Development of an Auxiliary Power Unit with Solid Oxide Fuel Cells for Automotive Applications

Delphi Corporation and the BMW Group are developing Solid Oxide Fuel Cell (SOFC) technology for application in the automotive industry as an on-board Auxiliary Power Unit (APU). Delphi is part of the US-DOE SECA initiative and is working with Battelle to develop SOFC for multiple applications including the automotive market. BMW is a leading customer in the development and is a key player in the introduction of new technologies to the market. The APU provides significant customer benefits with regard to the availability of electrical functions, in particular engine-independent functions such as auxiliary air conditioning. In addition, it has the potential to save fuel due to the high efficiency of producing electricity. The focus of this development is to apply the APU to the present car generation, i.e. using gasoline as fuel. This makes SOFC the most suitable fuel cell technology for this application, being able to utilize the high CO containing reformate expected from higher hydrocarbons without further gas purification steps. However, key challenges exist in using the SOFC technology to meet the particular needs for this automotive application. These challenges include rapid start-up, large number of thermal cycles, compact system, low cost and others. In this paper, the status of the Delphi/BMW APU and recent progress in the SOFC development will be reviewed.