View This Issue - December 2010

Choosing between LED and HPS street lights

Many municipalities are weighing the benefits of both LEDs and high-pressure sodium (HPS) as they consider their street-light options. The Lighting Research Center’s National Lighting Product Information Program (NLPIP) formally performed an “apples-to-apples” evaluation of existing street-lighting technologies as detailed in its September 2010 publication Specifier Reports: Streetlights for Collector Roads.

Streetlights: LED or HPS?
Established by the Lighting Research Center (LRC) in 1990, NLPIP has helped lighting professionals, demand-side management providers, contractors, designers, building managers, homeowners, and other consumers find and effectively use quality products that meet their lighting needs.

The program has a demonstrated history of transforming the market and upgrading the quality, reliability, and energy-efficiency of lighting products by providing objective, third-party information to verify product performance compared to manufacturer claims.

As is the case with all NLPIP publications, Specifier Reports: Streetlights for Collector Roads was designed to tell a story in an objective way. The report was widely publicized [see links to LEDs Magazine articles under Related Stories at right], but many third-party summaries and interpretations were misleading, so hopefully this article will clarify a few key points.

Process

To emulate the streetlight selection process used by typical specifiers, NLPIP purchased and analyzed eight LED streetlights that were recommended by manufacturer representatives as equivalent to an incumbent technology, namely a 150W HPS streetlight with a Type III distribution.

Much to NLPIP’s surprise, all six of the LED manufacturer representatives recommended streetlights with lower light output than the incumbent HPS technology. However, in order to most closely follow the typical specifier selection process, those were the street lights NLPIP purchased and evaluated.

NLPIP analyzed the pole spacing needed for the streetlights to meet a national roadway lighting standard for collector roads, ANSI/IESNA RP-8. NLPIP then compared the streetlights’ power demand and economic costs over a one-mile stretch of roadway.

Results

The report concluded that, on average, the recommended LED streetlights could use up to 10% less power, however, their life-cycle costs were higher. The LED street lights recommended by the manufacturer representatives would cost more than twice as much to own and operate as the incumbent technology over the life of the streetlights, primarily because the LED street lights required narrower pole spacings to meet the recommended practice for illuminating collector roads, and the cost of the poles per mile dominated the life cycle costs.

A recent addendum to the original report examined LED street lights that could match the pole spacing provided by incumbent 150W HPS street lights. The results of the life cycle cost analyses are summarized in the chart below.

Estimated life Average life cycle cost per mile of recommended LED streetlights Average life cycle cost per mile (excluding poles) of the "higher power" LED street lights
25,000 hours (6 years)2.6X incumbent 150W HPS2.3X incumbent 150W HPS
50,000 hours (12 years)2.1X incumbent 150W HPS1.7X incumbent 150W HPS

The results of these analyses reinforce the fact that specifiers need to evaluate all available products, regardless of the technology, to provide their customers, as well as society, with the greatest lighting value.

In many ways the LRC is grateful for the attention given to this report, because the overarching goal of NLPIP is to provide objective information to those specifiers. Without that attention, many specifiers would have remained unaware of these findings.

Results Summary

To meet the collector-road lighting criteria, NLPIP found that when compared to HPS, current LED street lights:

• can save a modest amount of energy, and

• usually have a greater life cycle cost, with or without the need for new poles

Also, be aware that manufacturer representatives may recommend street lights that are not equal in performance.

RELATED COMPANIES

Guardian Industries

Guardian Industries Corp. is a leader in float glass, fabricated glass and high performance coated glass products. Guardian lighting solutions deliver optimal performance, flexibility and...

LTF LLC

LTF, LLC is a U.S based solid-state lighting product development and manufacturing company with facilities located in both USA and China.

Illumination Machines

Illumination Machines designs custom optics, heat sinks, and remote phosphor systems for LED luminaires and lamps.

RELATED PRODUCTS

P3 Indoor Full Color LED Display Video screen

High-density pixel pitch,high resolution,high refresh rate,magnificent and high-definition image and video effect.P3,P5,P6,P7.62 to P10 available.Epistar SMD LED,wide viewing angle.High r...

Rotatable LED Down Light, beam angle adjustable 10-60°

Beam angle adjustable 10-60 degree.Shell can rotate 360°,vertical 0-40°.High power CREE LED,even and uniform light output,Die casting aluminum alloy housing,good heat sinking.Widely used ...

LED Panel Light

Designed to replace T8 fluorescent tube or Phillip Grille light.Epistar 3528/3014 SMD LED.Aluminum alloy body.Even and Soft light beam.Various mounting means.50,000 hours lifetime.Environ...

TOPIC INDEX

CONNECT WITH US

                

SOCIAL ACTIVITY

UPCOMING EVENTS

  • List View

NEWSLETTERS

LEDs Magazine Newsletter

Our weekly flagship news source
SUBSCRIBE

Product Focus

Monthly newsletter
SUBSCRIBE

Illumination in Focus

Bi-monthly newsletter
SUBSCRIBE

  •  
  •  
  •  
Copyright © 2007-2014. PennWell Corporation, Tulsa, OK. All Rights Reserved.