Reporting on pedestrian life in the D.C. area

D.C. pedestrians, prepare yourself for a new kind of street light

July 6, 2011 - 11:00 AM
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These solar-powered street lights could be everywhere one day. (Photo: DDOT)

An evening walk is nothing without the right lighting. Cities have long realized the need for good night lights, and street lamps have existed for countless years throughout the 20th century and before. They evolved from kerosene to mercury to the many high-pressure sodium lamps of today. But increasingly cities have been turning to a new source of illumination, one designed to help save power, the environment, and still shed a pleasant glow on your stroll home — the LED street lamp.

"We expect over 1,000 lights to be replaced over the next six months," says Jama Abdi, an electrical engineer who has worked with D.C. street lights for more than 11 years and now coordinates on LED initiatives with two colleagues. "And that's phase one."

The contract for a million dollars' worth of LED street lights slated for D.C.'s alleys goes into effect tomorrow. The contractor will have to assemble materials and various other scheduling elements, but the District Department of Transportation estimates that we might see these first alley lights lit up in about eight weeks or so. The department announced its intentions back in December, goals finally on the verge of reality. The District has 68,000 street lights,comprising a mixture of many different types. These include 60,000 high-pressure sodium lights, 6,570 incandescent ones, and 1,000 mercury-vapor lamps. Concerns over pollution and inefficiency have driven D.C.'s lamp gurus to look toward LED, as other cities have begun doing in recent years, and the new hope is to phase out incandescent and mercury-vapor lamps completely by 2015.

LED, which stands for light-emitting diode, makes sense for many reasons. Utilizing LED lighting in our street lamps would, according to Abdi, save around 50% in energy and maintenance costs. The life cycle of most street lights now is around four to five years, but LED lights are estimated to last around 12.

"LED provides better power, better color — it's a white color," the DDOT engineer explains.

America's 57 million street lights have always evolved, with better and more efficient variations every few decades, as Hal Espen chronicles with touching nostalgia in an Atlantic dispatch this month. Espen evokes the human connection of a warm, welcoming street lamp. The night can carry romance and mystery, and the tone of a street lamp helps define the texture of the darkness and its surroundings. You can't have light without shadow.

How did these broad changes begin in D.C.? The program began two years ago, and as with so many initiatives, it kicked off with a study. Working with the Howard University Transportation Research Center, the city government plotted out how they might integrate LED into the alley lamps. They had acquired a million-dollar grant to do so via American Recovery and Reinvestment Act. Another study launched this year to consider how to integrate LED into the main street lamps themselves. According to Abdi, the study should be completed over the course of the next six months in 2011. His team is looking at three different sites to test three types of LED lights: the copperhead, for which he's most hopeful, teardrop, and the globe-shaped post-top light. The Department of Energy has funded this new 2011 study with $100,000 to conduct these tests and analyses.

We are testing new solar and wind powered LED streetlights. Check it out! than a minute ago via Twitpic Favorite Retweet Reply

Plans don't stop there. Abdi told me his team is investigating other ways the District could save money and enhance street lights through "remote-control intelligent monitoring" that would better determine when any lights might go out or require maintenance. Perhaps most intriguing, the District has begun to experiment with one LED street light that's powered by the wind and the sun. The one experimental light was installed in front of the DDOT office at 55 M St. SE earlier this summer after department officials visited a lighting conference that featured these solar- and wind-powered designs. Last week, department spokesman John Lisle tweeted the photo above to showcase the new light. They're still testing to see how the special system could work — if the structure is unable to receive much sun on a given day, for instance, would the light still receive enough wind power? The current design fails to receive enough wattage (it only allows up to 70 currently), but Abdi says the experiment is working well and that he's very hopeful that it could eventually become integrated into broader city plans.

The big challenge in expanding the use of LED lights? Standardization, according to Abdi. But that'll resolve itself as more cities add the new technology.

"LED is the future of lighting," Abdi says.

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