Richard Young presented on energy efficient LEDs for sustainable solid-state lighting. Some key points include: - Blue LEDs produce light by combining positive and negative charges in a gallium nitride crystal. - LEDs have advantages over traditional lighting like long lifetime, robustness, size, energy efficiency, non-toxicity, and versatility. - LED efficacy has increased dramatically over time and some white LEDs now reach over 100 lumens per watt. - LEDs save significant energy compared to traditional bulbs and can cut energy usage by over 50% for some applications. - Practical LED applications include exit signs, vehicle lights, signage, task lighting, and replacements for traditional bulbs.

1. Presentation by:
Richard Young
Senior Engineer/Director of Education

2. The 6th Annual The Following background slides are from the
UC, CSU, CCC Sustainability Conference: June 24-27th, 2007
Energy Efficient LEDs
For Sustainable Solid-State Lighting
Slides are included in this presentation courtesy of:
Steve DenBaars
Solid State Lighting and Display Center
Materials and ECE Departments
University of California, Santa Barbara
What is a Blue LED?
L.E.D.= Light Emitting Diode
Blue LED An LED produces light by combining
positive and negative charges inside a
Gallium nitride (GaN) crystal.

3. The Advantage of LED Lighting
Long life – lifetimes can exceed 100,000 hours as compared to 1,000 hrs
for tungsten bulbs.
Robustness – no moving parts no glass no filaments
parts, glass, filaments.
Size – typical package is only 5 mm in diameter.
Energy efficiency – up to 90% less energy used
translates into smaller power supply.
Non-toxicity – no mercury.
Versatility – available in a variety of colors; can be pulsed.
Cool – less heat radiation than HID or incandescent
Luminous Efficacy of Various Light Sources
Current number for
GaN white LED at UCSB
is
i 116 lm/W ucsb chip
l /W b hi
143 lm/W partner chip
x
LED
First white LEDs were only
5lm/W at 20mA (1995)
2006
Graph taken from www.lampteck.co.uk

4. 3 Methods of Generating White LEDs
White Light White Light White Light
RGB Light Green, Red
phosphors
Blue GaN LED UV light Blue Light
UV GaN LED Blue GaN LED
Green GaN LED
Substrate Substrate
UV + Phosphors Blue + Phosphors
Red GaAs LED
-best CRI, color -lowest cost
-uniformity -30 lm/W
Multi-Chip, RGB -low cost ->90%market share
-best efficiency -improved reliability
-highest cost

5. “The Promise” Energy Usage Comparison
LEDs Save 53Watts
60
50
Power Used (Watts) 60W Bulb
40
30 Compact
Fluor.
20
LED
10
0
Light Source
“Best” White LED and Compact Fluorescent vs. 60Watt Light Bulb Comparison
Technical considerations
• Heat sinks are critical!
• Power supplies are critical!
– constant voltage and current
• Expensive at the moment
• Costs are dropping
• Can be placed in unique locations
• Install for eventual relamping
– non-permanent location
• Lots of innovative products!

6. Practical applications
• Exit signs
• auto/truck lights
• stop lights
• flashlights
fl hli h
• signage - backlighting
• spot lights, floodlights, basic “a” lamps
• pendants, down-lights
• linear, string and cove lighting
• ambient, textural theatrical
ambient textural, theatrical, ultraviolet
• parking lot, path lighting
• task (desktop)
• neon replacement
• case lighting and under-counter lighting
Promising applications
for food service
R16 flood light
4.8 watt LED = 20 watt halogen
cool or warm white and CRI = 80
R30 flood light $50
11 watt LED = 60 watt halogen
cool or warm white and CRI = 80
$120

7. LED Decorative ($180)
LED fixture = 2 watts incandescent fixture = 40 watts
mini - CFL fixture = 9 watts
www.everlumelighting.com
LED Downlight ($210)
source: www.everlumelighting.com

8. Neon replacement and Signage
Specialty applications
Decorative lighting

9. LED Cove Lighting Modules
($150)
2 lamps = 1 watt each unit
requires transformer
i t f
fits into flexible track sockets
source: www.everlumelighting.com

10. source: www.lighting.philips.com
Basic retrofit application:
LED lamps in existing EXIT signs.

11. The new standard: LED Exit signs
• $50/year savings
• new sign cost $30
• no relamping = reduced maintenance costs
• no burnouts = increased safety
• less than 5 watts per sign.
LED Candle
Norex enterprises

12. Korean Store wrapped in LEDs
source: www.xilver.nl
Future SSL Displays
Pocket Projector/Cell Phone
Prototype from Novalux using frequency double lasers