Never mind the movie stars pulling up to the Oscars in their
Priuses. When the U.S. Army announces, as it did recently, that
it is developing a new hybrid Humvee to save fuel and extend
range, you can be sure that hybrid technology has arrived.
Hybrid vehicles improve efficiency by integrating a combustion
engine with an electric drive train-a combo that recaptures
braking energy, stores unused idle power, and reduces engine
weight to increase mileage. But as today´s generation of hybrids
flies out of showrooms, the stage is set for the next fleet,
which will slash gas use and emissions much further. They´re
called plug-in hybrid electric vehicles (PHEVs), and they
recharge overnight in home garages to take advantage of low off-
peak electric rates. "The implications for our national oil
addiction are profound," says Daniel Kammen, director of the
University of California at Berkeley´s Renewable and Appropriate
Energy Laboratory. "If the current U.S. vehicle fleet were
replaced overnight with PHEVs, oil consum