Slide 1

1 LEDs - Past, Present and Future FAA Eastern Region Airports Conference Thursday, 3 March 2011 Presented by Pete Butler, P.E. Slide 2 2 Agenda Definition of LED Characteristics of LED Fixtures Evolution of LEDs in Airfield Lighting Systems Recent Developments Future Implementation Design Considerations Roundtable Discussion Slide 3 3 Definition of LED Light Emitting Diode Semiconductor light source Within device, electrons jump a gap to recombine with electron holes During jump, energy is released in form of photons Result - phenomenon called electroluminescence Color of LED determined by energy gap of semiconductor Slide 4 4 Characteristics of LEDs Positive Characteristics Lower energy consumption Longer lifetime Improved robustness Smaller size Faster switching Greater durability Higher reliability + + Slide 5 5 Characteristics of LEDs Negative Characteristics More expensive Require more precise current Sensitive to high temperatures Light output decreases Light spectrum in negatively impacted Heat sinks / beveled or ridged exterior (-) Slide 6 6 Evolution of LEDs in Airfield Lighting Systems Implemented in clusters to create a light source LED-lamped taxiway elevated edge lights emerged in early 2000s Original fixtures resembled lighthouses with lamp / LED cluster at base of fixture Inherent maintenance issues Water infiltration Slide 7 7 Evolution of LEDs in Airfield Lighting Systems LED technology improved, airport interest increased - additional manufacturers developed edge lights Mid 2000s, at least three vendors of edge lights Fixtures better resemble typical edge lights Slide 8 8 Evolution of LEDs in Airfield Lighting Systems Fixtures installed in existing 5kV airfield lighting environment LEDs are DC-based devices that operate in milliamp range As LED technology improved, experts discussed alternate power sources Test beds reviewed alternate power sources Slide 9 9 Evolution of LEDs in Airfield Lighting Systems Prescott Municipal Airport Testing Modified LED edge lights, incandescent edge lights, and LED guard lights Modified edge lights 2.8A max 0.28/0.84/2.8A circuit vs. 4.8/5.5/6.6A circuit (traditional) Testing proved successful, system still operating after five years with no fixture failures Slide 10 10 Evolution of LEDs in Airfield Lighting Systems Hartsfield-Jackson Atlanta International Airport Test Bed (2006 present) Modification to Standards / airport funded Re-used existing series circuit infrastructure DC-based system with LED taxiway centerline and edge lights (600V DC) Small, rack-mounted power supply Fixtures directly connected to circuit Slide 11 11 Evolution of LEDs in Airfield Lighting Systems LED Equipment has evolved significantly Lighting equipment available Obstruction Lights Elevated and in-pavement taxiway edge lights Taxiway centerline lights Elevated and in-pavement guard lights Medium-intensity runway edge lights Slide 12 12 Evolution of LEDs in Airfield Lighting Systems Other equipment available Signage Wind Cones REILS LED-supporting equipment available Smaller constant current regulators Isolation transformers Sign Retrofit Kits Slide 13 13 Recent Developments Orlando International Airport Test Bed (2010 to present) DC-powered circuits, pulse width modulated Two interleaved circuits LED Taxiway Centerline Lights No isolation transformers Rack-mounted power supply Slide 14 14 Recent Developments False River Airport Test Bed (2010 to present) Funded by State of Louisiana DC power supply fed by batteries connected to solar panels Two interleaved circuits LED Taxiway Edge Lights Rack-mounted power supply Slide 15 15 Recent Developments Runway centerline and touchdown zone lights certified over last year Moratorium on acquisition and installation Pilots fixtures too bright at lower steps FAA tested circuits and verified operation Result - LED fixtures brighter at lower steps than incandescent fixtures Light curves differ between fixture types Slide 16 16 Recent Developments Incandescent fixture output is linear, LED output is non-linear Engineering Brief 67C recently issued, moratorium lifted Light Dimming Curve modified for white LED lights only Slide 17 17 Recent Developments Airport / manufacturer focus on runway edge lights Will impact majority of airports Main restriction is intensity of white LEDs High-intensity elevated edge lights anticipated in 2011 FAA requirement for in-pavement light to match elevated fixtures will hinder production Slide 18 18 Future Implementation System Approach needed Embrace LED properties and maximize efficiency Cease adapting to existing environment / infrastructure Two approaches evolving Lower current system (possible maximum current of 2.8A) DC-based system with pulse width modulation Slide 19 Design Considerations Consider LEDs for lights, signs, wind cones, etc. Maximize energy savings Interspersing of LED and incandescent fixtures - not acceptable Segmenting of circuiting / operations Separate circuits for incandescent and LED fixtures Match isolation transformer sizes to maximize efficiency 19 Slide 20 Design Considerations Analyze impact of circuit load on circuits, vault, airport Perform Benefit Cost Analysis (BCA) Higher material cost Longer lamp life Lower energy consumption Higher replacement cost Training/expertise of maintenance staff 20 $$$ Slide 21 Design Considerations Arctic Kit or no Arctic Kit Apprehension to use LED lights, because fixture wont melt snow Snow melting is inherent property of incandescent fixture Arctic kit negates lower energy consumption Selection impacts circuit load, regulator size Snowplowing impacts 21 Slide 22 Design Considerations Test Beds w/ and w/o Arctic Kit Multiple sites in Midwest Taxiway Edge Lights Guidance Signs Current Testing at JFK Taxiway Centerline Lights Multiple vendors 22 Slide 23 Roundtable Discussion Denise De Natale - Director of Sales, Multi Electric Manufacturing Inc. Galen Dixon - Regional Sales Manager, ADB Airfield Solutions Tony Mancini - Director of Marketing, Cooper Crouse-Hinds 23 Slide 24 Roundtable Discussion Topics of Discussion Feedback / Lessons Learned on existing LED installations Interpretation / Impacts of recently issued Engineering Brief 67C Recent developments with LEDs / emerging equipment 24 Slide 25 25 THANK YOU