The Economist magazine looks at LED lights. Incandescents only output 5% of energy input as light. LED and florescents output 20%. LED can be further improved. 20% of the worlds electricity is used for lighting. LEDs could cut that in to 10%.
So far, only a handful of firms are specialising in this market. To compete with the light output of a single 60-watt incandescent bulb that emits about 800 lumens (a measure of light power as perceived by the human eye), companies such as LED Lighting Fixtures and Permlight of Southern California are designing lamps based on clusters of white LEDs that achieve a similar lumen output, but consume a fraction of the power. Initial costs are still higher for such fixtures than for traditional bulbs, but lower electricity bills could make up the difference within a year or two, says Dr Hunter.
The size of LEDs allows for far greater choice in fixture design. LED fixtures resembling large tiles that can be mounted on walls to create checkerboard-like effects or morphing colours. LEDs made of organic materials, called OLEDs, promise even more revolutionary design possibilities. Since they were first commercialised a few years ago, they have mostly appeared in small portable devices, such as mobile phones and digital music-players. Based on ultra-thin, lightweight plastic sheets, OLEDs emit a softer, more distributed light than conventional LEDs and might eventually be turned into softly glowing wallpaper or curtains.