Electric Vehicle Range Extension Using an SOFC APU 2005-01-1172
While the ZEV program's electric vehicles did not become successful market-driven products, many of the technical advantages of electric vehicles were validated by enthusiastic California consumers. Yet, battery technology has been and continues to be the limiting factor in terms of cost, functionality (range) and durability of EV systems.
The automotive industry has largely moved on to research and development of other approaches to extremely low emissions and reduced fossil fuel consumption. PZEV gasoline vehicles, Hybrid electric vehicles, clean (EPA Tier 2) diesel vehicles and Proton Exchange Membrane (PEM) fuel cell electric vehicles (FCEVs) are the focus of attention.
The purpose of this paper is to explore another possible solution: a battery electric vehicle with a relatively small fuel cell auxiliary power unit (APU) to recharge the battery pack during driving. The attraction of this configuration is the use of a relatively small battery pack (to allow 65 - 110 km of ZEV range) while increasing vehicle range and functionality to be equivalent to conventional vehicles (400 - 650 km). Another key attraction is that a majority of km could be efficiently refueled from the grid allowing low or zero CO2 power generating technology to be deployed in private transportation without the enormous cost and inefficiency of the H2 infrastructure.
The combination of Solid Oxide Fuel Cell (SOFC) APU and advanced Lithium Ion battery systems appears to make the fuel cell range extender EV an attractive system in terms of efficiency, weight and (in the midterm) cost. This paper will discuss the product attributes and advantages that such a system would bring to the customer and society and compare SOFC to Proton Exchange Membrane (PEM) fuel cell and other competing APU technologies. This paper will present system level assessment and analysis of the SOFC/Lithium Ion range extender EV applied to a GM EV1 platform.