Its one of the most novel ideas you’re likely to hear in a long time – but Purdue University researchers are hoping to develop technology that will turn the heat from vehicle exhaust into electricity.
The researchers are collaborating with General Motors to develop thermoelectric generators that take the heat and use it to run vehicle electrical systems while reducing fuel use.
There are a number of challenges that make the idea difficult to turn into reality – for example, they need to find materials that can withstand the heat of exhaust gases with Purdue professor of mechanical engineering, Xianfan Xu, outlining that the gases inside a catalytic converter reach 700-1,500 degrees.
As such they are working on the development of thermoelectric materials that can be embedded into chips at various points in the exhaust system – they need to be able to harvest energy from the hot portions like the catalytic converter on out. Then by transforming this heat into electricity they will cut down on the load of the engine and ultimately on fuel consumption. The material is hot on the side facing the exhaust gases and cool on the other side and it is this difference that is used to generate a current.
In an effort to maintain this heat difference, the team is working on improving efficiency and reliability such as by incorporating different materials so some will expand more under certain conditions. Skutterudite, a material made of cobalt, arsenide, nickel or iron is currently used as a base material with materials such as lanthanum, cesium, neodymium and erbium being mixed inside a furnace – although cheaper elements are needed.
The first prototype is expected to reduce fuel use by five per cent and the second, following further research and development, by 10 per cent.
