LED's starting to replace traditional light bulbs

[BT Technologies]

Here is a article from CNN. The question is how are LED's going to effect us as city dwellers from a light pollution prospective? Cities could have installed effective shielding years ago and reduce the wattage of the bulbs with efficient luminares. Now all of a sudden LED's are the "answer" to saving money?

DETROIT, Michigan (AP) -- How many Ann Arbor city workers does it take to screw in a light bulb?
Soon, none.
Instead, they will be installing light-emitting diodes, or LEDs, to replace about 1,400 street lights.
The eco-friendly city about 30 miles west of Detroit says it will be the nation's first to convert all downtown street lights to LED technology, which uses less than half the energy of traditional bulbs and could save the community $100,000 a year.
"LEDs pay for themselves in four years," said Mayor John Hieftje, who announced the city's plans this week as it joined Raleigh, North Carolina, and Toronto in the LED City initiative, an industry-government group working to evaluate, deploy and promote LED lighting.
"They provide the same light, but they last 10 years. We had to replace the old ones every two years."
LEDs, small chips usually encased in a glass dome the size of a matchstick head, have been used in electronics for decades. They usually gave off red or green light, but a scientific breakthrough in the 1990s paved the way for LEDs that produce white light.
Lighting consumes 22 percent of the electricity produced in the United States, according to the U.S. Department of Energy, and widespread use of LED technology could cut consumption in half.
Hieftje said Ann Arbor's lighting conversion will reduce the city's production of carbon dioxide and gases that contribute to global warming in an amount equal to taking 400 cars off the road.
The two-year project is being funded by a $630,000 grant from the city's Downtown Development Authority.
Greg Merritt, director of corporate marketing at Durham, North Carolina-based Cree Inc., which is making the components inside Ann Arbor's new lights, acknowledged LEDs can be costly. But "as we improve the technology, the economics make sense for more and more applications," he said


Any comments on this??

[budguinn]

Interesting.....I have been buying my flashlights with LED's...they work forever on a set of batteries.
Also, most of the recent solar lights that I have purchased are also LED....and the low voltage lighting leading to my OBS is also LED.
But, as you pointed out, unless they are properly installed...with the proper shielding to keep the light on the ground...it won't reduce the lp that much....but then the purpose of the article was talking about energy savings. It will take some time to teach people about light pollution...one of the reasons I moved to an area that doesn't have that many people.

[BT Technologies]

My main concern Bud is that the cities around the country will simply swap out their standard bulbs and install the newer brighter LED's without changing the fixture or luminare.

How hard is it for cities or municipalities to learn to direct the light at the ground where it is useful rather than scattering it everywhere??

Originally Posted by budguinn

Interesting.....I have been buying my flashlights with LED's...they work forever on a set of batteries.
Also, most of the recent solar lights that I have purchased are also LED....and the low voltage lighting leading to my OBS is also LED.
But, as you pointed out, unless they are properly installed...with the proper shielding to keep the light on the ground...it won't reduce the lp that much....but then the purpose of the article was talking about energy savings. It will take some time to teach people about light pollution...one of the reasons I moved to an area that doesn't have that many people.

[herbhighstone]

Hello to all the folks --

Can I ask if any forum members have tried the new, high-power LED's in optical testing devices? It seems to me that a streetlight-power LED could provide extremely bright Foucault images. This would enable shorter camera exposures, and would thus reduce image blurring due to air currents and vibrations.

Previous objections to using bright LED's in testing devices were connected with complaints about excessive brightness directed at the users' eyes. However, most of us now use video cameras and digitial imagers of various kinds to capture our optical test images, so surely our eyes are no longer in danger.

The Surplus Shed sometimes offers extremely bright LED's for sale.

Best wishes from Herbert Highstone