Electronics Weekly puts its questions to industry figures: Mark McClear, a director at Cree's solid state lighting business, and Ulrich Kastner-Jung, a director at Osram Opto Semiconductors

How will you judge when the power LED market has really taken off, and is 2008 the year?

Mark McClear (MM): The power LED market took off mid-2007 when the LED industry reached several key technology milestones in brightness, efficacy, and colour-point stability/lifetime, and when this technology was first implemented in real world, mainstream, general illumination applications.

We now have real installations in parking garage, outdoor, and indoor solid state lighting (SSL) fixtures that match their HID, compact fluorescent, and incandescent technological predecessors in brightness and light quality, but deliver tangible economic benefits.

Ulrich Kastner-Jung (UK-J): Despite the early market stage of solid state illumination, attractive lighting applications already show the clear LED advantages: high light output combined with fast dimming and RGB colour changing as well as high environmental robustness, proven technology and long lifetimes. First use cases show additionally the energy and cost saving potential.

What intensity/efficiency/cost points need to be hit for power LEDs to make a big impression in general lighting?

MM: This varies for different general illumination market segments. Efficacy generally needs to be at least 30 per cent better than the incumbent technology to drive the economic payback models in a reasonable time frame. Raw brightness of the LED lamps drives the number of LEDs in a system down, which, together with lower LED unit prices, drives much more competitive LED luminaire first-cost. Maintenance/re-lamping costs of traditional lighting technologies versus the long lifetimes/"zero maintenance" of LEDs also has a great impact on the economics of some applications.

In general, the efficacy, brightness, and long lifetime advantages of LEDs combine to make a compelling value proposition today for most outdoor HID applications less than 400W, and some indoor lighting applications can easily exceed incandescent or compact fluorescent in efficacy today.

UK-J: Concerning performance, LEDs already show significant advantages in various applications. High efficacy and long lifetime of LEDs already result in energy and cost savings - needing consideration over the product life cycle: higher initial purchase cost are overcompensated by low operational cost (energy, maintenance etc). There is progress on LED cost, efficacy, luminance and light quality.

In the long run, do you think you can cut lumens/$ far enough to beat OLED or electroluminescent technology as a florescent tube replacement?

MM: OLED and electroluminescent technologies may make inroads into the display market, but we do not foresee them eclipsing traditional lighting technologies on lumen output, efficacy, or lifetime in the near term, therefore we do not see them competing in the lighting space regardless of cost.

LEDs are on target to reach the right value point of brightness, efficacy, lifetime, and first-cost to compete with any known lighting technology - including the fluorescent tube - but look for the form-factor to change from the ubiquitous 2x4 'troffer' to an integrated SSL fixture that exceeds the fluorescent tube in efficacy, but lasts for decades with zero maintenance, works in cold temperatures, can be easily dimmed and controlled, and contains no mercury or other toxic elements.

UK-J: Our R&D setup is tuned to benefit fully from the synergies between both technologies, is focussed on successfully position the technology in volume lighting markets to enhance the portfolio of light sources with a clear value proposition. This means for instance that our technology programme is balancing technology breakthroughs with manufacturabilty concept at an early stage.

Aside from 'anything with a lot of LEDs', what is your favourite power LED application?

MM: We like the ubiquitous BR30 Indoor can light and the MR16 halogen lamp applications. These indoor applications demand very high quality, stable, warm white light. Technology advancements last year broke through the former barriers of raw light output, efficacy, colour temperature and colour point stability.

Important industry standards activity in chromaticity, measurement, and LED lifetimes were just completed last year, and will be published this quarter, and the US Department of Energy has recently published the Energy Star requirements for SSL. Taken together, this confluence should make 2008 the year for indoor SSL applications.

UK-J: Probably the most interesting is the lighting segment where "green" (eco) benefits, emotional power (colours, well being, new designs) and cost saving (total cost of ownership) are touched. These factors will enter the consumer and professional lighting segment at the same time.

The future has already begun: just look at 'architainment', decorative and shop lighting, street lighting and the first indoor applications. But also flash in portable camera devices and LCD backlights for notebooks and TV sets are very attractive applications.

Is there anything else needed to finally settle the patent issues between power LED makers?

MM: Patents are in integral part of the way technologies are brought to market. Certain companies and individuals invested in LED chip, phosphor, and packaging technologies in the late 1980s and throughout the 1990s when the payback was uncertain for the technology.

Those companies continue to invest the resources in research and development and in patent procurement. The patent system is doing its job sorting out the relative value of these inventions by ensuring an adequate return on investment for the shareholders and owners.

Net innovators largely already have the freedom to practice their inventions, and have the negotiating leverage to cross-license their technologies and/or practice the inventions of other companies to everyone's net benefit. Companies who did not innovate rapidly enough or came late to the LED space will have to pay license fees to practice the inventions of the innovators.

UK-J: Over the years we have built up a very strong patent position - one of the largest patent portfolios compared to other LED manufacturers. It is the foundation of our strong market position. We are taking legal measures to protect them but are also assigning licenses to international companies.

See also: The full index of Q5 interviews with electronics industry leaders

See also: Electronics Weekly's roundup of content related to LEDs, with a special focus on both white LEDs and coloured LEDs:

LED technology - White LEDs

LED technology - Coloured LEDs