Environment

Intelligent street light system uses 80 percent less electricity

Intelligent street light syste...
An experimental energy-saving streetlight system automatically dims the lights when no people or moving vehicles are in the area (Image: TU Delft)
An experimental energy-saving streetlight system automatically dims the lights when no people or moving vehicles are in the area (Image: TU Delft)
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An experimental energy-saving streetlight system automatically dims the lights when no people or moving vehicles are in the area (Image: TU Delft)
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An experimental energy-saving streetlight system automatically dims the lights when no people or moving vehicles are in the area (Image: TU Delft)

Of all the energy-saving tips out there, probably the one we hear most often is to not leave lights on when we leave a room. It's good advice, yet cities around the world are not following it in one key way - their streetlights stay on all night long, even when no one is on the street. The Netherlands' Delft University of Technology is experimenting with a new streetlight system on its campus, however, in which motion sensor-equipped streetlights dim to 20 percent power when no people or moving vehicles are near them. The system is said to reduce energy consumption and CO2 emissions by up to 80 percent, plus it lowers maintenance costs and reduces light pollution.

Delft Management of Technology alumnus Chintan Shah designed the system, which can be added to any dimmable streetlight. The illumination comes from LED bulbs, which are triggered by motion sensors. As a person or car approaches, their movement is detected by the closest streetlight, and its output goes up to 100 percent. Because the lights are all wirelessly linked to one another, the surrounding lights also come on, and only go back down to 20 percent once the commuter has passed through. This essentially creates a "pool of light" that precedes and follows people wherever they go, so any thugs lurking in the area should be clearly visible well in advance.

The lights' wireless communications system also allows them to automatically notify a central control room when failures (such as burnt-out bulbs) occur. This should make maintenance much simpler, as crews will know exactly where to go, and when.

Some fine-tuning is still ongoing, in order to keep the lights from being activated by things like swaying branches or wandering cats. In the meantime, Shah has formed a spin-off company named Tvilight to market the Delft technology. He claims that municipalities utilizing the system should see it paying for itself within three to four years of use.

14 comments
Roy van den Heuvel
It\'s a nice project, I remember the TU/e (University of Technology Eindhoven, Netherlands) is also doing the same kind of project on intelligent street lighting. I\'m not sure about the ready-for-market status, but here\'s the link anyway. http://www.tue.nl/onderzoek/instituten-groepen-scholen/top-research-groups/intelligent-lighting-institute/research-programs/roadlighting-2015/
Carlos Grados
I love this idea!
Mr Stiffy
Well it\'s an excellent idea to the usual \"Oh Duh\" kind of broad ranging, bad, and wasteful habits.
Renārs Grebežs
It\'s a great idea. The only downside is that most streetlights use high-pressure sodium bulbs, which need about 1-3 minutes to fully light up. The ignitor uses a 3-5kw spark, which would be pretty bad for the grid. So, I guess the project initiators use a different kind of bulb - what about the bulb\'s efficiency?
dsloan48
As a start . . this would be a great idea for our local school systems . . the electric utilities should be made to install these in every school parking lot . . of course the savings would pay for the equipment . . so the utilities would break even while not having to provide for extra capacity and our school boards would reduce the lighting bill . . . and hopefully pass on the savings in lower property taxes.
Doug MacLeod
Reminds me of trying to walk past the houses of security-mad people with sensor operated lights where I used to live. It made walking the dog unbearable as you were constantly assaulted by lights illuminating as you passed. It was like being on stage with a follow spot trained on you. It also ruined your night vision for about fifteen minutes each time one went on. A highly unpleasant idea. Do what I do in the countryside: buy a torch for about one pound/euro/dollar and take it with you. Cheap and cheerful, saves the planet and works fine. Street lighting is of more use to criminals than anyone else anyway.
mojojirz
Street lights around here (South-East Wisconsin) have started to convert to LED rather than the sodium bulbs.
dsiple
Los Angeles is changing over all street lighting to LEDs. The one in front of my house is almost too bright, so I\'d be all for this. They say they\'re working out problems of cats, branches, etc., but I wonder about prowlers movements.
AB
Excellent idea. Its already in use at a much more basic level in our apartment. We have motion sensors to activate a 22W CFL in floor lobbies on all floors and staircase. In the absense of any motion, when the 22W CFL is OFF, a 5W CFL is always lit up. Prior to this energy saving setup, we had 2x22W CFL on all floors lobbies and staircase. These lights were switched-on at 6:00pm and switched-off at 6:00am daily. Considering that people movement is present between 6:00pm to 12 midnight max, we end up saving considerably. Since LED lights were very expensive, CFL were used.
Adrian Akau
It sounds like a good idea but I don\'t know if it is. What if a criminal should hide and remain still. The lights would dim and then the unsuspecting person might walk into a trap thinking that all was safe.