Street light responding to moonlight
American-based Civil Twilight Collective works with exploring how our built, urban environment can apply natural phenomena in a practical way. One of their ideas is to involve the lunar cycle when lighting up the streets.
The lunar-resonant streetlights will sense and respond to the moon, dimming and brighting according to the particular phase the moon is in. The Civil Twilight Collective states on their website that the project will save energy and lower light pollution, giving urban dwellers a better experience of the lunar cycle.
Great idea, but I wonder if it is efficient enough. Each luminaire is equipped with a photosensor, so I suppose they can adjust for clouds. And the cost of equipping every street light with a photocell, dimmer and LED cluster? Must be high.
August 23rd, 2007 at 8:35 pm
That does sound expensive. The better alternative would be to use an astronomical clock in the segment controller combined with smart ballasts for individual poles, and light sensors. The combination gives you the ability to not only have lunar based output control for the segment, but adjust individual luminaire output to account for hardware degredation or performance variances. The smart ballast would further be able to communicate with the service back-end to provide additional major benefits.
Such an architecture gives delives:
Far better energy management through more granular control of light segments and individual luminaires;
Greater levels of safety (failure notifications in real-time);
Less light pollution; and,
Much, lower operating costs through better inventory management, smarter maintenance scheduling, immediate identification of outages, etc.
Here’s a link to an example of such a system in Oslo -
http://www.echelon.com/solutions/unique/appstories/Oslo.htm
October 8th, 2007 at 12:48 pm
I agree, Steve. Thanks for your input.
I know that Amplex in Denmark has installed a solution similar to the one in Oslo in several Scandinavian cities.
October 8th, 2007 at 7:59 pm
Yes, I can confirm that Amplex has several solutions running. We are covering other parts of Oslo and around 50% of all street light in Denmark and huge portions of southern Sweden.
The echelon solution installed in Oslo has one major problem, the ROI on the system is according to studies done by Danish consultancy companies around 9,5 years with an expected lifetime of 10 years.
November 4th, 2008 at 4:10 am
hello…
Great job. But not enought info. Where can i read more?…
November 19th, 2008 at 12:49 pm
To chineseman:
Thank you for your comment. What are you specifically interested in reading more about?