Waste heat could power computers, cell phones

Close to 60 percent of the energy produced by burning fuels or generated by power plants is lost as excess heat.  Computers, cars and cell phones all have to get rid of excess heat to run properly, creating a significant energy waste.  Researchers at MIT believe they've developed a way to reclaim a majority of that wasted energy and turn it into electricity.

Such an advancement in waste-energy harvesting could produce laptops and cell phones that run twice as long on a battery charge and highly efficient power plants, cars and planes.

The team carried out experiments to see how close to the Carnot Limit - the theoretical efficiency ceiling when converting heat to electricity - they could get.  Current devices only reach about a tenth of the limit, but using thermal diodes, the team was able to achieve 40 percent and they think as much as 90 percent is possible.

The secret to this new level of efficiency was reducing the amount of space between the hot surface and the conversion device, a quantum-dot semiconductor.

A company called MTPV Corp. is already working on commercializing this technology and sees great potential for its use in electronics and transportation.

via MIT News