On 29 Nov 2005 14:57:36 -0800, wrote:

The Natural Philosopher wrote:
I thought I would start a new thread..because having found the data on the
Tzero, it bears a bit more discussion.

http://www.acpropulsion.com/ACP_Bib_results.pdf

They got - at an average speed of 50mph - a figure of 217Wh per mile

Now I accept that they were probably driving in the sort of way that those
idiots trying to 60mpg out of skoda diesels drive..but its still a data
point.

That means to achieve 500 miles range they would need just 10KWh.

As AJH pointed out, its 10x that, which takes you upto 3 mill per car.
Thats why I'm not buying one!

200watt hours per mile is 100KWH. for 500 miles. Yup. That makes my 50Kwh
battery about right for 1-200 miles range..Oh well ...sorry for that
mistake, but anyway its in the ballpartk, I thought the battery came out a
bit light.

You said fuel economy was comparable, but you neglected the main route
of fuel consumption: not road fuel, but the fuel used in production. To
explain. Why do the batteries cost so much? The answer is because it
takes a huge amount of energy to get them produced. (That includes
production of the materials the batteries are made from.)

That is , in this case, simply not true.

While its not
exact, cost is a rough guide to energy use. If something takes me 1000
barrels of oil and 6 months to make, its gonna cost. The 6 months means
6 months of supporting a human being, and that comes down to energy. We
need money to buy energy firectly, and money to buy things that took
energy to produce, eg food, clothes, etc etc.


That is only true in mature technologies domianated by energy costs. This
is not true of lithium batteries. The materialsl - lithium salts - are not
especially energy intensive to make - no more so thatn the steel that car
bodies are made from, or the aluminium the engines are made from.

The batteries are expensive because mass production techniques have not
been applied to them: They are currently moderate vloume items with large
investments in R & D and factory tooling to pay back.

In short, the whole electric car system is energy hungry. It thus has
nothing to offer over fossils.


Its not. You are starying from a conclusion and using false data to
rationalise facts which are untrue.

Those batteries could cost no more than a typical engine to produce. In
dollars or in energy.


Its very hard to beat fossil fuel because it is so very available, in
such huge quantities. Its cost is therefore relatively low.


It won't be for that much longer - and anyway this particular thread is
not about fuel efficiency of electrical cars per se, Its about practicality
of them. I already showed that theyt are in fuel terms similar to a diesel
overall if diesel is what you burn at the power station. That is not where
I am coming from.

I see them as part of a move towards the main unit of energy being not the
barrel of oil, but the kiolowatt hour. The replacement of fossil fuel as
both prime energy AND storage medium, to nuclear or renewable being the
prime energy, and batteries the storage.


To use synthetic hydrogen in fuel cells, or synthetic hydrocarbons in heat
engines, generated from electricity...would be way more inefficient than
using batteries.

NT