Energy-Efficient LED Lighting Hits the Streets: 95 Percent of Cities Satisfied

| 10/30/2012 11:49:00 AM

Tags: led lighting, led streetlights, high pressure sodium, energy efficient lighting, kale roberts, mother earth news, northeast group llc,

Oct 30 2012 Fotolia/CozytaThere are more than 50 million streetlights in the United States. From parking lots to park trails to bridges, these ubiquitous lights permeate our night lives and go largely unnoticed by the sustainability-inclined city dweller.

But this necessary technology comes with a whopping energy cost. A 2009 University of Pittsburghstudy shows most streetlights use high-pressure sodium bulbs (also referred to as sodium-vapor lamps), which emit a gaseous form of sodium in an excited state to produce light. Considered efficient, a typical sodium streetlight will use a 70- to 150-watt bulb, increasing to 660 w and 1,000 w for very tall applications.

In the past decade, however, energy efficient light-emitting diode (LED) lamps have hit the streets using, by comparison, 58 w to produce a better quality of light with less spillage.

A 2012 survey by Northeast Group LLC was published in October, claiming 95 percent of U.S. cities that have tried LED streetlights are satisfied with the results, saving nearly 60 percent in costs.

Yet, LED lighting currently accounts for only about 1 percent of the streetlights in the country.

The study shows what vendors and other proponents have been trying to prove since the beginning: the cost savings of LED technology are real and so are the benefits.

anumakonda jagadeesh
11/30/2012 4:26:54 PM

Yes. LEDs are the answer for Energy Saving in Lighting. In India still people use inefficient Incandescent bulbs and Florescent lamps rather than CFL and LEDs.Dr.A.Jagadeesh Nellore(AP),India E-mail:

john d. bullough
10/30/2012 8:13:44 PM

I'm not sure the wattages for HPS and LED sources to produce similar amounts of light in this article are correct. Typical HPS streetlight wattages range from 70 W to 400 W. Only for high-mast installations on very tall poles near freeway interchanges will HPS lamps with wattages as high as 1000 W be used, typically. Nonetheless, LEDs are increasing in efficiency and can now exceed the efficacies of HPS systems by 10%-20% or even more. But replacing a 600-1000 W HPS with a 180-220 W LED, while obtaining the same amount of light, is not yet (and might never be) feasible.

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