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Chips turn more heat to power

The technology to cleanly and quietly turn heat into electricity without the use of a turbine or generator has existed for nearly a century. The trouble is, it has never been efficient enough for widespread practical use.

A pair of scientists at the Massachusetts Institute of Technology and Eneco Inc. have made a device that nearly doubles the amount of electricity that can be extracted from heat. The researchers' thermal diode converts about 18 percent of thermal energy to electricity, while current thermoelectric generators convert about 10 percent.

The technology could be used to generate additional electricity from power plants, which throw off enormous amounts of waste heat, and to generate electricity using the heat from automobile engines. The technology could also produce electricity in conjunction with devices that concentrate sunlight.