You know all that gas spitting out the exhaust of your car? Not only is it full of carbon monoxide and other things you shouldn't breathe, it's also full of heat. Heat is wasted energy, and students at Purdue University, led by mechanical engineering professor Xianfan Xu, are working to capture it. With some funding from General Motors the team is working to create better thermoelectric generators, or TEGs, that work at much higher temperatures than those we've seen before. A current Purdue prototype works at 700C, or 1,300F, which could be found behind a car's catalytic converter and generate enough electricity to reduce fuel consumption by around five percent. Future versions would work at higher temperatures and offer better results. Last year BMW indicated it is working on similar tech with deployments coming as early as 2014, and so now the race begins, though the culmination of their efforts will surely look something like this.