Your LED Lighting Supplier

The light bulb that has lit up our homes since the 1800s is officially on its way out. The inefficient incandescent, which loses most of its energy as heat, has fallen out of favor with the financially and ecologically concerned; starting in 2012, U.S. residents won't be able to buy one even if they want to [source: Linden]. The government is taking the little energy suckers off the market.

The prime replacement for the incandescent light bulb is the higher-efficiency compact fluorescent, or CFL. The CFL, though, has its own problems, primarily the inclusion of toxic mercury in the design and a strange, sometimes unpleasant color that even gives some people headaches.

Enter the LED, or light-emitting diode. LEDs have been around for many years -- they light up digital clocks, Christmas lights, flashlights and traffic signals, and they tell you when you've got a new voicemail message on your cell phone. But as far as household lighting goes, LEDs have never really taken off. Certain drawbacks have kept companies from manufacturing them in standard, replacement-size light bulb form.

In the last few years, though, these LED replacement bulbs, the kind you just screw into a lamp like you do an incandescent bulb, have become much more common -- which is to say a fair number of businesses and a handful of households are using them.

In some ways, LED light bulbs are a perfect technology. But they still have a way to go before they become the higher-efficiency bulb of choice. In this article, we'll find out why. We'll look into how they work, why they're a desirable lighting choice, and what will have to change before the rest of us start using them in our bedside lamps.

Let's begin with the basics: How does an LED produce light?

An LED is what's called a "solid-state lighting" technology, or SSL. Basically, instead of emitting light from a vacuum (as in an incandescent bulb) or a gas (as in a CFL), an SSL emits light from a piece of solid matter. In the case of a traditional LED, that piece of matter is a semiconductor.

Stated very simply, an LED produces light when electrons move around within its semiconductor structure. A semiconductor is made of a positively charged and a negatively charged component. The positive layer has "holes" -- openings for electrons; the negative layer has free electrons floating around in it. When an electric charge strikes the semiconductor, it activates the flow of electrons from the negative to the positive layer. Those excited electrons emit light as they flow into the positively charged holes.

Advantages of LED Lighting

First, there's the reduced energy use. The LED method of producing light loses far less energy to heat than do other lighting technologies. It's dramatically more efficient than the vacuum/filament method used in incandescent bulbs -- around 85 percent more efficient.

A single light fixture stocked with a 60-watt incandescent bulb consumes about 525 kWh of electricity in a year; put an LED bulb in that light fixture, and the annual energy use is more like 65 kWh! Also keep in mind that The annual CO2 reduction is in the hundreds of pounds for a single lamp.

But energy-efficiency is just part of the story. The other part is time-efficiency: You could go 20 years without having to change an LED light bulb. Solid-state lights like LEDs are more stable light sources than incandescent or fluorescent bulbs, and the difference is startling: A typical incandescent bulb lasts about 750 - 1,000 hours while an LED bulb lasts 50,000 hours!