Car exhaust being used to generate electricity, boost gas mileage
Car exhaust can be harvested to power the vehicle's electrical system while reducing fuel consumption.
Wed, Nov 24, 2010 at 04:20 AM
A Purdue University team, in collaboration with General Motors, is setting out to develop a new type of thermoelectic generator that can convert heat from a car's exhaust into electricity, according to Physorg.com.
The first prototype of the energy-saving technology could reduce fuel consumption by 5 to 10 percent.
The idea is to place a device built from thermoelectric materials (materials that can generate an electrical current from temperature differences) in the exhaust system behind the catalytic converter, where heat from gasses can reach temperatures nearing 1,000 degrees Celsius. That heat could then be converted into electricity by the thermoelectric materials.
"The material is hot on the side facing the exhaust gases and cool on the other side, and this difference must be maintained to continually generate a current," said Xianfan Xu, a Purdue professor working on the project.
One obstacle that has prevented technology like this from succeeding before is that current thermoelectric material cannot withstand the sweltering temperatures inside catalytic converters. That's what the Purdue team aims to remedy. For instance, the first prototype can harvest heat from gasses that are about 700 degrees Celsius.
"The biggest challenge is system-level design — how to optimize everything to get as much heat as possible from the exhaust gas," Xu said. "The engine exhaust has to lose as much heat as possible to the material."
The electricity generated from the exhaust could then help power a car's electrical systems, reducing strain on the engine and ultimately improving fuel economy.
Helping your auto to puff-puff along more efficiently is only the start of what this new technology could achieve, however. Thermoelectric technologies can also be used for other applications such as harnessing waste heat to generate electricity in homes and power plants. They might even lead to the development of a new type of solar cell or a solid-state refrigerator, said Xu.
Tease photo: dmitriyO/Flickr