lunar resonance streetlights

[greenman3610]

http://www.worldchanging.com/archives/006602.html

The winning team, a San Francisco-based design collective called Civil Twilight, landed the grand prize with a project called Lunar-Resonant Streetlights -- streetlights specially designed to "sense and respond to ambient moonlight, dimming and brightening each month as the moon cycles through its phases." The lights would replace standard bulbs with LEDs and a photosensor, which work together to reduce energy consumption by creating only as much light as is needed according to the natural illumination of the moon. They also minimize light pollution by "utilizing the available moonlight, rather than overwhelming it," bringing stars back into the urban skyscape. It's a brilliant integration of a high-tech design and an ultra-low tech natural resource.

[youngdem]

1. This makes far too much sense to ever happen

[Orrex]

2. Very cool in principle

But what happens on partly cloudy nights?

[kiahzero]

5. It's dynamically lit based on ambient light.

On cloudy nights, the ambient light would be less, so the street lights would do more.

[Orrex]

7. But what about intermittent cloudiness?

I don't mean a generally overcast night; if clouds are sporadically passing in front of the moon throughout the course of the night, will the lights keep cycling up and down the whole time? That would be tremendously annoying if I were walking down the street at the time.

[Old and In the Way]

9. That's what the photocell is for.

A photocell cell is really a photodiode...it looks like an LED, but instead of emitting light it collects it. The strength of light a photodiode "sees" is reflected in the voltage signal that it it puts out. That voltage signal can increase or decrease the lighting, depending on how much light the photodiode sees.

This is how streetlights are turned on. When light reaches a certain threshold, the lamp starter turns on. This is a little different in that the moon is not nearly as bright as the sun, so I would think the photodiodes would need to be especially sensitive to moon light level light change. Pretty cool concept, though. There are some nights here when you could walk around without any artificial lighting.

[magellan]

3. Brilliant idea

Saves energy, gives us back a little of our night sky.

[pinto]

4. On a brief read, sounds good. Interesting use of ambient light

to help minimize street light use/energy/costs - long as it pays out.

[SoCalDem]

8. Y'know what pisses ME off?

When I see sprinklers chugging away IN THE RAIN!

Timers need sensors for ambient moisture so they can override a turn-on cycle.

[Canuckistanian]

6. That doesn't make sense

If the lights go brighter when the moon is gone, we'll never see the stars.

Ask any backyard astronomer. Moonless nights are the only time to see dim details in the sky.