Thermoelectric Power Generation
- Researchers have developed a new low-cost electrical contact material for thermoelectric devices that is stable at high temperature.
- Thermoelectric materials convert thermal energy directly into electricity through a process that involves a solid-state electron and photon diffusion process.
- Though the principle is known for two centuries, it had limited utility as most known thermoelectric materials’ energy conversion efficiency is very low.
- Nanotechnology brought innovations to improve the efficiency of materials, but the mass-market application of such innovations has remained restricted due to the low device conversion efficiency of 6-10%.
- This makes the electricity produced costlier than other technologies.
Advantages of Thermo Electrical Generators
- Reliable source of energy
- Have high scalability, which means they can be applied to heat source of any size
- Lower the production cost
- Recycle wasted heat energy
Limitations of Thermo Electrical Generators
- Low energy conversion efficiency rate
- Require relatively constant heat source
- Lack of industry education about thermoelectric generators
- Slow technology progression
- High output resistance
- Adverse thermal characteristics
- Researchers from the International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), an autonomous institute of the Department of Science & Technology, have designed and developed thermoelectric modules using lead telluride (PbTe) and magnesium stannite silicide (Mg2Si1-xSnx) compounds.
- This gives more than 10% conversion efficiency.
Applications of Thermo Electrical Generators
- The heat source of the thermoelectric generator serves as a radioactive element for many space probes including the Mars Curiosity rover.
- Solar cells employ only the high frequency part of radiation, and the low frequency heat energy is wasted.
- Thermoelectric devices integrated with these solar systems can convert the wasted heat energy into useful electricity.
- Waste heat produced from cars and other automobiles, microprocessors and industrial processes can be harvested using thermoelectric generator, thereby increasing the efficiency of the systems.
- It can be used to power lights, fans, and several instruments like guard alarm systems, greenhouses, radio receivers and TV sets.
- The limited availability of primary energy resources, increasing concern of environmental issues of emissions and the growing global demand for conserving energy continue to accelerate the search for technologies of generating electrical power.
- Thermoelectric power generators have now emerged as a promising alternative green technology owing to their potential to directly convert waste-heat energy into electrical power.
- The application of this alternative green technology in converting waste-heat energy into electrical power can improve the overall efficiencies of energy conversion systems.
- Currently, a large amount of waste heat is discharged from industry including power utilities and manufacturing plants.
- Hence, most of the research activities have been directed towards the utilization of industrial waste heat.
- Research on thermoelectric generators is needed to focus on finding suitable thermoelectric materials that can withstand higher temperatures of various industrial heat sources at a feasible cost with good performance.