Ultra-Efficient Solid-State Lighting: Performance Frontier, Progress, Challenges

1. 103 CN 2005 CN 2006 WRLD-GRID 2005 102 JP+KR 2005 US 2001 OECD-EU 2005 FSU 2000 CN 1993 UK 2000 101 UK 1950 AU+NZ 2005 Luminous Efficacy (lm/We) UK 1900 1 UK 1850 WRLD-NONGRID 1999 UK 1800 10-1 UK 1750 UK 1700 10-2 1 101 102 103 104 105 Cost of Energy ($/MWeh) Ultra-Efficient Solid-State Lighting:Performance Frontier, Progress, Challenges 101.5 Jeff Tsao Physical, Chemical and Nano Sciences Center Sandia National Laboratories SSL HID Fluorescent Incandescent 102.8 Gas Kerosene Candles After “The World’s Appetite for Light” (Tsao and Waide, submitted to the Energy Journal) Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Security Administration under Contract DE-AC04-94AL85000.

2. 800 SSL Performance Frontier Human Eye Response (lm/W) 400 100 nm 0 573 nm 614 nm 90 463 nm 530 nm 90 CRI 90 408 lm/W Color Rendering Index (Ra) Color Rendering Index (Ra) 70 70 CCT 3,000K, after “Ultra-Efficient SSL” (J.M. Phillips, et al, Laser & Photonics Reviews, 2007) 50 50 375 400 425 450 3/8 Luminous Efficacy (lm/W) 2/8 1.0 2/8 Relative Power 1/8 0.5 All linewidths 1-nm FWHM 0 0.8 200 nm Relative Reflectances Munsell Samples 1-8 8 7 6 1 5 0.4 8 4 3 7 2 0 400 500 600 700 Wavelength (nm)

3. SSL Progress Report: Luminous Efficacy 14x B LED R LED GY LEDs 4x 1.6x 1.3x 2007 2006 2008 Fluor HID Perf Frontier Incand lm/W 245 71 96 190 17 22 30 120 408 14 SSL performances calculated using white LED simulator 5-3 (Ohno, NIST) SSL data from Luxeon K2 warm white lamps (Philips Lumileds 2008) RYGB 60% eff RGBB 60% eff RBGBB 15% eff RBGBB 60% eff 614 nm Power Spectra 400 550 700 400 550 700 400 550 700 nm 400 550 700

4. SSL Progress Report: Ownership Cost of Light 100 Costs: Ownership = Operating + Capital Traditional lighting data from survey of 2001 U.S. market (Navigant) SSL data from Luxeon K2 warm white lamps (Philips Lumileds 2008) Cost of light calculated following “Light Emitting Diodes (LEDs) for General Illumination” (J.Y. Tsao, Ed., OIDA, 2002) 10 1:6 Ratio Incandescent 2006 Electricity SSL 2007 Fluorescent 1 Capital Cost ($/Mlmh) 2008 Power Delivery Cost HID Luminous Efficacy 60% eff RBGBB 0.1 60% eff RGBB 60% eff RYGB Lifetime 0.01 0.01 0.1 1 10 100 Operating Cost ($/Mlmh)

5. Key Points • Lighting technology evolution in perspective • Over 3 centuries, 2.8 orders of magnitude improvement in luminous efficacy • SSL has potential to add final 0.6 orders of magnitude • Performance frontier of SSL • 408 lm/W at CRI 90 and CCT 3,000K • 1/8 Blue 463 nm, 2/8 Green 530 nm, 2/8 Yellow 573 nm, 3/8 Red 614 nm • Narrower lines better, particularly in the red • SSL Minor Challenge: Power Delivery Cost • 4x from 2006-2008 has reduced capital/operating cost ratio to 1/3 • 2.2x from higher drive currents and lower manufacturing costs will easily bring capital/operating cost ratio to 1/6, same as traditional lighting • SSL Major Challenge: Luminous Efficacy • 1.8x from 2006-2008 has been only modest improvement • 4x from maintaining high efficiency at high flux in blue LED droop will beat traditional lighting • 1.6x more from 60% efficient red LED at 614 nm • 1.3x more from 60% efficient green and yellow LEDs at 530 and 573 nm