Tenneco/Gentherm showcasing prototype of thermoelectric generator for waste heat recovery; targeting 5% fuel economy improvement
|TEG component (cartridge) and TEG architecture concept. Source: Crane (2013).Click to enlarge.|
Tenneco and Gentherm (formerly BSST/Amerigon) are part of a US Department of Energy (DOE) consortium actively developing a thermoelectric generator (TEG) for capturing waste exhaust heat in vehicles and converting it to electrical energy to be used to power electrical systems within the vehicle. The first rapid prototype of their Thermoelectric Generator (TEG) for light vehicle applications is on display at Tenneco’s booth at the 2013 Frankfurt IAA Motor Show.
Partnering with Tenneco and Gentherm are BMW and Ford, as well as CalTech and NREL. Gentherm is supplying modular, cylindrical-shaped thermoelectric cartridges that convert waste heat from the exhaust into electricity. Tenneco then integrates the cartridges inside a thermoelectric generator (TEG) that includes a unique heat exchanger.
Among the objectives of the project is delivering a 5% fuel economy improvement by direct conversion of engine waste heat to useful electric power for light-duty vehicle application. For light duty passenger vehicles, the fuel economy improvement must be measured over the US06 cycle. Total funding for the 4-year project, which started in October 2011, is $15,794,813; DOE’s share is $9,553,950.
Thermoelectric material is sandwiched together within the cartridges that are exposed to hot exhaust gas on one side and to engine coolant on the other side. The temperature gradient over the thermoelectric material results in a continuous electrical current flow, which is then redistributed to the vehicle. The modular design of the TEG enables packaging scalability depending on vehicle design, making it more cost-effective to integrate into the vehicle’s exhaust system.
Our new TEG cartridge design is the result of several years of research with the DOE and other important partners. We believe it is a breakthrough technology that has applications in a variety of global industries, but especially for automobiles in terms of reducing CO2 emissions, improving fuel economy and providing a new source of much-needed electricity. We are now working closely with Tenneco to integrate our thermoelectric cartridges into a new and innovative exhaust system design.—Gentherm President and CEO Daniel R. Coker
Tenneco is responsible for the overall system layout and integration, including validation testing for the project. TEGs must undergo rigorous durability testing, using a wide range of exhaust gas temperatures. The test process must also simulate harsh operating conditions on the underbody of the vehicle, such as road bumps, salt corrosion and other examples of severe conditions.
Testing and validation for the TEG is being conducted at Tenneco’s global emissions technical centers in Edenkoben, Germany and Grass Lake, Michigan. The consortium anticipates that initial demonstrators will be available in early 2014.
Doug Crane, Gentherm. Thermoelectric Waste Heat Recovery Program for Passenger Vehicles (US DOE Annual Merit Review 2013)