Based on the exhibits at this winter's auto shows, cars powered by next-generation technologies aren't too far away. At January's 2007 Auto Show in Washington, D.C., Ford rolled out a version of its Edge crossover vehicle that combines a lithium-ion (Li-ion) battery pack, a hydrogen fuel cell, and plug-in technology for fuel efficiency that exceeds 41 mpg with zero emissions—except for water vapor (Fig. 1).
The 336-V Li-ion battery pack drives the Edge for the first 25 miles of operation up to speeds of 85 mph. When the battery is depleted to 40% of its charge, the fuel cell automatically kicks in to recharge the battery and provide a range of 225 miles. Drivers also can recharge the battery pack by plugging it in to a standard electrical outlet.
Drivers who travel less than 50 miles a day could see 80 mpg or better for a range between fuel-cell fill-ups of more than 400 miles. The 350-bar hydrogen tank carries 4.5 kg of useable hydrogen (Fig. 2). Known as the HySeries Drive, this combination of electric and fuel-cell technology reduces the size, weight, and cost of conventional fuel-cell systems by more than 50% while doubling the lifetime of the fuel-cell stack.
Ford designed the HySeries Drive for fuel and engine flexibility. The fuel-cell power system can be removed and replaced with a diesel or ethanol engine connected to an electric generator to produce energy like the fuel cell in the current model. With this design, Ford hopes to adapt to new propulsion technologies as they become available without redesigning the vehicle.