New Material Provides 25 Percent Greater Thermoelectric Conversion Efficiency

[n2doc]

ScienceDaily (Feb. 15, 2011) — Automobiles, military vehicles, even large-scale power generating facilities may someday operate far more efficiently thanks to a new alloy developed at the U.S. Department of Energy's Ames Laboratory. A team of researchers at the Lab that is jointly funded by the DOE Office of Basic Energy Sciences, Division of Materials Sciences and Engineering and the Defense Advanced Research Projects Agency, achieved a 25 percent improvement in the ability of a key material to convert heat into electrical energy.

"What happened here has not happened anywhere else," said Evgenii Levin, associate scientist at Ames Laboratory and co-principal investigator on the effort, speaking of the significant boost in efficiency documented by the research. Along with Levin, the Ames Lab-based team included: Bruce Cook, scientist and co-principal investigator; Joel Harringa, assistant scientist II; Sergey Bud'ko, scientist; and Klaus Schmidt-Rohr, faculty scientist. Also taking part in the research was Rama Venkatasubramanian, who is director of the Center for Solid State Energetics at RTI International, located in North Carolina.

So-called thermoelectric materials that convert heat into electricity have been known since the early 1800s. One well-established group of thermoelectric materials is composed of tellurium, antimony, germanium and silver, and thus is known by the acronym "TAGS." Thermoelectricity is based on the movement of charge carriers from their heated side to their cooler side, just as electrons travel along a wire.

The process, known as the Seebeck effect, was discovered in 1821 by Thomas Johann Seebeck, a physicist who lived in what is now Estonia. A related phenomenon observed in all thermoelectric materials is known as the Peltier effect, named after French physicist Jean-Charles Peltier, who discovered it in 1834. The Peltier effect can be utilized for solid-state heating or cooling with no moving parts.

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http://www.sciencedaily.com/releases/2011/02/110215164336.htm

[txlibdem]

1. Would focusing the sun's rays onto this device increase output?

Here's an article from 2007 off the same site the OP links to about a researcher using an ingenious (all glass) design of lenses to focus the sun's rays onto a postage-stamp sized photovoltaic cell. The video at the link is interesting and it shows the entire facade of a building covered in these things but they are made of glass so they do not block the sun from the building occupants.

The lenses move throughout the day to precisely track the sun and maintain its focus onto the cell.

So why not do something like that with this device (take the sun's heat and turn that into electricity on a larger scale). Anyone who, as a kid, has ever taken a magnifying glass outdoors and started burning leaves will attest that the sun can be concentrated to become very, very hot.

...achieved a 25 percent improvement in the ability of a key material to convert heat into electrical energy.

...

The durable and relatively easy-to-produce material has innumerable applications, including recycling waste heat from industrial refineries or using auto exhaust heat to help recharge the battery in an electric car. "It's a very amazing area," Levin said, particularly since many years of prior research into TAGS materials enables researchers to understand their nature. Better understanding of the thermoelectric and their improvement can immediately result in applications at larger scale than now.

http://www.sciencedaily.com/releases/2011/02/110215164336.htm

If it works off of heat, not just certain wavelengths of light as today's solar PV cells do it stands to reason that focusing the sun's rays on this material may be beneficial:

"Conventional solar systems are about 14 percent efficient. This system has a combined heat and power efficiency of nearly 80 percent. "What they're doing is very efficiently capturing and transferring that light into electricity and the solar heat into hot water," Dyson explains."

http://www.sciencedaily.com/videos/2007/0507-bringing_sunlight_inside.htm

[JohnWxy]

2. very interesting.

recommended.