Water-Cooled Thermoelectric Generators for Improved Net Output Power: A Review

Abstract

Thermoelectric generators (TEGs) have the ability to convert waste heat into electrical energy under unfavorable conditions and are becoming increasingly popular in academia, but have not yet achieved a broad commercial success, due to the still comparably low efficiency. To increase the efficiency and economic viability of TEGs, research is performed on the materials on one hand and on the system connection on the other. In the latter case, the net output power of the cooling system plays a key role. At first glance, passive cooling seems preferable to active cooling because it does not affect the net electrical output power. However, as shown in the present review, the active cooling is to be preferred for net output power. The situation is similar in air and water-cooling. Even though air-cooling is easier to set up, the water-cooling should be preferred to achieve higher net output power. It is shown that microchannel cooling has similar hydraulic performance to conventional cooling and inserts increase the net output power of TEG. As the review reveals that active water-cooling should be the method of choice to achieve high net output power, it also shows that a careful optimization is necessary to exploit the potential.

An Experimental Study of the TEG Performance using Cooling Systems of Waterblock and Heatsink-Fan

“…When the cooling system uses a heatsink-fan, the electrical output voltage produced by TEG is 6.215 V, but the electrical output will increase if the cooling system uses a water block at 8.232 V. This indicates that the use of a water block cooling system will be more effectively used as a TEG cold surface cooling system because it produces higher voltage performance. This finding is in line with the research conducted by Pfeiffelmann et al [22], the results of the study found that active watercooling should be the method of choice to achieve high electric output generated by TEG.…”

Development of a Computational Fluid Dynamics (CFD) Numerical Approach of Thermoelectric Module for Power Generation

“…The results indicate a positive effect of the flow velocity on the output voltage and efficiency. Comparing these results to earlier research [45,46], it was found that using stripe-shaped surfaces on the cooling cold side of a TEG module is better than plate-shaped or diamond-shaped surfaces. In these earlier studies, temperature increases in the cooling fluid from the inlet-to-outlet conditions were 8.5, 6.2, and 10.5 • C, respectively, for stripe-, plate-, and diamond-shaped surfaces.…”

“…These results demonstrate better efficiency using an M-shaped channel rather than other shapes. It allows for maintenance of a higher temperature differential for heat transfer and therefore a higher output voltage [45][46][47]. In Figure 14, contour plots of the temperature distribution at a plane just below the cold surface of the TEG, for different inlet flow velocities, are presented.…”

Unlocking the Potential of Recycled End-of-Life Photovoltaic Modules As an Efficient Solar Absorber and Versatile Energy Conversion System

“…Therefore, we concluded that the use of concentrated optics is not suitable for the EoL PV sandwich, unless the surrounding EVA is removed. As another approach, appropriate water or air-cooling techniques can be applied on the heat sink to enhance the temperature difference between the hot side and cold side of the TEG . These approaches can effectively accelerate the heat dissipation process, leading to an improved overall performance of the EoL PV sandwich/TEG hybrid device.…”