Thermoelectric materials for cheap solar power

Thermoelectric devices made of different materials are already used for different applications, such as portable coolers and to cool off car seats. Researchers working on the INNOVTEG project sought to improve the heat-to-electricity conversion efficiency to open up thermoelectric devices to more applications.

With the support of the EU the researchers have made progress on the performance of nano-structured thermo-electric materials. Thermoelectric materials can turn a temperature difference into electricity by exploiting the flow of electrons from a warmer area to a cooler one. But an efficient thermoelectric material conducts electricity without conducting heat.

Most good electrical conductors are also good thermal conductors. INNOVTEG's solution is transition-metal sulphides: abundant, naturally occurring minerals that may have the potential to be more efficient than existing thermoelectric materials.

The thermoelectric efficiency of tens of different materials — including NiCr2S4 — was evaluated and reviewed and best candidate materials identified for further development. The performance of these materials was enhanced through modern synthesis techniques including nano-structuring.

Preliminary modelling carried out by the INNOVTEG team has shown that the materials developed can enable them to design a thermoelectric system suitable for building integration.

INNOVTEG technology is targeted to enter the market along side the existing photovoltaics industry.