Jones Beene wrote:
Frankly, I see no point to going that fast without the ICE. The ICE is
more efficient than the electric motor at that speed.
Actually no, it is far less expensive - perhaps half the cost - to go with
a larger electric motor and batteries recharged at night-time grid rates
6-7 cents per kwh than to use gasoline at $3.00+ gallon . . .
The cost probably is higher, because petroleum is more expensive than coal
or natural gas per MJ. I meant the fuel efficiency, or carbon emission per
passenger mile. At high speeds, ICE efficiency is as good as the path for
fossil fuel generator => battery => vehicle propulsion. Electricity from
nuclear power or wind turbines is another matter.
There is no doubt that if we had superb batteries right now, with a 300 to
600 mile range, a pure electric vehicle would be the most efficient and
least polluting overall. However, since we do not, and we have to make
hybrids that use some gasoline anyway, they might as well use the ICE
directly at high speeds. The cars have to have a heavy-duty powerful ICE no
matter what; they might as will use it at peak output from time to time to
prolong battery power. High speeds and long-distance will both quickly
drain the limited battery reserves of a plug-in hybrid, so you might as
well resort to using the ICE early on. (This is similar to the proposal
Beene made the other day when he suggested that you would start the
hydrogen genset the moment you left home if you intended to make a long
trip. You would do this because you know of the capacity of the batteries
is going to be exceeded anyway, so you might as well keep the batteries
fully charged.)
A typical urban driver with a plug-in hybrid will use little gasoline over
the course of a year even if the gasoline motor clicks on at 40 mph and
above before the battery is exhausted. A suburban driver commuting long
distances over high-speed roads will have to wait for better batteries and
a different hybrid design, or a pure electric vehicle optimized for high
speeds.
- Jed
