If reach defines a revolution, consider that LEDs are already preferred by Pennsylvania's Amish for horse-drawn buggy headlamps! Automakers are not far behind. LED brake lights are already in production with LED headlamps being prototyped for mid-decade introduction. For all applications the draw is the energy efficiency, long life and the easy deployment of the new high output, white LEDs, says Doug Silkwood, director of marketing, Lumileds Lighting LLC, San Jose, Calif. "For car designers the appeal of LED head lamps begins with styling and brand identification possibilities and continues with the functional advantages of light output and compactness," says Ron Steen, director of lighting R&D, Schefenacker Research LP, Rochester Hills, Mich. (The company supplies LED automotive tail lights and soon hopes to source LED head lamps.) Silkwood's Amish customers prize the power efficiency -- battery life increases to 100 hours from 6 hours with 50-watt halogen bulbs. "And they're experiencing at least a ten-fold increase in the useful life of the light source." Lumiled speculates that LED longevity could inspire some product designers to disregard the need for replacement. LEDs are fundamentally different from incandescent or fluorescent light sources. They're essentially solid-state semiconductors that release electrical energy in the form of light. They operate without the fragile glass and filament of incandescents and are notable for their lighting efficiency and long life. "For example, an incandescent bulb produces about 15 lumens per watt while our Luxeon LEDs reach 30. We are proceeding on a 'road map' to reach and surpass the 60 to 80 lumens per watt typical of fluorescents," adds Silkwood. Silkwood expects LEDs to win the efficiency race with fluorescents in as little as five years. In addition to competing on efficiency, LEDs also offer the advantage of being small, compact light sources. "Fixtures can be smaller, sleeker and lighter than those designed for fluorescents. The configuration makes it easy to capture and use the efficiency to maximum advantage." Will LEDs continue to displace conventional lighting? The pace will accelerate as prices drop, says Steen. In the automotive headlamp sector he predicts cost parity with incandescent bulbs within a decade. All of the world's major lighting firms are involved including Osram-Sylvania and General Electric Co., the company credited with the development of the first practical LED. Producing a low intensity red light, GE's invention did not seem to signal a technology that is now predicted to eventually displace conventional incandescent and fluorescent lighting.