Exhaust gases into electricity – the new prototype generator is capable of producing up to 146 W of power

Internal combustion engines used in cars utilize about a quarter of the potential energy of the fuel, while the rest is lost as heat through the exhaust system. New research demonstrates how this lost heat can be converted into electricity.

Scientists have presented a prototype thermoelectric generator that can help reduce fuel consumption and carbon dioxide emissions. This opens up new opportunities for the development of sustainable energy.

Low fuel efficiency contributes to greenhouse gas emissions and emphasizes the need to develop innovative waste heat recovery systems. Thermoelectric systems use semiconductor materials to convert heat into electricity based on temperature differences. However, most current thermoelectric devices are heavy and difficult to use, as they require an additional water cooling system to maintain the required temperature difference.

A team of researchers led by Wenjie Li and Bede Powdell has eliminated these problems. It has developed a compact thermoelectric generator system that efficiently converts waste heat from exhaust gases of high-speed vehicles – such as cars, helicopters, and drones – into electricity.

How the new generator works

The new thermoelectric generator contains a bismuth-telluride semiconductor and uses heat exchangers (similar to those used in air conditioners) to capture heat from vehicle exhaust pipes. In addition, the system is equipped with a radiator that regulates the temperature.

This radiator significantly increases the temperature difference, which directly affects the electrical power of the device. The prototype demonstrated an output power of 40 watts, which is about the amount of power needed to power a regular light bulb. Importantly, the results show that high airflow, like in exhaust pipes, improves the efficiency of the device and increases power generation.

The system demonstrated considerable flexibility when simulating the device’s operation at high speeds. It was able to generate up to 56 watts at exhaust velocities similar to those of an automobile and up to 146 watts at helicopter exhaust flows. This is equivalent to 5 and 12 18650 lithium-ion batteries, respectively.

According to the researchers, this system can be integrated directly into exhaust pipes without the need for additional cooling systems.

Source: techxplore