LED bulb that has a chance of being bright enough to be interesting tends to cost near $100 - too much cash to fling at a geek-interest object that I'm pretty sure will disappoint on the performance end.
Re:LEDs == Frustration (Score:1, Informative)
Actually, I have never found a LED bulb nor any CFLs that with a confortable color spectrum.
I used to have the same problem, but I wanted to stick with CFLs because my upstairs neighbour's heavy feet kept burning out my incandescents bulbs. So, I figured the guy at my friendly neighbourhood grow shop would know a thing or two about light bulbs...
Instead of trying to sell me fancy bulbs, he told me to just go down to the hardware store. The trick, he said, was to install them in pairs, and combine a couple of different temperature bulbs. With one 'cool' bulb and one 'daylight' bulb (or however they name them) you can get a pretty good spectrum.
Re:Not just cost, but optics (Score:5, Informative)
You normally get the best deals on Christmas lights the day after Christmas
Re:Physics of incandescents (Score:3, Informative)
I cannot understand why expensive efficient bulbs improve anything. Can anybody clarify?
An incandecent bulb produces heat from resistance. A resistance watt from a bulb or heater is the same except the heat from a bulb is typicaly at above head level leaving the floor cold unlike a heater. A heater cycles off when the room is warm enough. A bulb doesn't stop heating whent the room is warm enough.
If you use a heat pump, the effeciency of the heat pump is lost as it runs less while you heat more with resistive heat.
Is that clear?
Re:Not just cost, but optics (Score:3, Informative)
Um, no. That's nonsense. LEDs work just fine on DC, and that's the most common way to power them. In the simplest case, you just use a properly calculated current-limiting resistor as a current source, but any current source with the right output will work. For more complex needs (dimming, colour blending, etc) you can modulate them quite easily while keeping the pulses well above what the human eye can discern. You are alluding to that in the last sentence of your post, but a 10% duty cycle at 10kHz is DC, not AC (unless you're swinging both ways for some reason).
It's less common to run them off AC but as long as your circuit takes the negative supply swing into account you can do it. This is how (at least some) holiday LED strings work.
Also (Score:3, Informative)
In hot areas you get to double up on savings, so to speak. The wasted energy in a light bulb is given off as heat. So if you live in a climate warm enough to need to cool your house, the lightbulbs just add to the problem. You get a 100 watt bulb that is giving of like 90 of that in heat.
CFLs are much better of course. They still give off heat, but far less per amount of light output. So you get a double savings. You cut the amount of energy going in to the light, and cut the amount of heat waste which cuts the amount of cooling you have to do.
All that aside, I love CFLs because they have higher colour temperatures. 6000k lights are nice and blend real well with LCD monitors (which I calibrate to 6500k).
A good source for lamp specs (Score:1, Informative)
http://www.olino.org/us/
gives a nice summary of the qualities of available LED, CFL, etc lamps. CRI, Kelvin, Lumen etc.
LEDS became more usable in the last year. The only thing I'm waiting for is a LED lamp that can replace Solux halogens for color critical work, that will take more years. Especially red and blue colors suffer despite some CRI numbers above 85. The CFL's like True-light with improved CRI/Kelvin 5000 are acceptable replacements but do not have the same continuous spectrum the Solux have.
Ernst
Re:Projectors (Score:4, Informative)
Sure about that?
The bulbs themselves are actually not that cheap to produce. In the theatrical lighting world, we have various fixtures that accept HID lamps, very similar to those used in an LED projector.
Although they're not quite as expensive as what you'd put in the projector, they are standardized, and still cost up to $200 a pop.
I imagine that the projector companies are profiting a good bit, although HID lamps are most certainly not cheap to manufacture.
Re:LEDs can't even beat CFLs in growing plants! (Score:3, Informative)
But LED lighting doesn't show up on the police infra-red helicopter-mounted cameras - a great benefit to many "herb" growers.
You need newer grow lights (Score:1, Informative)
Take a look at the spectra of newer LED grow lights [prosourceworldwide.com]. You're right, the older ones were spotty. This is now being addressed just fine. Fwiw, NASA is now planning to use LED arrays as the primary growlights for long-duration missions to Mars.
Allow me to respectfully disagree (Score:2, Informative)
While I agree with some of your points, please allow me to disagree with your Mertz analogy.
IMO, the suitability of a CFL for a given application is directly tied to the construction and quality of the CFL and its electronics versus the application it is being used in. Some applications will never be good candidates for CFLs, I'll get to that in a bit.
The biggest issue with CFLs as I see it right now is that a lot of junk is being imported with nary a focus on issues that affect consumer utility. Instead, the focus is solely on the lumens/watt, which is but one aspect of how people benefit from a light. For example, most lamp manufacturers do not publish how long it takes their bulbs to come up to temperature, what ambient temperature effects are, nor the color temperature, nor the variability in color temperature, etc.
In other words, other aspects of the light not tied to the lumens being emitted are completely ignored and the cheaper the bulb, the worse the above issues tend to be. For example, I tried buying some CFLs for my in-laws at Home Depot and I was amazed how slow they were to come up to temperature, how nonuniform the light temperatures were, and so on. One bulb would be a dim yellow, the other more orange, etc. and none would have the same luminosity either. In other words, the QC in that factory on that run was completely and utterly off.
Then again, having bought them at Home Depot, I should have known better!
In my own home, I have used CFLs throughout, with a few exceptions. The only areas where CFLs are not used is one hallway that uses a combined light/movement sensor (CFL power supplies hate that due to the method which the light sensor uses) and then there are maybe 5 old sconces with exposed light bulbs where we prefer skinny traditional bulbs. Other than that, everything is CFL, including bathrooms, hallways, outdoor overhead lights, etc. None of these bulbs have needed replacement in over three years of use.
The brands I have had good luck with are TCP and Panasonic. The Panasonic gen IV bulbs we have are perfect replacements for globes, etc. even in antique light fixtures since they have the same approximate shapes as standard light bulbs. They are somewhat slow to warm up to full brightness (maybe 10 seconds - it's our version of a fancy dimmer effect) but we have had great luck using them even in applications that some bulbs are not rated for (i.e. ceiling cans, for example). The TCP springlamps have also been super, offering a wide range of almost instant-on CFLs in many color temperatures with even results. I've not worked for either company, not affiliated, your mileage may vary, etc.
Last but not least, the technology of LEDs will advance just as that for CFL has for the last 20+ years. At some point, manufacturers of CFLs will perhaps get together and come up with a industry standard for electronic dimmer wall switches to talk to CFL ballasts so that CFLs can successfully enter that application also. Unless such interoperability is assured, that is one application where CFLs are unlikely to have a lot of success. Being tied into a single-vendor solution (like the Leviton series of electronic ballast and switch combinations for overhead flourescent lights) is not a solution! And CFLs that can work around ancient rheostat, etc. technology are expensive and not very reliable.
Re:Not just cost, but optics (Score:2, Informative)
Diodes have a very sharp turn on, so from off to full on is a very small voltage change. To alter the brightness of an LED you pulse them at some cycle rate. For dim you turn them on for a little bit every cycle and for bright you turn the on for most of the cycle. That's pulse width modulation. If you don't use a high enough frequency then you can see the flicker especially when your eyes scan across them.