Scientists from GE Global Research, the technology development arm for the General Electric Company, GE Lighting, and the University of Maryland-as part of a two-year solid-state lighting program with the U.S. Department of Energy-have announced the successful demonstration of a 1,500-lumen LED bulb (a standard 100-watt halogen PAR38 bulb produces 1,500 lumens) that addresses key barriers to more widespread adoption of LED bulbs for general lighting.
The prototype provides a snapshot of the future: "The scientists and technology leaders involved in this collaboration are dissolving some major barriers to the commercialization of general lighting LED bulbs," says John Strainic, global product general manager for GE Lighting. "We're taking swings at issues such as higher light output options, thermal management, and bulb size and weight. This kicks open the door to the solid-state age that is upon us."
As part of the DOE project, GE and the research team of Professors Bongtae Han and Avram Bar-Cohen at the University of Maryland's A. James Clark School of Engineering have developed and demonstrated novel cooling technologies that effectively manage the heat and promote lower system costs by reducing the number of LED chips required, when compared to conventional cooling technologies.
Mehmet Arik, a mechanical engineer at GE Global Research and principal investigator on the LED project, says, "This is a revolutionary cooling technology with great promise. It has the potential to help us take LED lighting performance and efficiency to new heights. Through further research and improvements, we may be able to increase performance without compromising the efficiency or lifetime of an LED bulb."
GE's cooling solution is based on technology the company now uses in its Aviation and Energy businesses. GE dual cool jets are very small micro-fluidic bellows type devices that provide high-velocity jets of air, which impinge on the LED heat sink. These jets of air increase the heat transfer rate to more than ten times that of natural convection. The improved cooling enables LED operation at high drive currents without losses in efficiency or lifetime. For a given lumen output, the dual cool jets' improved thermal management reduces the necessary LED chip count. This, in turn, can dramatically lower the cost of the lamp. In addition to performance and cost advantages, this cooling technology enables reductions in LED lamp size and weight.
GE and the University of Maryland are in the final stages of the DOE project. The organizations are now studying ways to improve the reliability and lifetime of LED lighting systems.