You asked Mark Costigliola, Managing Director of Advanced Lumonics (producer of the EarthLED light bulbs, including the CL-3 and the new EvoLux line) a variety of LED-related questions. So read his answers and for the next few days, feel free to follow up with any comments or questions as Mark will be checking in to respond to all your posts.
Q: LEDs have been around forever as a technology, but using them in a consumer lighting application is what is novel. Obviously there are technological advancements in the clustering of the bulbs, etc. but is there anything particularly novel about the actual LEDs themselves vs. the classic technology?
A: Currently, the state of the art in LED lighting technology utilizes LED light chips as opposed to the traditional looking miniature light bulbs that you might be used to seeing used as indicator lights. You may have seen the first generation of LED light sources clustered many of these small LEDs together to form an array. LED chips provide many advantages over these types of setup in terms of reliability, packaging and thermal considerations. LED chips also allow us to provide a light source that is much more like traditional incandescent lights than clustered solutions can provide.
Q: It seems that quite a bit of R&D goes into creating a replacement type bulb, especially when trying to achieve higher brightness levels. Could you share some of the technical challenges of LED bulb development?
A: It is true that there are many challenges that go into creating LED lighting products. The current challenges we face are related to packaging, thermal dissipation and of course, we are always trying to find new ways of using LEDs in applications where incandescents and CFLs dominate. As power densities increase thermal management is going to become an increasing challenge. The best part about this industry though is that it is very well integrated with many specialized suppliers who look to solve each of these challenges head on. For instance, there are many players popping up who are specifically designing new thermal solutions for LED chips. Very soon, those looking to develop a new LED lighting solution will be able to do so by selecting “off the shelf” components to build a final product as opposed to engineering each component on their own. This will be a win-win for everyone as it will bring prices down and bring LEDs to applications never seen before.
Q: Are warm color LEDs technically more difficult [to make] than cooler colors? My family has noticed that "warm" LEDs are less yellow-orange than traditional incandescent bulbs - and tend to have a slight, almost green, tint to them - is this being addressed?
(combined question by celticsolar and SoCalSolar)
A: Warm color LEDs particularly those below 3000k in temperature are indeed more difficult to produce. This has to do with the phosphor mixture that gives LEDs their color. At high power and thermal levels these phosphors tend to shift in color to bluer or cool white color temperatures. This prevents the extremely high powered LED chips to run at warm white color outputs for the time being. LED chemistry is always changing though and these issues are being resolved literally on a monthly basis.
Q: Do you have any interesting new LED bulbs currently in development?
A: We are looking to expand our EvoLux lineup with several key additions in the next few months including a 7 watt version that we hope to introduce and a very attractive price point. Developing wall switch dimmable products are our current focus; we hope to have a full lineup before the end of the year.
Other than this, we have a new line called the Tri-Spectra which you’ll see on our site very shortly. We are also working very hard to develop a great solution to the U-Shaped CFL tubes that are commonly used.
Q: Hi Mark. Thanks for taking questions. Here's a two-part question for you: How does your LED dimming technology work? In general, is there a future for LEDs and dimmer switches working together?
A: Our current dimmer technology (EvoDim) uses a standard light switch or lamp switch to cycle the bulb through three dimming modes. This is accomplished through a microprocessor controlled system. LEDs and dimmers are very much going to be working hand in hand soon. Wall switch dimmable products are in development currently they are a challenge because there are so many different types of dimmers out “in the wild” and we have to ensure our products will work with all of them while at the same time surviving 10+ years of use.
Q: Hi, and thanks for taking questions. I have read that LED bulbs tend to be a more "directed" light source, especially when used in lamps - floor and wall type - for example. More like a spot, than a diffused light pattern. Are you working on bulb shapes, reflectors etc. that if incorporated, might make LED's more attractive for some residential apps?
A: Our new TriSpectra-10 and EarthPAR which you will hearing about shortly address many of these concerns by providing more diffused light patterns. Additionally, we are developing an EvoLux in a PAR38 form factor that takes advantage of some great reflector technology. Our ultimate goal is to have an LED solution for every bulb in the home.
Q: What is on the near horizon regarding increasing the actual brightness / lumens of LEDs?
A: Now that we are over the 100 Lumen per watt threshold we think we will see 150 to 200 Lumens per watt in mainstream products such as our EvoLux by the end of 2009. CREE and the rest of the LED chip makers are in constant development of higher and higher power densities. Our goal is to take the latest advances and put them in the hands of consumers as quickly as possible. When you consider a traditional incandescent is around 15 lumens per watt, we’ve really come a long way in a short amount of time. The next 6 to 12 months should bring some amazing solutions.
Q: LED themselves aren't especially expensive (in my experience) what goes into LED bulbs that increases the cost so much?
A: LED chips are indeed more expensive than traditional discreet LED modules you may have seen in the past. The major driver of cost though is the R&D expense as well as relatively low production volumes to spread these costs across. These are all issues that will be resolved with the development and recognition of LED as a true alternative to incandescent and CFL.
Q: How do you anticipate the costs of LEDs to change over the next few years?
A: Much like the PC industry in its early years we will see rapid declines in costs as volumes increase and components become more commoditized. The industry is also becoming very integrated allowing as mentioned previously, off the shelf shopping for components when you are building a product. We hope to offer something equivalent to our current EvoLux product at a price point under $40 around this time next year.
By 2010 something like the EvoLux should cost under $20 if things keep progressing like they are.
Q: LEDs have a long life span, over 10 years plus, although I've searched through endless manufacturers of LED Lights and the typical warranty period is 1 to 2 years, why is that considering that these bulbs are designed to last much longer?
A: Great question. We understand that this is a point of criticism and it’s something we have taken a close look at. We settled on one or two years initially because there are very few electronics, even those at the high end that offer lifetime warranties. Warranties on incandescent and CFL’s of course are non-existent but we feel that due to the high cost of entry on LEDs consumers are expecting more. With all of this in mind we are currently developing a extended warranty plan that will able to be added at a minimal cost to our products to cover them for their rated lifespan. We hope this will be a fair solution for everyone.
Edited by stins - Thu, 16 Oct 2008 00:25:55 GMT