GRENOBLE – Lighting is becoming the largest consumer of electricity in buildings, accounting for 25 percent or more of total costs. At the Leti’s Annual Review this week in Grenoble, France, Alexandre Lagrange at the CEA-Leti Optic and Photonic Department, demonstrated CEA-Leti’s engagement in research leading to smart lighting systems with adaptive and controllable properties.
Due to its high potential for CO˛ abatement, lighting is a fast moving business, and market growth expectations are high.
The white LED efficiency, said Lagrange in his keynote, is currently increasing sharply. Performances are there. But a plateau will be reached soon. There is not much to gain in terms of performances. And looking at the cost trajectory for LED luminaires, margins will drop dramatically. Today, LED cost is about 6$/klm but the cost reduction should be transferred to the customers so margins will be lower.
The white LED efficiency is growing sharply Source: EuroLED 2012
OLED technology is a few years behind in terms of performances. The cost is a blocking point as, in 2011, it was about 20.000$/klm. “It’s another dimension, and the OLED lighting market is not yet foreseen,” noted Lagrange.
Customers want more light, or lumen, per dollar. For that, Lagrange called for more than lumen. This means adding new functions, working on high-quality lighting, developing easy-to-integrate in-house solutions and adding more services through the light.
Lighting has become electronic, and LED should move to smart lighting, Lagrange continued. Intelligent lighting parameters should enable the user to adjust the quality, the quantity and the direction of light.
He commented: “We started with a simple packaged LED. [At Leti] we are adding actuators and smart sensors to detect presence, heat, ambient light and movement, leading to a smart luminaire that should be able to work in a network.”
Smartness goes down towards the light source, stated Lagrange. This
means that, prior to turning on the light, we should add some
intelligence at the building level with movement and light sensors as
well as clocks control lighting. Then, we should make the luminaire
smarter with movement and light sensors, means of communication into the
luminaire for an easier installation and adjustment. And, at the end of
the chain, light sources should include drivers, sensors (device
temperature, color temperature, light level, presence) and
Smartness goes down towards the light source
Eventually, at home, light should be part of a network, and “we should think about cooperation between luminaires or between users and luminaires. Embedded electronics and sensors open the door to high added-value with small added cost,” concluded Lagrange.
CEA-Leti has been working on LED lighting since 2006. Initially, its R&D programs were limited to the “upstream” end of the industrial supply chain, focusing mainly on new semiconductor materials such as gallium nitride or zinc oxide, and unconventional chip technologies such as nanowire-based LEDs. Since then, a variety of new “downstream” projects have been launched to deal with the key issues of thermal management, light extraction and wavelength conversion.
Leti is a partner of SMASH, an EU-funded development project coordinated by Osram Opto Semiconductors GmbH that aims to significantly reduce the production costs of LEDs by enabling the epitaxial growth of nanowire-based LED structures over large areas, using low-cost substrates such as silicon.
Leti is also supporting the CITADEL initiative led by France’s Center for Building Science and Technology (CSTB) in conjunction with other laboratories and the French branch of Philips Lighting. This project is intended to research and promote the optimal use of LED lights in buildings.
A third example is Leti’s engagement in “PACTE-LED”, an LED development project that aims to develop LED-based lamps to directly replace 25- and 35-watt halogen lamps, ensuring similar light quality while using one-fourth as much power.
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I see that few companies are trying to integrate the Hardware required to drive CFL and the communication module together in the existing small base of the CFL bulb, If we think outside the box and have this hardware external to CFL/LED bulbs, then it will be easy to maintain/upgrade the hardware and also the initial/replacement cost of the bulb will be cheaper.
Any thoughts on this?
The problem is the screw-in bulb form factor. Shoehorning a power converter and heat-sink into a standard size bulb will continue to yield substandard replacements. The I/O for traditional bulbs is inadequate (dimmers and 3-way switches) to make significant improvements in usability. The power supplies need to be made more reliable and their heat positioned away from the LED module. The fixture needs to provide the heat sink for the LED. I have seen some of this with integrated LED pot-lights, and some desk lamps, but not in other built-in lights for consumers. The problem is that the fixture industry does not see themselves in the electronics industry. Second is that for long-lived fixtures, the consumable replacements are not standardized - should there be separate power supply and LED replacement options?
Lighting research and adoption by the society is very slow I agree with Himanshu Gupta' comment. Event today still at most of the places we see the conventional switches, none of the affordable and reliable replacement of the mechanical switches are there in the market today. Yes but it is equally true to have development, so the show must go on.
Why not a single adjustable light bulb? Today we buy 40, 60, 75, 100, and 150 watt light bulbs. Why not a single bulb with a base switch to set the desired output? It could even have a second switch to set the desired color temperature. Then a single bulb could fill all applications in legacy light fixtures and avoid the need to warehouse a variety or depend upon unreliable "three way" switches. One challenge is device footprint. The high wattage (CFL and LED) bulbs are too big to fit into many light fixtures. Once size and cost are reduced, the "one bulb fits all" can become a reality.
There are a couple of questions needed to be addressed before next generation lighting solution becoming widely adopted.
1) Price is always the main driver. Price/ Lumen is a good way to look at it. However, if the price of LED lighting is not getting closer to the price of CFL, the adaptation will be very slow.
2) Life time of the product is another driver. Compared to incandescent light bulb, CFL last 3-5 times as much. The price reflects that properly. CFL does take 3-5 years for the crowd to adopt. The adaption in the States doesn't really take off until PG&E heavily subsidize few years ago. LED lighting is claim to be lasted 10 times longer than incandescent light bulb. Now, consumers will be more than happy to see a proof.
3) Availability of different lumen bulbs is important to the market. I used different brightness in different area. For example, I would like the den to be bright so that I can read and work better. I prefer to have my living room a little bit dimmer in addition to that I am able to control the brightness. Dimmable light bulb is a must. The last time I checked, LED light bulb has 40W equivalent incandescent light bulb. Where is the 100W equivalent?
4) If the BOM cost is heavily driven by the power electronic of an LED light bulb, shall the form factor and the presentation of the product be changed so as to increase the rate of adaptation?
"Intelligent lighting parameters should enable the user to adjust the quality, the quantity and the direction of light."
...sounds interesting...I get "the quantity", "the direction", but what is it meant by "adjust the quality" of light? Color?
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