Built to Last?
LED Strengths and
Limitations
Keith Graeber
kegraeber@ucdavis.edu
Director of Engineering
California Lighting Technology Center
Mark McClear
Mark_McClear@cree.com
Director of Applications Engineering
Cree, Inc
Agenda
•
•
•
•
Dramatic Change is coming to the lighting world: An LED Roadmap
The real differences between LEDs and traditional light sources
LED Anatomy: Lumen output, spectral qualities color binning…
50,000 hours? Lifetime ratings and evaluation methods
• Break
• Performance economics, payback, ROI, and LCCA
• Applications that make sense today, tomorrow, or possibly never
• What about LED light bulbs? Costs? When will they come down…?
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
…A Brief History of Lighting
1901
Fluorescent
1879 Tube 1919
Edison Light
Bulb
U.S. 223,898
Sodium
Vapor Lamp
2000
2008
~1990
White LED
Production White
“High
Lamp
LED Lamp
1970s
Brightness”
demonstrates
Exceeds 100
First Red
Red, Orange,
1995 Incandescent 2005
lm/W
LED
2010
Yellow, & Green “High
Efficacy
White LED
White LED
LEDs
Brightness” (17 lm/W)
Lamp
Exceeds 150
Blue, Green
demonstrates
lm/W
LEDs
Fluorescent
Efficacy (70
lm/W)
• Current lighting technology is about 100 years old
• LEDs began as just indicators, but have now become
the most efficient light source ever created
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Rapid Change is Coming to Lighting
Revenue (Billions)
General Illumination Market**
Conventional
Lighting
**Philips Lighting 2009
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED
Lighting
This Has Happened Before….
Vacuum
Tubes
Transistors
1940s – 1960s
VHS
DVD
1980s –
1990s
CRT
TV
1990s –
2000s
Film
1990s –
2000s
“Brick”
phones
Light Bulbs/
Fluorescent
Tubes
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
1990s –
2000s
2000s – …
Flat
Panel
TV and
Displays
Flash
Memory
Smart
phones
Solid
State
Lighting
…And the Economic Incentive Is Present
$108 Billion**
Outdoor *
Outdoor *
Lamps
Residential
Fixtures
Commercial
Industrial
** Source: Freedonia Group estimate for 2012 (Excludes manufactured goods)
* Non-Building
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Residential
Commercial
Industrial
Why Now?: Basic Advantages of LED
• LEDs are…very energy efficient  >150LPW
(near-term roadmap to >200LPW…)
• Are directional  No wasted light, any pattern
possible
• Have very long lifetime  >50,000 hours to
70% Lumen Maintenance (L70)
• Are inherently rugged  No filament to break
• Start instantly  nanoseconds vs. > 10 min
re-strike (HID)
• Are environmentally sound  no Hg, Pb,
heavy metals
• Are infinitely dimmable, controllable  New
lighting features, power savings
• Love cold temperatures  No cold starting
issues
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Rapid Technology Advancement
260
240
Theoretical maximum for LED
220
208 LPW
200
R&D Capability
CW Lumens/watt
180
186 LPW
161 LPW
160
140
131 LPW
3 yrs
120
100
80
60
XP-G
XP-E
HID
XR-E
Fluorescent
High Volume
Production
XR-E
CFL
40
20
LED
Incandescent
0
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LEDs Deliver Value Segment-by-Segment
Color
Specialty
White Specialty
Outdoor
Light
Indoor
Indoor
Directional, retail, High Bay, Highcommercial
end Residential
Indoor
Commercial,
residential
Market for LED General Illumination
80
70
60
50
40
Enabled by:
30
• Lumens
• LPW
• Lumens/$
20
10
0
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Time
Three Sources of Value
• Save energy
• Save money
• Protect the
environment
 More compelling
in higher energy
cost areas
 More compelling
in applications
that need long
service lifetimes
 Always a factor
but secondary
to $$ (in the
U.S.)…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
At the Tipping Point On Most C&I Applications…
400
Number of 1W LEDs Needed
350
150
300
125
250
100
200
75
150
50
100
50
25
0
0
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Expected Lumens per 1W LED
175
150W Roadway
400W HID Met
4x T5 FL Troffer
Lumens/1W LED
“How It’s Made…”
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
We’re Going To Need
Some New Tools…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Anatomy
• LED Chip:
– Determines raw brightness
and efficacy
• Phosphor system:
– Determines color point and
color point stability
• Package/Lens:
– Protects the chip and
phosphor
– Helps with light and heat
extraction
– Primary in determining LED
lifetime
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Luminaire Design Will Be Different…
Conventional
Lighting
Reflector
LED
Light
Heat
• LED Light is inherently directional
• LED thermal path accomplished by conduction
– No IR, no UV in the light beam
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Light Source Comparison
Data Sheet
lm/W
Usable*
lm/W
Lifetime
(hrs)
CRI
13-16
<15
3k
100
Halogen
20
12-20
6k
100
T12 fluorescent
60
40-50
20k
62-85
65-70
35-40
10k-20k
60-90
T5 fluorescent
90
75-85
30k
85
T8 fluorescent
90+
80-90
30-40k
78-85
95-110
55-65
24k
22
100
65-75
50k+
80-85
120-140
65-75
16k
<5
160
>110
50k+
75
Light Type
Incandescent
Metal halide
High-pressure sodium
Lighting-Class LED (Warm White)
Low-pressure sodium
Lighting-Class LED (Cool White)
* Typical expected performance in real-life applications. Based on mean lumens, and including
ballast/driver, thermal equilibrium and typical fixture Coefficient of Utilization losses.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
…But Source Comparison Can Be Misleading
Incand
“17 lm/W”
x
Fixture Efficiency
58%
=
Delivered Efficacy
10 lm/W
=
Delivered Efficacy
35 lm/W
CFL
“60 lm/W”
x
Fixture Efficiency
58%
CA
Title 24
LED
“100 lm/W”
x
x
x
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Fixture Efficiency
Driver Efficiency
Thermal Equilibrium
90%
85%
90%
=
Delivered Efficacy
69 lm/W
LED Color and Binning
Incandescent
Let’s Agree About One Thing…
This is what we are all working to prevent, right?
Good lighting
is technology
neutral and –
a lot of hard
work…
Picture: Taken from “The Roof”, The Wit Hotel, Chicago
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Describing Color: Numbers & Words
Spectral Power Distribution
(~100 numbers)
Chromaticity (xy or HSB))
(2-3 numbers)
“Warm White”
Descriptive Prose
(Language)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Color Temperature
(1 number)
Visible Light Spectrum
of Various Sources
• Which one is closer to the Sun?
• Normalizing Incandescent to CRI = 100
makes the CRI scale somewhat arbitrary
• A new standard – Color Quality System
(CQS) is currently being set for ALL light
sources
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Color Rendering Index System
• First proposed in the
1950’s
• Based on color
comparison of 14
sample tiles with
unsaturated colors
14
3000 2500
11
4
4000 2
6000
D65
5
8
6
• Incandescent bulbs
are – by definition –
CRI 100
10
3
13
1
9
7
12
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
• RGB LEDs have fully
saturated colors and
actually pay a
mathematical penalty
in the CRI system
Color Rendering/Color Quality In Real Life
CRI = 62
CRI = 93
CRI = 80
CRI = 92
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Binning – Root Cause
Yellow
Phosphor
White Light
Blue LED
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
• The human eye is
extraordinarily sensitive,
so small process
variations in LED chip
wavelength; phosphor
thickness,
concentration,
composition; and/or
deposition conditions
make a big perceived
difference in white light
CCT & quality
Binning – Two Types
• Chromaticity binning
– Some defined “box” in the
white area on or near the
Black Body Locus
– Bin sizes (x, y coordinates)
varies by supplier (currently)
• Brightness or LF binning
– Minimum luminous flux
(most suppliers)
– Bin sizes/flux range
varies by supplier
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
(currently)
Luminous Flux Binning
Flux:
119 lm
+
Driver
350 mA
25ºC
“R2” Luminous Flux Bin
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Chromaticity Binning
CCy: 0.41
CCx: 0.445
+
Driver
350 mA
25ºC
“7C4” Chromaticity Bin
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Bins in Context
~7-step MacAdams
ANSI C78.377A
XLamp MC, MP
~2-step MacAdams
Cree EasyWhite™
~2/4-steps
~4-step MacAdams
XLamp XM, MX, XP
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Summary on Color and Binning
• LEDs come in ALL CCTs of white (and colors,
too!)
• Cheap LEDs come mostly in bluish-white
(~10,000K CCT)
• Knowing how LED binning works can make you
a better specifier and consumer of LED
products, but
• LED binning is something any good fixture
manufacturer will master and make transparent
to the user
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Packages and Types
Lamp Type
T1-type
(3 – 7 mm)
Surface
mount
P4
Drive Current
5 – 20 mA
Light Output
Brands
(Commodity
product)
<1 – 4 lm
Applications
•
•
•
•
Indicators
Novelty lights
Traffic signals
Electronic signs
5 – 20 mA
1 – 10 lm
•
•
•
TopLED
SideLED
Cree CLA1A
•
•
•
Automotive
LCD backlighting
Electronic signs
20 – 100 mA
1 – 20 lm
•
Piranha
•
•
Automotive
Channel letters
DRAGON
LUXEON
XLamp XPG
•
•
•
General illumination
Portable
Architectural
High power
200-1500 mA
50-400 lm
•
•
•
Multi-small
chip
200-700 mA
150-500 lm
•
•
XLamp MX6
XLamp MLE
•
General illumination
300-3000 lm
•
•
•
OSTAR
XLamp MPL
XLamp MCE
•
General illumination
Multi-power
chip
200-1000 mA
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Thermal Path is Critical to LED Lifetime
5mm LED
No Thermal
path
• 5mm lamps have almost
no thermal path
• RTH >350ºC/W typical
• Chip (TJ) and phosphor
can essentially cook
themselves
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Lighting-class LED
Thermal path
• Lighting-class LEDs are
designed for high temp
operation
• RTH <10ºC/W typical
• Lamp can stay within data
sheet parameters with
good thermal design
50,000 hours is:
137
68.5
34.2
22.8
17.1
11.4
5.7
Years at 1 hour/day
Years at 2 hours/day
Years at 4 hours/day
Years at 6 hours/day
Years at 8 hours/day
Years at 12 hours/day
Years at 24 hours/day
…A WAG when it comes to LED lifetime…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Semiconductor Reliability Testing
• Reliability test methods and acceptance criteria for
semiconductor components have been standardized
(JEDEC, EIAJ, others…) and practiced for decades
– Think: processors, regulators, microcontrollers, etc..
Every time you’ve flown in an airplane, driven in a
car, or talked on a cell phone, you’ve depended on
this body of scientific work and testing…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Reliability Testing
• LEDs are semiconductor
components that happen to emit light
• Most LED manufacturers conduct the traditional standardized
semiconductor component reliability testing on their LED lamps
(http://www.cree.com/products/pdf/XLamp_Reliability.pdf)
• The Illumination Engineering Society of North America published
IES LM-80-2008 18 months ago to characterize the Lumen
Maintenance aspect of LED semiconductor components
• Note: Lumen Maintenance ≠ LED Lifetime. Another standards
committee – TM-21 – is working on that aspect of the problem
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Lifetime
110%
Lumen Output (%)
100%
90%
100 W Incandescent
5mm LED
42W CFL
50 W Tungsten Halide
400 W Metal Halide
25 W T8 Fluorescent
Lighting-class LED
80%
70%
60%
50%
40%
0
10
20
30
40
50
60
Operating Time (k hrs)
70
80
90
100
Courtesy LRC, Rensellaer Polytechnic Institute
• Lighting-class LEDs typically become dimmer
over time with no catastrophic failure
• End of life defined by the LED becoming too dim
– needed to define Lumen Maintenance (L70)
• Not all LED types have a long L70 or lifetime
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LEDs Last Forever!
[under ideal conditions]
LowAttemp
is a goodLighting-class
surrogate for
lower(25ºC)
ambienttesting
air temperatures,
the LED chipLEDs
depreciation
– 1-2%
@ TJ = 65ºC
hardly depreciate
at all
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Everyone Asks for an “LM-80 Test Report”
Here is what one looks like (too detailed, no interpretation, just data…):
Product
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
Product
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
Lamp Color
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Temperature
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
Drive Current (mA)
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
BoardID
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
Lamp Color
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Lamp Number
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
0
ccx
0.31780
0.31781
0.31942
0.31856
0.32009
0.31961
0.32138
0.31786
0.32359
0.32012
0.30957
0.30992
0.30350
0.31022
0.30857
0.30798
0.30921
0.30685
0.30739
0.30734
0.31256
0.31004
0.31113
0.31545
0.31444
0.31571
0.31137
0.31557
0.31114
0.31350
Temperature
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
0
ccy
0.33520
0.33644
0.33512
0.33609
0.33523
0.34096
0.34430
0.33375
0.34138
0.34131
0.32778
0.32951
0.31697
0.32142
0.32362
0.32173
0.32296
0.32063
0.31953
0.32060
0.31962
0.31810
0.31543
0.32814
0.32145
0.32306
0.31313
0.31917
0.31388
0.32077
168
ccx
0.31776
0.31725
0.31791
0.32010
0.31910
0.32095
0.32088
0.31581
0.32158
0.32091
0.30914
0.30882
0.30341
0.30911
0.31059
0.30819
0.30847
0.30608
0.30889
0.30811
0.31371
0.31028
0.31193
0.31662
0.31482
0.31514
0.30908
0.31275
0.31054
0.31508
Drive Current (mA)
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
168
ccy
0.33226
0.33421
0.33385
0.33708
0.33556
0.34111
0.34325
0.32791
0.33984
0.34271
0.32669
0.32711
0.31658
0.32278
0.32470
0.32251
0.32159
0.31987
0.32023
0.31969
0.31889
0.31906
0.31617
0.32750
0.32177
0.32210
0.30924
0.31525
0.31281
0.32276
336
ccx
0.31697
0.31706
0.31668
0.31877
0.31877
0.31963
0.32170
0.31775
0.32154
0.32019
0.30949
0.30791
0.30273
0.30926
0.30763
0.30855
0.30868
0.30596
0.30906
0.30576
0.31042
0.30976
0.30998
0.31562
0.31412
0.31314
0.31156
0.31265
0.30980
0.31510
336
ccy
0.33263
0.33107
0.33310
0.33541
0.33484
0.34097
0.34259
0.33182
0.33937
0.34240
0.32701
0.32641
0.31507
0.32247
0.32140
0.32226
0.32210
0.31986
0.32094
0.31847
0.31493
0.31760
0.31388
0.32707
0.32103
0.31933
0.31201
0.31640
0.31116
0.32203
BoardID
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
672
ccx
0.31722
0.31517
0.31668
0.31792
0.31901
0.31933
0.32101
0.31596
0.32134
0.31958
0.31002
0.30857
0.30347
0.30907
0.30733
0.30768
0.30969
0.30448
0.30779
0.30575
0.31159
0.31030
0.30924
0.31469
0.31475
0.31482
0.30922
0.31207
0.31067
0.31455
Lamp Number
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
672
ccy
0.33264
0.32965
0.33329
0.33452
0.33440
0.34038
0.34215
0.32934
0.33886
0.33965
0.32631
0.32635
0.31750
0.31734
0.32125
0.32186
0.32021
0.31690
0.32131
0.31866
0.31802
0.31857
0.31101
0.32311
0.32056
0.32180
0.31095
0.31259
0.31250
0.32093
840
ccx
0.31755
0.31622
0.31691
0.31894
0.31865
0.32001
0.32050
0.31653
0.32155
0.32114
0.30779
0.30895
0.30373
0.30959
0.30902
0.30651
0.30846
0.30581
0.30736
0.30623
0.31067
0.31024
0.31166
0.31369
0.31411
0.31429
0.30870
0.31313
0.31255
0.31489
840
ccy
0.33281
0.33168
0.33356
0.33480
0.33454
0.34062
0.34179
0.33019
0.33892
0.34173
0.32356
0.32864
0.31776
0.32238
0.32486
0.31797
0.32166
0.31964
0.31982
0.31929
0.31576
0.31903
0.31510
0.32513
0.32094
0.32215
0.30951
0.31836
0.30988
0.32162
0
119.56
120.68
118.83
120.38
122.92
122.38
120.91
119.57
120.19
121.60
99.24
100.77
100.35
102.73
97.67
101.04
98.79
101.24
102.19
99.18
97.48
97.16
96.73
96.29
97.11
97.56
97.11
95.08
96.43
96.64
1008
ccx
0.31698
0.31691
0.31678
0.31841
0.31802
0.31954
0.32051
0.31848
0.32234
0.31980
0.30833
0.30881
0.30289
0.30864
0.30923
0.30743
0.30851
0.30591
0.30993
0.30620
0.31207
0.31160
0.30926
0.31533
0.31514
0.31407
0.30924
0.31058
0.30959
0.31433
168
117.79
117.35
117.36
118.24
121.63
120.78
118.77
118.10
117.72
120.19
98.26
99.83
98.17
102.12
97.87
100.58
98.89
101.75
101.46
97.31
98.37
95.95
97.69
94.96
96.56
97.30
96.35
94.82
96.11
96.18
1008
ccy
0.33271
0.33336
0.33338
0.33545
0.33301
0.34064
0.34245
0.33025
0.33854
0.34179
0.32485
0.32823
0.31533
0.32128
0.32374
0.32071
0.32180
0.31919
0.32126
0.31930
0.31809
0.31842
0.31245
0.32659
0.32040
0.32179
0.31084
0.31398
0.31083
0.32023
336
117.89
118.22
117.99
118.79
121.95
121.19
118.52
119.03
118.51
119.78
99.18
100.81
99.08
101.92
97.83
100.74
99.08
101.38
101.58
98.19
97.86
95.58
96.73
95.40
96.16
96.89
96.47
94.64
96.06
96.06
1176
ccx
0.31685
0.31670
0.31622
0.31765
0.31840
0.31902
0.31992
0.31750
0.31970
0.31930
0.30905
0.30907
0.30290
0.30760
0.30881
0.30707
0.30853
0.30476
0.30789
0.30461
0.31067
0.31085
0.31130
0.31454
0.31417
0.31339
0.30871
0.31363
0.31007
0.31258
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
1176
ccy
0.32973
0.33320
0.33063
0.33397
0.33386
0.33961
0.34111
0.33080
0.33571
0.34069
0.32666
0.32815
0.31580
0.31908
0.32445
0.31780
0.31966
0.31563
0.32091
0.31556
0.31579
0.31818
0.31453
0.32527
0.31842
0.32037
0.30957
0.31744
0.31196
0.31693
672
119.25
119.45
118.98
119.81
123.00
122.33
119.81
120.05
119.43
120.77
99.96
101.47
99.81
103.39
99.40
102.20
100.51
103.27
103.02
98.90
98.88
96.73
97.86
95.92
97.05
97.95
97.24
95.48
96.76
96.84
1512
ccx
0.31430
0.31570
0.31684
0.31908
0.31736
0.31906
0.31990
0.31639
0.32150
0.31895
0.30911
0.30852
0.30322
0.30883
0.31027
0.30941
0.30807
0.30603
0.30719
0.30572
0.31031
0.30971
0.31014
0.31390
0.31345
0.31426
0.30864
0.31310
0.31089
0.31347
840
119.35
119.56
119.15
119.71
123.05
122.32
120.69
119.56
119.01
121.58
99.81
101.21
99.55
103.10
99.27
102.09
100.43
103.13
102.82
98.72
100.06
97.90
98.14
96.28
97.36
98.07
97.62
95.96
97.10
97.05
1512
ccy
0.32670
0.33072
0.33208
0.33470
0.33189
0.33978
0.34035
0.32834
0.33631
0.34002
0.32479
0.32787
0.31671
0.32150
0.32386
0.31943
0.32097
0.31792
0.31882
0.31840
0.31466
0.31808
0.31433
0.32591
0.31974
0.32097
0.30965
0.31712
0.31168
0.32121
2016
ccx
0.31638
0.31602
0.31612
0.31808
0.31837
0.31813
0.32079
0.31631
0.32095
0.32007
0.30853
0.30774
0.30269
0.30919
0.31070
0.30699
0.30830
0.30542
0.30568
0.30543
0.31104
0.31114
0.31011
0.31251
0.31460
0.31339
0.30701
0.31162
0.30972
0.31376
1008
119.29
119.92
119.34
119.69
123.21
122.53
120.85
119.72
119.02
121.53
99.93
101.21
99.60
103.08
99.27
102.24
100.53
102.92
102.88
98.80
99.95
97.74
98.62
96.17
96.96
97.80
97.40
95.81
97.18
96.96
2016
ccy
0.33148
0.33172
0.33220
0.33441
0.33317
0.33773
0.34019
0.32998
0.33489
0.33866
0.32591
0.32403
0.31475
0.32098
0.32353
0.31943
0.32058
0.31705
0.31613
0.31551
0.31689
0.31740
0.31248
0.32275
0.31911
0.32060
0.30587
0.31471
0.31119
0.32063
1176
119.66
120.48
119.88
120.17
122.55
122.94
120.66
119.41
118.70
121.32
100.58
101.02
99.38
102.96
99.18
102.04
100.41
102.94
102.67
98.64
99.34
97.14
97.99
96.18
96.77
97.67
97.45
95.69
97.14
96.86
2520
ccx
0.31622
0.31606
0.31532
0.31874
0.31870
0.31752
0.32052
0.31621
0.31978
0.31849
0.30852
0.30868
0.30292
0.30977
0.30848
0.30754
0.30781
0.30437
0.30737
0.30489
0.31098
0.30926
0.30854
0.31229
0.31329
0.31302
0.30950
0.31213
0.30958
0.31382
2520
ccy
0.33109
0.33141
0.33017
0.33388
0.33274
0.33627
0.34081
0.32982
0.33625
0.33756
0.32559
0.32650
0.31604
0.32072
0.32368
0.31887
0.32042
0.31648
0.31995
0.31646
0.31696
0.31702
0.31118
0.32105
0.31933
0.31960
0.31058
0.31188
0.31100
0.32059
1512
119.12
119.68
118.90
119.32
122.90
122.50
121.06
119.71
118.75
121.37
99.93
101.10
99.31
102.80
99.33
101.94
100.28
102.96
102.59
98.53
99.90
97.68
97.73
95.83
96.75
97.79
97.17
95.44
96.79
96.57
3024
ccx
0.31692
0.31626
0.31716
0.31744
0.31673
0.31816
0.31879
0.31492
0.32007
0.31812
0.30790
0.30799
0.30207
0.30778
0.30703
0.30660
0.30615
0.30460
0.30686
0.30521
0.30849
0.30908
0.31007
0.31104
0.31217
0.31288
0.30665
0.31031
0.30825
0.31139
2016
120.01
120.78
119.95
120.20
122.84
123.48
121.21
119.97
119.11
121.56
100.96
101.23
99.42
102.82
99.46
102.01
100.56
103.05
102.56
98.60
99.39
97.53
98.05
96.14
96.81
97.74
97.31
95.45
96.93
96.76
3024
ccy
0.33010
0.33024
0.33070
0.33281
0.33078
0.33829
0.33899
0.32436
0.33472
0.33857
0.32458
0.32485
0.31360
0.31997
0.32070
0.31953
0.31698
0.31751
0.31922
0.31677
0.31143
0.31670
0.31279
0.31918
0.31718
0.31965
0.30407
0.31225
0.30830
0.31670
3528
ccx
0.31613
0.31544
0.31532
0.31624
0.31802
0.31799
0.31826
0.31506
0.31932
0.31804
0.30767
0.30707
0.30074
0.30675
0.30837
0.30739
0.30605
0.30438
0.30750
0.30459
0.31041
0.31059
0.30878
0.31204
0.31502
0.31273
0.30714
0.31177
0.30889
0.31030
2520
118.40
119.30
118.34
118.42
122.21
121.86
120.52
118.90
118.07
120.37
99.46
100.61
98.81
102.10
98.99
101.40
99.90
102.29
101.92
98.11
99.17
97.50
97.70
95.24
95.72
96.79
96.51
94.62
96.08
95.89
3528
ccy
0.33048
0.33156
0.33136
0.33228
0.33127
0.33858
0.33842
0.32828
0.33642
0.33774
0.32500
0.32530
0.31122
0.31738
0.32297
0.31943
0.31743
0.31750
0.31925
0.31692
0.31652
0.31692
0.31258
0.32287
0.31925
0.31825
0.30665
0.31535
0.31052
0.31507
3024
118.91
119.94
119.01
119.03
121.52
122.34
120.11
118.56
117.88
120.21
100.04
100.52
98.56
101.78
98.90
101.08
99.72
102.08
101.52
97.80
98.16
96.67
96.80
94.99
95.40
96.56
96.03
94.42
95.62
95.55
4032
ccx
0.31484
0.31530
0.31549
0.31630
0.31639
0.31730
0.31893
0.31492
0.32022
0.31693
0.30663
0.30710
0.30322
0.30749
0.30628
0.30558
0.30639
0.30452
0.30574
0.30409
0.31104
0.30987
0.30762
0.31097
0.31236
0.31245
0.30804
0.31045
0.31006
0.31239
4032
ccy
0.32955
0.33027
0.33005
0.33255
0.32976
0.33748
0.33926
0.32831
0.33553
0.33704
0.32282
0.32598
0.31298
0.31901
0.31937
0.31835
0.31833
0.31621
0.31730
0.31574
0.31320
0.31548
0.31011
0.32072
0.31837
0.31972
0.30966
0.31530
0.30997
0.31918
3528
118.75
120.05
118.97
118.86
121.65
122.52
120.33
118.68
118.00
120.27
100.07
100.66
98.51
101.74
99.06
101.02
99.79
101.97
101.51
97.79
97.85
96.47
96.71
94.91
95.02
96.29
95.92
94.20
95.41
95.48
4536
ccx
0.31470
0.31484
0.31445
0.31692
0.31480
0.31776
0.31853
0.31648
0.31807
0.31729
0.30699
0.30644
0.30069
0.30838
0.30678
0.30645
0.30611
0.30352
0.30585
0.30343
0.31016
0.30829
0.30871
0.31105
0.31313
0.31272
0.30688
0.30939
0.30986
0.31196
4032
117.61
118.55
117.64
117.63
120.26
121.19
118.88
117.44
117.14
119.19
99.09
99.58
97.56
100.73
98.17
99.88
98.50
101.34
100.11
96.63
96.90
95.82
96.16
93.75
94.03
95.54
94.93
93.21
94.54
94.46
4536
ccy
0.32934
0.33019
0.33010
0.33179
0.32760
0.33672
0.33944
0.32793
0.33411
0.33805
0.32256
0.32444
0.31253
0.31879
0.32147
0.31810
0.31829
0.31619
0.31825
0.31237
0.31632
0.31506
0.31281
0.32075
0.32001
0.32032
0.30725
0.31328
0.31001
0.31938
5040
ccx
0.31483
0.31468
0.31457
0.31599
0.31641
0.31730
0.31941
0.31353
0.31902
0.31742
0.30663
0.30724
0.30112
0.30685
0.30684
0.30555
0.30603
0.30451
0.30589
0.30390
0.31194
0.30856
0.30821
0.31263
0.31472
0.31491
0.30829
0.30834
0.30830
0.31175
4536
117.87
119.12
118.17
118.05
120.74
121.58
119.21
117.67
117.32
119.37
99.21
99.76
97.63
100.77
98.29
100.07
98.81
101.37
100.41
96.94
97.03
96.20
96.15
93.92
92.96
94.86
95.81
94.19
95.41
95.36
5040
ccy
0.32951
0.33026
0.32997
0.33225
0.32986
0.33570
0.33946
0.32552
0.33648
0.33817
0.32281
0.32334
0.31054
0.31906
0.32152
0.31822
0.31817
0.31467
0.31816
0.31560
0.31652
0.31665
0.31158
0.32422
0.32049
0.32077
0.31034
0.31058
0.30535
0.31883
5040
116.63
117.91
116.96
116.78
119.56
120.32
118.08
117.67
117.17
118.09
98.00
98.48
96.30
99.50
96.88
98.69
97.63
100.01
99.22
95.72
95.27
94.84
94.79
92.45
91.41
93.43
94.40
92.85
93.85
94.01
5544
ccx
0.31404
0.31475
0.31381
0.31464
0.31647
0.31725
0.31870
0.31563
0.31836
0.31744
0.30731
0.30677
0.30013
0.30672
0.30856
0.30538
0.30590
0.30508
0.30388
0.30404
0.30941
0.30873
0.30943
0.31419
0.31581
0.31181
0.30996
0.31027
0.30729
0.31258
5544
ccy
0.32734
0.33017
0.32777
0.32884
0.33124
0.33721
0.33969
0.32806
0.33468
0.33817
0.32360
0.32459
0.31121
0.31898
0.32112
0.31811
0.31793
0.31592
0.31355
0.31545
0.31443
0.31681
0.31344
0.32421
0.32232
0.31783
0.31068
0.31500
0.30610
0.31971
5544
116.18
117.41
116.70
116.36
120.45
120.35
118.62
117.31
116.76
118.94
97.74
99.38
97.27
100.26
97.92
99.67
98.61
100.82
100.27
96.67
94.95
94.80
94.59
92.65
90.94
92.95
94.21
92.84
93.98
94.14
6048
ccx
0.31380
0.31411
0.31421
0.31529
0.31713
0.31723
0.31715
0.31666
0.31840
0.31709
0.30541
0.30678
0.30091
0.30547
0.30742
0.30614
0.30495
0.30251
0.30549
0.30411
0.31196
0.30800
0.31035
0.31252
0.31532
0.31396
0.30863
0.31131
0.30902
0.31188
6048
116.77
118.23
117.28
116.80
121.06
120.76
119.25
117.68
117.48
119.21
98.24
99.87
97.82
100.72
98.56
100.13
99.08
101.22
100.78
97.21
94.70
94.77
94.48
92.85
90.65
92.93
94.24
92.92
93.96
94.26
6048
ccy
0.32532
0.32891
0.32928
0.33069
0.33075
0.33659
0.33617
0.32730
0.33377
0.33770
0.31972
0.32350
0.31339
0.31616
0.32068
0.31746
0.31453
0.31401
0.31767
0.31484
0.31708
0.31451
0.31277
0.32412
0.32146
0.32200
0.30851
0.31630
0.31120
0.31929
6552
ccx
0.31416
0.31524
0.31394
0.31421
0.31657
0.31688
0.31872
0.31481
0.31994
0.31709
0.30841
0.30675
0.30291
0.30590
0.30728
0.30440
0.30768
0.30383
0.30519
0.30329
0.31124
0.30897
0.30968
0.31317
0.31407
0.31481
0.30948
0.31154
0.30992
0.31102
6552
115.09
116.58
115.70
115.20
119.20
119.11
117.21
116.00
115.41
117.40
96.64
98.14
96.01
98.92
96.82
98.40
97.35
99.43
98.99
95.34
92.33
92.85
92.50
91.06
88.58
90.94
92.00
90.83
91.31
91.79
6552
ccy
0.32759
0.32957
0.32842
0.32797
0.33126
0.33490
0.33952
0.32808
0.33694
0.33660
0.32355
0.32134
0.31209
0.31695
0.31925
0.31569
0.31578
0.31529
0.31664
0.31453
0.31848
0.31746
0.31463
0.32527
0.32104
0.32366
0.31270
0.31769
0.31276
0.31540
LM-80 & TM-21
LM-80
(testing)
+
TM-21
(projection)
=
Something
useful
• LM-80 is just an LED testing standard
• Luminaire manufacturers rightly want and need to
understand and have confidence in the real lifetime of the
LED lamps they are buying (and to set their warranties)
• LM-80 alone cannot give this
• IES TM-21 will provide the mathematical framework for
taking LM-80 data and making useful LED lifetime
projections from it
• TM-21 is in committee now, expect ballot 1Q11
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Lifetime Is Irrelevant
System Lifetime is What Creates Value
Heat Sink: Linchpin of the entire system.
If this is poorly designed, all the other
components can be compromised
Driver: Can be the weak
link in the system if cheap
components are used
LED Lamps: Practically never
fail; depreciate very slowly in a
well-designed system
Optical Components: Can
(rarely) yellow over time and
lose light; system design choice
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Poor Choice of LED Type…
Time zero
1000 hours
LED Puck
84.1% Drop
16.5” Linear
97.8% Drop
22” Linear
96.9% Drop
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Other Problems: Driver & Thermal
• Driver/circuit board
failure
• Color Shift Due to poor
thermal design
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Optical Design & Poor LEDs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Your LED Lighting Mileage May Vary…
Lighting-class LEDs
Thermal design
Optical design
Electronic design
Bad
Good
–
–
–
–
Good
Excellent
BAD
Bad
• Keys to success
Luminaire Design
Quality of LED
• To enable general
illumination, LED
systems must deliver
real benefits
BAD
BAD
Results
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Excellent Results – Indoor SSL
• Good LEDs
• Good Design
• Excellent Results
– 650 lumens
– 60 LPW
Cree LR6
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Excellent Results – Outdoor SSL
• Good LEDs
• Good Design
• Excellent Results
– >20,000 lumens
– Up to 100 LPW
Outdoor LED lighting fixture,
Courtesy of Beta Lighting
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
BEFORE
Incandescent 65W BR30 - Total Power =5,135W
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
AFTER
Cree LR6 - Total Power = 948W
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
TWO YEARS AFTER
Total Power = 948W
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Burger King, Ben & Jerry’s
• 80% Energy Savings
• Excellent Color Rendering
(CRI >92)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Sheraton Hotel
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Sheraton Hotel
Cree LR4
2010 DALLAS
MARKET CENTER INTERNATIONAL LIGHTING MARKET
Sheraton Hotel
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Red Robin
Replacing Incandescent and Halogen lamps with
GE LED technology as part of an interior lighting
retrofit program in 274 restaurants
• 77% energy reduction per lamp
• Saves 14.8 metric tons CO2 per
store per year
• Lasts more than 6x longer than
Inc/Hal types
Courtesy of GE Lighting
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Yum Brands
• 46%/77% below ASHRAE
90.1 2007 (interior/exterior)
• 81% energy reduction from
baseline store
• 95% of lighting is highperformance LEDs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Courtesy of Derry
Berrigan, DBLD
McDonald’s
• 52%/70% below ASHRAE
90.1 2007 (interior/exterior)
• 78% energy reduction from
baseline store
Courtesy of Derry
Berrigan, DBLD
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
• 97% of lighting is highperformance LEDs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Starbuck’s
Replacing incandescent bulbs with GE LED
technology as part of a global interior lighting
retrofit program (over 8,000 worldwide locations)
• 7% energy reduction per
store
• 7.6 metric tons CO2 per
store
• Payback in 1.4 years
• Reduces bulb replacement
labor
• Included in 2 stores
registered for LEED(R)
certification
(1st and Pike, Seattle, Washington)
Courtesy of GE Lighting
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
• Implementation in US and
Int’l markets planned for
2010
Rome, Italy
40% Energy Savings
iGuzzini
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
NC State University Student Housing
Recessed fixtures in student housing
60% energy savings
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Walmart
Cree LRP38
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Residential Installation
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
More Residential Installations…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Hospitality
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Commercial / Office
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Driving Lumen Affordability with Technology
Need to work both
sides of the
equation
110%
Cool White (6000K)
Normalized $/lm
100%
90%
XR
80%
70%
60%
50%
XR-E
40%
XR-E
30%
(improved)
XP-E
20%
XM-L
XP-E
10%
(improved)
XP-G
2009
2010
2011
0%
2005
$/lm Change
Efficacy*
50 LPW
Increase (LPW)
2006
2007
2008
-50%
-30%
-14%
-33%
-45%
-36%
50 LPW
60 LPW
73 LPW
78 LPW
81 LPW
90 LPW
0%
20%
46%
56%
62%
80%
* At maximum drive current (except XR)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Real Example of the Cost Impact of
Increasing LED Performance
Cree LR6
Cree CR6
2007
2010
• 42 LEDs
• 650 lm
• 12W
• 8 LEDs
• 650 lm
• 10.5W
>$100 Commercial
Wholesale
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
$50 Retail
LED Fixture Levels of Performance (Current)
• Just like traditional lamps, ballasts and fixtures, LEDs have
losses beyond the boiler plate data sheet specs…
• …but the source of losses are somewhat different:
– Thermal (also a source of Lumen Depreciation)
– Optical (lenses, etc.)
– Driver (electrical losses in power conversion)
6000K
4100K
3500K
2700K
Data Sheet LPW
132
110
110
90
Typical* Thermal Loss
10%
10%
10%
10%
Typical* Optical Loss
10%
10%
10%
10%
Typical* Driver Loss
15%
15%
15%
15%
Achievable* LPW
86
72
72
59
CRI
~75
~80
~82
~83
* Typical with average/good design practices
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Fixture Levels of Performance (2012)
• LEDs will be the most efficient mainstream source
available
– >100 delivered LPW roadway light possible
– Indoor fixtures >80LPW (wall-plug)
• Efficiency drives COST in the LED world…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The Real Problem With LEDs – Education
You may not [YET] know how to tell on LED…
• You know extravagant
marketing claims on this
are not realistic
• You know what you are
getting when you buy one
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
• You expect top quality,
know how to tell when
you are getting it, and
are willing to pay for it
One More Point:
Everything we just
discussed is
irrelevant if the LED
luminaire fails to
pass the “Wife”
test…
No, really, honey. These LEDs will
pay for themselves in 50,000 hours…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Summary (So Far)
• LEDs are coming and will take their place and compete
in nearly every lighting application
• C&I segments will be first, residential mainstream in less
than three years
• LED technology is quite different from traditional
sources, and knowing a bit about “how it’s made” can be
an advantage to a consumer or specifier (essential for a
luminaire manufacturer)
• Well-designed LED luminaires will last for decades, may
change the whole bulb/fixture paradigm
• Poorly designed fixtures with cheap LEDs are
EVERYWHERE – caveat emptor!! (hope this was
helpful…)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Agenda
•
•
•
•
Dramatic Change is coming to the lighting world: An LED Roadmap
The real differences between LEDs and traditional light sources
LED Anatomy: Lumen output, spectral qualities color binning…
50,000 hours? Lifetime ratings and evaluation methods
• Break
• Performance economics, payback, ROI, and LCCA
• Applications that make sense today, tomorrow, or possibly never
• What about LED light bulbs? Costs? When will they come down…?
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Built to Last?
LED Strengths and
Limitations
Part 2
Keith Graeber
Director of Engineering
California Lighting Technology Center
LED strengths and limitations
• What to take into consideration when
choosing an LED luminaire
– Performance
– Economics
• Payback
• ROI
• LCCA
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Performance
What to look for?
•
•
•
•
Performance testing
Photometrics
Lifetime estimates
Claims of “equivalency”
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Lighting Measurement (LM) Series
• A series of approved methods written to permit reliable
comparison of test results among laboratories by establishing
uniform test methods
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What is IES LM-79-08
IES Approved Method for Electrical and Photometric
Measurements of Solid State Lighting Products
• Describes the method of absolute photometry for LED luminaires
and integral replacement lamps
• Provides performance data for the entire integrated SSL product
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Independent Testing Laboratories
• Independent laboratories can provide an unbiased report of a
SSL luminaire performance
• Laboratory should be certified to conduct tests in accordance
with LM-79
• CALiPER, NVLAP
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What information is contained in a
Certified Test Report?
• Photometric reports for SSL products tested in accordance with
LM-79 will contain the following key metrics:
– Electrical characteristics:
Input Voltage (V), input current (A), input power (W)
– Light output:
Total luminous flux (lm)
– Luminous intensity distribution:
Light distribution in tabular and polar graph format (cd)
– Color Characteristics:
Spectral power distribution that may be used to derive CRI, CCT, and
chromaticity coordinates
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Spectral Power Distribution
WARM WHITE LED
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
CERAMIC METAL HALIDE
Request Lumen Depreciation Test Data
from the Manufacturer
• Rate at which luminaire loses light is a direct measure of the
life of the luminaire
• Luminaire longevity claims should be supported by data from
the LED chip manufacturer
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED “Life”
• Rated lumen maintenance life (Lxx) is a
function of several operational and
environmental parameters
– Ambient temperature
– Junction temperature
– Operating current
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Rated Lumen Maintenance Life
• It is defined as the elapsed operating time over which the LED light
source will maintain a designated percentage of its initial light output
Example:
L70 = Time to 70% lumen maintenance, in hours = 50,000
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Sample Lifetime Prediction
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What is IES LM-80-08
IES Approved Method for Measuring Lumen
Maintenance of LED Light Sources
• Describes the procedures by which LED light sources can be
operated under controlled conditions to obtain optimally comparable
data on changes in light output during the life of the lamp.
• Only requires a minimum of 6,000 hours of life testing
• LM-80 does not specify how to predict long-term lumen maintenance
based on this data
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LM-80 Explained
• LM-80 is only a procedure to monitor lumen depreciation and
color shift, it is not a method to define life…life is still an unofficial
metric which may be calculated differently by different manufacturers
Cree XLamp XP-E Long-term Lumen Maintenance, November, 2010
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Example of LM-80 Data
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Product Warranty
• The manufacturer’s warranty is an indication of their confidence in
the product they are selling
• Get specifics on warranty and warranty programs up front
• It’s best when the manufacturer has demonstrated experience and
history with LEDs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
TM-21 to the rescue…
• Will consider different chip characteristics and effects to create an
extrapolation appropriate for the particular LED
• Unify procedures to define LED lumen maintenance and “life”
beyond LM-80 data
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Economics of LED Luminaires
Consider the Economics
• All project costs, over the lifetime of the luminaire, should be
considered before making a purchase decision
–
–
–
–
Maintenance costs for re-lamping or cleaning
Cost of money/interest on capital investment
Replacement cost of luminaires
Recycling costs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
IESNA RP-31-96
Recommended Practice for the
Economic Analysis of Lighting
• Describes an economic procedure for selecting from a group of
competing luminaires
• Provides a method for gauging the profitability of a capital
investment in a lighting system
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Second-level Economic Analysis
• Consider more than just simple payback or other
first-level analysis methods
• Adopt life cycle cost benefit analysis (LCCBA)
• Key feature is the evaluation of time and money
• Compares: Dollars today vs. Dollars tomorrow
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Life Cycle Cost Considerations
INITIAL COSTS
System, Labor, Material
Utility Incentives
Other First Costs Disposal
Total Costs
Salvage Value of the Fixture
Total Initial Costs
Annual Costs
Energy Costs
Annual Sensor/Controller Failure Costs
Normal Lamp replacement: equipment
Normal Ballast replacement costs
Labor Cost for Ballast Replacement
Labor Cost for Lamp Replacement
Vandalism Expense
Total Annual Costs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Case 1
Present Value of initial costs
Equivalent Annual Cost
Annual Cost of O/M
Interest Rate
Period
in years
Present value muliplier
Total Equivalent Annual Cost
Case 2
P
A
i
n
M
$
-
$
-
Consider All Available
Financial Incentives
• Group purchasing programs
• Utility rebates or incentive programs
• Tax credits
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Utility Rebate and Incentive Programs
Example: Pacific Gas & Electric Company
offers the LED Streetlight Program
• Customers who have installed or replaced existing street light
fixtures with LED fixtures will be able to switch to a lower billing rate
under the one type of rate schedule
• Customers who perform such replacements will be eligible for a
rebate for every qualified LED fixture purchased and installed
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Luminaire Rebates
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Applications
• Today
• Tomorrow
• Possibly never
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Today
• ENERGY STAR qualified products
– Residential
•
•
•
•
•
•
•
Kitchen undercabinet
Portable desk lights
Recessed, pendant downlights
Ceiling-mounted luminaires
Cove lighting
Surface-mounted directional lights
Outdoor porch, step, pathway, and decorative
lights
• All others
– Nonresidential
•
•
•
•
•
Recessed downlights
Undercabinet
Portable desk lights
Wall-wash luminaires
Bollards
• These are a done deal
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Tomorrow
• Proposed ENERGY STAR categories
– Outdoor lighting
• Spectrally tunable lighting
– Commercial
• Productivity
– Residential
• Ambiance
– Health
• Hospitals
• Assisted living
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Possibly Never
• High lumen density applications
– Stadium lighting
– High mast
• Spectrally sensitive applications
– Biological considerations
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What about LED light bulbs?
• Why do they cost so much?
– Early adoption phase
– Relatively high component cost
– In SSL you get what you pay for…it’s not
a commodity yet
• Three main approaches in the industry:
– Non-standard (“snow cone”)—
many suppliers
– Standard (standard optical pattern)
• GE’s approach— 40W equivalent
available now
• Philips’ approach— 40W and 60W
equivalents available now
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Snow Cones
• Neck becomes the heat sink
• Driver is embedded in the neck/heat sink
• LEDs (multiple approaches) mounted face up
in the top of the “cone”
• Simple diffuser dome, hemispherical light pattern
Kaipis A19 (1 MC-E LED)
LSG THD Bulb (2 Citizen arrays)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Tess 40W (7 MX-6 LEDs)
GE approach (40W equivalent)
• Standard LEDs face upward
(like snow cone)
• True omni-directional emission pattern
affected by proprietary optical design in globe
• Smaller neck, heat sink distributed around
lighting emitting surface in fin structures
6 XLamp XP-G LEDs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Philips approach (40W & 60W equivalent)
• LEDs face sideways to affect true
omni-directional emission pattern
• Blue LEDs are used; phosphor is located
remotely, on the three yellow lobes
• Heat sink and driver down in the neck
(same as snow cone”
w/remote phosphor removed
Blue!!
True 60W Equivalent!
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
18 Rebel LEDs (3*6)
Question:
How / when will LED bulbs get cheaper?
•
•
Answer: LEDs get cheaper AND brighter
Simple analysis
2010
– 2010: 40W snow cone: $20 retail
• 7 LEDs
– Assumptions:
• LEDs get 10% brighter each year—need
fewer LEDs
• LEDs get 10% cheaper also
•
•
– BOM drops by 50% 20102014
– 2014: 40W snow cone: <$10 retail
Simple analysis ignores any radical LED or
LED system innovation. Expect $5, not $10.
LED bulbs are a BAD idea. LED fixtures—that
last forever—will use less energy, look better,
and make better economic sense.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
7 LEDs
2014
3 LEDs
End of First Seminar
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What to look for in a
well-designed
LED luminaire.
Keith Graeber
kegraeber@ucdavis.edu
Director of Engineering
California Lighting Technology Center
Mark McClear
Mark_McClear@cree.com
Director of Applications Engineering
Cree, Inc
LED Luminaire Design Will Be Different…
Conventional
Lighting
Reflector
LED
Light
Heat
• LED Light is inherently directional
• LED thermal path accomplished by conduction
– No IR, no UV in the light beam
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
An Integrated Approach is Required
Heat Sink
Driver
LED Lamps
Optical Components
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
We’re Going To Need
Some New Tools…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Thermal:
LEDs Create Significant Amounts of Heat
35-45%
35-45%
55-70%
From DOE website:
http://www1.eere.energy.gov/buildings/ssl/comparing_lights.html
* Updated by Cree Jan 2010
 1W input = ~0.65W heat output
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Removing Waste Heat: 3 methods
• Conduction
– The LED’s first line of defense
to get the heat out. Typically
“through” a solid surface.
• Convection
– Must follow conduction.
Usually to the ambient air.
Typically from flow.
• Radiation
– Not a major factor unless very
high wattage system level.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Example of a Well-designed Heat Sink
Rule of Thumb (literally):
– The LEDs are probably too hot if:
• The luminaire is cool to the touch
• The luminaire is too hot to touch
LED
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
– Most people can touch and hold on to
about 45-50˚C – this is a “good”
thermal design range
Example fixtures – 150W Halogen Sconce – 2–12 LPW
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The Future of Halogen Fixtures?
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Sconce Equivalents – 50-65 LPW
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Optical: LED Secondary Optics
If the LED radiation pattern does not work for a particular application,
secondary optics are needed to change the light beam pattern from
LED.
Secondary Optics
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Secondary Optics
Colliminating: Focus the wide beam to narrower beam
Reflector + Lens
TIR Lens
Lens
Reflector
Spatial Radiation Pattern for LED with
Secondary Optics
Spatial Radiation Pattern for LED only
1
1
LED with secondary optics
0.8
Relative Intensity
Relative Intensity
0.8
0.6
0.4
0.6
0.4
0.2
0.2
0
0
-100
-50
0
50
100
Angle (º)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
-100
-50
0
Angle (º)
50
100
Driver: Make or Buy?
Make (Custom Design)
Advantages:
• Lower Cost
• Higher performance
Disadvantages:
• Longer design cycle time
• Longer UL, FCC certification
time
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Buy (Turnkey, Off-the-Shelf)
Advantages:
• Longer design cycle time
• Longer UL, FCC certification
time
Disadvantages:
• Lower Cost
• Higher performance
LED Retrofits Normally Don’t Work Out
So Well…
• Rolled or stamped
steel construction
• No thermal path to
the outside
• LEDs and driver
can get very hot
 reduces light
output, LED and
driver lifetime
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Quick Background – LED Packages and Types
Lamp Type
T1-type
(3 – 7 mm)
Surface
mount
P4
Drive Current
5 – 20 mA
Light Output
Brands
(Commodity
product)
<1 – 4 lm
Applications
•
•
•
•
Indicators
Novelty lights
Traffic signals
Electronic signs
5 – 20 mA
1 – 10 lm
•
•
•
TopLED
SideLED
Cree CLA1A
•
•
•
Automotive
LCD backlighting
Electronic signs
20 – 100 mA
1 – 20 lm
•
Piranha
•
•
Automotive
Channel letters
DRAGON
LUXEON
XLamp XPG
•
•
•
General illumination
Portable
Architectural
High power
200-1500 mA
50-400 lm
•
•
•
Multi-small
chip
200-700 mA
150-500 lm
•
•
XLamp MX6
XLamp MLE
•
General illumination
300-3000 lm
•
•
•
OSTAR
XLamp MPL
XLamp MCE
•
General illumination
Multi-power
chip
200-1000 mA
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Anatomy
• LED Chip:
– Determines raw brightness
and efficacy
• Phosphor system:
– Determines color point and
color point stability
• Package/Lens:
– Protects the chip and
phosphor
– Helps with light and heat
extraction
– Primary in determining LED
lifetime
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Thermal Path is Critical to LED Lifetime
5mm LED
No Thermal
path
• 5mm lamps have almost
no thermal path
• RTH >350ºC/W typical
• Chip (TJ) and phosphor
can essentially cook
themselves
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Lighting-class LED
Thermal path
• Lighting-class LEDs are
designed for high temp
operation
• RTH <10ºC/W typical
• Lamp can stay within data
sheet parameters with
good thermal design
50,000 hours is:
137
68.5
34.2
22.8
17.1
11.4
5.7
Years at 1 hour/day
Years at 2 hours/day
Years at 4 hours/day
Years at 6 hours/day
Years at 8 hours/day
Years at 12 hours/day
Years at 24 hours/day
…A WAG when it comes to LED lifetime…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Semiconductor Reliability Testing
• Reliability test methods and acceptance criteria for
semiconductor components have been standardized
(JEDEC, EIAJ, others…) and practiced for decades
– Think: processors, regulators, microcontrollers, etc..
Every time you’ve flown in an airplane, driven in a
car, or talked on a cell phone, you’ve depended on
this body of scientific work and testing…
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Reliability Testing
• LEDs are semiconductor
components that happen to emit light…
• Most LED manufacturers conduct standardized
semiconductor component reliability testing – the same
tests Intel tests their microprocessors with – on their LED
lamps
• The Illumination Engineering Society of North America
published IES LM-80-2008 two years ago to characterize
the Lumen Maintenance aspect of LED semiconductor
components
• Note: Lumen Maintenance ≠ LED Lifetime. Another
standards committee – TM-21 – is working on that aspect
of the problem
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Lifetime
110%
Lumen Output (%)
100%
90%
100 W Incandescent
5mm LED
42W CFL
50 W Tungsten Halide
400 W Metal Halide
25 W T8 Fluorescent
Lighting-class LED
80%
70%
60%
50%
40%
0
10
20
30
40
50
60
Operating Time (k hrs)
70
80
90
100
Courtesy LRC, Rensellaer Polytechnic Institute
• Lighting-class LEDs typically become dimmer
over time with no catastrophic failure
• End of life defined by the LED becoming too dim
– needed to define Lumen Maintenance (L70)
• Not all LED types have a long L70 or lifetime
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LEDs Last Forever!
[under ideal conditions]
LowAttemp
is a goodLighting-class
surrogate for
lower(25ºC)
ambienttesting
air temperatures,
the LED chipLEDs
depreciation
– 1-2%
@ TJ = 65ºC
hardly depreciate
at all
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Everyone Asks for an “LM-80 Test Report”
Here is what one looks like (too detailed, no interpretation, just data…):
Product
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
Product
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
XRE XLamp
Lamp Color
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Temperature
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
Drive Current (mA)
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
BoardID
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
Lamp Color
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Cool White
Lamp Number
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
0
ccx
0.31780
0.31781
0.31942
0.31856
0.32009
0.31961
0.32138
0.31786
0.32359
0.32012
0.30957
0.30992
0.30350
0.31022
0.30857
0.30798
0.30921
0.30685
0.30739
0.30734
0.31256
0.31004
0.31113
0.31545
0.31444
0.31571
0.31137
0.31557
0.31114
0.31350
Temperature
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
55C
0
ccy
0.33520
0.33644
0.33512
0.33609
0.33523
0.34096
0.34430
0.33375
0.34138
0.34131
0.32778
0.32951
0.31697
0.32142
0.32362
0.32173
0.32296
0.32063
0.31953
0.32060
0.31962
0.31810
0.31543
0.32814
0.32145
0.32306
0.31313
0.31917
0.31388
0.32077
168
ccx
0.31776
0.31725
0.31791
0.32010
0.31910
0.32095
0.32088
0.31581
0.32158
0.32091
0.30914
0.30882
0.30341
0.30911
0.31059
0.30819
0.30847
0.30608
0.30889
0.30811
0.31371
0.31028
0.31193
0.31662
0.31482
0.31514
0.30908
0.31275
0.31054
0.31508
Drive Current (mA)
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
350
168
ccy
0.33226
0.33421
0.33385
0.33708
0.33556
0.34111
0.34325
0.32791
0.33984
0.34271
0.32669
0.32711
0.31658
0.32278
0.32470
0.32251
0.32159
0.31987
0.32023
0.31969
0.31889
0.31906
0.31617
0.32750
0.32177
0.32210
0.30924
0.31525
0.31281
0.32276
336
ccx
0.31697
0.31706
0.31668
0.31877
0.31877
0.31963
0.32170
0.31775
0.32154
0.32019
0.30949
0.30791
0.30273
0.30926
0.30763
0.30855
0.30868
0.30596
0.30906
0.30576
0.31042
0.30976
0.30998
0.31562
0.31412
0.31314
0.31156
0.31265
0.30980
0.31510
336
ccy
0.33263
0.33107
0.33310
0.33541
0.33484
0.34097
0.34259
0.33182
0.33937
0.34240
0.32701
0.32641
0.31507
0.32247
0.32140
0.32226
0.32210
0.31986
0.32094
0.31847
0.31493
0.31760
0.31388
0.32707
0.32103
0.31933
0.31201
0.31640
0.31116
0.32203
BoardID
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011H
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011K
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
DUR011M
672
ccx
0.31722
0.31517
0.31668
0.31792
0.31901
0.31933
0.32101
0.31596
0.32134
0.31958
0.31002
0.30857
0.30347
0.30907
0.30733
0.30768
0.30969
0.30448
0.30779
0.30575
0.31159
0.31030
0.30924
0.31469
0.31475
0.31482
0.30922
0.31207
0.31067
0.31455
Lamp Number
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
672
ccy
0.33264
0.32965
0.33329
0.33452
0.33440
0.34038
0.34215
0.32934
0.33886
0.33965
0.32631
0.32635
0.31750
0.31734
0.32125
0.32186
0.32021
0.31690
0.32131
0.31866
0.31802
0.31857
0.31101
0.32311
0.32056
0.32180
0.31095
0.31259
0.31250
0.32093
840
ccx
0.31755
0.31622
0.31691
0.31894
0.31865
0.32001
0.32050
0.31653
0.32155
0.32114
0.30779
0.30895
0.30373
0.30959
0.30902
0.30651
0.30846
0.30581
0.30736
0.30623
0.31067
0.31024
0.31166
0.31369
0.31411
0.31429
0.30870
0.31313
0.31255
0.31489
840
ccy
0.33281
0.33168
0.33356
0.33480
0.33454
0.34062
0.34179
0.33019
0.33892
0.34173
0.32356
0.32864
0.31776
0.32238
0.32486
0.31797
0.32166
0.31964
0.31982
0.31929
0.31576
0.31903
0.31510
0.32513
0.32094
0.32215
0.30951
0.31836
0.30988
0.32162
0
119.56
120.68
118.83
120.38
122.92
122.38
120.91
119.57
120.19
121.60
99.24
100.77
100.35
102.73
97.67
101.04
98.79
101.24
102.19
99.18
97.48
97.16
96.73
96.29
97.11
97.56
97.11
95.08
96.43
96.64
1008
ccx
0.31698
0.31691
0.31678
0.31841
0.31802
0.31954
0.32051
0.31848
0.32234
0.31980
0.30833
0.30881
0.30289
0.30864
0.30923
0.30743
0.30851
0.30591
0.30993
0.30620
0.31207
0.31160
0.30926
0.31533
0.31514
0.31407
0.30924
0.31058
0.30959
0.31433
168
117.79
117.35
117.36
118.24
121.63
120.78
118.77
118.10
117.72
120.19
98.26
99.83
98.17
102.12
97.87
100.58
98.89
101.75
101.46
97.31
98.37
95.95
97.69
94.96
96.56
97.30
96.35
94.82
96.11
96.18
1008
ccy
0.33271
0.33336
0.33338
0.33545
0.33301
0.34064
0.34245
0.33025
0.33854
0.34179
0.32485
0.32823
0.31533
0.32128
0.32374
0.32071
0.32180
0.31919
0.32126
0.31930
0.31809
0.31842
0.31245
0.32659
0.32040
0.32179
0.31084
0.31398
0.31083
0.32023
336
117.89
118.22
117.99
118.79
121.95
121.19
118.52
119.03
118.51
119.78
99.18
100.81
99.08
101.92
97.83
100.74
99.08
101.38
101.58
98.19
97.86
95.58
96.73
95.40
96.16
96.89
96.47
94.64
96.06
96.06
1176
ccx
0.31685
0.31670
0.31622
0.31765
0.31840
0.31902
0.31992
0.31750
0.31970
0.31930
0.30905
0.30907
0.30290
0.30760
0.30881
0.30707
0.30853
0.30476
0.30789
0.30461
0.31067
0.31085
0.31130
0.31454
0.31417
0.31339
0.30871
0.31363
0.31007
0.31258
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
1176
ccy
0.32973
0.33320
0.33063
0.33397
0.33386
0.33961
0.34111
0.33080
0.33571
0.34069
0.32666
0.32815
0.31580
0.31908
0.32445
0.31780
0.31966
0.31563
0.32091
0.31556
0.31579
0.31818
0.31453
0.32527
0.31842
0.32037
0.30957
0.31744
0.31196
0.31693
672
119.25
119.45
118.98
119.81
123.00
122.33
119.81
120.05
119.43
120.77
99.96
101.47
99.81
103.39
99.40
102.20
100.51
103.27
103.02
98.90
98.88
96.73
97.86
95.92
97.05
97.95
97.24
95.48
96.76
96.84
1512
ccx
0.31430
0.31570
0.31684
0.31908
0.31736
0.31906
0.31990
0.31639
0.32150
0.31895
0.30911
0.30852
0.30322
0.30883
0.31027
0.30941
0.30807
0.30603
0.30719
0.30572
0.31031
0.30971
0.31014
0.31390
0.31345
0.31426
0.30864
0.31310
0.31089
0.31347
840
119.35
119.56
119.15
119.71
123.05
122.32
120.69
119.56
119.01
121.58
99.81
101.21
99.55
103.10
99.27
102.09
100.43
103.13
102.82
98.72
100.06
97.90
98.14
96.28
97.36
98.07
97.62
95.96
97.10
97.05
1512
ccy
0.32670
0.33072
0.33208
0.33470
0.33189
0.33978
0.34035
0.32834
0.33631
0.34002
0.32479
0.32787
0.31671
0.32150
0.32386
0.31943
0.32097
0.31792
0.31882
0.31840
0.31466
0.31808
0.31433
0.32591
0.31974
0.32097
0.30965
0.31712
0.31168
0.32121
2016
ccx
0.31638
0.31602
0.31612
0.31808
0.31837
0.31813
0.32079
0.31631
0.32095
0.32007
0.30853
0.30774
0.30269
0.30919
0.31070
0.30699
0.30830
0.30542
0.30568
0.30543
0.31104
0.31114
0.31011
0.31251
0.31460
0.31339
0.30701
0.31162
0.30972
0.31376
1008
119.29
119.92
119.34
119.69
123.21
122.53
120.85
119.72
119.02
121.53
99.93
101.21
99.60
103.08
99.27
102.24
100.53
102.92
102.88
98.80
99.95
97.74
98.62
96.17
96.96
97.80
97.40
95.81
97.18
96.96
2016
ccy
0.33148
0.33172
0.33220
0.33441
0.33317
0.33773
0.34019
0.32998
0.33489
0.33866
0.32591
0.32403
0.31475
0.32098
0.32353
0.31943
0.32058
0.31705
0.31613
0.31551
0.31689
0.31740
0.31248
0.32275
0.31911
0.32060
0.30587
0.31471
0.31119
0.32063
1176
119.66
120.48
119.88
120.17
122.55
122.94
120.66
119.41
118.70
121.32
100.58
101.02
99.38
102.96
99.18
102.04
100.41
102.94
102.67
98.64
99.34
97.14
97.99
96.18
96.77
97.67
97.45
95.69
97.14
96.86
2520
ccx
0.31622
0.31606
0.31532
0.31874
0.31870
0.31752
0.32052
0.31621
0.31978
0.31849
0.30852
0.30868
0.30292
0.30977
0.30848
0.30754
0.30781
0.30437
0.30737
0.30489
0.31098
0.30926
0.30854
0.31229
0.31329
0.31302
0.30950
0.31213
0.30958
0.31382
2520
ccy
0.33109
0.33141
0.33017
0.33388
0.33274
0.33627
0.34081
0.32982
0.33625
0.33756
0.32559
0.32650
0.31604
0.32072
0.32368
0.31887
0.32042
0.31648
0.31995
0.31646
0.31696
0.31702
0.31118
0.32105
0.31933
0.31960
0.31058
0.31188
0.31100
0.32059
1512
119.12
119.68
118.90
119.32
122.90
122.50
121.06
119.71
118.75
121.37
99.93
101.10
99.31
102.80
99.33
101.94
100.28
102.96
102.59
98.53
99.90
97.68
97.73
95.83
96.75
97.79
97.17
95.44
96.79
96.57
3024
ccx
0.31692
0.31626
0.31716
0.31744
0.31673
0.31816
0.31879
0.31492
0.32007
0.31812
0.30790
0.30799
0.30207
0.30778
0.30703
0.30660
0.30615
0.30460
0.30686
0.30521
0.30849
0.30908
0.31007
0.31104
0.31217
0.31288
0.30665
0.31031
0.30825
0.31139
2016
120.01
120.78
119.95
120.20
122.84
123.48
121.21
119.97
119.11
121.56
100.96
101.23
99.42
102.82
99.46
102.01
100.56
103.05
102.56
98.60
99.39
97.53
98.05
96.14
96.81
97.74
97.31
95.45
96.93
96.76
3024
ccy
0.33010
0.33024
0.33070
0.33281
0.33078
0.33829
0.33899
0.32436
0.33472
0.33857
0.32458
0.32485
0.31360
0.31997
0.32070
0.31953
0.31698
0.31751
0.31922
0.31677
0.31143
0.31670
0.31279
0.31918
0.31718
0.31965
0.30407
0.31225
0.30830
0.31670
3528
ccx
0.31613
0.31544
0.31532
0.31624
0.31802
0.31799
0.31826
0.31506
0.31932
0.31804
0.30767
0.30707
0.30074
0.30675
0.30837
0.30739
0.30605
0.30438
0.30750
0.30459
0.31041
0.31059
0.30878
0.31204
0.31502
0.31273
0.30714
0.31177
0.30889
0.31030
2520
118.40
119.30
118.34
118.42
122.21
121.86
120.52
118.90
118.07
120.37
99.46
100.61
98.81
102.10
98.99
101.40
99.90
102.29
101.92
98.11
99.17
97.50
97.70
95.24
95.72
96.79
96.51
94.62
96.08
95.89
3528
ccy
0.33048
0.33156
0.33136
0.33228
0.33127
0.33858
0.33842
0.32828
0.33642
0.33774
0.32500
0.32530
0.31122
0.31738
0.32297
0.31943
0.31743
0.31750
0.31925
0.31692
0.31652
0.31692
0.31258
0.32287
0.31925
0.31825
0.30665
0.31535
0.31052
0.31507
3024
118.91
119.94
119.01
119.03
121.52
122.34
120.11
118.56
117.88
120.21
100.04
100.52
98.56
101.78
98.90
101.08
99.72
102.08
101.52
97.80
98.16
96.67
96.80
94.99
95.40
96.56
96.03
94.42
95.62
95.55
4032
ccx
0.31484
0.31530
0.31549
0.31630
0.31639
0.31730
0.31893
0.31492
0.32022
0.31693
0.30663
0.30710
0.30322
0.30749
0.30628
0.30558
0.30639
0.30452
0.30574
0.30409
0.31104
0.30987
0.30762
0.31097
0.31236
0.31245
0.30804
0.31045
0.31006
0.31239
4032
ccy
0.32955
0.33027
0.33005
0.33255
0.32976
0.33748
0.33926
0.32831
0.33553
0.33704
0.32282
0.32598
0.31298
0.31901
0.31937
0.31835
0.31833
0.31621
0.31730
0.31574
0.31320
0.31548
0.31011
0.32072
0.31837
0.31972
0.30966
0.31530
0.30997
0.31918
3528
118.75
120.05
118.97
118.86
121.65
122.52
120.33
118.68
118.00
120.27
100.07
100.66
98.51
101.74
99.06
101.02
99.79
101.97
101.51
97.79
97.85
96.47
96.71
94.91
95.02
96.29
95.92
94.20
95.41
95.48
4536
ccx
0.31470
0.31484
0.31445
0.31692
0.31480
0.31776
0.31853
0.31648
0.31807
0.31729
0.30699
0.30644
0.30069
0.30838
0.30678
0.30645
0.30611
0.30352
0.30585
0.30343
0.31016
0.30829
0.30871
0.31105
0.31313
0.31272
0.30688
0.30939
0.30986
0.31196
4032
117.61
118.55
117.64
117.63
120.26
121.19
118.88
117.44
117.14
119.19
99.09
99.58
97.56
100.73
98.17
99.88
98.50
101.34
100.11
96.63
96.90
95.82
96.16
93.75
94.03
95.54
94.93
93.21
94.54
94.46
4536
ccy
0.32934
0.33019
0.33010
0.33179
0.32760
0.33672
0.33944
0.32793
0.33411
0.33805
0.32256
0.32444
0.31253
0.31879
0.32147
0.31810
0.31829
0.31619
0.31825
0.31237
0.31632
0.31506
0.31281
0.32075
0.32001
0.32032
0.30725
0.31328
0.31001
0.31938
5040
ccx
0.31483
0.31468
0.31457
0.31599
0.31641
0.31730
0.31941
0.31353
0.31902
0.31742
0.30663
0.30724
0.30112
0.30685
0.30684
0.30555
0.30603
0.30451
0.30589
0.30390
0.31194
0.30856
0.30821
0.31263
0.31472
0.31491
0.30829
0.30834
0.30830
0.31175
4536
117.87
119.12
118.17
118.05
120.74
121.58
119.21
117.67
117.32
119.37
99.21
99.76
97.63
100.77
98.29
100.07
98.81
101.37
100.41
96.94
97.03
96.20
96.15
93.92
92.96
94.86
95.81
94.19
95.41
95.36
5040
ccy
0.32951
0.33026
0.32997
0.33225
0.32986
0.33570
0.33946
0.32552
0.33648
0.33817
0.32281
0.32334
0.31054
0.31906
0.32152
0.31822
0.31817
0.31467
0.31816
0.31560
0.31652
0.31665
0.31158
0.32422
0.32049
0.32077
0.31034
0.31058
0.30535
0.31883
5040
116.63
117.91
116.96
116.78
119.56
120.32
118.08
117.67
117.17
118.09
98.00
98.48
96.30
99.50
96.88
98.69
97.63
100.01
99.22
95.72
95.27
94.84
94.79
92.45
91.41
93.43
94.40
92.85
93.85
94.01
5544
ccx
0.31404
0.31475
0.31381
0.31464
0.31647
0.31725
0.31870
0.31563
0.31836
0.31744
0.30731
0.30677
0.30013
0.30672
0.30856
0.30538
0.30590
0.30508
0.30388
0.30404
0.30941
0.30873
0.30943
0.31419
0.31581
0.31181
0.30996
0.31027
0.30729
0.31258
5544
ccy
0.32734
0.33017
0.32777
0.32884
0.33124
0.33721
0.33969
0.32806
0.33468
0.33817
0.32360
0.32459
0.31121
0.31898
0.32112
0.31811
0.31793
0.31592
0.31355
0.31545
0.31443
0.31681
0.31344
0.32421
0.32232
0.31783
0.31068
0.31500
0.30610
0.31971
5544
116.18
117.41
116.70
116.36
120.45
120.35
118.62
117.31
116.76
118.94
97.74
99.38
97.27
100.26
97.92
99.67
98.61
100.82
100.27
96.67
94.95
94.80
94.59
92.65
90.94
92.95
94.21
92.84
93.98
94.14
6048
ccx
0.31380
0.31411
0.31421
0.31529
0.31713
0.31723
0.31715
0.31666
0.31840
0.31709
0.30541
0.30678
0.30091
0.30547
0.30742
0.30614
0.30495
0.30251
0.30549
0.30411
0.31196
0.30800
0.31035
0.31252
0.31532
0.31396
0.30863
0.31131
0.30902
0.31188
6048
116.77
118.23
117.28
116.80
121.06
120.76
119.25
117.68
117.48
119.21
98.24
99.87
97.82
100.72
98.56
100.13
99.08
101.22
100.78
97.21
94.70
94.77
94.48
92.85
90.65
92.93
94.24
92.92
93.96
94.26
6048
ccy
0.32532
0.32891
0.32928
0.33069
0.33075
0.33659
0.33617
0.32730
0.33377
0.33770
0.31972
0.32350
0.31339
0.31616
0.32068
0.31746
0.31453
0.31401
0.31767
0.31484
0.31708
0.31451
0.31277
0.32412
0.32146
0.32200
0.30851
0.31630
0.31120
0.31929
6552
ccx
0.31416
0.31524
0.31394
0.31421
0.31657
0.31688
0.31872
0.31481
0.31994
0.31709
0.30841
0.30675
0.30291
0.30590
0.30728
0.30440
0.30768
0.30383
0.30519
0.30329
0.31124
0.30897
0.30968
0.31317
0.31407
0.31481
0.30948
0.31154
0.30992
0.31102
6552
115.09
116.58
115.70
115.20
119.20
119.11
117.21
116.00
115.41
117.40
96.64
98.14
96.01
98.92
96.82
98.40
97.35
99.43
98.99
95.34
92.33
92.85
92.50
91.06
88.58
90.94
92.00
90.83
91.31
91.79
6552
ccy
0.32759
0.32957
0.32842
0.32797
0.33126
0.33490
0.33952
0.32808
0.33694
0.33660
0.32355
0.32134
0.31209
0.31695
0.31925
0.31569
0.31578
0.31529
0.31664
0.31453
0.31848
0.31746
0.31463
0.32527
0.32104
0.32366
0.31270
0.31769
0.31276
0.31540
LM-80 & TM-21
LM-80
(testing)
+
TM-21
(projection)
=
Something
useful
• LM-80 is just an LED testing standard
• Luminaire manufacturers rightly want and need to
understand and have confidence in the real lifetime of the
LED lamps they are buying (and to set their warranties)
• LM-80 alone cannot give this
• IES TM-21 will provide the mathematical framework for
taking LM-80 data and making useful LED lifetime
projections from it
• TM-21 is in committee now, expect ballot 1Q11
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Lifetime Is Irrelevant
System Lifetime is What Creates Value
Heat Sink: Linchpin of the entire system.
If this is poorly designed, all the other
components can be compromised
Driver: Can be the weak
link in the system if cheap
components are used
LED Lamps: Practically never
fail; depreciate very slowly in a
well-designed system
Optical Components: Can
(rarely) yellow over time and
lose light; system design choice
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED Junction Temperature (TJ)
The LED junction is the area of the chip that actually creates
light. Under normal operation, this area of the chip will get hot
Running an LED above its
rated maximum junction
temperature will decrease
its active lifetime and
accelerate its lumen
maintenance loss
The LED junction temperature is affected by:
• Ambient temperature of the LED’s immediate surroundings
• Thermal path between the LED junction and ambient conditions
• Power dissipated by the LED
The LED junction temperature is measured by:
• Measuring the board temperature (Solder Point)
adjacent to the LED (TSP)
• Computing the junction temperature (TJ) based on the drive
current and data sheet parameters (RTH) is straight-forward
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Junction Temperature Calculation
• TJ = TSP + RTH * IF * VF
– TSP is solder point temperature
– RTH is the thermal resistance of the LED in ºC/Watt
(LED datasheet)
– IF is the forward current in Amperes
– VF is the forward voltage in Volts
• Example:
–
–
–
–
TSP = 60 ºC
RTH = 9 ºC/Watt (from data sheet)
IF = 700mA (0.7A)
VF = 3.2V
TSP
 TJ = 60 + [(9) * (0.7) * (3.2)] = 80 ºC
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
LED System Integration
LED + Thermal + Optics + Driver
SSL Luminaire: Multi-Disciplinary Effort
Electrical
Thermal
Optical
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
• Integrated systems approach
required
• LED light is different than
existing light technologies
• Not intuitive at first
Delivered
lumens
Delivered
LPW
• These charts are on all LED data
sheets; familiarization with them
is essential to good results
Lumens, LPW in the REAL World
Case Study:
Can Light, 650 lumens
Warm white (3000K)
XLamp XP-E, Q2 LF Bin (87.4 lm)
700mA IF
1.
Find 700mA point on
relative intensity curve
2.
Typical LF should be:
LF = 87.4 lm * 175%
LF = 154 lm
EASY!!
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Lumens, LPW in the REAL World, p.2
Case Study:
Can Light, 650 lumens
Warm white (3000K)
XLamp XP-E, Q2 LF Bin (87.4 lm)
700mA IF
3. Determine your thermal
pad temperature (Tsp)
– Requires
measurement
Assume Tsp = 60°C
LF = 154 lm * 87%
LF = 134 lm
EASY!!
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Lumens, LPW in the REAL World, p.3
Case Study:
Can Light, 650 lumens
Warm white (3000K)
XLamp XP-E, Q2 LF Bin (87.4 lm)
700mA IF
4. Find 700mA on VF curve
VF = 3.36V @ 25ºC
5. Calculate VF @ 60ºC from
data sheet (TCOV)
VF = VF@25ºC –(TCOV(60-25))
VF = 3.36-(0.004(60-25))
VF = 3.22V @ 60ºC
6. LPW
= lumens / Watts
= lumens / VF * IF
= 134 / 3.22 * 0.7
= 59.6 LPW
EASY (kind of…)!!
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Optical Losses
Secondary Optics
Diffuser
Reflector
Lens
85%-90% Efficient
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
75%-95% Efficient
Driver Losses
90
Efficiency (%)
85
80
75
70
65
60
0
20
40
60
80
Output Load (%)
Generally, 80% - 85% is a good
estimate – but some can be higher
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
100
Lumens, LPW in the REAL World, p.4
Delivered Lumens, LPW
= 134 * 86% (optical loss)
7.
= 115 lumens per LED
= 115/3.22 * 0.7
= 51 LPW, 6 LEDs needed, ~650 lm
= 51 LPW * 80% (driver loss)
= 41 LPW (wall-plug, delivered LPW)
Your Boss shows you press
releases from LED companies and
the spec sheets of LED luminaires
from your competitors and wants
to know why your design is so
uncompetitive?
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Assume:
– 86% Efficient Diffuser
– 80% Efficient Driver
Iterative
…But
More
Process:
Power =
More
Lower
Power
Efficacy
= More
(Droop)
Light…
100
90
70
60
50
40
30
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Lumens per Watt
80
The Point of Going Through all this:
Many Degrees of Freedom for System Optimization
If(mA)
700
550
400
LPW
41
44
48
# of LEDs
6
7
9
Energy Star?
No
Cost
$
$+
$++
• There is almost always an opportunity to trade-off drive current
and thermal design for both system LPW (efficacy) and overall
system cost
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Tools For Doing It: Product Characterization Tool (PCT)
System:
650
Target Lumens :
Current (A)
Pass #1: 25'C Tj
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.500
0.550
0.600
0.650
0.700
0.750
0.800
0.850
0.900
0.950
1.000
1.100
1.200
1.300
1.400
1.500
1.600
1.700
1.800
1.900
2.000
Model
Flux
Price
Tj (ºC)
$
64
62.2
59.3
57.4
54.7
53.6
51.7
50.6
49
48.1
46.9
45.8
44.4
43.3
42.2
41.2
40.4
39.5
38.6
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
Flux
Price
-
SYS # LED SYS lm/W
28
19
15
12
10
9
8
7
7
6
6
6
5
5
5
5
5
4
4
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
25
LED Vf
2.99
3.03
3.08
3.12
3.16
3.2
3.24
3.27
3.3
3.33
3.35
3.38
3.4
3.42
3.44
3.45
3.46
3.47
3.48
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
LED lm
28
41
53
65
76
87
98
108
118
128
137
146
154
162
169
176
183
189
195
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
Tsp (ºC)
$
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
60.7
58.2
55.6
53.3
51.9
50.1
48.4
47.4
45.4
44.1
43.1
41.9
40.9
39.7
38.9
37.7
36.6
35.6
34.7
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
60
LED Vf
2.87
2.91
2.95
2.99
3.02
3.06
3.09
3.11
3.14
3.16
3.18
3.2
3.22
3.23
3.24
3.25
3.26
3.26
3.27
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
(none)
Flux
Price
-
SYS # LED SYS lm/W
30
21
16
13
12
10
9
8
8
7
7
6
6
6
6
5
5
5
5
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
LED 3
Model
Cree XLamp XP-E {CW/NW/WW}
Q2 [87.4]
80%
Electrical Efficiency:
Pass #2: 60'C Tsp
Model
Cree XLamp XP-E {CW/NW/WW}
Q2 [87.4]
86%
Optical Efficiency:
Tsp (ºC)
$
25
2.10
LED lm
26
37
48
58
69
78
87
96
104
112
120
127
134
140
146
151
156
161
165
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
www.cree.com/PCT
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
#N/A
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#N/A
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#N/A
#N/A
#N/A
#N/A
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#N/A
#N/A
#N/A
16.5”Go
Lowes
When Things
Wrong…
Time zero
1000 hours
LED Puck
84.1% Drop
16.5” Linear
97.8% Drop
22” Linear
96.9% Drop
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Other Problems: Driver & Thermal
• Driver/circuit board
failure
• Color Shift Due to poor
thermal design
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Optical Design & Poor LEDs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Your LED Lighting Mileage May Vary…
Lighting-class LEDs
Thermal design
Optical design
Electronic design
Bad
Good
–
–
–
–
Good
Excellent
BAD
Bad
• Keys to success
Luminaire Design
Quality of LED
• To enable general
illumination, LED
systems must deliver
real benefits
BAD
BAD
Results
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Future-proofing Your
Design
Rapid Technology Advancement
260
240
Theoretical maximum for LED
220
208 LPW
200
R&D Capability
CW Lumens/watt
180
186 LPW
161 LPW
160
140
131 LPW
3 yrs
120
100
80
60
XP-G
XP-E
HID
XR-E
Fluorescent
High Volume
Production
XR-E
CFL
40
20
LED
Incandescent
0
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Strategy #1 for Coping With Rapid
Change in LED Performance
Modular Approach to MH Source Replacement
Generic LED Strip
Driver
Circuit
(optional)
Fixed Number of LEDs
Generation 1
Generation 2
A modular design approach can yield constant photometric output while
facilitating ongoing cost reductions each time LED brightness is improved
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Generation 3
Strategy #2 for Coping With Rapid
Change in LED Performance
Aim Ahead of the Duck…
LF Distribution
0.8*$X
$X
0.8*$X
1.2*$X
$X
1.2*$X
Prototyping with the highest performance LEDs currently available is more expensive,
but can yield a more competitive and longer life product over the long term
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Strategy #3 for Coping With Rapid
Change in LED Performance
Plan for BOM savings
Generation 1
Generation 2
25% brighter LEDs can also mean 25% fewer LEDs. Need to plan
flexibility in your driver design to accomplish this
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Strategy #4 for Coping With Rapid
Change in LED Performance
Luminous Flux Bin
Plan To Switch LEDs
LED “A”
LED “B”
LED “C”
$
$$
$$$
Multi-vendor
strategy
2010 DALLAS MARKET CENTER INTERNATIONAL
LIGHTING
MARKET
or broad line supplier of LEDs
What to Look For (Summary so far…)
• Be skeptical of LED retrofits of traditional lighting fixtures
– Thermal design can be very challenging
• Don’t specify fixtures with toy LEDs (watch for 5mm
LEDs)
• Remember the thermal touch test (rule of thumb…)
• Fixture should demonstrate a balanced, integrated
approach
–
–
–
–
LEDs
Thermal
Optical
Electrical
• Bonus points: Some future-proofing strategy
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What to look for in a
well-designed
LED luminaire.
Part 2
Keith Graeber
Director of Engineering
California Lighting Technology Center
Federal and State Performance Standards
Federal Standards
• ASHRAE 90.1
• ENERGY STAR (DOE and EPA)
• Lighting Facts (DOE)
SSL Standards (U.S.)
• 4 years ago Major and reasonable
objection to LED
• Today:
–
–
–
–
–
RP-16: SSL Definitions
ANSI C78.377: Chromaticity
IES LM-79-2008: SSL photometry
IES LM-80-2008: Lumen maintenance
UL 8750: Safety
• Most of the major pieces are in place,
many more on the way
• Being practiced and referenced
worldwide by industry and government
programs
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Many
Others
UL 8750
LM-80
LM-79
ANSI C78.377
RP-16 – SSL Definitions
ANSI Chromaticity Standard
0.45
2700 K
0.44
3000 K
0.43
3500 K
0.42
+
4000 K
0.41
0.40
+
4500 K
+
CCy
0.39
5000 K
0.38
5700 K
0.37
0.36
+
+
+
6500 K
0.35
+
0.34
0.33
BBL
+
0.32
0.31
0.30 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.40 0.41 0.42 0.43 0.44 0.45 0.46 0.47 0.48 0.49 0.50
CCx
ANSI Fluorescent Lamp Standard
ANSI C78.377A LED Standard
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
NEMA SSL-3 Binning Standard
Under Development
• Common chromaticity bins
• Flux bins by decades:
• 100, 110, 120…lumens
• VF binning also…
New NEMA “SSL-3” Binning Standard
ANSI C78.377A SSL Chromaticity Standard
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
ANSI/ASHRAE/IESNA 90.1 – 2010
Energy Standard for Buildings Except Low-rise Residential Buildings
• ANSI – American National Standard Institute
• ASHRAE – American Society of Heating, Refrigerating and Air-Conditioning Engineers
• IESNA – Illuminating Engineering Society of North America
• Established by U.S. Department of Energy (DOE) as the
commercial building reference standard
(Energy Policy Act of 2005)
• Lighting Scope
– Interior spaces
– Exterior building features
– Exterior building grounds lighting
Scope exceptions: Some emergency lighting, lighting within dwelling units,
mandated health or safety lighting, decorative gas lighting systems
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
ASHRAE 90.1 Power Allowance Limit
Defines the allowed installed lighting wattage in a building or space
– Includes lamp, ballasts, transformers and control devices
– The maximum lighting power in watts allowed for a building/space
Defining the Lighting Power Allowance
– Lighting Power Density (LPD) Watts per square foot
• LPD Values provided by ASHRAE 90.1 LPD Charts (next slide)
– Building Area Method
» (Whole building LPD) x (Total building area)
» Simple calculation, but less flexible
– Space-by-Space Method
(𝑆𝑝𝑎𝑐𝑒 𝑏𝑦 𝑆𝑝𝑎𝑐𝑒 𝐿𝑃𝐷) 𝑥 (𝑆𝑝𝑎𝑐𝑒 𝑎𝑟𝑒𝑎)
» Sum of spaces in building:
» Power allowance limit increases for spaces using automatic controls
(LED consumes very little wattage compared to conventional lighting!)
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
ASHRAE 90.1 – 2010 LPD Allowance
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
ENERGY STAR
• Joint effort of U.S. Department of Energy (DOE) and Environmental
Protection Agency (EPA)
• Program that identifies energy-efficient products and practices to
reduce greenhouse gas emissions
– Marked with the ENERGY STAR label
• ENERGY STAR qualified LED lighting
– Reduces energy, maintenance and cooling costs over
conventional lighting
– Minimum three-year warranty
– Offers convenience features: dimming, occupancy/daylighting sensing
– Meets high durability, color temperature, color spatial uniformity,
CRI and thermal management criteria as defined by standardized
testing procedures
“Not all LED lighting is created equal”
Reference: http://www.energystar.gov
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
CIE 1976 (u’,v’) diagram
ENERGY STAR Qualified LED
SSL Luminaire Criteria
• CCT: 2700K, 3000K, 4000K, 4500K, 5000K, 5700K, or 6500K
• CRI: ≥75
• Lifespan: All commercial with minimum 35,000 hours to
70% lumen maintenance
• Color Spatial Uniformity: The variation of chromaticity in different
directions (i.e., with a change in viewing angle) shall be within 0.004 from
the weighted average point on the CIE 1976 (u’,v’) diagram.
• Color maintenance: Change of chromaticity over the product’s lifetime
must be within 0.007 on the CIE 1976 (u’,v’) diagram
• Warranty: Minimum of 3 years from purchase date
• Thermal Management: Luminaire manufacturers shall adhere to device
manufacturer guidelines, certification programs, and test procedures for
thermal management.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
ES for Integral Lamps
•
•
•
•
•
•
•
•
Minimum efficacy: 50/55 LPW (<10W/ ≥10W)
Minimum lumens: varies by thermally stabilized
“wattage equivalent”
Minimum CRI: 80, R9>0
Lumen maintenance (L70): 25,000 hours
CCT: 2700K, 3000K, 3500K, or 4000K
Duv tolerances: per ANSI C78.377-2008
Power factor: >0.7 for lamps ≥5W
Intensity distribution:
–
•
•
Dimming NOT required (very desired)
Must provide:
–
–
•
•
Less than 80% of total flux in the 0° to 60° zone
and at least 20% of total flux above 90°
IES LM-79-2008, sec 10 goniophotometer report
IES LM-80-2008 report on LEDs used
Restrictions on “product equivalency” marketing
claims, claims, must use “Lighting Facts” label
Warranty: 3 years
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Wattage Equivalent
Lumens
ENERGY STAR for
Integral Lamps: Next Steps
• Nov 15, 2010: EPA disqualified non-standard lamps;
eliminated the category
• EPA will complete the re-work this DOE program and merge it into
the existing EPA CFL bulb program in 2011
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Note on CALiPER
• CALiPER has and continues to perform
an invaluable service to the industry
– Realistic appraisal of the technology
– Trend line to show direction, improvement
– “Outing” of deceptive marketing practices
and misapplication of the technology
• The LED lamps in any CALIPER reports
are generally 2 to 3 years old and are not
even close to the current state of the art
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
DOE Energy STAR SSL 1.1
• Residential
–
–
–
–
–
–
–
–
–
–
–
Kitchen under-cabinet
Portable desk lights
Recessed , pendant downlights
Ceiling-mounted luminaires
Cove lighting
Surface-mounted directional lights
Outdoor porch lights
Outdoor step lights
Outdoor pathway lights
Outdoor decorative lights
All others
24 (29*) lm/W
29 lm/W
35 (42*) lm/W
30 (45*) lm/W
45 lm/W
35 lm/W
24 lm/W
20 lm/W
25 lm/W
35 lm/W
(70*) lm/W
• Non-residential
–
–
–
–
–
Recessed downlights
Under-cabinet
Portable desk lights
Wall-wash luminaires
Bollards
35 (42*) lm/W
29 lm/W
29 lm/W
40 lm/W
35 lm/W
http://www.energystar.gov/ia/partners/product_specs/program_reqs/SSL_prog_req_V1.1.pdf
* Proposed update as of Oct 2010
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
CRI>75;
2700K,
3000K
3500K
EPA’s Plan for SSL 1.1
• SSL 1.1 will be merged into the EPA
ENERGY STAR program for luminaires,
effective September 1, 2011
• New requirements:
– Labeling and merchandising requirements
– Lighting Facts
– Laboratory accreditation
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
ENERGY STAR Summary
• 2 ½ ENERGY STAR programs
(bulbs, luminaires, outdoor) based on:
– Energy savings
– Quality metrics
– Labeling and merchandising requirements
• Good Housekeeping Seal for SSL
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
DOE’s Lighting Facts Program
Reference: http://www.lightingfacts.com/
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
State Standards
• California Title 24
• California Title 20
California’s Title 24
California’s Energy Efficiency Standards for Residential and
Nonresidential Buildings
• Established by
California Energy Commission
– Implemented in 1978 in response to a
legislative mandate to reduce California's
energy consumption
• State mandated building efficiency code
in California
• Goals of Title 24
– Promote cost effective, energy efficient
building practices
– Reduce green house gas emissions to
meet global warming codes and initiatives
(i.e., AB 32)
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cltc.ucdavis.edu/title24
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Title 24 2008
Residential
High Efficacy LED Requirements
• LED must be certified to Energy Commission to be classified as
high efficacy
• LED system:
– LED luminaire (LED light source, driver, and fixture)
– OR LED light engine + integral heat sink
• Minimum requirements:
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Title 24 2008
Nonresidential, High-Rise Residential and Hotel/Motel Occupancies
LED Luminaire Requirements
• LED luminaire wattage to be tested in accordance to specified
protocol California
– Joint Appendix JA8 – 2008, “Testing of Light Emitting Diode Light
Sources”
• Maximum rated input wattage permanently listed on factory-installed label
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
California’s Title 20
California’s Appliance Efficiency Regulation
• Established by California Energy Commission
– Implemented in 1976 in response to a legislative mandate to reduce
California's energy consumption
• State mandated appliance efficiency code in California
– Updated periodically to allow consideration and possible incorporation
of new energy efficiency technologies and methods.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
California’s Title 20
California’s Appliance Efficiency Regulation
As of January 1, 2010…
• LED luminaire or LED Light Bulb products:
– Portable luminaires
• Minimum requirements for Portable LED luminaires and portable luminaires
with LED light engines with integral heat sink
• Other light source options for portable luminaires:
– Fluorescent
– GU-24
– Non-screw halogen, 100W
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
When LED designs go awry
• Beware of the square peg
• There are many lighting applications that
LED products don’t fit into
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The Glare Bomb
• Those lumens/watt are great…
but at what cost?
• Visual comfort constraints
vary by application
• Color consistency requirements
vary by application
– Color variation can cause visual
discomfort independent of intensity
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The Boat Anchor
• Mechanical constraints
– Weight
– Dimensions
• Seismic code
• ANSI lamp specifications for replacement lamps
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The EASY BAKE Oven
• The LED system
– Is there a heatsink?
– Does it get hot?
• The application
– Is the system designed for where you are
putting it?
– Is where you are putting it designed for
the system?
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The Money Pit
• Just because you can doesn’t mean
you should
• Light levels and uniformity requirements
can price you out of the LED market
depending on the application
– High mast
– Certain roadway applications
– Etc.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
The Swiss Army Knife
• Just because you can doesn’t mean you
should (again)
• Beware of getting carried away with
features
– Communications
• It’s already expensive… throw a little more
on top
– Tunable color
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
12 Questions to ask your
manufacturer to ensure quality
Which LED supplier
did you choose and why?
• Is it a reliable company you have
heard of?
• What references can be provided?
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Has your LED supplier provided an
IESNA LM-80 test report?
• Any good LED supplier will be able to
supply this beginning in mid-2009; if not,
why not and when?
• Be particularly careful about 5mm LEDs
and the cheaper, plastic SMD LED lamps.
– Often marketed as having >50,000 hours
of rated life, but may not be able to deliver
it under all temperature and environmental
conditions.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What is the operating temperature range
specification and what is the maximum
junction temperature of the LED lamps
over that operating range?
• Calculation based on the maximum temperature inside the fixture
and drive current the fixture manufacturer has selected for the
LED lamps.
• The fixture maker should be very familiar with this concept and
readily able to provide this information. Some LED products are not
capable of being operated in high ambient temperature conditions
without violating maximum LED junction temperatures.
• In colder climates, some drive electronics may not function properly.
It is important to look at both temperature extremes to make sure the
fixture is suitable for your application.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What is the expected L70 lifetime of
your fixture? How did you calculate it?
• In the longer term (beyond mid-2009), any fixture L70 lifetime should
be based on the IESNA LM-80 test report for the LEDs used, and
also the worst case expected internal ambient temperature the LEDs
will see, as well as the maximum junction temperature of the LEDs.
These latter two points are critical and must be provided by the
fixture manufacturer.
• The LM-80 report alone from the LED supplier is almost
meaningless without these other two data points. Over the short
term—until the LED makers have time to comply with LM-80—you
may have to rely on vendor data, but don’t let that stop you from
asking the question.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Can you supply an IESNA LM-79 test
report from an independent 3rd party
laboratory for your fixture and an .ies
data file?
• The LM-79 report will give you the assurance that the photometrics
reported in the marketing literature (lumens, spatial distribution,
CCT, CRI, etc.) have been verified by a third party.
• The LM-79 report also gives total fixture efficacy (lm/W), Power
Factor, and a data file in a .ies format.
• Without this assurance, the marketing literature is subject to
question.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What are the delivered lumens and LPW
of the fixture?
• Some fixture makers take the number of lumens on the ELD data
sheet in optimal test conditions (say, 100 lm) and multiply the
answer times the number of LEDs int eh system (say, 10), and
report that they have a 1,000 lumen luminaire system.This is not
only misleading, it is not physically possible.
• LEDs lose lumens through thermal stabilization and optical losses,
and all LED driver types have conversion losses.
• Make your fixture make do his homework and report the data in
terms of delivered lumens for the application and LPW in terms of
wall plug efficiency.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Is the chromaticity of the fixture in the
ANSI C78.377A color space and is it
stable over time? How do you know?
• Especially important for indoor luminaires.
• If it is not in the ANSi color space, then the color of the luminaire
could be pinkish or greenish in hue. Color point stability is a
common problem in lower quality LED fixtures. IT can be a result of
poor LED selection, poor thermal management, or both.
• Make your fixture supplier convince you that the LEDs he has
selected are right for the application (Lighting-class LEDs; not 5mm
lamps designed for toys and novelties, for example.), and that the
fixture design has a good thermal management capacity for the
worst-case expected operating environment (an insulated ceiling,
for example).
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Does the color of the light output vary
from fixture to fixture or in different
spatial locations for a single fixture?
• Common problem with lower quality LED fixtures.
• This problem can be solved through various technical means
(binning, color mixing of LEDs, control systems) in the luminaire
system design, but again, your fixture maker has to do his
homework to prevent you from having this headache later.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What is the Power Factor of your fixture?
How much power does it consume in the
“off” state?
• Power Factor should be at least 0.7 for residential applications,
0.9 for commercial (U.S. DOE ENERGY STAR criteria)
• Easily achieved with a fairly standard driver design, but also often
ignored on lower quality luminaire products.
• Poorly designed LED systems can consume almost as much power
in the “off” state as they do in the “on” state. The DOE ENERGY
STAR requirement is for no more than 0.5 W.
• Make your fixture supplier check these boxes now to save you
heartache—and energy—later.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Have you applied for DOE ENERGY STAR
for this fixture? Why or why not?
• DOE has a very well thought-out set of criteria required to get an
ENERGY STAR.
• Does not yet apply to all fixture types, but the ENERGY STAR
criteria are a rigorous way to assure the quality of a fixture, and it
could be instructive to know if a manufacturer applied for this (or not).
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Is your fixture lead-free, mercury-free and
RoHS-compliant
• This is a key question regarding sustainability.
• Lead-free and RoHS compliance—all the way through the
packaging the luminaire arrives in—are easily achievable with
modern manufacturing technology. You should insist on this.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
What is your warranty and do you have
the means to stand behind it?
• A reasonable warranty should be about one third to one half of the
expected L70 lifetime (e.g. For an expected 50,000 hour L70,
15,000–25,000 hour warranty is reasonable), and the company
giving the warranty should be of reasonable size and solid financial
means. The ENERGY STAR program requires 3-year warranty,
for example.
2010 DALLAS MARKET CENTER INTERNATIONAL LIGHTING MARKET
Thank you for attending!
Keith Graeber
kegraeber@ucdavis.edu
Director of Engineering
California Lighting Technology Center
Mark McClear
Mark_McClear@cree.com
Director of Applications Engineering
Cree, Inc