In 1821, Thomas Johann Seebeck, a German physicist discovered the thermoelectric effect. This effect takes place when a thermoelectric material is heated thereby causing the electrons move from the hot end to the cold end creating a current.
For the Seebeck effect to be maximum, a material must conduct the electricity very well while it should also be a bad conductor of heat.
Usually good electrical conductors are also good conductors of heat and electrical insulators also have the property of thermal insulation.
Scientists at Manchester University in UK have discovered that addition of Graphene has made a significant difference. The material in which around 0.6% graphene has been introduced can function at a range from room temperature to 750 degree celsius and convert upto 5% of the supplied heat into electricity. Considering how much heat is lost in various boilers and other equipments in chemical plants through exhausts, if the thermal content of this can be converted directly into electricity, it will be a huge advance. Even an ordinary car wastes nearly 70% of the energy supplied by its fuel. If this material is used, at least the wasted heat can be converted to electricity to run the air conditioner in the car free of charge. Of course, the efforts will be on to increase the conversion efficiency from 5% to a much higher percentage.
Image source: CNN