July 05, 2011
LED Will Not Wipe Out Fluorescent Lighting?
Light Emitting Diodes (LEDs) are expected by some observers to become so cheap, efficient, and long-lasting that they will displace fluorescent light bulbs. Francis Rubinstein, a scientist in the Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division, says the imminent death of fluorescent lighting at the hands of LEDs has been exaggerated.
"The common view," says Francis Rubinstein, a scientist and energy-efficient lighting expert at Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division, "is that LED lighting is replacing fluorescent lighting with the same inevitability that mammals replaced dinosaurs as the dominant large life forms on Earth."
But wait, says Rubinstein, who has been delivering a talk to lighting industry audiences titled "Why Fluorescent Lighting Isn't Dead." He believes that modern fluorescent lighting will continue to dominate the general lighting market and that solid-state LED lighting will coexist in the marketplace with fluorescent lighting for some time to come. Rubinstein sees a near-term future in which LED and fluorescent lighting coexist in hybrid systems that will be more adaptable to the lighting needs of a wide variety of residential, commercial, and industrial building types and space configurations.
Established technologies often last way longer than expected. Look at the 4 stroke internal combustion engine (ICE). The Wankel rotary failed to displace it. Hydrogen fuel cells are still a long way off. Previous attempts to commercialize electric vehicles have failed. This time around high oil prices and advances in battery tech suggest better prospects for EV. But while projections for electric vehicle sales in 2020 vary over a wide range none of the estimates I've found have EVs replacing the ICE from the top spot by 2020. It is hard to unseat the incumbent because incumbent technologies generate huge cash flows that help fund refinements and improvements to the incumbent's design and manufacture.
In the comments of Green Tech Media's coverage of this report you can read a few people who work in the lighting industry explaining obstacles to more widespread uptake of LEDs. Cost is not the only concern. Color quality, existing fixtures designed for fluorescents, and continued improvements in fluorescent technologies all slow down the adoption of LEDs.
We could genetically modify our vision to detect infrared, thereby obviating lamps.
Using electric vehicles may not be a good examples as they were the established technology before ICE took over. The others mostly failed because they were worse than what they should replace.
But your post is also wrong because fluorescent lighting will soon be replaced by LED because it doesn't contain mercury. Fluorescent lighting will just be banned in the first world.
Humans as a whole are generally adverse to change, so what you're saying that both will co-exist for some time to come is certainly true. Although it won't be a quick change, I do believe that eventually LEDs will become the norm, as shifts in environmental and economic changes occur. People obviously see the benefit of LEDs, but because they're so expensive, it's just not worth changing yet.
The other day we went to the pool warehouse and the LED lights for pools were $300! That's a bit steep. But just like with anything, that price will be going down within the next 5-10 years as people realize LEDs are far more efficient.
The key obstacles for LEDs are cost per lumen and quality of light. One major lighting company thinks this will be solved in the next 3-5 years.
My employer has done some LED replacement of fluorescents in some high cost of replacement applications (a location several hundred miles away ... up) and in some high reliability applications in the same domain and we have found a few other engineering problems that most manufacturers of commercial lighting haven't worked out. For example, the taillight and traffic light LED arrays tend to quickly have several of the LEDs burn out. This is most likely due to infant mortality or another problem that I can't discuss. The first can be solved by burn in cycles, the second by proper design of the fixture.
"Established technologies often last way longer than expected"
True, but sometimes they disappear quickly. Look at the demise of the cathode ray tube in televisions and computer displays.
LEDs are very sensitive to heat. I have an on-camera video light that has five CREE LEDs in it. It cost $300 and is as large physically as a conventional incandescent unit because for it to put max lumens on the subject continuously requires a sophisticated heat sink system to draw heat off each individual LED, or the LEDs will fail.
I also have two identical CREE LED flashlights designed to run a few seconds, then be turned off. They don't have good heat removal, but are super compact, putting out remarkably bright light from a single AAA cell. I left one on for a long time. The other is new. The older one is significantly dimmer due to its heat damage.
If LEDs are going to replace an Edison tungsten incandescent or CFL of the same physical size and illumination, heat removal will have to be taken into consideration. I'm guessing that LED lamps will need to be a bit larger than their incandescent or CFL counterparts to fulfill their long-life potential. Packing high-output LEDs close together, then pulling the heat out, especially if the lamp is in a enclosed area like a ceiling can, is going to be a major engineering challenge.
As for CFLs, Mythbusters conclusively proved that it was the number of on/off cycles that killed them.
I'm not particularly fond of the light from either LEDs or CFLs, either. Neither is full spectrum and can be subconsciously annoying.
I paid $500 for a multi-colored LED pool light that was rated for 50,000 hours. I don't think it had 300 hours on it when it died. Brand was Hayward; don't aste your money like I did.
Alas the Post and all the comments about the advantages and disadvantages of LED compared to CFL miss the point. LED's will replace CFL's in the same manner that CFL's are replacing incandescent's - our political masters will decide that is what is to be done and they will decree it. It has nothing to do with cost, or performance or your personal preferences silly lumpkin's - our master's will decide what we will use.
Mammals superceded reptiles as the dominant life form....
But reptiles never went away entirely.
Some reptiles exist today (even in quite large forms).
Other reptiles evolved into birds.
So lighting may follow similar trends.
The real answer is to produce more electricity -- possibly man's greatest invention.
We need more electrical generation and distribution, not less. More creativity in generating, not less.
When I was ten, "All-Electric Homes" were all the rage and we were told that electrical power was going to be so cheap they might have to give the power away. Since then, we have built very few new power plants, tear down the dams and power plants we have, and decry power transmission lines... all while pushing to get everyone into electric cars or electric trains.
It can be done. We built the Hoover dam in a few years. It's a matter of political will.
@Koblog ... I agree. When my parents added an apt to the house for my grandmother, they made it all electric ... But at the time, a lot of nuclear plants were being built and more were on the drawing boards ... then the NRC was formed ...
"Established technologies often last way longer than expected."
Sometimes yes, sometimes no. Analog film photography disappeared with frightening speed. Some previously successful players, such as Minolta dumped their assets and walked away.
BEVs are a poor comparison. They were a successful technology a century ago, with an inherent manufacturing cost advantage, the lost to ICE for good reasons, that have only grown more in ICE's favor. (HVAC anyone?).
Whether or not LEDs overtake florescent in several markets is an open question. The biggest barrier right now is probably cost.
Look at the 4 stroke internal combustion engine (ICE). The Wankel rotary failed to displace it.
Mostly because the Wankel has a very high surface/volume ratio in the combustion chamber and long squish spaces, leading to low thermal efficiency and high unburned HC. The oil price shocks and Clean Air Act removed it from everything but sports cars.
I'm looking at building myself some LED lights because nobody seems to make what I want. My experience with the commercial screw-in LED units is that they're good lights but emit bad RFI.
I doubt if LED's will, but electro-lumenescent panels might.