leds for lighting professionals
DESCRIPTION
This is a presentation I delivered to several IESNA chapters in fall, 2014.TRANSCRIPT
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LEDS FOR LIGHTING PROFESSIONALS
Donald G. Hirsh, Sr. Manager, Lighting Experience Center,
November, 2014
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N. B.
• Credit(s) earned on completion of this presentation will be reported to AIA
CES for AIA members. Certificates of Completion for both AIA members
and non-AIA members are available upon request.
• This presentation has been registered with AIA CES for continuing
professional education. As such, it does not include content that may be
deemed or construed to be an approval or endorsement by the AIA of any
material of construction or any method or manner of handling, using,
distributing, or dealing in any material or product.
_______________________________________
Questions related to specific materials, methods, and services will be addressed at the
conclusion of this presentation.
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Learning Objectives
• At the end of this course, participants will have
information to:
– Compare and contrast modern LED technology with
major categories of evacuated tube technologies.
– Analyze evolving techniques in the design and
development of SSL luminaires.
– Identify recent Advances in LED component
technology.
– Compare categories or types of LED components.
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The Agenda – What’s All the Fuss About
• Review of Some General Properties of
LEDs vs. Evacuated Tube Technologies
• LED Typology & Technology
• LED Lighting Futures
– Efficacy and the future of LED Product
Development
– Example: The evolution of the color mixing
technology platforms
• TM-21 & LM-80
• Conclusions: LEDs will rule in the
Medium Term
(What’s In It For Me?)
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Film
Vacuum
Tubes Transistors
1940s – 1960s
VHS DVD
1980s – 1990s
CRT Flat Panel
Displays1990s – 2000s
Flash
Memory1990s – 2000s
“Brick”
phones
Smart
phones1990s – 2000s
Creative Destruction: Hard At Work in Your Industry
Use pervasiveness price path to market … all changed
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Creative Destruction: Hard At Work in Your Industry
Next up … Lighting
Evacuated
Tubes
Solid State
Lighting
2007 – 2020s
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What Is a Light Emitting Diode (LED)?
• Light Emitting Diodes (LEDs) are solid-state
semiconductors that convert electrical energy
directly into visible light.
Packaged LED Chip
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Blue + Yellow Phosphor
Blue Peak
Yellow Phosphor
White Light from Blue LEDs
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Lighting
Class LEDsFilament Fluorescent HID
Source Efficacy (lm/w) 130 -200 15-25 80-100 80-130
Optical Control +++++ +++ + +++
Applicability/Adaptability +++++ ++ ++ +++
Lifetime (hrs) 104-5 103 103-4 104
Lumen Depreciation *
Chromatic Stability +++++* +++++ +++ ++
Spectral Profile ++++++ +++++ +++ +++
Thermal Sensitivity ++ ++
Start-Up/Restrike µs ms s m
Dimmable, Controllable Superior Good Possible Not
Toxicity (Hg, Pb, Heavy Metals) + +
Rugged ++++ ++ + +
Illumination Source Review
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The Inexorable March of Technology: Efficacy & Packaging$
/lm
, n
orm
alize
d(C
oo
l W
hite
, 6
50
0K
)
Annual Improvement
in $/lm @ 100 LPW43% 45% 35% 29% 45% 40% 27%
Eff
ica
cy (
LP
W)
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Evolution of Size: Different Die, Same Performance
96% smaller than Gen 1
78% smaller than Gen 2
Gen 1 Gen 2 Gen 3
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Example: Flux Groups circa 2008
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Flux Groups circa 2014
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Contrasting Emission Patterns
Bare HID Lamp Illustration Bare LED Component
Illustration
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Small Hemispheres Allow for Precise Optical Control
Bare LED Chip Package
IllustrationIllustration of Altered Distribution
(Secondary Optic Added)
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Allows for Dramatically Improved Uniformity
The Prairie School, Racine, WI 2007
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LED HPS
141W Total System Wattage 300W
8,040 Average Delivered Lumens 20,520
57 Luminaire Efficacy (Lumens/Watt) 68
1.01fc Maintained Average Footcandles 1.96fc
0.30fc Maintained Minimum Footcandle 0.30fc
53% 2007 Energy Savings -
Allows for Dramatically Improved Uniformity
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Similar illumination performance from recent products
1st Generation
141 Watts
(2007)
Seven Years of LED & Systems Innovation
53W
82% Energy Savings
80% Price Reduction vs 2007 Product
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So Many Lamps…
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So Many LEDs - A Representative Components Portfolio
Discretes Arrays Integrated
Arrays
• One
component
simplifies
design and
assembly
• High efficacy,
high lumen
output
Modules
• High lumen
density for
optical
control
• Excellent
LED-to-LED
color
consistency
• Highest level
of integration
• Speed time
to market
• Excellent
color
consistency
• Design flexibility
• Enables lower system cost
CXA HD
CXA SD
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Average Rated Life vs. Average Useful Life
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Thermal Management: Radiation vs. Conduction
• LEDs Require Appropriate Thermal Management for Superior Long-Term
Performance
• Thermal Management Drives the Tendency to Integral Luminaire Designs
L70 25,000H L70 100,000H
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Comparing Representative Spectral Power Distributions
Incan-
descent
Daylight Fluorescent
LED
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White CCx, CCy Space
2700K
3000K
3500K
4000K
4500K5000K
5700K
6350K
7000K
8300K
2450K 2200K
AB2
AB1
AA2
AA1
AB3
AB4
AA3
AA4
AC2
AC1
AD2
AD1
AC3
AC4
AD3
AD4
0.28
0.29
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
0.2
7
0.2
8
0.2
9
0.3
0
0.3
1
0.3
2
0.3
3
0.3
4
0.3
5
0.3
6
0.3
7
0.3
8
0.3
9
0.4
0
0.4
1
0.4
2
0.4
3
0.4
4
0.4
5
0.4
6
0.4
7
0.4
8
0.4
9
0.5
0
0.5
1
0.5
2
0.5
3
0.5
4
0.5
5
CC
y
CCx
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LED Production:
Recipes Process Yield, A Hypothetical Example
2700K
3000K
3500K
4000K
4500K
5A1
5A2
5A3
5A4
5B1
5B2
5B3
5B4
5C1
5C2
5C3
5C4
5D1
5D2
5D3
5D4 6A1
6A2
6A3
6A4
6B1
6B2
6B3
6B4
6C1
6C2
6C3
6C4
6D1
6D2
6D3
6D4
7A1
7A27A3
7A4
7B1
7B27B3
7B47C1
7C27C3
7C4
7D1
7D27D3
7D48A1
8A28A3
8A4
8B1
8B28B3
8B48C1
8C28C3
8C4
8D1
8D28D3
8D4
0.35
0.36
0.37
0.38
0.39
0.40
0.41
0.42
0.43
0.44
0.45
0.460.36
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
CCy
CCx
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DISCRETES ARRAYS INTEGRATED ARRAYS MODULES
Non-DirectionalA & E Bulbs,
Sconces
DirectionalMR & PAR, Spot,
Track
DownlightCeiling Mount,
Pendant
LinearCove, FL Retrofit,
Panel
Outdoor &
High BayRoadway, Industrial
PortableConsumer, High End
Lighting Applications Matrix
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Example Lamp and Luminaire Constructions: COB
Matches HID performance with no down sides:
• 50% less power
• 50% less weight
• Lower operating temperature
• 10x longer lifetime
• Instant-on/Instant restrike
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LEDs Win vs. CMH Tracklight
Matches CMH
performance with
no down sides:
• Higher lm/W
• Lower temperature
• No explosion risk
• 10x longer lifetime
• Instant-on
• Instant restrike
Parameter 39W CMH COB COB
System Lumens 2400 lm 3846 lm 4471 lm
System Power 44 W 47 W 53 W
System Efficacy 55 lm/W 82 lm/W 85 lm/W
Beam Angle 15° 16° 16°
CBCP 29,000 cd 25,070 cd 29,150 cd
3000K, 80CRI
Parameter 20W CMH Modern COB
System Lumens 1000 lm 1,260 lm
System Power 20 W 15.6 W
System Efficacy 50 lm/W 74 lm/W
Beam Angle 8° 13°
CBCP 13,000 cd 10,943 cd
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Increasing Efficacy Leads to Redesigns + Cost Reduction
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The Future: Smaller
High Density COB
Prototype Fixture
70W Halogen
PAR38FL
CCT, CRI 3000K, 82 CRI 2900K, 98 CRI
CBCP 2,093 cd 2,379 cd
Beam Angle 40° 40°
Initial Lumens 1010 lm 1381 lm
System Power 14.4W (20%) 74W
Optic 30 mm x 23 mm (~22%) 135 mm x 121 mm
70W halogen flood performance at 1/4 the size
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Some Heuristics of LED Phosphor Systems Conversion
Efficiency
• Phosphor Systems Introduce Conversion Efficiencies, which are
(Roughly) Linear and CCT Dependent
– Blue-to-red is least efficient
• Efficacy vs. CCT
– Example: from 5000K 70 CRI to 2700K 80 CRI expect a 20-25%
LPW loss, with roughly linear interpolation.
• (4000K 70 CRI would be ~10% LPW loss)
• Efficacy vs. CRI
– Example: from 2700K CCT, 80 CRI to 2700K CCT, 90 CRI
20% LPW loss
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Example SPDs of a Modern LED Component
Representative SPDs
90 CRI, Outdoor White SPD
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DOE LED Roadmap
US DOE MYPP, April 2013, p.47
Consensus: We’ll get to 250 LPW in production
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Uses of a 250LPW LED Source:
1. Trade LPW for cost; save a ton
of money on luminaire first-cost2. Trade LPW for high CRI
3. Trade LPW for CCT ANY
CCT
4. Enable applications you
thought impossible. Really!
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The Evolution of High CRI Lighting Applications
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LED Standards Define Many Aspects of Quality
IES TM-21 Lumen
Maintenance Projections
UL 8750 LED Equipment for
use in Lighting Products (Safety)
IES LM-80-2008 LED Lumen Maintenance
IES LM-79-2008 SSL Photometry
ANSI C78.377-2008 (Chromaticity)
IES RP-16 SSL Definitions
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TM-21 LED Luminous Stability Over Current, Temp, Time
LED
I
Data Set 7+ 8+ 9+
Tsp 55°C 85°C 105°C
Sample Size 11 21 14
Test Duration 11,088 hrs 12,096 hrs 8,568 hrs
α 1.182E-06 4.238E-06 6.627E-06
β 1.005E+00 9.999E-01 1.000E+00
Calculated Lifetime L70(11k) = 306,000 hours L70(12k) = 84,100 hours L70(9k) = 53,800 hours
Reported Lifetime L70(11k) > 61,000 hours L70(12k) > 72,600 hours L70(9k) > 47,100 hours
Reported L70
Calculated Lifetime
Reported Lifetime
XLamp XM-L White
2000 mA
TM-21 Lifetime Report
50
55
60
65
70
75
80
85
90
95
100
105
110
1,000 10,000 100,000 1,000,000
% L
um
ino
us
Flu
x
Time (hours)
55°C (LM-80)
85°C (LM-80)
105°C (LM-80)
55°C (TM-21)
85°C (TM-21)
105°C (TM-21)
LED
I
Data Set 15 16 16
Tsp 55°C 85°C 85°C
Sample Size 25 25 25
Test Duration 8,568 hrs 8,568 hrs 8,568 hrs
α 1.064E-06 2.174E-06 2.174E-06
β 9.913E-01 9.971E-01 9.971E-01
Calculated Lifetime L70(9k) = 327,000 hours L70(9k) = 163,000 hours L70(9k) = 163,000 hours
Reported Lifetime L70(9k) > 51,400 hours L70(9k) > 51,400 hours L70(9k) > 51,400 hours
Reported L70
Calculated Lifetime
Reported Lifetime
XLamp XP-G White
1500 mA
TM-21 Lifetime Report
50
55
60
65
70
75
80
85
90
95
100
105
110
1,000 10,000 100,000 1,000,000
% L
um
ino
us
Flu
x
Time (hours)
55°C (LM-80)
85°C (LM-80)
85°C (LM-80)
55°C (TM-21)
85°C (TM-21)
85°C (TM-21)
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Example High Power LED (LM-80) Data Set
Current Ta (ºC) Tsp (ºC) Tj (ºC)
1500 mA55 55 75
85 85 105
50
60
70
80
90
100
110
0 2,000 4,000 6,000 8,000 10,000 12,000 14,000
% L
um
ino
us
Flu
x
Time (hours)
55°C (LM-80)
85°C (LM-80)
ENERGY STAR 35k
ENERGY STAR 25k
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Outstanding Chromatic Stability Over Current, Temp, Time
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0 2,000 4,000 6,000 8,000 10,000 12,000
Ch
rom
atic
ity
Shif
t (d
u'v
')
Time (hours)
XLamp XP-G White: If=1.500A, Tsp=85°C
XLamp XP-G White: If=1.500A, Tsp=55°C
XLamp XP-G White: If=1.000A, Tsp=105°C
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What Does This Mean? This is Superior Color Stability.
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0 2,000 4,000 6,000 8,000 10,000 12,000
Ch
rom
atic
ity
Shif
t (d
u'v
')
Time (hours)
XLamp XP-G White: If=1.500A, Tsp=85°C
XLamp XP-G White: If=1.500A, Tsp=55°C
XLamp XP-G White: If=1.000A, Tsp=105°C
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And Now For Something Completely Different
US Dept of Energy, 2013, Color Maintenance of LEDs in Laboratory and Field Applications, PNNL-22759
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Recap: LEDs Are Restructuring A Lot of Things
• Applications
• Markets
• Livelihoods
• It’s Early Days
Lighting
Class LEDsFilament Fluorescent HID
Source Efficacy (lm/W) 130 -200 15-25 80-100 80-130
Optical Control +++++ +++ + +++
Lifetime (hrs) 104-5 103 103-4 104
Lumen Depreciation *
Chromatic Stability +++++* +++++ +++ ++
Dimmable, Controllable Superior Good Possible Not