Presentation by:Richard Young

Senior Engineer/Director of Education

Energy Efficient LEDs For Sustainable Solid-State Lighting

The 6th Annual The Following background slides are from the UC, CSU, CCC Sustainability Conference: June 24-27th, 2007

For Sustainable Solid-State Lighting

Steve DenBaars

Slides are included in this presentation courtesy of:

Steve DenBaarsSolid State Lighting and Display Center

Materials and ECE DepartmentsUniversity of California, Santa Barbara

What is a Blue LED?

L.E.D.= Light Emitting Diode

An LED produces light by combiningpositive and negative charges inside a

Gallium nitride (GaN) crystal.

Blue LED

The Advantage of LED LightingLong life – lifetimes can exceed 100,000 hours as compared to 1,000 hrs for tungsten bulbs.

Robustness – no moving parts no glass no filamentsRobustness – no moving parts, no glass, no 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

i 116 l /W b hi

x

is 116 lm/W ucsb chip143 lm/W partner chip

LED

2006

First white LEDs were only5lm/W at 20mA (1995)

Graph taken from www.lampteck.co.uk

White LightWhite Light White LightWhite LightWhite LightWhite Light

3 Methods of Generating White LEDs

Substrate

UV GaN LED

UV light

RGB Light

Substrate

Blue GaN LED

Blue Light

Green, Red phosphors

Blue GaN LED

Green GaN LED

Red GaAs LED

Multi-Chip, RGB-best efficiency-highest cost

UV + Phosphors-best CRI, color -uniformity-low cost-improved reliability

Blue + Phosphors-lowest cost-30 lm/W->90%market share

“The Promise” Energy Usage Comparison

50

60

LEDs Save 53Watts

10

20

30

40

5060W Bulb

CompactFluor.LED

Pow

er U

sed

(Wat

ts)

0Light Source

“Best” White LED and Compact Fluorescent vs. 60Watt Light Bulb Comparison

Technical considerations• Heat sinks are critical!• Power supplies are critical!Power supplies are critical!

– constant voltage and current• Expensive at the moment• Costs are dropping• Can be placed in unique locationsCan be placed in unique locations• Install for eventual relamping

– non-permanent location• Lots of innovative products!

Practical applications• Exit signs• auto/truck lights• stop lights

fl hli h• flashlights• signage - backlighting• spot lights, floodlights, basic “a” lamps • pendants, down-lights• linear, string and cove lighting • ambient textural theatrical ultraviolet• 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 light4.8 watt LED = 20 watt halogen

R30 flood light11 watt LED = 60 watt halogen

cool or warm white and CRI = 80$120

4.8 watt LED 20 watt halogencool or warm white and CRI = 80

$50

LED Decorative ($180)

LED fixture = 2 watts

mini - CFL fixture = 9 watts

incandescent fixture = 40 watts

www.everlumelighting.com

LED Downlight ($210)

source: www.everlumelighting.com

Neon replacement and SignageSpecialty applications

Decorative lighting

LED Cove Lighting Modules($150)

2 lamps = 1 watt each uniti t frequires transformer

fits into flexible track sockets

source: www.everlumelighting.com

source: www.lighting.philips.com

Basic retrofit application:LED lamps in existing EXIT signs.

The new standard: LED Exit signs

• $50/year savings• new sign cost $30new sign cost $30• no relamping = reduced maintenance costs• no burnouts = increased safety• less than 5 watts per sign.

LED Candle

Norex enterprises

Korean Store wrapped in LEDs

source: www.xilver.nl

Future SSL DisplaysPocket Projector/Cell Phone

Prototype from Novalux using frequency double lasers