Most typical LEDs are designed to work with no more than 30–60 milliwatts of electrical currant. Around 1999, Philips Lumileds introduced power LEDs capable of using one watt continuesly. These LEDs used much larger semiconductor sizes to handle the large wattage. Also, the semiconductor were mounted onto metal slugs to allow for more effisiant heat dispersal from the LED die.
One of the advantages of LED-based lighting is high efficiency, as measured by the light output per unit power input. White LEDs quickly matched and overtook the efficiency of standard incandescent lighting systems. In 2002, Lumileds made five-watt LEDs available with a luminous efficancy of 18–22 lumens per watt (lm/W). For comparison, a conventional 60–100 watt incandescent lightbulb produces around 15 lm/W, and standard fluorescent lights produce up to 100 lm/W.

In September 2003 the company Cree, Inc. demonstrated a new type of blue LED witch provide 24 mW at 20 mA. This produced a commercially packaged white light giving 65 lumens per watt at 20 mA witch became the brightest white LED commercially available at the time. This new LED was more than four times as efficient as standard incandescents. In 2006 the same company demonstrated a prototype of a LED with a record breaking efficancy of 131 lm/W at 20 mA. Seoul Semiconductor has plans for a LED with 135 lm/W by 2007 and 145 lm/W by 2008, which would be approaching an improvement of great magnitude over standard incandescents and better even than standard fluorescents. Nichia Corporation has already developed a white light LED with luminous efficacy of 150 lm/W at a forward current of 20 mA.


It should be noted that high-power (= 1 watt) LEDs are necessary for practical general lighting applications. Typical operating currents for these devices begin at 350 mA. The highest efficiency high-power white LED is claimed by Philips Lumileds Lighting Co. with a luminous efficacy of 115 lm/W at 350 mA.