What you should know about HBLEDs - and nobody will tell you, part 1
Over the past 7-8 years the introduction of useful white-light High Brightness Light Emitting Diodes (HBLEDs) has captured the fancy of not only the engineering community but also the financial community.
Press releases have described how these new devices will render obsolete the 140-year-old invention of Thomas Edison and that ”the future is now!.” In fact, there is a recently published book, by Jane Brox, on the history of artificial light. The book was summarized in an 8/1/10 Boston Globe article as “The Incandescent Lamp: An Obituary”.
The Internet today is packed with hundreds of companies offering HBLED products of one kind or another. Furthermore, many component makers and design consultants— for LEDs, lenses, power supplies, heat sinks, control circuits--- have an agenda—nothing wrong with that .--- but they are unlikely to be an expert in all the companion elements and they certainly are not going to tell you things which might be limitations of their own products.
There is evidence that, because LED technology has evolved so rapidly, there are actually very few people who really understand all the technical interactions beyond a superficial level. Unfortunately, customers are also confused, whipsawed and otherwise befuddled by the various claims being made by the many firms now hoping to cash in on this increasingly evident technology.
There is extraordinary potential here for energy savings, new functionality, longer product life and greater reliability. However, in order to separate “the steak from the sizzle,” we need to look at some of the lesser-known physical principles and manufacturing technologies that make HBLED lighting possible and at some of the irksome issues not talked about.
Hopefully, the following commentary will put a few developments in perspective and provide an understanding for some of the aspects of the market that are not usually evident.
The Lighting Market: A Two-Part Equation
In a discussion of the lighting market and the potential for HBLEDs, it is important to make some fundamental distinctions. They will not apply to all market categories but can safely apply to over 95% of the areas of opportunity. First of all, we can divide the market into its two principle areas: Illumination and Indication. Even the hearty souls involved with the alpha-tests of fire as a light source made the made this distinction.
Illumination is that kind of light which helps us view our surroundings or perform tasks better. Indication is that kind of light which informs or alerts us relative to the status of something or otherwise provides us with information. They are as different as night and day and it is critically important to appreciate the difference.
Applications involving illumination fall into three subcategories: a) general area lighting, b) directed lighting and c) backlighting. The applications where light is used for indication include a) panel indicators and b) messaging.
Table 1 provides a way of looking at the HBLED market in a little more detail. The items marked with an asterisk (*) show where HBLEDs have enjoyed their principal successes. It’s interesting to note that until 2011 there was not much change in this makeup over the last 7-8 years but there has been accelerated movement since.
TABLE 1: The Lighting Market Broken Down by Application
Incandescent room lighting
Ceiling fluorescents for offices, factories, stores
HID lamps for factories, warehouses, streetlights, ballparks
High Bay Lighting for warehouses/”big box” stores/factories
*Cell phone, camera, automotive and other large LCD displays
High Awareness Messaging
*Highway and Railway Traffic Lights
*Hotel/Theater Marquee signs
*Commercial & Highway Message signs
*Giant Color Graphic Displays,including TV’s
Each of these subcategories has its own unique performance, cost, and reliability expectations. It’s also worth noting that in some cases there are additional physiological and psychological nuances that have to be considered in the marketing of such items.
Up to now, the lighting industry has been represented by thousands of different types of incandescent lamps, developed over a hundred years in response to evolving market needs. Those needs are extraordinarily diverse and one might suggest that the chances for replacement of all these by a single super-efficient LED technology would be slim to none. Similarly, there have been hundreds of fluorescent lamp types developed over the last 50 years.
It does mean, however, that an increased appreciation of all the nuances of these categories can lead to more effective leveraging of HBLED technology by companies with new and exciting value-add technologies which are market and application driven.
In this pioneering market, the HBLED makers are saying: “Here’s my fantastic new LED…. please find a way to use it!.., and please give us feedback on how you got around the various limitations… because we haven’t figured that out ourselves yet!” As this paper is being written there is not yet a single, truly high volume application for LEDS in general lighting over 10 watts. Nevertheless, as LED prices have dropped significantly since 2013, LED bulbs and luminaires are increasingly finding their way into mainstream applications for legitimate reasons.. and that trend seems likely to accelerate.
Indeed, many lamp and fixture makers are collaborating with this or that government entity, on a subsidy basis, with a commercial entity to install LED lighting on a trial, promotional or utility rebate basis… so,until 2013 very few installations to date have happened on the merits alone…. but that has changed.
One must be careful in extrapolating the early pace of success of HBLEDs in some a very few markets toward inevitable success in most all other possible markets. Success in traffic lights (the most publicized HBLED success story) has been no surprise because of the dramatically better lamp longevity (eliminating the very high cost of highway department bulb replacement labor costs) and elimination of need for the red, green and yellow colored lenses which curtail light efficiency.
With traffic lights, it simply was obvious that conversion to LEDs was a foregone conclusions—virtually all plusses and no minuses. For supermarkets, malls, warehouses, streetlights, museums, sports and entertainment complexes etc, there still are many technical issues, beyond just lumens per watt that the industry is still learning to appreciate. Addressing these nuances will “separate the men from the boys”
Traffic lights were a real functionality and “return on investment” success story. High end automotive lighting for brakes or headlights has also been getting attention but that has been more style driven and does not represent a mainstream application
The contrast between Indication and Illumination is striking. The fact that there are some products being offered in every single category including Illumination simply confirms that there are some “early adopter” buyers for almost any high tech product, whether it’s a Segway vehicle (12 years ago), video conferencing (20 years ago), or the first generation Kindle-type readers (10 years ago).. At this stage of a developing market, it’s sometimes not clear whether an innovation is simply a solution in search of a problem or really the next big thing, but it is important to appreciate that it could be either.
A good example of the time lag between a technology’s introduction and its finding a home in the mainstream market is the energy-saving compact fluorescent lamp (CFL). Some major lighting companies, such as Westinghouse and Philips were making and promoting their first CFLs in 1983 but that did not mean either were ready for prime time. In fact, it took 15 years, for CFLs to get market traction. Gas/electric hybrid vehicles are also following a similar long adoption curve. Despite this caveat, it’s also useful to note that the mistakes or off-the -mark assumptions of the earliest product innovators are often a textbook for the next individuals or companies to ”get it right” from a pragmatic business standpoint.