On Thu, Nov 13, 2008 at 12:51:29PM -0500, gardenyu wrote:
> 
> 

I'm going to take a crack at this.

> I was told by people in Argonne lab that nowadays people can make Lithium
> ion batteries large enough so that they can run the vehicle for 300 miles
> on highway without recharging. (maybe the Tesla technology)? In such a
> system where batteries privide average power request, a supplementary
> sterling engine will be a good option.

To run a stirling engine you need to burn something. Doesn't that kind of
defeat the purpose.

As for the 300 miles without recharging, what exactly is the need. The vast
majority of driving that is done doesn't require that type of range. The
100+ miles per charge that current tech has is sufficient for the vast
majority of driving needs. The problem with the technology is the cost, not
the range. Get LiFePo4 batteries down to a reasonable price, even in their
current configuration, and you'll have a winner.

The problem is that Lithium with a battery management system is still about
$USD0.75/Wh. So a reasonable range battery pack (25 kWh and up) will still
run about $USD 20k and up and will need to be replaced periodically.


> 
> For example, if you forget to recharge the battery in the morning, the
> engine can at least carry you to a nearby "electric" station.

Nearby? Electric cars can plug in anywhere that has electricity, and in
urban and suburban environments, that pretty much anywhere.

The other point is that once electric cars become commonplace then charging
will become automatic. It's pretty easy to have an inductive pad that sits
in the driveway under the car. So simply parking it will be enough to
charge it.

Finally if there is wholesale change occurs, then a logical extension will
be charging directly from the roadway. Several studies on the process has
been conducted by the California PATH project. A summary paper can be found
here:

http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1257&context=its/path

Such electrification would facilitate long range electric vehicle travel
and would depress the need for ultra long range battery systems.

Finally there are simple, plentiful, powerful battery technologies that can
serve well in emergency capacities. Zinc/Air and Aluminum/Air batteries
have even more power than lithium and are lightweight. The problem is that
they are not rechargable. However, they can easily serve as emergency power
in the case that the primary battery system fails.

The fundamental problem is that everyone seems to want new transportation
systems to function exactly like the current system. Gasoline is as close
to a magic liquid fuel as one will ever find. That's why the whole
transporation economy is based upon it. But even though the price has
temporarily gone down, it is a finite resource. Also the emmissions are an
issue.

New ways of transportation will be different than the current way. As long
as the requirements remain the same (i.e. can be refuled in 5 minutes,
400-600 mile range, etc) there's not going to be any movement away until
the gas pumps run dry.

BAJ
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