By most accounts, the light-emitting diode (LED) revolution is well underway, even though LEDs still remain a small fraction of today’s total lighting market. Government estimates predict that solid-state lighting (SSL) will rise from around 1 percent of the installed base today to the lion’s share of the market in just two decades. Whether those predictions prove to be accurate remains to be seen, but the insistence on dramatic gains for the LED is notable and only should be discounted by electrical contractors at their own peril.


The 2010 U.S. Lighting Market Characterization Report, published by the Department of Energy (DOE) last year, notes that, of the more than 8 billion lamps deployed in the United States in 2010, only 67 million of them were LEDs. Incandescents, everyone’s favorite whipping boy, were nearly half of the 8 billion. Those numbers tell a story of the huge opportunity for SSL, a clearly disruptive technology in its long-term significance, if not in its immediate impact on the industry.


LEDs appeared commercially as early as 1962 and are based on the principle of electroluminescence, which occurs when an LED is forward-biased (switched on) and electrons recombine within the device, releasing energy in the form of photons. Because of the technology’s early physical limits and high cost, LEDs were chiefly used as indicator lamps in appliances such as televisions, radios, telephones and calculators.


Innovation in the last few decades, however, has made SSL much more efficient and much less costly. Today, the 60-watt (W) incandescent lamp provides 13–15 lumens per watt (LPW). The halogen lamp provides 15–20, and the compact florescent lamp (CFL) provides 53–63. By that measure, at 70–100 LPW, the LED handily beats the others.


Last year, the DOE awarded Philips Lighting North America its first L Prize for LED Lighting Technology and Manufacturing. The competition, a DOE-sponsored search for a 60W replacement lamp, required entrants to meet rigorous technical requirements, including efficiency, light output, wattage, light quality and control. The $10 million award to Philips reflects the government’s commitment to SSL, and the DOE is doubling down. It is offering two more L Prizes, one for a PAR 38 halogen lamp and another for the 21st century lamp.


The innovation curve seems to be getting ever steeper, with breakthroughs seeming to occur every few weeks. In December 2012, Cree announced the XM-L, an LED that appears to meet Cree’s efficiency claims of 17 percent improvement over the previous generation. Several weeks before that, Philips announced what it claims to be the world’s smartest LED lamp. 


Controls also are undergoing innovation. The Philips’ web-enabled hue system allows users to control residential lighting using a smartphone or tablet. The system was made available exclusively through Apple’s App Store on Oct. 30, 2012.


There is an end in sight to such rapid innovation, but that end will be a good place to be. By 2030, the DOE predicts that LED technology will approach its physical theoretical efficiency limits. By that time, it will have reached the 200 LPW threshold, compared to 86 LPW for conventional 4-foot T8 general lighting.


Recent cost and efficiency gains, and the developments apparently yet to come, emboldened the DOE to make the following predictions for LED technology:


• Its share of lumen-hour sales will grow to 10 percent by 2015, 36 percent by 2020, 59 percent by 2025, and 74 percent by 2030, all amounting to 50 percent of total market share measured in lumen-hours.


• Its share of the residential market will rise to 25 percent by 2020 and to 62 percent by 2030, saving enough energy to power more than 80 million households.


• In the commercial space, LED technology will capture a 28 percent market share by 2020 and 70 percent by 2030.


• The average life of LED indoor lighting will increase from 25,000 hours in 2010 to 73,000 hours by 2030 and beyond.


• The average service life of LED replacement lamps will increase from 25,000 hours in 2010 to 48,000 hours in 2020 and beyond.


Chris Bailey, SSL technology strategist at Hubbell Lighting, would not dispute those predictions. He said competition between overseas giants, such as LG and Samsung, will help drive costs down in the coming years and thus make LEDs even more marketable. The improving economics of the technology notwithstanding, Bailey said the underlying condition that will most support the growth in LED installation is that “environmentally efficient lighting is now a part of our consciousness.” 


He noted that, while energy costs may have leveled off in the last few years, the growth in the LED market continues to persist. So, aside from envisioned cost savings customers capture by using LEDs, they want to believe in the technology and its environmental benefits. 


“Consciousness is the motivation,” Bailey said, adding that, “Payback becomes the justification. The adoption of solid-state lighting by Hubbell’s customer base has grown approximately 100 percent every year for the past five years.”


So, what could slow adoption and delay the victory dance that the DOE says is in the cards for the LED? Doug Widney, a San Francisco-based energy consultant and active circuit designer, outlined a few possible impediments facing the LED market:


• LED efficiencies have risen about 400 percent since the turn of the century. That mega-growth is gone. From the 60 percent of the Haitz endpoint, there is probably not another doubling in the cards. (Haitz’s Law, often compared to Moore’s Law for integrated circuits, is named after Dr. Roland Haitz, who posited in 2000 that, in every decade, the cost per lumen falls by a factor of 10, and the amount of light generated per LED package increases by a factor of 20. He also said the efficiency of LED-based lighting could reach 200 LPW in 2020.)


• The cost of LEDs—while having dramatically decreased in recent years—is still an obstacle to market growth. 


• Engineering is incremental. It has taken 20 years for the CFL to get to where it is today, and circuit boards still overheat when mounted tube-down. It might take years to obtain the right quality of light for the right environment. For instance, as opposed to any other kind of light, the LED is a unidirectional emitter (rather than omnidirectional). That’s great for a downlight but is limiting in other applications. 


• LED driver circuits are not naturally compatible with the billions of installed phase dimmers from various manufacturers. While there are new standards for LED dimming, the winners are not certain: analog or digital, AC or DC, high- or low-voltage, high- or low-frequency.


• Green energy subsidies may tend to drive over-use or misapplication of LED technology. 


Despite the heightened consumer consciousness, consumer education (or lack thereof) is still an issue. The DOE implicitly recognizes this in its stated goals to “increase knowledge about the technology’s characteristics, appropriate application, and energy and economic performance in order to maximize national energy savings.” Katya Evstratyeva, a blogger for Strategies Unlimited, a market intelligence firm that specializes in the LED market, recently noted that “the shift in consumer mentality does not occur at the same rate the industry progresses. New ways of selling LED products are needed, and the immediate need of consumer education can be addressed in the stores … manufacturers provide a lot of useful information about their products on their websites, but consumers are not spending time studying and comparing product specifications. So, the critical go/no-go decision happens in the store, in front of the bulb. It is time to transfer the knowledge onto the floor and, more importantly, translate it into simple and clear terms.”


A May 2012 report prepared for the DOE’s Solid State Lighting Program, “Multi-Year Market Development Support Plan,” notes a paucity of clear information for both consumers and lighting professionals. The report states buyers have “difficulty understanding the performance of new products, and in particular, whether selected products are suitable replacements for the conventional light sources they are presently using. Similarly, lighting professionals, while typically holding far more sophisticated understanding of SSL technology, still struggle with a wide range of conflicting information on LED performance characterization and appropriate application.” The report further notes that even electric utilities, which spend millions to promote efficient technologies to their consumers, “still routinely struggle with how and whether to incorporate SSL products into their energy-efficiency programs.”


Widney believes all these obstacles in the way of LED adoption, while real, won’t upset the LED apple cart in the long term. The short term is another matter. After attending the 13th Annual Strategies in Light show last year in Silicon Valley, which had record attendance, Widney said that the immediate market prognosis for LEDs is not sanguine. 


And yet, he said, “Despite the current dysfunction in the marketplace, LED technology continues to improve, pricing continues to drop, and the inevitability of LEDs vanquishing incandescents and halogens in general illumination remains.”


Of course, that inevitability is being given a world-class boost by the U.S. Congress and other governing bodies around the globe, which are banning the incandescent for its inefficiency. In the United States, the phaseout of the 100W incandescent began in January 2012, although implementation funding was delayed by Congress for nine months. Lower wattages get the boot in subsequent years. The United States held out on a ban longer than some other countries, partly due to consumer resistance. Brazil, Venezuela, the European Union, Australia and Switzerland all had bans in place by 2009. Many other countries plan to ban them soon—among them China, Russia and Canada.


It’s an advantage few other technologies have the luxury of enjoying. If there were any doubts that the LED would assume a dominant position in the lighting market, the bans on the lowly incandescent have surgically removed them.