Reuse of wasted heat: Scientists in Bengaluru have been able to develop a material which would be able to utilise the waste heat that all domestic and industrial appliances produce. This wasted heat would be used by this new material for other purposes, like recharging a phone from the waste heat generated by laptops and using waste heat produced from phones to recharge a watch, according to a report in IE. Moreover, the amount of waste heat generated by power plants and during industrial processes is enough to carry out a significant amount of work.
The material, called Silver Antimony Telluride, is a material that would be able to convert the heat into electrical energy so that other processes can be undertaken, the report stated. This feat has been achieved by Jawaharlal Nehru Centre for Advanced Scientific Research’s Kanishka Biswas and his team. The team has also worked in this area previously, and this work is an improvement over the earlier work. The team has published their recent development in the journal Science.
The report further said that the process of conversion of energy generally is not very efficient, with only a small fraction of it being productive, and the remaining becoming waste and escaping as heat. While the waste heat can also be converted into energy, this process as well is inefficient, with not more than 15-20% heat being utilised. The thermo-electric effect has been known for long now, as per which current flows from the hot end of a conductor of electricity to the cold one, if the two ends are kept at different temperatures. However, the issue is the fact that most electricity conducting materials are also good conductors of heat, and therefore, the temperature differential cannot be maintained for long.
Therefore, researchers have been looking to find such metals that are bad conductors of heat while being good conductors of electricity.
That’s where Biswas and his team came in. Two years ago, such a property was demonstrated by Silver Copper Telluride, a compound of copper, silver and tellurium. Before that, the team had been working with Lead Telluride, but due to the harmful effects of lead in the environment, they continued to look for other alternatives. Silver Copper Telluride had been a big development, because it was not harmful for the environment. But, it was also less efficient than Lead Tellurium, and thus, the team kept looking, and ultimately, now, it has developed Silver Antimony Telluride, which offers a 14% efficiency.