Posted by: Jonathan Marshall

Bright, efficient, long-lasting LEDs are about as “green” as lights get. Ironically, the only thing they lack is a good source of green light itself.

That’s all about to change, according to the National Renewable Energy Laboratory (NREL), which modestly claims that a new discovery there may “prove to be the biggest boost for illumination since Edison’s light bulb.”

The holy grail for all lighting technology is bright white light. As we all learn as kids, white is the combination of all the colors of the spectrum. At minimum, you need to mix red, blue and green together to make white out of color.

Mass-market LEDs first came out in red, as old-timers may remember from the early days of HP hand calculators. Pioneered by Monsanto, they were made of gallium arsenide phosphide. They were bright enough for indicator lights, not for illumination.

In the mid-1990s, Japanese scientists used indium gallium nitride to produce the first bright and blue LEDs. Combined with a yellow phosphor, they could emit a white light—but only with low efficiency. 

Now a team of NREL scientists specializiing in high-efficiency solar photovoltaic cells—which convert light into electricity—has figured out a way to use some of the same principles to convert electricity into light, in particular, green light. 

Solar cells, like LEDs, can be made of gallium indium nitride. NREL’s Angelo Mascarenhas and his colleagues had figured out how to fine-tune the manufacturing of solar cell lattices to better absorb light energy from the green part of the spectrum. Using the same tricks, they managed on their first try to trick an LED into emitting a deep green light.

Combined with blue and red, the technology “will give you one of the finest color-rendering white lights” available, Mascarenhas promises. And by varying the intensity of the underlying colors, the hue can be changed on command.

Note: contrary to NREL's breathless story, other scientists also claim to have cracked the green-light barrier, using zinc selenide. We'll let them fight it out for credit, as long as they hurry up to market.

Posted by: Katie Romans

We all know the movie...picturesque Camp Crystal Lake, young summer camp counselors frolicking in the night, then...the lights go out.

And nobody thought to thank that thoughtful Jason Voorhees?? Teenagers.

The International Dark Sky Association, a group dedicated to preserving and protecting the nighttime environment, might even argue that the notorious Friday the 13th villain, Jason, did that campground a favor by eliminating all that pesky light pollution.

In fact, the group will host a Congressional Briefing on the subject next Friday, June 20. Among the topics to be discussed are consequences of light pollution on human health and the environment, as well as energy wasted as a result of light pollution. Of those presenting will be representatives from the Bassett Healthcare Institute (New York) and The Urban Wildlands Group. PG&E will also present, addressing IDA's estimate that more than $10 billion is wasted annually on unnecessary lighting.

Call me devil's advocate, but I think that poor Jason was misunderstood.