By Nicholas Wilbur

Thomas Edison, eat your heart out.

While the inventor of the light bulb will forever hold a place in history for his scientific revelations, changing the way we light our homes, offices and even our city’s traffic signals is long over-due.

Dr. Qiming Li, scientist at Sandia National Laboratories

While the inventor of the light bulb will forever hold a place in history for his scientific revelations, changing the way we light our homes, offices and even our city’s traffic signals is long overdue.

Thanks to a $777 million investment from the Department of Energy, researchers at New Mexico’s own Sandia National Laboratories are leading the way to a brighter – and more efficient, more economical – future.

One of 46 Energy Frontier Research Centers to receive DOE funding, Sandia is now researching various aspects of the current energy problem, from solar to hydrogen energy all the way to the storage of carbon dioxide from greenhouse gas emissions.

The five-year funding totals $18 million, and the research is receiving national attention already. U.S. Sen. Jeff Bingaman (D-N.M.) has been instrumental pushing such technologies. He was one of the first to advocate for public/private partnerships with solid-state lighting in 2003. Two years later he authored the “Next-Generation Lighting Initiative” in the Energy Policy Act of 2005, which laid the foundation for public/private partnerships that are now funded at about $50 million per year, according to Bingaman spokesperson Jude McCartin.

“Switching to this next generation of lighting will allow our country to take a major step toward reducing our energy consumption,” said Bingaman, who chairs the Senate Energy and Natural Resources Committee. “Performing the necessary research in the United States also means we will be more likely to manufacture this new technology domestically.”
He added, “Sandia is doing a tremendous job advancing solid-state lighting research and I will continue to strongly support its efforts in this very important area.”

Currently, lighting accounts for about 22 percent of the nation’s electricity usage. But more than 80 percent of the energy needed to produce light from an incandescent bulb is wasted. Although cheap, such bulbs can boast no more than 5 percent efficiency. The combustion-based technology of incandescent lighting produces excessive heat and minimal output considering the amount of energy that goes into them, not to forget the millions of tons of carbon dioxide they release into the atmosphere worldwide.

Halogen bulbs, which have twice the efficiency and two to three times the lifespan of the incandescent, were a great improvement to the industry. Fluorescent lights, being four to five times as efficient, go even further. However, there are drawbacks even to fluorescents, such as their generally bulky size, their high voltage, the toxic waste involved in the mercury vapor used in the bulb, and their inability to fully operate in low temperatures.

While there have been significant improvements in lighting efficiency and savings, they are but ripples before the title wave in comparison to the current Solid State Lighting research underway at Sandia Labs.

“This was a big deal for us,” said Mike Coltrin, a co-director and one of several lead researchers at Sandia’s EFR Center. “Today you’re seeing the first commercial products you can use in your bedside lamp. Five or so years from now, you’ll see an LED (Light Emitting Diode) that’s much more efficient than an incandescent light bulb, and significantly cheaper after they go into mass production.”
LED technology has been around for years, and already 70 percent of the red traffic lights are LED, according to information provided by Sandia Labs. They are 10 times as efficient, they pay for themselves in less than a year, and after that, the cost-savings is nearly $1,000 annually. LEDs are already eight to 10 times more efficient than incandescent lights, while fluorescents hover around the 25 percent range. It won’t be long before Solid State Lighting hits 50 percent efficiency, “and it could go somewhat higher,” Coltrin said.

LEDs last about 50,000 hours compared to the 5,000 to 10,000 hours of fluorescents. Incandescents, on the other hand, have a lifetime of barely 1,000 hours.
So what, exactly, does all of this mean? And how is it possible?

It means that in the next decade, the $35 billion spent on lighting in America will be cut drastically. The change eventually will result in a 10 percent reduction in worldwide electricity usage. Already, LEDs are said to cut in half the 22 percent of energy used by lighting.

Sandia is investigating the conversion of electricity to light using “radically new designs,” which include relatively new technologies such as luminescent nanowires, quantum dots and hybrid architectures.

“One way of understanding this is, the technology is somewhat similar to computer chips that you have on your desktop computer,” Coltrin explained. “And for chips you put in electrons and it performs works to do calculations. For Solid State Lighting we use a different type of material in this chip, and when you put the electricity in, the energy of the electricity is converted to the energy that is in light.”
LED lights have such a long lifespan because they don’t have a filament that will burn out over time. Rather, the illumination comes from the interaction of electrons within a semiconductor, which produce a more lasting electrical current. These systems are produced as wafers, similarly to a solar panel.

“The trick is then that, depending on which material you’ve put into the chip, a different color of light will come out, and so in Solid State Lighting we’re interested in all the colors that the eye can see.”
A decade ago, he said, the scientific community understood collectively how to make red light come out of these chips with high efficiency. It’s harder to accomplish the same efficiency with green lighting, so a lot of research is now being focused there. It won’t be long before lighting from the full color spectrum will reach the same efficiency.

Companies already are getting on board with the new technology, including Costco and Sam’s Club, as well as a few ahead-of-the-curve restaurants, where the first LEDs have replaced incandescent lighting. Intensive market saturation is about five to 10 years away, Coltrin said.

“They are actually quite a bit more expensive on the purchase end, but they are more efficient and last much, much longer, and so over the lifetime they are cost-effective.” Already, he said, we’re seeing the first commercial products such as bedside lamp bulbs, which will grow significantly more affordable once they go into mass production.

“It’s going to be based on cost. It’s a tough sell to the consumers (because) you may well be plunking down five dollars for a replacement light bulb, but that could last years, so the cost of the light fixture next to your bed could be 10 times less, but the initial cost is going to look high.”
That is why the other main component of Sandia’s focus is the manufacturing aspect.

“The cost of the LEDs will reach some tipping point five to 10 years from now,” Coltrin said, and at that point, when it comes to decidaing on an incandescent versus an LED, “it will be a no-brainer.”
Sandia is just a few months into the process, having just received the DOE funding in the last year, but already it seems apparent that the research could extend far beyond the parameters of lighting technology.

“Solar may benefit from this as well,” Coltrin said. “I think it would be fair to say that the process of converting solar energy into electrical energy is almost the reverse of what an LED is doing. The things that we are learning about now to make LEDs better will also have impact on this solar energy conversion.”