So this is where a group of researchers have created a metallic device which is attached to the exhaust pipe, producing electricity from the otherwise wasted heat: a thermoelectric generator, a device that uses temperature differences to create electricity. When installed on a Chevy Suburban, it improved by 1mpg (which is 5 percent). The generated electricity was used to reduce the load on the alternator, therefore using less fuel through reduced parasitic losses. A Suburban produces 15 kilowatts of exhaust heat energy during city driving, which is enough to power three or four air conditioners simultaneously. When cruising between 50 and 60 mph, the generator can produce about 800 watts of power, which is enough to power the GPS device, the DVD player and potentially the water pumps. This device will be installed in a 2009 Suburban and a BMW to check how effective it becomes in real life. Thanks to my friend Chuck for the tip.
[Source: Associated Press]