The world is facing an energy crunch, countries like China and the UK have been hit by power cuts and fuel shortage. India isn't far behind. Our soaring petrol prices are at the highest they've ever been in the past 13 years. But what's the solution? A lot of research is currently underway on how energy can be saved or used judiciously around the world. Researching and working in the field of thermoelectric conversion is Prof Kanishka Biswas who works at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR). He says, "Thermoelectric means you can convert the temperature difference between two different objects into electricity. We have developed inorganic solid materials in our lab at JNCASR that can convert the temperature difference between hot and cold objects. We have a massive number of materials that can help in the energy conversion quite efficiently."
Helping us understand how it works, Kanisha explains, "We drive to work every day or take public transport. So, we use either diesel or petrol in our vehicles and buses. One must understand that vehicles use only 35 per cent of the energy from these two fuels, the remaining 65 per cent goes out as waste heat. Now, this waste heat can be considered as the hot end of the device and the cold end can be the room's temperature. The material that we have developed can convert that waste heat into electricity, which, in turn, can be used to charge phones and other gadgets. Basically, with this, the efficiency of fuel increases enormously. The Science behind this is thermoelectricity."
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Kanishka and his team of researchers claim that converting the waste heat from cars is only a medium-scale initiative. They have also researched how the waste heat from industries like steel, nuclear or thermal power plants can be repurposed. "We have developed materials that can be used in these large-scale industries where a lot of heat is wasted. It is a new innovation in the field of thermodynamics but we have been researching this for almost ten years now. Our research paper on the same subject got published in Science, a reputed journal. It was also a great boost for us to get the Shanti Swarup Bhatnagar Award this year," says this Indian Institute of Science alum.
With nearly 65% of Indians living in rural areas, it shouldn't come as a surprise that LPG isn't available in every household. A lot of villagers use chulhas to cook. Kanishka, who pursued his PhD from Northwestern University, explains, "The material is such that we can convert even this chulha heat also to electricity and it can be useful in the absence of an electricity grid, which is the case in many villages. Similarly, when you use your laptop, it heats up because of the presence of a lithium-ion battery. If you can believe it, even this heat energy can be used for other purposes. The government is trying to implement mobility through electric vehicles and the heat generated from those batteries can be used for other purposes as well." In short, if it produces heat, it can be repurposed.
Other areas that Kanishka and his team are working on are solar-thermoelectricity, quantum materials and purification of water. "We have seen solar panels on rooftops and so on. Here, only light from the Sun is converted into electricity. We are hoping to devise a way where the heat of the Sun can also be turned into some form of energy," concludes Kanishka.
