Combustion engines, the engines in gas-powered cars, only use a quarter of the fuel’s potential energy while the rest is lost as heat through exhaust.

Now, a study published in ACS Applied Materials & Interfaces demonstrates how to convert exhaust heat into electricity. The researchers present a prototype thermoelectric generator system that could reduce fuel consumption and carbon dioxide emissions—an opportunity for improving sustainable energy initiatives in a rapidly changing world.

Fuel inefficiency contributes to greenhouse gas emissions and underscores the need for innovative waste-heat recovery systems. Heat-recovery systems, called thermoelectric systems, use semiconductor materials to convert heat into electricity based on a temperature difference.