Scientists have made a breakthrough in harnessing waste heat from combustion engines, creating a device that converts exhaust emissions into usable electricity.
Gas-powered vehicles generate immense power by burning fuel, yet they waste approximately 75% of that energy as heat is expelled through the engine and tailpipe. Researchers have long sought ways to recapture this lost energy, but practical implementation has remained elusive due to cost and design challenges.
A team of scientists has developed a thermoelectric generator (TEG) capable of converting exhaust heat into electrical energy. Published in ACS Applied Materials & Interfaces, their study details how this compact device can be retrofitted onto existing car tailpipes or even integrated into helicopters’ exhaust vents.
The prototype generator produced up to 40 watts of power in initial experiments—enough to power a lightbulb. Further simulations suggested it could generate up to 56 watts in a moving vehicle and an impressive 146 watts in a helicopter.
TEGs function by utilizing temperature gradients. The device employs a bismuth-telluride semiconductor to generate an electric current as electrons move from the hot side (exhaust heat) to the cold side. However, a key challenge is maintaining this temperature difference, as the cold side tends to heat up, reducing efficiency.
Many thermoelectric systems rely on water cooling, which adds complexity and bulk. Instead, the researchers designed a cylindrical heatsink with fin-like protrusions that wrap around the tailpipe, increasing surface area for heat dissipation. This method leverages airflow from a moving vehicle to cool the system naturally, ensuring continuous power generation.
The findings suggest that thermoelectric generators could become a practical addition to vehicles, enhancing fuel efficiency and reducing energy waste.
