Deconstructing the $10 Million LED Bulb

Aug. 9, 2011
I think the L-Prize was a well-intioned bad idea.

   To begin: an apology to Philips. In an Engineering Radio segment last Saturday, I said I didn’t think that the U.S. Congress had set aside any money to fund the $10 million “L-Prize” that was established in 2007 for the first screw-in LED replacement for a 60-Watt bulb that met certain criteria. I was wrong. My PR contact at Philips phoned around the company and confirmed that they’d already cashed the check.

   My congratulations to Philips for some good engineering, and for getting to the bank before it occurred to somebody in Washington to stop payment. (If you’ll recall (I’m trying to forget), last week, Congress did get around to stopping funding the Federal Aviation Administration for a while. Good Intentions, etc.

   I think that the L-Prize was a well-intentioned bad idea, and I’ll explain why shortly, and point to a private-enterprise effort that makes more sense, but first, let me explain the L-Prize.

   It was written into the Energy Independence and Security Act (EISA) of 2007, which President Bush signed into law in January of 2008. One of the things the act did was to direct the U.S. Department of Energy (DOE) to establish a “Bright Tomorrow Lighting Prizes” (L Prize) competition.

   The winning bulb was required to be the first to demonstrate:

  • An output greater than 90 lumens. Energy consumption less than 10 W, in other words, a luminous efficacy better than 90 lumens/W,
  • A lifetime of at least 25,000 hours, which would be 25 times better than the average incandescent. (This is more about gradual loss of brightness, rather than burn-out.)
  • The Color Rendering Index (CRI) had to be greater than 90, i.e., colors had to be rendered naturally.
  • The color temperature had to be between 2700 and 3000 K.

   There was a dimming requirement, too, a fairly modest one -- the performance specifications required “continuous dimming down to at least 20% of maximum light output without visible flickering.” That’s easy because a number of semi companies have dimmer circuits that work with just about any legacy triac-style dimming control that’s out there and somehow manage to avoid conspicuous flicker.

   Naturally, you wouldn’t just mail one bulb to the EPA and settle back and wait to see if you’ve won. There’s was a requirement for a big sample size, and a lot of give and take with the EPA engineers about precisely how the measurements were to be made went on.
Location, Location, Location?

   To open the contest up, so it wasn’t sandbagged for American companies, the domestic-contents requirements were modest. The rules read, “The entrant which submits the SSL product is required to be incorporated in and maintain a primary place of business in the United States; or must be a U.S. citizen or lawful permanent resident in the case of an individual,”

   Beyond that, the requirements related only to the LED chips themselves. (One makes a “white” LED by putting a blue or UV-emitting diode inside a glass envelope that’s been coated on the inside with a yellowish phosphor.)

   Recognizing that, the rules said only that, “The LED die or chip… must be manufactured in the U.S.” That’s it. The mechanical parts and the phosphors could come from Mars, if necessary, and there were no requirements for other components or for where the bulbs would be assembled if the bulb were placed into production.
Engineering Jobs: Subvert the Dominant Paradigm
   Those were the criteria that Philips won on. They sent me a sample bulb last week, and you probably want to know how it works. The answer is, I don’t know yet, and the story behind that contains the explanation for why I think the L-Prize was a misguided idea. Another press release I got last week points to what I think would have been a better idea.
We Don’t Need No Stinkin’ Sockets!

   The reason I can’t tell you about the bulb is that my house doesn’t have any fixtures I can easily reach to screw it into. Desk lamps, reading lamps, the lights in the range hood, are all halogens or CFLs with funny sockets, or if they’re Edison-base, the shade doesn’t accommodate full-size incandescents. I have some ceiling lights and porch lights with CFLs that I could unscrew, but the ladder’s in the garage and I’d have to move the motorcycle to get to it.

   What I’m saying is that the Edison base is already obsolescent. Coming up with a 60-W replacement – what it reminds me of is my great-grandma’s house when I was a little kid, and some of the gas-light wall-sconce fixtures had been converted and wired for electric bulbs.

   Folks, we’ve got to shake this buggy-whip-socket mentality. If you have a lighting technology in which (soon enough) the light-emitters will still be shining long after we’re dead, you do not need to provide sockets. (Yes, I’m using hyperbole to make a point.)

   Which brings me finally, to that second press release. The company is called Dialight, although they have nothing to do with the old pilot-light company. They're headquartered in the UK, have offices in New Jersey, and they've been doing industrial LED lighting full time since 2007.

   The announcement was about a new 14,000-lumen LED High Bay fixture that delivers 93 lumens/W. That means it's 156 times brighter than Philip’s 60-W bulb, with a bit more luminous efficacy than called for by the L-prize rules. In addition, it's guaranteed not to burn out for 10 years, and it's been tested to meet a number of environmental standards, including humidity and salt fog, that I haven't seen since I stopped writing about MIL-STD-812. It's even Dark Sky compliant.

   What it isn't, is anything like a screw-in light bulb, looking more like an exceptionally ugly Euro-style shower fixture. But that’s not the point. I believe that the future of lighting lies in new construction, particularly of commercial buildings and public facilities.

   If you’re seeking design-engineering opportunities connected to LED lighting, that’s where to look. I expect more potential engineering jobs relate to controlling these things than to driving them. That’s mostly because they can be controlled, even, or let’s say, especially, in an industrial/commercial environment, where the accountants don’t want to pay to have the lights on all the time, no matter how efficient they are.

   So please, forget about rinky-dink fillers for obsolete sockets. It's time to send Edison’s 19th-century lighting paradigms to assisted-living, the way we did when we abandoned re-plumbing my great-granny's gaslight sconces.

About the Author

Don Tuite Blog

Don Tuite covers Analog and Power issues for Electronic Design’s magazine and website. He has a BSEE and an M.S in Technical Communication, and has worked for companies in aerospace, broadcasting, test equipment, semiconductors, publishing, and media relations, focusing on developing insights that link technology, business, and communications. Don is also a ham radio operator (NR7X), private pilot, and motorcycle rider, and he’s not half bad on the 5-string banjo.

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