LED lamp

Edison's incandescent bulb had dominated lighting for over a century. It worked by heating a filament until it glowed—a process that converted 95% of electrical energy into waste heat and only 5% into light. This spectacular inefficiency persisted because alternatives were worse: fluorescent tubes required toxic mercury, early LEDs could only produce dim colored light, and nothing matched incandescent's pleasant warm glow.

The breakthrough came from white LEDs, developed by Shuji Nakamura and colleagues in the early 1990s. By coating blue LEDs with yellow phosphors, they could produce white light that approximated incandescent quality. But these early white LEDs were expensive and dim—suitable for indicator lights and flashlights, not room illumination. General lighting required orders of magnitude more brightness at dramatically lower costs.

The path from white LED to LED lamp required relentless improvement in efficiency (lumens per watt) and cost reduction (cents per lumen). In 2000, white LEDs produced around 20 lumens per watt at costs prohibitive for general lighting. By 2010, commercial LED lamps exceeded 100 lumens per watt—far surpassing incandescent (15 lm/W) and compact fluorescents (60 lm/W). The learning curve that had driven semiconductor costs down applied equally to LED manufacturing.

The adjacent possible included several converging factors. Government regulations accelerated adoption: the US Energy Independence and Security Act of 2007 effectively banned incandescent bulbs. EU and Australian regulations followed. These policies created guaranteed markets that justified manufacturing investment. Meanwhile, the LED industry scaled up for display backlighting (phones, TVs, monitors), creating production volume that reduced lighting costs.

Geographic concentration reflected LED manufacturing's roots. Japan's Nichia (Nakamura's employer) and South Korea's Samsung and LG dominated early production. China rapidly entered, driving prices down through massive investment and scale. European and American companies (Philips, Osram, GE, Cree) maintained research leadership but increasingly relied on Asian manufacturing.

LED lamps required solving practical engineering challenges beyond the LED chip itself. Heat management was critical—LEDs are damaged by high temperatures, yet lamps must fit standard sockets without ventilation. Driver circuits needed to convert AC power to the DC that LEDs required. Color quality had to satisfy consumers accustomed to incandescent warmth. Standards for dimmer compatibility had to be established.

By 2015, LED lamps had achieved price parity with compact fluorescents while offering superior efficiency, instant-on performance, and longer life. Global LED lighting adoption accelerated. The International Energy Agency estimated that LEDs would capture 90% of the lighting market by 2030, reducing global electricity consumption for lighting by half compared to 2010 levels.

The LED lamp represents a rare case of a truly superior replacement technology: more efficient, longer-lasting, free of toxic materials, and ultimately cheaper than all alternatives. The century-old incandescent, one of Edison's most enduring inventions, was finally superseded by semiconductor physics.