A new study published by the American Chemical Society (ACS) has demonstrated the capability to convert fuel exhaust heat to energy. Currently, only about a fourth of the potential energy of the fuel in a combustion engine (the engine most gas cars use), is being utilized to power the engine. The rest is all turned into heat as exhaust. Thermoelectric systems, systems used to recover heat, are typically very large and complex, requiring cooling water to maintain a temperature difference. Now, a team led by Wenjie Li and Bed Poudel of Penn State has developed a compact thermoelectric generator, utilizing a bismuth-telluride semiconductor and heat-exchangers to capture heat. Also included in the design are heatsinks, which heavily increase the temperature difference, improving the energy output. The team says that a benefit of their design is the ability to implement it on top of existing exhaust outlets without the need for additional cooling. The prototype was able to produce 40 Watts or up to 146 Watts in high-speed exhaust conditions (such as those of a helicopter). Although this is not a very significant amount of energy as of yet, it demonstrates the efficacy such systems could have in the very near future. As our world turns to more sustainable and efficient initiatives, this could signal a significant shift in our consumption of fossil fuels and be a large step in the move towards climate neutrality. ¹

1. “Turning Car and Helicopter Exhaust into Thermoelectric Energy – American Chemical Society.” American Chemical Society, 11 Feb. 2025, http://www.acs.org/pressroom/presspacs/2025/february/turning-car-and-helicopter-exhaust-into-thermoelectric-energy.html. Accessed 29 Mar. 2025. ↩︎