Wednesday, August 25, 2010
The program, funded by the Department of Energy, is designed to figure out the best way to wring out energy savings by using new technologies.
The plan is to combine energy monitoring systems with LED lights, plus appliances that react to conditions on the electric grid and solar panels.
GE said it hopes that its efforts can reduce home energy use by 70 percent.
The project will also evaluate how whole neighborhoods can benefit from the technology.
New and existing homes in Sacramento and Phoenix will also be part of the project.
By Onell R. Soto, UNION-TRIBUNE
Tuesday, August 24, 2010
As competition for LED lighting expands, new Habitat for Humanity homes for low-income people are benefiting. One such house broke ground this weekend in Durham, N.C., that will have only LED fixtures.
Cree, a Durham-based manufacturer of LED lighting, is sponsoring the home's construction to showcase its energy-efficient lighting, which it estimates will save $250 worth of electricity each year. The house, expected to be completed in October 2010, is part of Cree's $1.5 million pledge to provide its CR6 LED downlights for the kitchens of all new Habitat homes built in the USA in the next three years.
Monday, August 10, 2009
Energy efficiency of light sources can be characterized in several different ways. Luminous efficacy indicates how much light the source provides per watt of electricity consumed. This is stated in lumens per watt (lm/W). Another measure of energy efficiency is the total watts a device consumes in providing the intended service. Both measures are important to consider. For example, an LED-based refrigerated display case light has lower lumens per watt compared to linear fluorescent systems, but uses about half the total watts to provide the necessary lighting.
Lighting quality is a subjective term, but generally includes color quality (including appearance, color rendering, and color consistency); illuminance levels (the amount of light the light source provides on a task or surface); photometric distribution of the light source in a fixture or luminaire; lifetime; ease of maintenance; and cost.
This section is designed to provide useful information for energy efficiency program sponsors, utilities, government agencies, lighting fixture manufacturers, lighting designers, and others who are interested in energy-efficient lighting technology.
* LED Basics: This section provides basic information on how LEDs work, and explores important technical issues (energy efficiency, color quality, lifetime, thermal management) in greater detail.
* LED Applications: Learn more about using LEDs for recessed downlighting, undercabinet, and portable desk/task lighting applications. Information on additional applications will be added to the site over time.
* LED Measurement: This section provides information about measurement protocols and test procedures that are currently being developed or revised to accommodate specific attributes of LEDs.
Sunday, February 15, 2009
Professional conferences always have refrains, leitmotifs that begin to define the thrust of many of the discussions. One of the popular ones at last week’s Solid State Lighting Conference in San Francisco was, “We don’t want to screw up like we did with compact fluorescents.”
The point was that when compact fluorescent bulbs first hit the market, they were poorly engineered, overpriced and oversized alternatives to traditional light bulbs. They buzzed, created harsh light, took 30 seconds to warm up, and didn’t last as long as promised.
The trick is how to avoid that problem with LED lighting, the technology that many believe will eventually replace most other lighting technologies in office buildings and homes.
As I’ve noted before, there is already plenty of LED junk for sale in the nation’s home improvement stores. Many products use significantly more power than they claim and last a fraction of the time they advertise. At the conference, lighting designers chimed in to say that they rarely found LED products that performed properly.
“Some LED products are only delivering 30 percent of the illumination that they claim,” said James Brodrick, the Department of Energy’s solid state lighting head.
To stem the disaster of a potential consumer backlash against a technology that, done right, could have major positive environmental impacts, the D.O.E. is bringing LED lighting products into its Energy Star program.
Those products that get Energy Star certification will have to perform according to a set of Energy Department guidelines, as to the amount of light they produce and their effective life.
A handful (but just a handful) of products have received the Energy Star imprimatur. But Mr. Brodrick thinks he’ll have up to 300 LED certified products by the end of the year.
If his agency pulls it off, it could help provide a comfort level for consumers concerned about new technologies. It’s just too bad there’s no Energy Star certification for price. With early LED replacement lamps priced at $60 a pop, the industry could use one.
By Eric A. Taub "The New York Times"
Monday, February 9, 2009
In our wired, Western world we take electricity for granted. Blackouts cause chaos.
It's a far cry from the small villages in Nepal to which Jacqueline, 17, and 10 other Canadian teens will trek this spring. The youngsters will deliver solar panels, batteries and high-efficiency LED lights and wiring to villages so cut off from the world they have no electricity.
The Himalayas are a natural barrier that prevents the import of electricity.
"They don't have proper infrastructure; they don't have electricity. They only have kerosene lamps," Jacqueline explained.
"These kerosene lamps are fire hazards, health hazards and they are environmentally unfriendly," she said.
The trip is under the auspices of Light Up The World, a non-profit Alberta-based organization that delivers solar-powered and hand-generated LED lighting to developing nations. It has so far lit up 17,000 homes in 50 different countries.
"It isn't good for children to sit at home and work with kerosene lamps," Jacqueline said. She points out Nepal has a literacy rate of just 42% -- one of the lowest in Asia.
Light Up The World is the brainchild of University of Calgary electrical engineering professor, Dr. Dave Irvine-Halliday. Ever since his first trip to Nepal in 1997, he has made it his mission to bring safe lighting to remote parts of the world.
Nepal was his first project. Since then, the organization has expanded to 17,000 homes in 50 countries worldwide. It estimates that 2 billion people around the world have no access to electricity.
Aside from Nepal, they have projects in Tibet, Papua-New Guinea and parts of Africa.
Along with Jacqueline, who's from Toronto, students from the Yukon, Nova Scotia as well as from London, Ont. will fly to Kathmandu at the beginning of April to start their climb. From there, they will fly to Nepal's second largest city, Pokhara, and transfer to Thare Khola to begin the trek.
The group are all students at Neuchatel Junior College in Switzerland. The aim is to light up three villages. They'll spend 11 days trekking through the remote Annapurna sanctuary of Nepal hauling not just the lights but their hiking gear to an elevation more than 4,100 metres. The region is so isolated, it was cut off from the world until 1956. They'll be accompanied by guides from Canadian Himalayan Expeditions. The youngsters will also help install the lights.
Part of the project requires the students to raise money.
They're aiming for a total of $50,000. Toronto businessman John Bitove was so impressed by Jacqueline's pitch that he's pledged his support. But they need more people like him to help them out.
The young people hope to take along two Nepalese students, so they need to do some extra fundraising to pay for their expenses.
It will be a learning experience for the Canadians, too. Jacqueline hopes also she will be able to learn more about the rich culture of Nepal. And she's already in training for the hard climb, which she knows will be physically challenging.
"We hope we can reach out to the people of Nepal," she says.
"If they take advantage of these lights and excel in reading because of it, then we feel we have achieved something," she said.
You can donate to the trek on the Light of the World website. Go to www.lutw.org/home.htm and click "Donate now." If you mention Neuchatel Junior College, your donation will be directed to the Nepal trek. Or you can mail cheques to LUTW at 500, 340-12 Ave., SW, Calgary, Alberta T2R 0H2.
PAYING THEIR WAY
The students are paying their own way, so all the money raised will go to purchase lights and batteries.
There's a Chinese saying that it is better to light one candle than curse the darkness. Jacqueline and her friends are taking it one step further.
With their batteries, lights and solar panels, they're hoping they can light up three villages -- and chase away the dark shadows of illiteracy for children a world away.
By CHRISTINA BLIZZARD, SUN MEDIA
Sunday, February 1, 2009
LED lights are a technology that most EcoGeeks are hoping to see in widespread distribution. LED lights can be even more efficient than compact fluorescent lights, and they don't contain mercury like CFLs do. LEDs also have a much longer lifespan, and can operate for 10 times longer than fluorescents and 100 times longer than incandescents. They're just still a little expensive, up to $100 / bulb.
One problem with producing LEDs is that the substrate typically used for LEDs is sapphire, rather than silicon, which can be used for many other semiconductors. Many LEDs are made from gallium nitride which is grown into crystals at a temperature of around 1000 C (1832 degrees F). Unlike other electronic components, which can be fabricated on a silicon base, gallium nitride shrinks faster than silicon when it cools, which leads to cracking and failure. Sapphire has a rate of shrinkage and cooling that closely matches the LED compounds, which makes it a suitable substrate.
The University of Cambridge team's development is a method to make LEDs incorporating aluminum gallium nitride, which shrinks much more slowly as it cools, and allows the production of LEDs on silicon wafers like other components. "A 15-centimetre silicon wafer costs just $15 and can accommodate 150,000 LEDs making the cost per unit tiny."
With the commercialization of this process, inexpensive LEDs may become available, and a superior alternative for lighting can help save billions of kilowatt hours of electrical demand.
via: New Scientist