Theoretical model and application potential of hybrid passive cooling for power yield improvement of thermoelectric generators

Thermoelectric Generators (TEGs) offer the green and sustainable solution to power shortages in remote areas. Their energy conversion efficiency can be significantly improved by maximizing the temperature difference between the hot and cold sides. This work introduced a novel TEG system, utilizing concentrated solar energy as the hot source and hybrid coolers combining radiative and evaporative cooling as the cold source. The effects of structural design and meteorological factors on hybrid cooling in TEGs were analyzed, and their application potential was explored, which has not been thoroughly investigated in previous literature. Results revealed that the thermal conductivity of hydrogels exhibited a significant role among structural parameters. Meanwhile, wind speed and backplate temperature markedly influenced the power output. Notably, hybrid coolers demonstrated global potential, particularly in low- and mid-latitude regions. In Senegal, a low-latitude region, hybrid coolers achieved an annual average temperature difference of 159.15 °C, enabling an annual output power of 5566.76 W/m², a 13.6 % improvement over heat sinks. In high-latitude regions, lower ambient temperatures resulted in an annual average temperature difference below 90 °C, compromising power generation. Overall, the developed mathematical model provides valuable guidance for material design and paves the way for broader applications of hybrid cooling technology.