Featured Research

from universities, journals, and other organizations

New report on street lighting technologies

Date:
September 30, 2010
Source:
Rensselaer Polytechnic Institute
Summary:
A new report designed to provide objective performance information on existing street lighting technologies -- including light-emitting diode (LED), induction, and high pressure sodium (HPS) streetlights has just been published. This report comes at a critical time when many municipalities, some with funding from the American Recovery and Reinvestment Act of 2009, are in the process of replacing HPS streetlights with LED and induction models.

The National Lighting Product Information Program (NLPIP) released its latest Specifier Report, designed to provide objective performance information on existing street lighting technologies including light-emitting diode (LED), induction, and high pressure sodium (HPS) streetlights. This report comes at a critical time when many municipalities, some with funding from the American Recovery and Reinvestment Act of 2009, are in the process of replacing HPS streetlights with LED and induction models.

NLPIP performed photomet­ric evaluations of 14 streetlights that used either HPS, pulse-start metal halide (PSMH), or induction lamps, or LED modules. NLPIP analyzed the streetlights for light output and distribution, energy use, spectral effects on visual performance, discomfort glare, and economic factors. The streetlights were evaluated as part of installations that meet the lighting criteria as defined in the American National Standard Practice for Roadway Lighting, ANSI/ IESNA RP-8-00 (R2005), for a simulated one-mile stretch of collector roadway (a road servicing traffic between local and major roadways).

According to NLPIP, when replacing the pole-mounted HPS streetlights on a one-mile section of collector road with the LED or induction streetlights used in the study, it would take twice as many of the pole-mounted LED or induction streetlights to meet the lighting criteria as defined in RP-8-00.

Complete performance results are published in Specifier Reports: Streetlights for Collector Roads, which is available online.

"The LED and induction streetlights we tested required narrower pole spacing. As a result, the life cycle cost per mile was dominated by the installation cost of the poles, as opposed to the initial cost of the streetlights or any potential energy or maintenance cost savings, as one may assume," said Leora Radetsky, LRC lead research specialist, principal investigator and author of the report.

LED and induction technologies are often marketed as money saving alternatives to HPS, with some manufacturers claiming reductions in energy and main­tenance costs. However, NLPIP found that the HPS and PSMH streetlights evaluated in this test provided a better cost value than the LED and induction streetlights evaluated, which would need to produce about the same street-side lumens as the HPS models to be economically competitive.

The average power demand of the LED streetlight layouts evaluated was slightly lower than the average power demand of the HPS streetlight layouts, but there was wide variation among LED models, according to NLPIP.

Mesopic Vision

The human visual system uses two types of photoreceptors, cones and rods, found in the retina. Cones are used to process visual information under daytime or "photopic" light levels, while rods work under completely dark "scotopic" conditions. There is, however, a range of light levels called "mesopic," where both cones and rods together provide input to the visual system. Mesopic light levels are typically found outdoors at night. However, commercial photometry is based entirely upon the photopic luminous efficiency function, which considers how the eye "sees" during daylight hours. As a result, conventional photometry may misestimate the effectiveness of some light sources used in nighttime applications in terms of energy efficiency and visual performance.

NLPIP notes that, at the illuminance levels typical of collector roadways, "white light" sources such as LED streetlights could be slightly dimmed and provide equal levels of visual performance, based on mesopic photometry. However, in the collector roadway scenario used in this study, the reduced power requirement would have little impact on the life cycle cost per mile described above.

Report.


Story Source:

The above story is based on materials provided by Rensselaer Polytechnic Institute. Note: Materials may be edited for content and length.


Cite This Page:

Rensselaer Polytechnic Institute. "New report on street lighting technologies." ScienceDaily. ScienceDaily, 30 September 2010. <www.sciencedaily.com/releases/2010/09/100930154612.htm>.
Rensselaer Polytechnic Institute. (2010, September 30). New report on street lighting technologies. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2010/09/100930154612.htm
Rensselaer Polytechnic Institute. "New report on street lighting technologies." ScienceDaily. www.sciencedaily.com/releases/2010/09/100930154612.htm (accessed September 17, 2014).

Share This



More Matter & Energy News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) — MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com
Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) — Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com
Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Reuters - US Online Video (Sep. 15, 2014) — New York officials unveil subway tunnels that were refurbished after Superstorm Sandy. Nathan Frandino reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins