Revolutionary technology converts vehicle emissions into clean energy, harnessing exhaust heat to greatly increase vehicles’ efficiency and pave the way for a more sustainable transportation system.
The combustion engines in gas-powered cars can produce a significant amount of power by burning dead dinosaurs, but they’re surprisingly inefficient at it. Most of the energy they consume is lost as heat off the engine and through the tailpipe, an estimated three quarters of it. This raises an obvious question: what if you could recover some of those wasted thermal emissions and put them to use, recapturing the lost power to greatly increase vehicles’ efficiency?
A Breakthrough in Thermoelectric Generators
Scientists have long been chasing this idea, but progress has been limited by cost-effectiveness challenges. However, a team of researchers has created a device that can turn exhaust heat into electricity with a relatively simple design that can be added to an existing car’s tailpipe or the exhaust vents of other vehicles like helicopters.
Thermoelectric generators convert heat into electrical energy through the Seebeck effect.
This phenomenon occurs when a temperature difference is applied to a thermocouple, causing a voltage to be generated.
The efficiency of thermoelectric generators depends on the materials used, with bismuth telluride being one of the most common and efficient options.
Applications range from powering spacecraft to monitoring industrial processes.
Research continues to improve performance, but current limitations include low power output and high cost.
The prototype thermoelectric generator was able to produce a maximum power output of 40 Watts in their limited experiments. Thermoelectric generators rely on temperature gradients to work, where electrons are drawn from the ‘hot side’ to the cold side, creating an electric current. The researchers used a semiconductor made of bismuth-telluride to facilitate this process.
A Clever Solution to Maintaining Temperature Difference
Maintaining the temperature difference was the main challenge. Without intervening, the cold part of the generator would start to heat up, too, and you’d lose the current. To address this, the researchers used a clever but relatively simple heatsink design using a cylinder with fin-like protrusions that wraps around a tailpipe, providing additional surface area to let off heat via forced convection.
This design proved effective in simulating high-speed environments. When traveling at the speed of a car, the thermoelectric system could produce up to 56 Watts of power. For helicopters, it was nearly thrice that: 146 Watts.
Paving the Way for Practical Applications
The researchers’ results could potentially pave the way toward the integration of TE devices into complex system designs for practical applications. With this technology, vehicles could recover some of their wasted thermal emissions and put them to use, greatly increasing efficiency.
