Researchers discover new material to produce clean energy
Phys.org, March 3, 2015
Researchers at the University of Houston have created a new thermoelectric material, intended to generate electric power from waste heat – from a vehicle tailpipe, for example, or an industrial smokestack – with greater efficiency and higher output power than currently available materials.
The material, germanium-doped magnesium stannide, is described in the current issue of the Proceedings of the National Academy of Sciences. Zhifeng Ren, lead author of the article and M.D. Anderson Chair professor of physics at UH, said the new material has a peak power factor of 55, with a figure of merit – a key factor to determine efficiency – of 1.4.
The new material – the chemical compound is Mg2Sn0.75Ge0.25 – is important in its own right, Ren said, and he has formed a company, called APower, to commercialize the material, along with frequent collaborator Gang Chen of the Massachusetts Institute of Technology and two former students.
But he said another key point made in the paper is the importance of looking for materials with a high power factor, or output power density, in addition to the traditional focus on a high figure of merit, or efficiency, commonly referred to as ZT.