DEC 19

It's neat to see the 'green' movement stretching to such innovative territory. Not only are these lights more environmentally friendly but they are also more practical and effective. I think it is particularly important for us, as consumers, to support ‘green’ business. For example, http://www.simplestop.net stops your postal junk mail and benefits the environment.

It would be interesting to come up with a design that dims (turns off most LEDs) when no-one is present, with a pedestrian/car detector to turn the lights on. The streetlights could be linked by wireless to light up sections of streets on demand. It seems like the power bill could be cut in half that way-- maybe more outside a big city.

Any specs on the Color Rendering of these lights? I mean compared to low pressure sodium it can only be the same or better, but high pressure sodium or metal halide HID lamps have made some great strides in color rendering. LEDs have very sharp color spikes, which make their color rending low. Also as an array, they cast odd shadows (hundreds of points of light, versus one). This I can imagine as an issue for public safety. Many cities went to Metal Hallide lamps in their street lights to be able to better identify night time activity. Doesn't help is a blue car looks black, like under a sodium lamp, since those lights tend not to project that portion of the visible spectrum. Without combining multiple colors of LEDs into the fisture I would imagine there are similar issues. Also, I know I don't like the LED christmas lights because of the color white and sharp colors they produce, versus the warmer, broader spectrum light of traditional incandescent, I wonder if these will cast the same cold glow and how the will affect the city in reaction to that phenomenology.

Perhaps the biggest savings from using LED lighting comes from the fact that they last so long. The cost of a replacement bulb is small compared to the cost of the ladder or boom truck, crew, fuel, and overhead in CHANGING that bulb. With LED's lasting 10's of thousands of hours, the maintenance costs (taxpayer money) should be lower.

Now if only we saw some "Made in USA" incentive for making more LED's here. My 2000 holiday lights use less than 100 watts of power, but (Damn it) they're all from China. I bought LED's when the price was 5x the cost of traditional (4-5 years ago), and I'd buy US made LED strings if I could find them.

In answer to CRI, I heard that these new lights will be able to change color from a warm white when over a sidewalk to a cool white when over a roadway. They will be able to upgrade to cool features like light dimming as well. I doubt whether they will be turned all the way off though considering New York's crime issues.

That would be great for robbers

They should also be dimmed when the street is covered with snow.

Streets are overlit in general and I have heard illumination has little effect on actual safety from muggings etc... only the perception of safety...

There are some places in Europe that have roadway lighting that dim. Traffic sensors detect the amount of traffic and dim sets of roadway lights as needed. Philips, I think is one leader in that area. They presently use HID type lights for this. Philips CosmoWhite CHM (Ceramic Metal Halide)and CosmoGold HPS type lamps. There would be no reason that this couldn't be utilized with LED or even the newer Luxim LIFI STA-40 Plasma lamps.

GoSolar,

I agree with you that there needs to be more companies that produce L.E.D.'s in the United States. There has been a large amount of money in the stimulus package for cities to purchase L.E.D. streetlights. The money needs to stay in the US.
www.millenniatechnologies.com

I like this idea. I know some businesses are using lights that are WAY overpowering to light up their vacant buildings at night. Such a distraction.