By Reed Brown Have you noticed how much has changed in recent years when it comes to light bulbs? Traditional light bulbs (incandescent light bulbs) have been a staple in American homes since Thomas Edison first invented them more than 100 years ago, but changes in technology and new regulations have led to a significant shift in the light bulb landscape towards...
Virtually overnight we are starting to see energy-saving LED lighting almost everywhere. Not only was last weekend's Super Bowl played under LED lights, the new flat panel TVs for watching the game were illuminated by LED backlights, and the lights on the poles in the parking lot outside the sports bar and the streets and highways between there and home may have been retrofitted with LEDs as well.
Light-emitting diodes, more commonly known as LEDs, are revolutionizing functionality and styling of automotive lighting. The technology, once found only on luxury cars, is becoming standard on many headlamps and taillights of mainstream vehicles to set them apart from the competition. The increase in usage comes as the price of LEDs declines and automakers are finding new ways to use them.
Nestled between the transforming semiconductor and energy industries, the lighting industry is amidst one of the most remarkable shifts of its time. It’s no accident that the 2014 Nobel Prize in physics recently was awarded to three scientists for the invention of efficient blue LEDs and 2015 has been decreed as the International Year of Light by the United Nations.
In December, the Nobel Prize for physics went to the team behind a significant invention: the blue light-emitting diode (LED). While red and green LEDs have been around since the 1960s, figuring out how to make blue diodes bright enough stumped engineers until the early nineties. That advance—enabled by high-quality gallium nitride—quickly led to another. By converting blue light to white, engineers produced the crisp beams now ubiquitous in computer screens and smartphones. More recently, they found yet another application: street lamps.
I first tested an LED bulb seven years ago. It was not a promising beginning. The bulb was a Par 38 spotlight for a recessed ceiling fixture. The color of the light was a silvery metallic — so chilling and wintery that it made the room feel cold. The final kicker was the price — $125. Things have changed a lot since then.
COPENHAGEN — On a busy road in the center of town here, a string of green lights embedded in the bike path — the “Green Wave” — flashes on, helping cyclists avoid red traffic lights. On a main artery into the city, truck drivers can see on smartphones when the next light will change. And in a nearby suburb, new LED streetlights brighten only as vehicles approach, dimming once they pass.
A single wafer-level LED chip that produces more than 150 Watts of light output has been made in work form China. This level of output from a single chip makes applications for LEDs in high power lighting from stadiums to runways feasible, and the researchers have long term plans for a new way to light buildings and towns.