There can be no doubt that LED technology has realized significant gains over the past couple of years. Higher brightness levels, higher efficiencies, longer lifetimes and decreasing costs have spun out from the many advances made in terms of heat dissipation, packaging and processing. Unlike incandescent light bulbs, LEDs do not have a filament that will burn out and they tend to run cooler.
A high-power, or high-brightness (HB) LED’s light output has already exceeded the critical milestone of 100 lm/W, with some manufacturers already claiming >230 lm/W in the laboratory. Another added benefit is LED lifetime. Depending on how it is calculated, a white LED bulb has at least a 50,000-hour lifetime while an incandescent bulb’s life is around 1,000 to 2,000 hours.
The primary driver behind the high growth rate of LED lighting is the dramatic reduction in power consumption that LED lighting offers over traditional lighting. Compared with incandescent lighting, LEDs require less than 20 percent of the electrical power to provide the same level of light (in lumens). As can be seen in Table 1, there are additional advantages that LED lighting offers but also some additional challenges. LED advantages include a lifetime orders of magnitude higher than incandescent bulbs, which dramatically reduces replacement costs. The ability to dim LEDs using the previously installed base of TRIAC dimmers is also a major benefit, especially in residential retrofit applications. Instant turn-on eliminates the warm-up period associated with CFLs, and LEDs are not sensitive to power cycling like their CFL counterparts. Additionally, LED lighting fixtures do not contain any toxic materials to manage or dispose of, whereas CFL utilizes toxic mercury gas to operate. Lastly, LEDs enable new very low profile form factors that other technologies could not.
Table 1: Comparison of LEDs, CFL and incandescent light sources Click on image to enlarge
As a result, LEDs are now being used in many commercial applications, such as high bay lighting for factories; outdoor architectural lighting for bridges and buildings, as well as sports stadiums and other large event arenas.
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.