Lighting More With Less

LEDs are everywhere today. But what does L. E. D. stand for anyway?

Luminous Efficiency Device? Less Electricity Demanded?

Not quite – though both correctly describe Light Emitting Diodes. They make more light, from less electricity, than any other technology.

Incandescent bulbs of the 20th century heat a metal filament until it glows white hot. They produce light, but much more electricity is converted into, and wasted as, heat.

Fluorescent tubes pass energy through a gas that glows. They consume less electricity, but their light is not so attractive, they must be disposed of properly, and the bulbs can be fragile.

So scientists kept pushing for something better, and invented LEDs in the 1960s. The initial technology was basic and expensive, but worked the same way it does today:

Electricity flows through a two-layered semiconductor. One layer has an excess of negatively charged electrons.

The electricity forces electrons to jump to the other positively charged layer to equalize. As they do, they release a small amount of energy as light.

Multiply that over millions of electrons and these diodes can emit a great deal of light, with very little energy wasted as heat.

They’re such a step up over old bulbs, that LEDs now make up half of global lighting, and growing.