Environmental Engineering Reference
In-Depth Information
delivered from there to the vehicle. There is a potential
problem with the electrical power grid, however,
because the amount of power needed for a large
number of PHEVs or all-electric vehicles is large.
A preliminary industry estimate for electric vehicles is
that on the average they will use about
watt-hours
per mile traveled. In the United States, vehicle miles
traveled (VMT) in the year
trillion
miles. That implies that if all vehicles were PHEV
was about
sit
would take about
gigawatts (GW) of electric power
to charge them (
-hour charging time) and about
GW for all-electric. That much power is not now
available during the day, but is available at night when
electricity demand drops.
However, not all the extra capacity is available where
the cars are, and so the electric power distribution grid
will need modi
cation. (It needs it anyway to be able to
ship around electricity generated from wind and from
solar power sources; the big potential sources in the
United States are in the Great Plains and the South-
west, while in the United Kingdom the wind sources
are in the north whereas the largest demand is in the
south.) The California Energy Commission has said
the state can handle a million plug-in hybrids with its
present grid (I have no information about Europe).
Ifmarketpenetrationisasslowasithasbeenfor
conventional hybrids there is plenty of time for an
upgrade to the electrical distribution system. The total
number of hybrids sold in the United States from
their introduction in
to the end of
is only
about
million. High gas prices will make the intro-
duction of plug-ins faster.
