As around 70 per cent of energy in the world is wasted as heat that is released into the environment and is one of the key factors in global warming, Indian Institute of Technology Mandi (IIT) is developing technology to convert the heat into electricity.

The researchers at IIT Mandi are developing thermoelectric materials that can efficiently convert heat into electricity and reduce the effects of global warming.

In recent times, solar power has received a lot of attention but other alternative sources are equally promising even if less known.

Generating power from heat, for example, is attractive as there is a lot of heat that is generated through human activities in industry, power plants, home appliances and automobiles where most of this heat is lost.

A research team led by Dr Ajay Soni, Associate Professor (Physics), School of Basic Sciences, IIT Mandi, is studying materials that can convert heat into electricity.

The team has been prolific in its research on thermoelectric materials and many of its papers have been published in reputed peer-review international journals.

These journals include Applied Physics Letters, Physical Review B, Journal of Alloys and Compounds, ACS Applied Energy Materials and RSC Journal of Materials Chemistry and Energy Environmental Sciences.

Talking about the concept, Ajay Soni said there has been considerable interest in recent years in the development of technologies that can dynamically harvest energy from the environment and convert it to electricity.

Such futuristic technologies consider sun, heat and mechanical energy as sustainable sources of energy.

“Thermoelectric materials work on the principle of Seebeck effect in which electricity is generated due to temperature differences across the junction of two materials.

A typical thermoelectric material must have the trifecta properties of high thermoelectric power and electrical conductivity, low thermal conductivity with a capability of maintaining a temperature gradient.

This combination of properties is hard to come by and a few semiconducting materials must be tweaked further for a good thermoelectric efficiency,” he added.

In the western world, many automobile companies, including Volkswagen, VOLVO, Ford and BMW are developing thermoelectric waste heat recovery systems that promise 3 per cent – 5 per cent improvements in fuel economy.

Other potential applications for thermoelectric energy harvesting include powering consumer devices and electronics, aviation and even space applications.

Soni’s team works on a range of such materials and studies their efficiency through experimental and numerical simulation studies.

Soni’s research group has observed novel soft phonon modes which are demonstrating the inherent crystalline anharmonicity in the materials, thus giving better thermoelectric performances with a high figure of merit in the range of 1-1.6 for various materials.

The outcome gives scope for further explorations and improvements.