Sample from the book

Light-emitting diodes are the future of lighting. Just as the incandescent gave way to the compact fluorescent lamp (CFL) in our homes and offices, the CFL is yielding to the light-emitting diode. These are inherently slow processes given the number of bulbs that need to be replaced and the lifetime of those bulbs, but a tectonic shift is underway. In a few short years, the household incandescent will be a quaint thought, and CFLs will be looked upon as a misguided, poison-laced stepping stone.

LEDs are, of course, nothing new. The technology has been around since the early 1900s, and for years we’ve seen LEDs in almost all our electronic equipment, regardless of the device, its function, or its maker. For decades they have been affordable to purchase and cheap to operate, but they’ve largely been relegated to the red, blue, and green status indicators on our computers, radios, and routers. Powered by just a few milliamps and usually outlasting any device they operated within, LEDs served their purpose but were far from fulfilling their potential. Recently, high-power, high-quality LEDs have started lighting our homes and offices, and the big lighting com-panies—General Electric, Osram Sylvania, and Philips—as well as a number of competitors, are pushing them into the mainstream.

According to the US Department of Energy (DOE), lighting consumes over 14 percent of all the electricity we use. That means lighting is large industry, but it operates under a number of masters. Not only do organizations like the Department of Energy get involved in lighting, but so does Congress, and all businesses have to take a stance, as does anyone concerned with their energy footprint. Over the course of the next few years, cost-conscious con-sumers and energy-savvy businesses will ultimately decide if any product or underlying technology is viable or not. And the stakes are not insignificant: according to the DOE, future changes will yield a 19% drop in the energy consumption of lighting. That drop is forecasted to be 46% by 2030 ac-cording to a January 2012 report examining the “Energy Savings Potential of Solid-State Lighting.

You wouldn’t be here if you didn’t already know what a light-emitting diode is, but you should remember this: an LED is just a source of light. How that light is generated—by running electrons through a semiconductor, resulting in a process known as electroluminescence—is fundamentally different than how the incandescent, filament-based bulb works. That our light is being provided by a semiconductor, not the heating of a material (electroluminescence vs. incandescence), is the key to everything you’ll read in this book… and the future of mankind’s light.

We’re at the start of a revolution in home, commercial, and public lighting that will be the biggest shift in the sector since the development of the tungsten filament over 100 years ago. Solid-state lighting is the future and the LED is the engine moving it forward. In a few years the market will almost certainly have settled on LED bulbs (not entirely, but predominantly). Before then, the technology has a long way to go and we as consumers have a lot to learn.