New material made from dirt can convert heat into electricity

An incredible new material made from common dirt can take heat and directly convert it into an electrical current, researchers have claimed.

Researchers said that they produced the groundbreaking substance using commonly found materials and that it can be cheaply manufactured, the Daily Mail reported.

They believe that it could spark a revolution in eco-friendly power generation by taking waste heat from a range of common sources and converting it directly to electricity.
So-called thermoelectric materials are able to directly convert differences in temperature to electrical voltage, and vice versa.

Scientists said that these are potentially important because the vast majority of heat that is generated from, for example, a car engine, is lost through the tail pipe.  It’s the thermoelectric material’s job to take that heat and turn it into something useful, like electricity.

Such materials have been made before, but previous examples have been derived from rare and sometimes toxic elements, often by way of expensive synthesis procedures.

Donald Morelli, a professor of chemical engineering and materials science at Michigan State University, led the team which developed the material based on natural minerals known as tetrahedrites.

“What we’ve managed to do is synthesize some compounds that have the same composition as natural minerals,” Professor Morelli, director of MSU’s Centre for Revolutionary Materials for Solid State Energy Conversion, said.

“The mineral family that they mimic is one of the most abundant minerals of this type on Earth – tetrahedrites.  “By modifying its composition in a very small way, we produced highly efficient thermoelectric materials,” he said.

The MSU researchers’ method involves the use of very common materials, grinding them to a powder, then using pressure and heat to compress into useable sizes.  “It saves tremendously in terms of processing costs,” Dr Morelli added.

The researchers expect this discovery could pave the way to many new, low-cost thermoelectric generation opportunities.

Potential applications include waste heat recovery from industrial power plants, conversion of vehicle exhaust gas heat into electricity, and generation of electricity in home-heating furnaces.

The research, supported by the US Department of Energy, was published in the online journal Advanced Energy Materials.