Researchers at General Motors and elsewhere believe that they are close to developing a thermoelectic generator which would use the heat from a car’s exhaust to generate electricity. The electricity would be used to reduce fuel consumption by running the vehicle’s air conditioning and accessories.

A thermoelectric generator works when one side of its metallic material is heated and excited electrons move to the cold side. The movement creates an electric current.

According to General Motors. in an internal combustion engine, only about a quarter of the total energy from petrol is used to actually turn the wheels – 30 percent is lost through cooling the engine and 40 percent is lost in exhaust heat. The researchers believe that thermoelectric devices which use some of this wasted heat could reduce fuel consumption by up to 10 percent and that such devices could be brought to market within three years.