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Monday, July 21, 2008

Purdue LED Us to More Efficient Lighting, Less Mercury

posted by on July 21 at 15:19 PM


Longtime readers know of my aversion to compact fluorescent lightbulbs:

The “mercury vapor” that fluorescent bulbs require is quite toxic. While new compact fluorescent bulbs are voluntarily limited to five milligrams of mercury each, as little as a tenth of a milligram per square yard will make you seriously ill. Shaking hands, drooling, irritability, memory loss, depression, weakness—sounds like fun. And that’s what happens to adults; kids can be permanently injured by mercury exposure. If you break one of these bulbs in your house—and think of all the times a bulb breaks—the current advice is to open a window and run, not to return for at least 15 minutes. Whereas if it’s a traditional bulb, you grab a broom and screw in a new one.

And even if you manage to not accidentally dump hazardous waste in your living room, what do you do with a fluorescent bulb when it just plain wears out? Most places cannot recycle fluorescent tubes.

There is another. LED (light emitting diodes) have a similar energy efficiency to fluorescent bulbs with a far friendlier environmental impact. In the least, they involve no mercury.

Great! Why not use them everywhere? Huge expense. Most LEDs are based upon a substrate of sapphire. Urk. Requiring a precious stone means LED lightbulbs are about twenty times more expensive than traditional lightbulbs.

Enter some clever researchers at Purdue University:

The Purdue researchers have solved this problem by developing a technique to create LEDs on low-cost, metal-coated silicon wafers, said Mark H. Oliver, a graduate student in materials engineering who is working with Sands.

(Who would think something good could come from Indiana?)

Replacing the sapphire with silicon (made from sand) makes the bulbs fantastically cheaper. Good work people. Expect the cheaper, environmentally sound and energy efficient bulbs in stores in about two years.


RSS icon Comments



Posted by Jubilation T. Cornball | July 21, 2008 3:25 PM

Hooray! I hate having my living room with the same light color quality as the inside of a Fred Meyer store.

LED's can also operate on a dimmer without having to jump through any extra hoops (yes, there are dimmable fluorescents, but they suck).

Posted by Mahtli69 | July 21, 2008 3:34 PM

Some comments:


I'm from Indiana, so way to represent the Crossroads of America, Purdue! For reals.

My partner is a materials science and engineering prof, so this is cool to *both* of us.

Posted by Balt-O-Matt | July 21, 2008 3:34 PM


The color spectrum of white LEDs still suck relative to tungsten (traditional) bulbs--far too cold for most people's taste.

But, most of the spiffy lighting effects on the 787 are courtesy of LEDs, so who knows.

Purdue is pretty sweet, as are Material science engineers. God bless and keep them both.

Posted by Jonathan Golob | July 21, 2008 3:42 PM

In my role as pedant, isn't it "emitting" not "emanating"?

Posted by leek | July 21, 2008 3:46 PM

Urp. Correct leek. Now I'll correct.

Posted by Jonathan Golob | July 21, 2008 3:50 PM

Cheap LED lighting!  Wo0t!  Woo-hoo!  And did I mention WOOOOOOOOOOOOOO-hooooty-hoo-hoo!!!?

But from Purdue?  Crap; now I'll never get anyone to spell my name right.

Posted by lostboy | July 21, 2008 3:53 PM

I like the color of my solar/LED yard lights. They're the color of moonlight.

What kind of cretin hates moonlight?

Posted by elenchos | July 21, 2008 4:04 PM

GE is ramping up LED production as we speak, and it's expected to be huge in their profit forecasts as we move into the next decade.

Posted by Will in Seattle | July 21, 2008 4:13 PM

I dunno, I got some LED bulbs a year or so ago, and they really suck, both in light intensity and quality. I had really high hopes, and they are crushed and leaking toxics, like a compact fluorescent in the trash ...

Posted by Huh | July 21, 2008 4:27 PM

Moonlight fucking sucks, Elenchos. God, how I hate it. Moonlight is like Hitler as far as I'm concerned.

Posted by Fnarf | July 21, 2008 4:54 PM

Sounds to ME like elenchos wants to ruin the mystique and romance of moonlight by replicating it throughout our homes. NEVER!

Posted by leek | July 21, 2008 5:04 PM

As a Hoosier, I take offense at your comment about nothing good coming from Indiana.

I give you, alphabetically: Birch Bayh, Hoagy Carmichael, James Dean, Eugene Debs, Theodore Dreiser, Florence Henderson, Alfred Kinsey, Sean Kemp (wasn't he a Sonic?), David Letterman, Carole Lombard, John Mellencamp, Cole Porter, Knute Rockne and Kurt Vonnegut.

There are many many others. Before you besmirch an entire state (even one so seemingly backwards as mine), please check wikipedia:

Granted, we can't lay claim to Dan Savage, Eddie Vedder, or seemingly, most of the staff of The Stranger, but neither can Washington.

Posted by DMC | July 21, 2008 6:46 PM

I'll take a "wait and see" here. All the "super-bright" LED's I've bought can't hold a candle to a single match. But if this does come on-line and is any good, it will do so about the time all my CFL's go kaput.

Posted by Silverstar98121 | July 21, 2008 7:47 PM

Go Boilermakers!

Posted by Daniel K | July 21, 2008 9:58 PM

DMC - How can you leave out three of the most famous Purdue Alum: Neil Armstrong (first man on the moon), Gene Cernan (last man on the moon), and Orville Redenbacher (the king of popcorn)!

Posted by Daniel K | July 21, 2008 10:01 PM

I didn't say you should buy them today, but starting around 2010 they will be in such volumes that the price should be way way cheaper per lumen per watt than anything else.

Posted by Will in Seattle | July 21, 2008 11:41 PM

Out of South Bend, I give y'all Umphrey's McGee.... the best damn band to go follow these days.

Posted by Umph | July 22, 2008 12:17 AM

Thank you #13.

. . .and don't forget the Indy 500. . .the greatest spectacle in racing!

Hopefully Evan will be Obama's VP too!

Posted by irl | July 22, 2008 7:24 AM

@13 - And don't forget John Wooden, Purdue alum and the Wizard of Westwood, who coached UCLA to 10 national titles.

Posted by Bruins Fan | July 22, 2008 8:07 AM

As a Hoosier, I praise all the Indiana recognition going on here.

However, as a graduate of Indiana University, I can assure you these Purdue lightbulbs will smell like cow ass when they are left on too long.

Carry on.

Posted by Jubilation T. Cornball | July 22, 2008 8:50 AM

Elenchos @8 has uncovered the conspiracy. To wit, the chorus of Indiana's state song:

Oh, the moonlight's fair tonight along the Wabash,
From the fields there comes the breath of newmown hay.
Through the sycamores the candle lights are gleaming,
On the banks of the Wabash, far away.

Love it or hate it, it is now clear that the Purdue team's goal was to replicate moonlight everywhere. I wouldn't be surprised if the bulbs smelled like newmown hay if you left them on for a while.

Posted by Joe M | July 22, 2008 9:34 AM

Jonathan, agreed, affordable bright LED's are better than CFL's in almost every way but CFL's use far less electricity than conventional. Since most of our electricity is currently made from coal over their lifetime CFL's keep 10 times as much mercury out of the atmosphere as they contain. No doubt their's some risk but more and more places are recycling them, including every Ikea location, so it's getting better. They're not ideal but they're a good step on the way to ideal.

Posted by Colin | July 22, 2008 10:54 AM

Sapphire is doped aluminum oxide, and the sapphire used to make LEDs is synthetic. Don't sensationalize it. Silicon comes from sand, but the energy required to get the oxygen out is not exactly cheap either. Both silicon and aluminum are very common elements in the earth's crust.

Posted by glasspusher | July 22, 2008 6:25 PM

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