Citizen Will

Wed 21 Mar 2007

6 Responses to “Raleigh LEDs the Way”

1. anthony barbuto says:

   March 21, 2007 at 3:22 pm

   LEDs will be the future in auto lighting. To hear talks from OEMs and lighting companies, and see examples of lightint systems…. attend the 3rd Automotive Lighting Design & Technologies conference, hosted by my company IQPC,,,,,May 21-23 2007 in dearborn MI. SEATING is LIMITED……contact me for a flyer and registration information…..Anthony Barbuto, Delegate rep for IQPC, anthony.barbuto@iqpc.com……
2. Terri says:

   March 21, 2007 at 5:37 pm

   Don’t accept what the N&O says about the difference in energy efficiency. The comparisons in energy consumption between LED and CFLs are close to equal. Raleigh’s current parking deck project is comparing LEDs with low-sodium fixtures. The lighting is much better and safer with LEDs and the maintenance costs are much less so a life cycle cost analysis weighs in favor of LEDs even if they aren’t much more efficient. That said how efficiency is measured differs between fluorescents, low sodium, etc. and LED since LEDs gradually lose brightness but rarely fail completely.
3. Administrator says:

   March 22, 2007 at 11:56 am

   Terri, the efficiency and performance have improved greatly. As I noted above, I’m a Cree investor – I get notices like the below because of that:

   DURHAM, NC, MARCH 1, 2007 — Cree, Inc. (Nasdaq: CREE), a leader in LED solid-state lighting components, today announced that Guangzhou Multi-Cell Semiconductor Lighting Technology Co., Ltd. (Multi-Cell) is installing energy-saving, solar-powered streetlights based on Cree’s award-winning XLamp XR-E power LEDs. Multi-Cell is demonstrating its new XR-E LED-based streetlight product with a 20-light project in Guangzhou.

   White Cree XR-E LEDs produce typical luminous flux of 80 lumens at 350 mA, yielding 70 lumens per watt, and establish a new lighting class of LED performance. Cree XLamp XR-E LEDs lead the industry in brightness and efficiency.

   “By using the Cree XR-E LED in Multi-Cell’s MZSLB-130 streetlight, we have significantly improved the performance of these products,” said Peng Zhoulong, Multi-Cell general manager. “The Cree XR-E is very bright and efficient but also exceptionally consistent and stable. Its package design is especially beneficial to the mass-production assembly line, providing a streamlined manufacturing process.”

   A bit of a PR piece but the underlying tech is improving and, from what I’ve read, easily surpasses the existing “efficient” mercury lamps.

   From the EPA

   Light Emitting Diode (LED) technology for traffic signals and exit signs offers big energy savings over traditional incandescent lamps. LED signals use less electricity to produce the same amount of light output as traditional traffic signals. Furthermore, the lifetime of an LED signal is more than ten times that of an incandescent bulb signal, reducing maintenance and replacement costs drastically. A third advantage is that LED signals are made up of hundreds of small diodes rather than a single light source, so the signal is less likely to burn out and cause traffic delays or accidents. These factors, combined with technological advances that have driven the cost of LED signals down by 50% in the last few years, make LEDs a logical and cost effective choice. Local governments using this technology are showing short payback periods.

   Improve Streetlight Efficiency
   The City of Charleston is responsible for 8,935 streetlights. Of these, only 1201 are high efficiency high-pressure sodium lights. The remaining 7734 are less efficient mercury vapor lights. High-pressure sodium streetlights use on average 54.91% less electricity than do mercury vapor lights. Implementation of this measure could result in annual savings of $15,673 and in the elimination of 97 tons of CO2.

   You’re right about high pressure fixtures being better. I was pushing the heck out of moving to them 6 6-7 years ago (during my attempts to fix my one streetlight I discovered how crappy our streetlights were – high glare, inefficient, light polluting, etc.)

   Energy Efficient Streetlights

   Responsible Department: Highway, DPW
   CO2 Savings in 2010: 97 tons

   In October of 2001, the town purchased 3,800 street lights from Boston Edison both in order to improve the level of service to the community and to achieve the benefits that will accompany town ownership. Of the 4,130 lights now owned by the town, 348 are mercury vapor. This measure would encourage the town to convert the remaining 348 to more efficient high pressure sodium technology. High-pressure sodium streetlights use on average 54.91% less electricity than do mercury vapor lights. Implementation of this measure could result in annual savings of $15,673 and in the elimination of 97 tons of CO2.

   Now the LEDs are better than competitive – I’m going to push for them…
4. craig o, iald says:

   April 20, 2007 at 1:23 pm

   The best uses of LED’s right now are for visual indication – where the brightness of the source is the visual task. Traffic lights and automobile lighting is a great example. LED’s have a long, long way to go before they can be successfully utilized for architectural or roadway lighting – lighting systems that direct light onto a surface. As for the metric of “lumens per watt,” white LED’s are gaining on fluorescent and metal halide, but are not comparable yet. And the issue raised by Terri about LED’s never burning out is a huge obstacle right now. As a professional lighting designer, I can’t risk an underlit condition in 15 years due to “lamp lumen depreciation.” The jury is in – if the system doesn’t provide IESNA lighting levels, the designer and Owner are liable for any accidents (or worse) that occur. End of story there. A few manufacturer’s are including a timer that shuts down the system after a certain number of hours based on the theoretical curve of lumen depreciation. That solves the problem but at the expense of the best characteristic of the LED – long long life.

   Also please understand the embodied energy of LED’s is very very high. LED’s are manufactured in a “clean room” which requires high amounts of energy to filter the air. Arsenic and other highly damaging materials are used in the production, and most are shipped across the Pacific Ocean from China. Oh, and when the are finally retired from use, the LED’s and their associated circuit boards are electronic waste.

   The best solution today is to use ceramic metal halide lamps for exterior lighting (mounted in the proper luminaire, of course.) White light, good optical control, good lumen maintenance, and reasonable life.
5. Administrator says:

   April 20, 2007 at 2:22 pm

   Thanks Craig. Are you familiar with RTP’s Cree Research? They produce high lumen, efficient LEDs using a gallium arsenide substrate. Part of the appeal of LED in Chapel Hill is having a local supplier (who, I believe I read either in their proxy statements or in a PR piece, plan to recycle their products). If they do recycle that does take care of part of the e-waste stream.

   You’re a lighting expert, maybe you can illuminate (sorry, I’m a terrible punster) us on the halide degradation curve. Someone told me that halides don’t degrade smoothly over time and that in their end of life they can actually consume more electricity than when they were properly functioning. I took this statement with a tiny grain of salt – is there anything to this?

   Also, as a lighting professional, are you familiar with the International Dark Skies initiative. I took several runs at getting their recommendations merged with our current lighting ordinances (so far to no avail).

   I’ve been around Chapel Hill long enough to remember seeing the Milky Way from the Downtown-side of North Street! Now I have to jump through hoops to get decent views through our Celestron.
6. Terri says:

   April 20, 2007 at 8:47 pm

   One of the problems with using metal halides is the slow degradation of light intensity over time. From walking around on campus, designers are specifying higher output lights to achieve ‘average’ output over time as a result of the degradation.

   I know you own stock in Cree Will, but I’ve been working fairly closely with them for the past several months and they are not vendors. They partner with fixture vendors who handle the sales, marketing, and tech support.