As sustainability and energy efficiency requirements continue in relevance to lighting installations the question of being able to assign an efficiency rating to public lighting installations (A through to G) requires consideration. This paper looks at how the application of an energy efficiency rating can be considered for road lighting and will reference work undertaken in Spain, the Netherlands, and Australia as well as within the EU under their Directives and good practice guidance. It also considers the requirements for measuring the energy performance of road lighting installations as laid out in the draft Standard prEN13201-5:2013, Performance requirements. Talk by Allan Howard, WSP | Parsons Brinckerhoff

1. Allan Howard
Eng.(Hons) CEng FILP FSLL
Technical Director (Lighting)
How effectively can we
apply energy efficiency
ratings to public lighting?
Sept 2015

2. WHY HAVE AN ENERGY RATING?
2
 Everyone likes and understands a label
 Energy consumption is high profile
 Looking to achieve the required Standards
 Utilisation of the most efficient technologies
 Ability to identify similar installations and compare efficiencies

3. THE PROBLEM
3
 Many household electrical items such as cookers can easily be scored and
assessed in terms of energy rating.
 A lighting installation is made up of a range of components and equipment
that have differing energy consumptions and optical and operational
controls
 Public lighting installations are lit based upon the:
 Lighting class required
 Authority policy
 Applications of Standards
 Range of light sources used
 Efficiency of the luminaire

4. WHY HAVE A RATING?
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 Pr EN 13201-5:2013 outlines sound calculation principles for determining
key energy efficiency parameters
 Power density, installation efficacy, and
 Annual energy consumption indicator
 How do we use them?
 Their usefulness as a comparative tool for the full road design is evident;
but this standard alone does not lay out clear indication of a minimum
performance level to be achieved by the lighting design
 Adoption of a road lighting design efficiency grading scale would be a
powerful tool

5. REINFORCEMENT
5
 Pr EN 13201-5:2013: Part 5: Energy Performance indicators
 Power Density Indicator (PDI) (Dp)
 Annual Energy Consumption Indicator (AECI) (DE)
 Seasonal variations of burning hours
 Change in traffic densities / flows

6. REINFORCEMENT
6
 System power
 The area within the power density calculation must be the same as the
area used for the lighting calculation
 Sum of the operational power of the light source(s) and associated
control gear / parasitic power

7. LIGHT SOURCES AND LUMINAIRES
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 A vast range of light source and luminaire technologies with various
performances
 Indicator of overall energy efficiency of a luminaire is the luminaire efficacy
rating (LER)
 A measure of total luminaire light output divided by the total luminaire
power input
 HID sources show little significant variety in the performance levels, the
values shown here for any HID technologies are fairly indicative for any
make of lamp
 LED luminaire models however, are packaged within a complete luminaire
and the range of efficacies available is substantial

8. HID AND LAMP SOURCES
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Source Light Naturally 2014

9. LED LUMINAIRES
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Source Light Naturally 2014

10. ENERGY PERFORMANCE REQUIREMENTS
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 Several countries have moved to establish minimum energy efficiency
performance requirements (MEPS) into their road lighting standards
 The energy efficiency component is contingent on the road lighting design
first meeting relevant minimum illuminance / luminance requirements of the
road lighting category
 The onus being the lighting designer to choose efficient technologies that in
conjunction with the luminaire optics provides a satisfactory lighting
distribution and satisfy the technical requirements

11. EU APPROACH
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 Pr EN 13201-5:2013 Performance requirements
 The purpose of this standard is to define energy performance indicators for
road lighting installations using a calculated:
 Power Density (D), and
 A calculated Annual Energy Consumption Indicator (AECI)
 Its scope is lamp technology neutral

12. SPAIN
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 ITC-EA-01 Regulation of energy efficient lighting exterior facilities
 Performance standard has been enforced since 2009 by the Ministry of
Industry, Tourism and Trade via Royal Decree 1890/2008
 Energy efficiency measures are enforced by setting a minimum limit for
outdoor lighting installation energy efficiency

13. SPAIN
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 Limit the maximum luminance values or average luminance in installations
due to the reference values.
 It limits the light emission values that contribute to obtrusive lighting
aspects.
 It demands a smart operational system so considers the application of
adaptive lighting approaches

14. NETHERLANDS
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 A voluntary initiative that defines levels of energy efficiency for energy
labels for public lighting installations with the intention of enabling
objectives for saving energy to be specified
 The minimum performance levels outlined in EN 13201-2 must first be
shown to complied with
 The energy labelling is based on the EU standard EN13201-5
 Streetlight Energy Efficiency Criterion (SLEEC)
 SLEEC = Power Density Indicator
 RLE = Road Lighting Efficiency parameter

15. SLEEC
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 Practical values for the SLEEC standard were calculated for various types
of road, lighting class and mounting height to simplify choice of lighting
label
 An upper limit was made in order to stimulate the market, set to 0.01
W/lux/m²
 The lower limit (less efficient than level G) is 0.07 W/lux/m² for illuminance
based road lighting designs, and 10.5 W/(cd/m²)/m² for luminance based
designs

16. SLEEC
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 The merit of using a rating system rather than a single MEPS level is that it
affords much opportunity for comparison of lighting solutions and
incremental improvement
 There will be sections of road that have greater lighting demand such as at:
 Conflict areas and
 Pedestrian crossings
 It will be the case that the illuminance levels for these areas must first be
satisfied as stipulated

17. SLEEC
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 It may be that for a given stretch of road, it might not be possible to achieve
better than a ‘D’ rating, irrespective of lamp technology and luminaire type
 Under lit roads should be noted as such and not assigned a rating
 A clear energy rating comparison between lighting solutions

18. AUSTRALIA
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 Greenlight Australia initiative in 2005
 Australian Government commissioned a review of energy efficiency of road
lighting in Australia
 The objective of the report was to develop measures aimed at removing
inefficient practices
 Road Lighting Efficiency parameter

19. LOOKING FORWARD
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 The A - G rating scale used in the Netherlands shows a clear comparative
resolution between road designs offers a good street light design energy
efficiency comparison
 It is not possible to directly compare luminaire product performance levels
to installation efficiency
 It is possible to have a luminaire of exceptionally high efficacy, but still not
achieve the highest overall energy savings once this luminaire has been
deployed into a compliant road lighting design

20. ADAPTIVE LIGHTING
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 If a public lighting installation is dimmable, a separate dimming label might
be used to indicate dimmability
 Account for adjustment in output and/or power consumption on the second
label. The second label can specify how much more economical the
installation would become as a result of dimming.

21. BENEFITS
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 Minimum Efficiency Performance (MEP) requirements for luminaires will
provide a simple method for ensuring that energy is not wasted on
inefficient products
 A design energy classification scale would encourage energy efficient
practice in road lighting
 Allowing a degree of flexibility of designers of these installations.

22. DRIVERS
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 MEPS levels remain technology-neutral
 Provides industry with opportunity and incentive to conduct R&D on
application appropriate technology solutions
 A diversity of products possibly with other superior light technical
parameters
 European generic classification system for energy efficiency (A+++ to G)

23. ROAD LIGHTING EFFICIENCY REPORT
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 Proposed road lighting design energy efficiency report
 Unique site identifiers
 A+++ to G Rating
 Dimave (default is 100%)
 Road lighting classification justifications and associated dimming
schedule
 Lamp types and associated lamp efficacies
 Key design parameters
- Lamp / source Lumen Maintenance Factor (LLMF)
- Life of lamp / source at assigned LLMF

24. ROAD LIGHTING EFFICIENCY REPORT
24

25. EU GREEN PUBLIC PROCUREMENT
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 GPP for street lighting and traffic lights
 Looks to apply SLEEC
 SE = P / (Eh.av * A) W/(lx m2)
 SL = P / (Lav * A) W/(cd/m2)
 References the Netherlands work

26. APPLYING A RATING
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 Consider the designed / real average illuminance or luminance
 Look to the lower limit of the lighting class applied
 Normalised SLEEC
 Any measure of over lighting based upon lighting class will result in a
higher SLEEC value and hence a lower energy rating
 Under lit roads should be noted as such and not assigned a rating

27. APPLYING A RATING
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Lamp type &
wattage
Av luminance
(cd/m2)
Target SL W/(cd/m2) SLEEC
label
Norm SL
W/(cd/m2)
Norm
SLEEC
label
Class Luminance
MH 45W 0.89 ME4a 0.75 0.551 D 0.523 C
MH 90W 2.07 ME1 2 0.455 C 0.337 C
HPS 100W 2 ME1 2 0.407 C 0.326 B
HPS 250W 2.38 ME3b 1 0.331 B 0.631 D

28. SUMMARY
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 Minimum efficiency performance requirements for luminaires will provide a
simple method of ensuring that energy is not wasted on inefficient products
 Allows a degree of flexibility to designers
 The merit of using a rating system rather than a single Minimum Energy
Performance (MEPS) level is that it affords more opportunity for
comparison of lighting solutions and incremental improvement
 Authorities will have the power to indicate the minimum energy efficiency
level at which they wish a project be designed, providing impetus for faster
improvement in the energy efficiency of luminaires

29. SUMMARY
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 Achieving a minimum design efficacy is a secondary priority to ensuring
that the roadway is lit in compliance with safe minimum lighting levels
 SLEEC approach can be applied in the determination of energy
performance within Lighting Value Management Models
 A D rating may currently be the best for a road type, encourages ongoing
technology development

30. THANK YOU FOR YOUR ATTENTION
Promoting sustainable lighting
allan.howard@wspgroup.com
@illuminator_42