Oh sure, make me back up my claim.  :-)

The following two pages give a pretty good overview of energy
efficiency in vehicles:
http://science.howstuffworks.com/fuel-cell4.htm
http://science.howstuffworks.com/fuel-cell5.htm

They indicate that in general gasoline engines are about 20% (I always
figured 30%, but I suppose everyone has their AC on, headlights on,
and radios cranked)

Batteries are generally 80%
Inverters combined with motors are generally 80%

So an electric may be right around 64% efficient.  It's at least 2x
more efficient, and possibly 3x more efficient.

The pages linked above then go into power plant efficiency vs fuel
cell efficiency.  If you disregard market cost of electricity, the
fuel cell + inverter + motor combination is the most efficient
combination of fuel to mechanical energy, compared to gas engine, or
electric plant + battery + inverter + motor.

They don't go into the fuel processing for the fuel cell, nor the fuel
processing for the electric plant, nor the fuel processing for the gas
car.

If my numbers are right, and your numbers are right, then gasoline (at
20%) needs to cost $1 per gallon to give the mechanical energy that
the electricity (at 60%) would give.

And, of course, none of these take into account maintenance and
initial cost.  The simple fact that you can fit more energy (even at
lower efficiency) into a smaller space with gas than with electricity
makes it a better deal for many Americans.  Even if they only drive
within a 50 mile radius of their home 95% of the time, they don't want
to rent a car for the other 5%, and they don't want to stop to
recharge or fill up every hour.

Most cost comparisons indicate that once all factors are taken into
account (strictly monetary factors, I should say) then electric
vehicles are still more expensive per mile than gas cars.

Now, if we can get a fuel cell that runs straight off of gasoline with
80% efficiency, we'de be all set...

-Adam

On 4/27/06, Mike Hord <mike.hord@gmail.com> wrote:
> > Electricity is already cheaper than gas.
>
> Numbers on this claim?
>
> Gasoline is about $3US per 135 MJ.  Electricity has to beat $0.08 per
> kwH to match that- which is pretty close to the current cost of
> electricity.  What is the efficiency of the two systems, on average, to
> allow head-to-head competition?
>
> I suspect electric may finally win, but only because gas has nigh
> tripled in cost in the US over the last few years.
>
> Mike H.
>
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist