Reply #37: Wikipedia (yes, I know, it's not completely reliable) [View All]

[muriel_volestrangler]

seems to say LEDs are just about now approaching the efficiency of fluorescent lights.

In 2002, 5-watt LEDs were available with efficiencies of 18-22 lumens per watt. It is projected that by 2005, 10-watt units will be available with efficiencies of 60 lumens per watt. These devices will produce about as much light as a common 50-watt incandescent bulb, and will facilitate use of LEDs for general illumination needs.

In September 2003 a new type of blue LED was demonstrated by the company Cree, Inc. to have 35% efficiency at 20 mA. This produced a commercially packaged white light having 65 lumens per watt at 20 mA, becoming the brightest white LED commercially available at the time. In 2005 they have demonstrated a prototype with a record white LED efficiency of 70 lumens per watt at 350 mA CompoundSemiconductor.
...
Lighting systems using incandescent bulbs are cheap to buy but inefficient, generating from about 16 lumens per watt for a domestic tungsten bulb to 22 lm/W for a halogen bulb. Fluorescent tubes are more efficient, from 50 to 100 lm/W for domestic tubes (average 60lm/W), allowing large energy savings, but are bulky and fragile and require starter circuits. LEDs are robust and moderately efficient, up to 80 lumens per watt (but the average commercial LED outputs 32 lm/W).

http://en.wikipedia.org/wiki/Light-emitting_diode