faces of the future - Illuminating Engineering Society

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LRC Specifier Report
NLPIP Study Questions Effectiveness of
LED and Induction Streetlights
LED and induction streetlights may be popular alternatives
to traditional high-pressure sodium (HPS) streetlights,
but they may not be better options. According
to a new study from The National Lighting Product
Information Program (NLPIP) at Rensselaer Polytechnic
Institute’s Lighting Research Center, it may take more
LED and induction streetlights than HPS streetlights to
meet necessary design criteria.
In the study, NLPIP performed photometric
evaluations of 14 streetlights
that used either HPS, pulse-start metal
halide (PSMH), induction lamps or LED
modules. It 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).
The NLPIP found that if LED or induction streetlights
replaced the pole-mounted HPS streetlights, it would take
twice as many of the streetlights to meet the lighting criteria
as defined in RP-8-00. Additional findings included:
• On average, the LED streetlights and the induction
streetlight could be spaced only about one-half the
distance of the HPS and PSMH streetlights and still
meet the RP-8 lighting criteria. If an HPS or PSMH
streetlight system just meeting RP-8 is replaced with
the LED or induction streetlights tested in this report
on a one-for-one basis, the streetlight system will
not meet RP-8.
• The life-cycle cost per mile is dominated by the initial
and installation cost of the poles, not the initial cost
of streetlights or any potential energy or
maintenance cost savings. Because of the
narrower pole spacing required to meet
RP-8, the life-cycle cost of the LED streetlights
tested for this study is up to twice that
of the HPS and PSMH streetlights tested.
However the study acknowledges that:
• On average, the LED streetlights require
between 1 percent and 10 percent less
power per mile than the HPS streetlights
tested in staggered and single-sided layouts,
respectively. On average, the LED
streetlights require between 8 percent and 24 percent
less power than the PSMH streetlight tested in singlesided
and staggered layouts, respectively.
• At the illuminance levels typical of collector roadways,
power requirements for “white light” sources
are 3 percent to 19 percent lower than HPS sources
based on models of mesopic photometry.
The NLPIP’s finding were published in a Specifier
Report, which is available online at www.lrc.rpi.edu/
nlpip/publications.asp.
NALMCO Certification
More Letters in the Alphabet Soup
Move over LEED, the newest sustainable certification program is all about lighting. The interNational Association
of Lighting Management Companies (NALMCO) has announced its new certification—Certified Sustainable Lighting
Consultant (CSLC)—the industry’s first “sustainability certification” for lighting professionals. The certification can be
earned through an exam that tests 10 areas of knowledge, touching on such topics as materials, recycling, transportation,
light pollution, manufacturing and other environmental impacts. Only individuals who are already Certified
Lighting Management Consultants, another NALMCO certification, are eligible to take the exam.
16 www.ies.org