The Case for Battery Electric Vehicles

Publisher Summary This chapter focuses on the battery electric vehicles (BEV). The case for battery electric vehicles (BEVs) has been greatly enhanced by significant recent improvements in lithium batteries. New lithium batteries have about three times greater energy density than nickel metal hydride (NiMH) batteries. BEVs with lithium batteries are similar to hydrogen fuel cell electric cars. In both, the primary energy source may be the same. Energy sources include oil, coal, natural gas, nuclear, hydropower, wind, and direct solar energy. These sources can power both types of vehicles when converted to an energy carrier, which could be electricity or hydrogen. Fuel cell vehicles use hydrogen as well as electricity energy carriers, but in both cases the end point is the same: mechanical energy delivered to the drive wheels. Both vehicles use electric motors and power electronics after the primary energy source passes through an electrochemical step. It is also true for both vehicle types that the possibility of avoiding oil use exists. BEVs with lithium batteries are presently showing well-to-wheel energy efficiencies between 1.5 and 4.0 times better than gasoline powered vehicles or fuel cell vehicles, depending on the primary energy source, and even much more when considering regeneration during braking.