Cx Energy Conference
.
High Performance Lighting:
Lamp Source & Energy Usage
Howard Wolfman, PE
Lumispec Consulting
h.wolfman@ieee.org
847 656 5753
1
Learning Objectives
By the end of this hour you should
• Understand the different efficiency or efficacies in light
source systems and plan for maximum lighting efficiency for
each application
• Recognize the important performance characteristics of light
source systems and select those that are needed for a
specific application
• Understand the relative cost implications of different light
source systems and make an educated decision as to which
system to utilize
• Learn about the impact of mandatory and voluntary lighting
regulations and standards, and their impact on lighting
system selection
2
Disclaimer
• Although I list a number of manufacturers and
models, these are examples and none are
endorsed. There are other manufactures with
similar products
• Also, I do not have any financial arrangement or
consulting agreements with any of these
manufacturers (friendships with some – yes)
3
Energy Use and Cost for Lighting Systems
in Commercial Buildings
Cost of lamps (bulbs & tubes) and labor cost to
replace them is small percentage of total
operating costs.
Electricity to operate lighting systems far
outweighs lamp and labor costs.
The higher purchase price of efficient lamps is
quickly recovered through lower electricity costs.
4
GOAL: To safely place the correct amount and type of light
where it is needed, when it is needed, and for the lowest
life cycle cost
Need:
•Consistency in products
•Cost-effective products
•Quality in products
•Reliability in products
Then products will:
•Allow interchangeability of system components
•Provide “superior” lighting
5
User Lighting Goal
• Save money
– Reduce power consumption
– Reduce maintenance
• Provide “proper” level of illumination
– Safe
– Adequate light level
• Be environmentally friendly
6
7
Definitions
•
•
•
•
•
•
Light Sources
CCT (Correlated Color Temperature)
CRI (Color Rendering Index)
Efficacy
Lamp life
Lumen Depreciation/Lumen Maintenance
8
Light Sources
• Incandescent
• HID
• Fluorescent
• CFL
• LED
9
- Terminology
CCT (Correlated Color Temperature) Kelvin (K)
• Color temperature – a
measure of the “warmth”
or “coolness” provided by
the lamp, expressed in
Kelvin (K).
– Generally, sources below
3200K are considered
“warm” while those above
4000K are considered
“cool.”
– The higher the color
temperature, the “cooler”
or bluer the light.
– Also called “Chromaticity”
10
- Terminology
Color Temperature by Application
SSL
SSL
SSL
SSL
SSL
New area: Human Centric Lighting
11
- Terminology
CRI (Color Rendering Index)
• Color Rendering Index (CRI) - a scale from 0100, is a measure of how well a lamp renders
color.
– A lamp with a CRI of 100 makes objects appear as
they do in sunlight.
– CRI can only be compared for lamps of similar
color temperature.
12
Source: IES
13
Light Source Color Summary
CRI
Natural daylight
100
Mercury vapor
20 - 50
Metal halide
65 – 93
Fluorescent
70 - 96
Incandescent
100
Induction
80
Standard HPS
22
LED
70 - 90
Low pressure sodium
-44
Source: BOC
CCT (°K)
5000o – 8500o
4000o – 6000o
2900o – 6500o
3000o – 8000o
2500o – 3000o
2700o – 5000o
2200o
3000o – 8000o
1700o
14
Lamp Characteristics:
LPW & Average Rated Life
Lumens Per Watt (LPW)
light output (lumens)
LPW =
power input (watts)
Average Rated Life for Incandescent, HID, and Fluorescent is
the point in time at which 50% of a large group of lamps have
failed.
Ratings in catalogs are result of standard lab tests.
(Ex: Fluorescent lamps 20,000 hrs. @ 3 hrs./start)
Rated life for LED is when lumen output has dropped to 70%,
or L70
Source: BOC
15
Definition of life-traditional light sources
Source: IES Lighting Handbook, 10th Edition
16
Light Source Lifetimes
17
Efficacy of Light Sources
DOE SSL R&D Multi-Year Program Plan (2012-04, www.ssl.energy.gov/techroadmaps.html)
18
Lamp Characteristics:
Lumen Maintenance (lumen light depreciation)
Most lamps lose ability to
produce light after
burning for some time
Lumen maintenance
measures the rate of
depreciation and
indicates the remaining
light output
LLD
=
mean lumens**
initial lumens*
Ex: 32-W T8 Fluorescent
2,775
LLD =
= 0.95
2,900
*Initial lumens measured at 100 hrs
**Mean lumens measured at 40% rated life
Source: BOC
19
- Human Needs
Comfort Issues
• Adequate
Illumination
• Lake of Glare
• Color Recognition
• Eyestrain relief from the
ability to change focus
from close (computer
screen) to distance
(wall/window)
20
Light Levels:
Considerations
Proper light levels required
■ IESNA recommendations
■ State/local standards
Where light levels are correct, visual tasks are
easier.
Too little is bad - cannot see, eye strain
too much is bad – glare, wastes energy
Source: BOC
21
- Lighting Types
High Intensity Discharge (HID)
• An HID lamp relies on light emitted by a gas or vapor
that has been excited by an electric current
• Long life, high efficacy, and small in physical size
• Warm up (2-6 minutes) and “restrike” (up to 20
minutes)
• Point source -glare
22
- Lighting Types
High Intensity Discharge (HID)
• The most common
types of HID lamps
are
– Mercury Vapor,
– Metal Halide
– High Pressure
Sodium
– Low Pressure
Sodium.
23
Lumen Depreciation-HID Lamps
Source: IES Lighting Handbook, 10th Edition
24
25
Collectively, what have we learned so far and what do we
need going forward?
26
Why SSL
 Rapid ongoing improvements
DOE SSL R&D Multi-Year Program Plan (2012-04, www.ssl.energy.gov/techroadmaps.html)
27
SSL Penetration - future
28
Source: DOE
LED luminaire efficacy
29
Source: DOE
($/lm)
Annual Improvement in
$/lm @ 100 LPW
Source: Cree
43%
45%
35%
29%
Efficacy (LPW)
Working on both
numerator and
denominator!!
(Cool White, 6500K)
$/lm, normalized
Performance Drives LED Cost Roadmap
45%
40%
27%
30
Driving LPW Makes Systems Cheaper.
A Lot Cheaper.
Fewer LEDs & optics for the same system
(Hypothetical Example)
135
95 LPW
23
XM-L2
70
XP-G
85 LPW
System Efficacy
XP-G
17
XM-L2
0
20
40
60
80
100
120
140
160
Number of LEDs Required To Deliver 10,000 Lumens
Source: Cree
31
A Real Example
3
2007
3
2
2011
5
• 8 LEDs
• 650 lm
• 10.5W
• 42 LEDs
• 650 lm
• 12W
10W
9.5W
>$100 Commercial
Wholesale
Source: Cree
$39.97
$19.97
$49.97 Retail
32
LED Cost Conclusions
• LED costs have been coming down rapidly over the last 3 years
– typical semiconductor learning curve
• Luminous Flux and therefore LPW efficacy have also been
improving dramatically – 200 LPW is now in production
• Since cost is measured in lumens per dollar, working on both
the numerator and denominator simultaneously have yielded
over 40% year-on-year gains for the past several years
• Every time LEDs are made 10% brighter they also become 10%
cheaper because you need 10% fewer LEDs per luminaire
system
• Taking LEDs out of a system is a much stronger lever on cost
than simply reducing the cost of LEDs because 10% fewer LEDs
also means 10% fewer optics, smaller and cheaper housings
and PWB assemblies, etc.
• Increasing efficacy reduces the size, weight, cost of heat sinks
33
Heat
• Stated very simply, heat is death to electronics
and LEDs are electronics – transistors
• For every 10°C increase in temperature over a
component’s rated temperature, the
component’s life is reduced by half
34
Dimming of LEDs
• Good News
–
–
–
–
LEDs love dimming
Dimming reduces the LED junction temperature
Saves additional power/energy
Should increase LED life and color stability
• Bad News
– Not all LED systems are compatible with all dimmers
– Need to get compatibility assurance from
luminaire/dimmer manufacturer
35
Warranties
• 10 years @ 24 X 7 X 365 = 87,600 hours
• What is covered
• “Limited” warranty
• What is not covered
Source: Stephen Naor Leapfrog Lighting
36
Glare
37
Glare
•
•
•
•
•
Incandescent/HID/LED - point light source
Proper defusing
Proper focusing
Control
Curfew
38
Model Lighting Ordinance (MLO)
39
Model Specification for LED Roadway Luminaires
Version 1.0 October 2011
• This document is intended to be used as a model or template
specification.
• It should be customized as needed to meet the needs of each
owner,
• The template is composed of two separate documents:
• The body of the specification and appendix
• The Editor may choose ONE of two versions of Appendix A,
depending on available information
– System Specification (application efficacy), which characterizes luminaire
performance based on site characteristics such as mounting height, pole
spacing, number of drive lanes, input power, and required light levels
and uniformity.
– Material Specification (luminaire efficacy), which characterizes luminaire
performance without consideration of site characteristics.
40
BUG RATINGS – Backlight, Uplight, and Glare
IES-TM-15 and addenda)
An attempt to define, measure, and control unwanted
light
41
Focused vs. spread lighting - Uniformity
 Minimize the number of metrics used
 Avoid using metrics and criteria which may overlap and conflict
• For example, if a minimum lumens value is specified for a parking lot
luminaire, high-performance products which improve uniformity
(thereby needing fewer lumens) might be inadvertently excluded from
consideration
42
What we don’t want!!!!!
• Spot LED failures
• Complete luminaire
Failures
• Driver
43
Retrofit 400 MH to
T8 Fluorescent Example
Before
After
High-bay fixtures
e/w 400-w metal halide
(458-watts/fixture)
30 FC
Industrial fixtures
e/w 6 – F32T8 lamps
(224-watts/fixture)
50 FC
CRI = 85
CRI = 65
Source: BOC
44
HID & Incandescent
to T5HO Fluorescent
Before
After
54, 400-w HPS HB fixtures 465-w
6, 400-w MH HB fixtures 458-w
4, 500-w Incand fixtures 500-w
42, 4-lamp T5HO fixtures 234-w
4, 6-lamp T5HO fixtures 351-w
(all e/w wire grills)
11,932 W
29,859 W
Source: BOC
45
46
FLICKER
• IEEE working on P1789, "Recommending practices for
modulating current in High Brightness LEDs for
mitigating health risks to viewers"
– grouper.ieee.org/groups/1789/
• DOE - PNNL has been working on this and is continuing to
work on this
– Testing methods
– Metrics
– Good webinars
• www1.eere.energy.gov/buildings/ssl/webcasts.html
• ledsmagazine.com/features/9/10/5
47
ANSI C82.377
• This standard specifies the range of chromaticities
recommended for general indoor lighting with SSL products,
as well as to ensure that the white light chromaticities of the
products can be communicated to consumers
• This standard applies to LED-based SSL products with control
electronics and heat sinks incorporated--that is, those devices
that require only AC mains power or a DC voltage power
supply to operate
• This document does not cover products that require external
operating circuits or additional external heat sinks.
• The chromaticity requirement in this standard is for general
indoor lighting applications. For other applications,
chromaticities of light broader than the range specified in this
standard are often acceptable
48
NEMA SSL – 1, ELECTRONIC DRIVERS
FOR LED DEVICES, ARRAYS, OR SYSTEMS
• Provides specifications for and operating characteristics of
non-integral electronic drivers (power supplies) for LED
devices, arrays, or systems
• However, the driver generally is or contains the weakest
link in the luminaire system – electronic components and
the electrolytic capacitor.
• Electronic components and heat
• +10º C = life/2
49
IEEE P1789 - Recommended Practice of Modulating Current in
High Brightness LED’s for Mitigating Health Risks to Viewers
• Under development – estimate late 2014 publish date
• There are no standards on safe modulating frequencies for LEDs.
Driving frequencies suggested by vendors, range from very low to
high frequencies. Past work has shown that modulation at low
frequencies can cause health related problems, such as headaches,
eye strain and epileptic seizure.
• The detrimental effects depend on factors such as brightness, angle
of viewing, wavelength, depth of modulation, among others. The
purpose of this standard is to
1) describe some possible health risks, such as headaches, eye
strain and epileptic seizure, associated with low frequency
modulation of LEDs in different applications and
2) provide recommended practices to aid design of LED driving
systems to modulate at safe frequencies for their particular
applications in order to protect against the described health
risks.
50
US Safety standards
• UL 8750
• UL 1598
• FCC part 15
51
UL 8750 Light Emitting Diode (LED) Equipment
for Use in Lighting Products (Canada C250.13)
• “Voluntary” Safety requirements for LED equipment that is
an integral part of a luminaire or other lighting equipment
and which operates in the visible light spectrum between
400 – 700 nm
• Requirements also cover the component parts of light
emitting diode (LED) equipment, including LED drivers,
controllers, arrays, modules, and packages as defined within
this standard
• Requirements in this standard are intended to supplement
those in 12 other UL end-product standards including
UL1598
52
UL 1598
• “Voluntary” Standard for Safety for Luminaires – 304
pages
• This Standard applies to luminaires for use in nonhazardous locations and that are intended for
installation on branch circuits of 600 V nominal or
less between conductors
• Covers Incandescent, HID, Fluorescent, and SSL
luminaires
• Similar to IEC 598
53
UL 1598(C)
These requirements apply to light-emitting diode (LED) retrofit
luminaire conversion kits intended to replace existing light sources
and systems in previously installed luminaires that already comply
with requirements in UL 1598. The kits are intended for use on:
• LED retrofit kits covered by these requirements include but are
not limited to LED lamps and arrays, LED control modules, LED
drivers, LED power supplies, wiring, lampholders, brackets, wire
connectors, reflectors, diffusers, and other associated mechanical,
electrical, or optical devices.
• This standard does not cover luminaire conversion lamps intended
to replace existing lamps without any modification in the
luminaire other than replacement of the lamp using the existing
lampholder. Requirements for these direct replacement lamps
specified in the Standard for Self-Ballasted Lamps and Lamp
Adapters, UL 1993.
54
FCC Part 15/ICES 003
•
•
•
•
Mandatory per US and Canadian governments
Covers conducted and radiated EMI and EMC
Somewhat similar to CISPR 15 (IEC and Europe)
FCC practice faster and less costly than IEC
55
Zhaga standard
• Lighting industry used to standardized light sources,
but LED engines are not
• Zhaga promotes interchangeability of LED light
engines by specifying interfaces
• Zhaga specs to be limited to mechanical, thermal,
photometric, electrical interfaces
• Initially voluntary, but will submit spec to IEC for
standardization
• Both US and Europe expected to adopt as standards
56
EPA Energy Star Standards
ENERGY STAR Product
Specification for Luminaires
Voluntary – 36 pages
• Photometric Performance
Requirements.
• Electrical Performance Rqrmnts
• Thermal Performance Rqrmnts
• Safety Requirements
• Product Labeling & Packaging
Requirements
• Lighting Toxics Reduction
Requirements: Directional and
Non-Directional Luminaires
• Warranty Requirements:
Directional and Non-Directional
Luminaires
ENERGY STAR Product
Specification for Lamps Voluntary - 53 pages
Contains lamp requirements for
• Beam spread
• Color
• Life
• Lumen depreciation
• Efficacy
• Stress testing
• Electrical
• Dimming
• Labeling
• Warranty
57
DLC Qualified Products List
• Produced by DesignLights Consortium
• Specifications and list of qualified products for
utility incentive programs
• January 1, 2014, v.2.1 update updated specs for
37 LED product categories
• Over 16,000 products listed
58
See product list at www.designlights.org
Light Source Costs
Source
Incandescent
HID
Fluorescent
CFL
LED
relative
cost
100
400
200
150
400
cost
trend
level
level
level
level
decreasing
59
Twelve questions you need to ask when
specifying LED products
1) Is your LED supplier a reliable company? How do you
know?
2) Has your supplier provided an IES LM-80 test report from
an accredited laboratory?
3) What is the operating temperature range specification and
what is the maximum junction temperature
4) What is the expected L70 lifetime of the fixture? How was it
calculated – TM 21 or?
5) Can the manufacturer supply an IES LM-79 test report from
an accredited laboratory as well as an .ies data file?
6) What are the delivered lumens and lumens per watt (LPW)
of the fixture?
60
Twelve questions you need to ask when
specifying LED products
7) What is the chromaticity of the fixture in the ANSI
C78.377A color space and is it stable over time? How do
you know?
8) Does the color of the light output vary from fixture to
fixture or in different spatial locations for a single fixture?
9) What is the power factor of the fixture? How much power
does it consume in the “off” state?
10) Do you have or have you applied for the EPA Energy Star
or Design Lights Consortium listing?
11) Is the fixture lead-free, mercury-free and RoHS compliant?
12) What is the warranty and do you have the means to stand
behind it?
61
Learning Objectives
Have we helped you to
• Understand the different efficiency or efficacies in light
source systems and plan for maximum lighting efficiency for
each application
• Recognize the important performance characteristics of light
source systems and select those that are needed for a
specific application
• Understand the relative cost implications of different light
source systems and make an educated decision as to which
system to utilize
• Learn about the impact of mandatory and voluntary lighting
regulations and standards, and their impact on lighting
system selection
62
Thank You
Are there any questions?
Howard Wolfman, PE
Lumispec Consulting
O: 847-656-5753
C: 847-366-6700
h.wolfman@ieee.org
63