LEDs: A small light source with a big future

There is one point on which all the experts in the lighting industry agree: LEDs will continue to advance, and supplement conventional lights by delivering a wide range of additional functions. Those additional functions are made possible by the special features of LEDs, such as quick and easy colour changing and mood settings which are barely possible – if at all – using other forms of lighting. In the view of light designer Michael Podgorschek, co-proprietor of podpod design, the opportunities opened up by such features will in future mean that there is not only more light, but also more awareness of light.

Uli Lemmer This does, however, require that the possibilities offered by lighting design using LEDs are made widely known. As Professor Dr. Uli Lemmer, head of the Institute of Light Engineering at the University of Karlsruhe, says: “Many of those possibilities could not be made available to customers in the past.” He explains that the lead time in terms of lighting technology from the original laboratory development through to a new television set is just one and a half years, whereas in light systems the lead time until the latest laboratory developments are implemented in private households is 25 years. He asserts that in order for LEDs to become more widespread, awareness of their efficiency and improved light needs to be disseminated.

Klaus Ziemssen Dr. Klaus Ziemssen, Vice President and General Manager LED Systems at OSRAM believes LEDs will have to become established in professional applications before finding their way into private households!

RGB – the magic formula in terms of acceptance

Michael Podgorschek The automotive industry has already taken the first successful steps down the LED route, and with the latest-generation third brake light has helped familiarize a broad public with the term “LED”. Another area of application which will enhance familiarity with LED technology is in architectural lighting. Michael Podgorschek sees ideal opportunities for LEDs in that field, provided architects are provided with good, reliable products to install. One of the key features of LEDs in terms of architectural, mood and advertisement lighting is their facility to change colour by the use of RGB modules, as Dr. Ziemssen reports.

One notable development is that in advertising 10 per cent of neon lighting has already been replaced by LEDs. Applications in building exterior lighting and for ambient lighting in bars and wellness facilities are attracting particular attention, and arousing people’s curiosity about the durable little magic lamps. That is especially true when LEDs are deployed over large surface areas, and not just as spotlighting.

Patrick Trueson Patrick Trueson, European Pro-duct Marketing Manager of Avago Technologies, sees the future of the LED in wide-area lighting. This will mean impressive full-wall systems for the home – such as have already been created by light designer Ingo Maurer – will become more and more a part of architectural lighting solutions for private clients.

Dragging other forms of lighting along in its wake

Advances in LEDs are also resulting in improvements to conventional forms of lighting in terms of energy-saving and service lifetime. Dr. Ziemssen expects to see an upgrade in service life specifications for fluorescent lamps in particular – as a response to their impending substitution by LEDs.

Karl Weinhold Yet even if the energy efficiency of a compact fluorescent lamp is 30 per cent better than that of an individual LED, and although LEDs do not at present offer acceptable value for money in terms of price, LED technology does offer long-term advantages in operation. Karl Weinhold, Chief Executive of KWL Lighting, says: “In order to calculate efficiency and service life you have to look at the system as a whole.“ And it is indeed for reasons of efficiency and length of service life that LEDs, despite their high purchase price, have already succeeded in establishing themselves in a large number of applications.

One example: The corporate design colour of a chain of stores is red, and the management is looking to display a wide array of different light density effects on 1.5 m2 surface area in its branches. Such a lighting effect could be realised with white fluorescent lamps and colour filter transparencies. The cost would be cheaper than a variant employing red LEDs. However, the installation would need 35 Watts of power, and would also lose part of its energy through the colour filters.

A solution with LEDs would need just 6 Watts of power to create a comparable effect, and would utilise that power in full. So in order to select the truly more cost-effective solution, it is not only a question of comparing the purchase cost, but also the savings to be gained over the years resulting from the lower power consumption of LEDs and from the lower maintenance costs incurred by virtue of their long lives. Consequently, the difference in purchase price would be very quickly amortised.

New markets based on intelligent light

Wolfgang Lex All LED lighting is customised. This means detailed analysis and planning are essential to optimum lighting applications. Clamouring for higher power and light density is not always the right way to achieve the desired result. In the view of Wolfgang Lex, head of the LED Division at OSRAM Opto Semiconductors, a good lighting installation can fail due to a lack of understanding of the overall system – inadequate knowledge and failure to comply with requirements are often encountered. All too often, key aspects are overlooked, such as the fact that the service lives of the individual components are less than those of the LEDs, or that the LED modules require a certain thermal management, and need to be correctly controlled.

Jürgen Waldorf Wolfgang Lex also sees the key to the success of LED lighting in the intelligence of the appropriate control systems. Intelligent light will broaden the lighting market so that new, additional applications arise. Illuminated water taps, indicating the water temperature by lighting up red and blue, are one example of such new applications envisaged by Dr. Jürgen Waldorf, head of the Electric Luminaires and Electric Lamps divisions within the German Electrical and Electronic Manufacturers‘ Association (ZVEI), in the private households of the future. Intelligent light could react to movement, time of day and temperature.

Cordula Carlin LEDs will also open up potential for new applications in the non-visible range, such as for driving with infrared main beam headlights: An infrared camera captures the invisible light and the road ahead is laid out on a head-up display on the windscreen. The driver, in effect, sees a fully lit road ahead, without dazzling oncoming traffic. Infrared radiation is a particularly attractive option in the surveillance field. There will also be a technology leap in the UV field. Professor Dr. Lemmer sees potential for a multi-billion market resulting from replacement of plasma emitters by ultraviolet LEDs in applications such as sterilisation, curing and coatings.

Homework for LED developers

The energy-saving potential and special qualities of LED light are the main factors driving the bright future promise of LEDs. However, the experts agree that LED developers still face a number of challenges: The current white-quality of LEDs and optics needs to be improved; electronic ballasts need to be miniaturised; control systems need to deliver more features, and their communication with the LED modules needs a standard. The standardisation of control system communications and of output voltages is vital, and will open up new markets to LEDs.

Such improvements are essential even though global developments are advancing at a different pace – with a much greater readiness to make the move to LED technology in Asia than in Europe for example. In the USA, too, LEDs will become established more quickly, because power consumption is very high, though outages often occur.

Even with regard to the film and television studios in Hollywood, for example, it is clear to see that the potential savings from using LEDs are enormous. Another factor is that LEDs discharge less heat, so air conditioning costs can also be saved. Moreover, the brightness variation and colour changing properties of LEDs enable many more effects and moods to be achieved, which can only be of benefit to the future generations of dream factory blockbusters.

This represents a typical example of how LEDs – provided they are applied correctly, with intelligent control and good thermal management – are creating many advantages which are gradually being widely recognised and utilised.

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This article is an extract of The Quintessence, a new know-how magazine that tells you all you want to know about the special features of LED technology.

Get your free copy today at www.ebv.com/thequintessence.

Highlights of the first issue include applications demonstrating the design scope offered by LEDs, such as the impressive lighting concept for the Torre Agbar in Barcelona and the fascinating use of LEDs by light designer Ingo Maurer.