New material makes electricity from waste heat

- U.S. researchers say they've found a material that can generate electricity from the waste heat of car exhaust systems or industrial processes and equipment.

Researchers at Northwestern University placed nanocrystals of rock salt into lead telluride to create a material that is expected to be able to convert 14 percent of heat waste to electricity, a university release said recently.

"It has been known for 100 years that semiconductors have this property that can harness electricity," chemistry Professor Mercouri Kanatzidis said. "To make this an efficient process, all you need is the right material, and we have found a recipe or system to make this material."

"We can put this material inside of an inexpensive device with a few electrical wires and attach it to something like a light bulb," said Vinayak Dravid, professor of materials science and engineering and co-author of the paper. "The device can make the light bulb more efficient by taking the heat it generates and converting part of the heat, 10 to 15 percent, into a more useful energy like electricity."

Automotive, chemical, brick, glass and other industries that use heat to make products could make their systems more efficient with the use of this scientific discovery, Kanatzidis said.