LEDs

LEDs (light-emitting diodes) are semi-
conductors that convert electricity into light. Once used just as indicator lights for electronics, LEDs have evolved into a major lighting technology that may change the future of general illumination. LEDs are highly regarded for their long life, energy efficiency, non-toxicity, durability, and flexibility. Yet as a fairly new and rapidly changing lighting technology, much research is still needed in order to fully realize the energy and cost savings potential of LEDs.

The Solid-State Lighting Program at the LRC conducts necessary research and educational programs to enhance this technology, overcome barriers to effective use, and help it to gain acceptance for general illumination purposes.

Download the LRC Solid-State Lighting Program brochure

Publications

Investigation of Remote-phosphor White LEDs with Multi-phosphor Layers - LRC researchers questioned the impact of randomly mixing phosphors versus stacking different phosphors in layers, as well as the effect of layer order.

Considerations for Successful LED Applications - Matching the needs of each application to the specific atributes of LEDs is critical to achieving successful applications.

LED Residential Under-cabinet Luminaires - NLPIP compared four LED linear under-cabinet luminaires with four traditional models in order to determine if the LEDs improved uniformity, color, illuminance, and efficacy.

Availability of LED Lighting Products for Consumers - NLPIP provides information about general illuminaition LED products available for consumer-oriented retail stores.

Field Test DELTA Snapshots: LED Street Lighting - Investigates claimed benefits of LEDs in street lighting applications, such as long life, improved uniformity, reduced maintenance, promotion of vision at low light levels, and energy savings.

ASSIST recommends: Parking Lot Lighting - An alternative metric for evaluating parking lot luminaires based upon its application efficacy. An online calculator estimates performance based upon this metric.

L ong-term Performance of White LEDs and Systems - The LRC life-tested commercially available white LEDs and downlight systems for long-term performance.

Extracting Phosphor-scattered Photons to Improve White LED Efficiency - A new method developed by the LRC, called Scattered Photon Extraction (SPE™), improves the light output of white LEDs by up to 60% by using remote placement of phosphor and optimally shaped optics.

View more Solid State Lighting publications

View more ASSIST recommends publications

Related Programs

Solid-State Lighting - Improving, using LEDs
Alliance for Solid-State Illumination Systems and Technologies - Industry, academia, and government working together to advance LED lighting.
Light & Health - Visual, circadian systems
Transportation Lighting - Vehicle, roadway, signal
NLPIP - Product testing

Education Programs

Lighting Education Online is an interactive, Internet-based education program for building, design, and facility management professionals who want to learn more about light and lighting. Available courses include:

The LED Lighting Institute is a three-day, hands-on workshop for people who want to learn more about this quickly evolving lighting technology in a small-class setting.

Projects

Dimming Behaviors of LED Replacement Lamps - LRC researchers investigated the dimming performance of commercially available LED replacement lamps and the performance variations among different residential dimmers.

Designing a Better Recessed Downlight Using SPE Technology - The LRC developed a highly efficient LED downlight to replace an equivalent 75W incandescent or 26–32W CFL downlight.

Accelerated Life-test Method for LED Drivers - The LRC conducted a study to understand what factors influence the failure modes of standalone LED drivers, and to develop an accelerated test method to predict the useful life of an LED driver.

LED Beacon Lights on Maintenance Trucks are a Safe, Economical Alternative - A recent study by the LRC has shown that LED beacon lights use less power without compromising safety.

Lighting Supermarket Freezers with LEDs - A field study investigating the use of white LED lighting inside supermarket freezers, including energy comparisons with fluorescent, sales analyses, and shopper preferences.

LEDs: Saving Energy in Retail Display Windows - A field study using LEDs as colored background lighting for retail window displays in order to reduce accent lighting power by up to 50%.

Innovative Lighting Solutions for Senior Care Facilities - A demonstration showing how innovative lighting designs and advanced technologies, including LEDs, photosensors and occupancy sensors, can help seniors in long-term care facilities maintain independence and be more comfortable.

Improving White LED Efficiency Through Scattered Photon Extraction (SPETM) - A new method of extracting more light from white LED packages, SPE™ significantly increases the light output and luminous efficacy of white LEDs.

Characterizing the Thermal Resistance Coefficient of LEDs - The accuracy of measuring LED junction temperature—a strong predictor of LED performance—depends upon the value of the LED's thermal resistance coefficient. This study explored how thermal resistance changes with different parameters.

Electronic Walls and Ceilings Offer Adaptable Solid-State Lighting - The LRC and ASSIST are developing a flexible interior infrastructure that will integrate solid-state lighting with other building materials and systems. Such an infrastructure would allow for rapid reconfigurations of built-in lighting, making it as easy to redesign lighting.