Currently used TEG modules have low efficiency of about 5%. The energy generated by the TEG module depends on the temperature difference between the module surfaces. Heat exchange between the heat source and the module surface takes place through the contact between two rough solid surfaces. This creates contact resistance. It can be reduced by using a substance filling the empty spaces between the contact surfaces and applying pressure. During the tests, the efficiency of electricity generation with a thermoelectric generator was measured (TEG) at various pressure forces. The tests were carried out at a pressure force of 250 N, 500 N, 750 N and 1000 N. The selected values of pressure do not exceed the limit value arising from the thermoelectric generator (TEG) design. A copper element constituting the heat source was heated in a furnace. Next, it was pressed at an adequate force to the generator, which was placed on a water cooler. The impact of conductive materials placed between the faces of the heat source and the TEG on the generation of electricity was examined. At low forces, the use of a thermal pad as an intermediary substance does not result in improved heat transfer in the heat source—TEG generator system. Better filling of voids is provided by thermally conductive paste due to its properties.

The article presents research on the utilisation of low-temperature waste heat from vertical industrial surfaces using a thermoelectric generator (TEG). This technology was chosen due to the possibility of directly converting thermal energy into electrical energy without interfering with the structure of the heat source. The system comprises thermoelectric modules, a copper heat exchanger, and a water cooler made of aluminium and copper. The study was conducted within a heat source temperature range of 100 °C to 350 °C and at three cooling water flow rates: 150, 200, and 250 dm³/h. The results showed that the number of modules in the generator significantly affects its efficiency. A generator with 20 modules produced less power than a system with 4 modules due to a reduction in the heat exchanger’s temperature caused by module densification. The highest power output – 12.41 W – was achieved with a generator containing 4 modules at the maximum temperature and the highest water flow rate. On the other hand, a water flow rate of 200 dm³/h proved to be the most optimal, providing a balance between performance and resource consumption. The developed TEG generator features a modular design, enabling flexible adaptation to various operating conditions and integration with existing heat recovery systems. This technology has the potential to significantly reduce operational costs in the industry and enhance energy efficiency, contributing simultaneously to minimizing energy losses and reducing CO₂ emissions.

The article focuses on the issue of efficiently recovering waste heat from low-exergy process gases, which poses a significant challenge for improving energy efficiency in many industrial sectors. To address this problem, the application of a thermoelectric generator (TEG) has been proposed, allowing for the direct conversion of thermal energy into electrical energy. In the course of the research, experimental measurements were conducted for process gases at temperatures of 240 °C and 300 °C, along with CFD (computational fluid dynamics) simulations using Ansys Fluent 2023 R2 software. These simulations enabled the analysis of the temperature distribution in the TEG and the determination of the safe operating range of the device for process gas temperatures of 350 °C, 400 °C and 450 °C. The results obtained from both experiments and simulations demonstrated the effectiveness of the TEG in recovering waste heat from low-exergy gases. Additionally, these findings suggest the potential for scaling the solution to larger industrial systems, making TEG a promising technology for long-term sustainable development efforts. The developed numerical model proved to be a valuable tool in the design of TEG systems, allowing for the analysis and optimization of heat recovery systems. The innovation of the solution lies in the use of TEG for efficiently utilising waste heat from low-temperature gases, which holds significant potential for improving energy efficiency in processes where traditional energy recovery technologies are not effective.