Today, with the increase of industrialization, the waste heat emitted by the industrial machines used has started to increase. Therefore, the energy efficiency of these devices also decreases. In addition, this waste heat remains a bad factor that plays a role in the world's climate change. Governments are implementing incentive policies to increase energy efficiency and reduce greenhouse gas emissions. Therefore, both scientists and engineers strive for a cleaner environment and energy. Thermoelectric generators (TEGs) are one of the devices that contribute to energy efficiency and sustainable energy production by ensuring the recovery of a certain part of the waste heat emitted by these machines to the environment. The TEGs have found traditional uses from the waste heat of microprocessors to the waste heat of stoves. However, their proliferation is limited by their efficiency less than 10% and their high purchasing costs. Academicians and engineers continue to work without slowing down to overcome these. The semiconductors with low thermal conductivity and high electrical conductivity are the main subjects studied in this field. With overcoming these difficulties, it is aimed to use thermoelectric generators in the future to convert the waste heat of almost all devices into electrical energy. Therefore, the main purpose of this study is to investigate the current innovations of TEGs and to determine the future trend. Among the main findings of this study, it is predicted that TEGs will be widely used in areas where there is a need for silent and maintenance-free energy in the future.

Environmental pollution, global warming and increasing energy demands are urgent challenges facing society. Governments all over the world have set a national policy target for the transition to a zero or low carbon dioxide economy. As a result, scientists and engineers in industry and academia are working to develop cleaner, alternative and sustainable energy production technologies. One technology that has potential in this green technology transition is thermoelectric generators (TEGs), traditionally used off-grid and isolated from things such as stand-alone solar–thermal cells for military and aerospace applications such as missile-testing systems and space telescope cameras. However, future applications based on home entertainment, security systems and smart metering applications are imminent. Key limitations to this are low efficiency, high costs and self-heating with low thermal conductivity. Hence, this study aims to examine the current state of the art of TEGs and identify future research directions to achieve support for the green technology transition. The key findings of this study show that present successes will fulfill the future advancement of thermoelectric technology by supporting a low carbon dioxide economy.

This research employs the COMSOL Multiphysics software (COMSOL 6.2) to conduct rigorous simulations and assess the performance of a thermoelectric module (TEM) meticulously crafted with alumina (Al₂O₃), copper (Cu), and Bi₂Te_2.70Se_0.30 thermoelectric (TE) materials. The specific focus is on evaluating diverse aspects of the Bi₂Te_2.70Se_0.30 thermoelectric generator (TEG). The TEM design incorporates Bi₂Te_2.70Se_0.30 for TE legs of the p- and n-type positioned among the Cu layers, Cu as the electrical conductor, and Al₂O₃ serving as an electrical insulator between the top and bottom layers. A thorough investigation is conducted into critical parameters within the TEM, which include arc length, electric potential, normalized current density, temperature gradient, total heat source, and total net energy rate. The geometric configuration of the square-shaped Bi₂Te_2.70Se_0.30 TEM, measuring 1 mm × 1 mm × 2.5 mm with a 0.25 mm Al₂O₃ thickness and a 0.125 mm Cu thickness, is scrutinized. This study delves into the transport phenomena of TE devices, exploring the impacts of the Seebeck coefficient (S), thermal conductivity (k), and electrical conductivity (σ) on the temperature differential across the leg geometry. Modeling studies underscore the substantial influence of S = ±2.41 × 10⁻³ V/K, revealing improved thermal conductivity and decreased electrical conductivity at lower temperatures. The findings highlight the Bi₂Te_2.70Se_0.30 TEM’s high potential for TEG applications, offering valuable insights into design and performance considerations crucial for advancing TE technology.

This study analyzed the significant performance using COMSOL Multiphysics software of thermoelectric modules (TEMs) fabricated from aluminium oxide (Al2O3), copper (Cu), and bismuth telluride (Bi2Te3) materials, with a particular focus on investigating various leg geometries. The TEM design had Al2O3 for insulation, Cu for conducting, and Bi2Te3 for TE legs among the Cu. Investigated the influence of square and rectangular TE legs with heights of 2.0, 2.75, and 3.5 mm on critical parameters such as the normalized current density, electric potential, temperature gradient, and total internal energy within the TEM. Furthermore, the impact of varying thicknesses in the insulator and conductor layers of the TEM was explored. The results consistently demonstrated that the square leg geometry, particularly when configured with a height of 2.75 mm, outperformed other leg geometries. Consequently, it is suggested to adopt a square-shaped Bi2Te3 TEM measuring 1 mm × 1 mm × 2.75 mm with a 0.50 mm Al2O3 thickness and 0.125 mm Cu thickness during the manufacturing process. Investigate how temperature differences in TE device leg design are influenced by parameters such as the Seebeck coefficient (S), thermal conductivity (k), and electrical conductivity (σ). At lower temperatures, modeling reveals lower electrical conductivity and enhanced thermal conductivity, highlighting the significance of S = ± 2.37×10⁻⁴ V/K. This illustrates the high potential of TEM for applications in thermoelectric generator (TEG) manufacturing.