May 5, 2011

MIT Researchers Make Solar Power More Efficient

MIT researchers have found a way to make solar power perform more efficiently.

The team's system produces power using the sun's heat with about eight times the power than previously reported for a solar thermoelectric device.

Gang Chen, MIT's Carl Richard Soderberg Professor in Power Engineering and director of the Pappalardo Micro and Nano Engineering Laboratories, said on MIT's website that the concept "is very radical."

The new system uses flat, stationary panels similar to traditional solar panels, which helps eliminate the need for tracking systems.

It requires less material than conventional photovoltaic panels, which could inevitably cost less to produce.  The system can also be integrated into solar hot water systems, which have become a highly successful product in China and Europe.

The researchers used materials made through a nanostructured process in order to build these solar thermoelectric generators. 

They have continued to work on improving these materials and integrating them into complete systems.

Chen says the U.S. Department of Energy has programs to develop thermoelectric systems, which are geared toward harnessing waste heat from car and truck engines. 

He said in a statement that solar applications for these types of devices can "have an important role to play" in reducing carbon emissions. 

"Hopefully we can prove that," he adds.

Li Shi, associate professor of mechanical engineering at the University of Texas, said in a statement that this approach to solar power is "very novel, simple, and easy for low-cost implementation."

"With the use of other or new thermoelectric materials that can operate at a higher temperature," Shi told MIT, "the efficiency may be improved further to be competitive with that for state-of-the-art amorphous silicon solar cells. This can potentially provide a different approach to realizing the $1-per-watt goal for solar-electricity conversion."

Chen said the new system offers "another way" of tapping into the Earth's solar energy. 

He said the thermoelectric device could be relatively inexpensive because it can be piggybacked onto the existing solar hot-water industry.

Their research was published online in the journal Nature Materials.


Image 2: Doctoral student Daniel Kraemer, right, and Professor Gang Chen display a prototype of a flat-panel solar-thermoelectric generating device.
Photo: Melanie Gonick


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