On May 19, 12:40 pm, Martin Gregorie
wrote:
Can you supply the URL(s) for more reputable site(s) that look at the
same area? Its an area I'd like to know more about.

All the hard data is proprietary and so the truth is no-one knows
_exactly_ what the costs of each technology are. CNW's report is
purely a guess with a rather obvious bias.

What's without doubt is that a hybrid's batteries are more energy
intensive to construct than a conventional car of the same size.
What's also without doubt is that right now no car of similar size
approaches the mileage of the Toyota and Honda hybrids, and they also
get a lot of tax breaks which are likely to only getter bigger as
governments try to get "green". Only Toyota really knows hows much
energy is needed to build the battery, and how that compares to how
much energy is saved in fuel. However, using the back of an
envelope...

Let's assume that over 100,000 miles a hybrid saves 10% fuel. That's
enough fuel for 10,000 miles, or (at 45mpg, which is about typical for
a current hybrid) 222 gallons of petrol. 222 gallons of petrol is
about 1,000l and at 35MJ/l that liberates 35,000MJ. Reduce that by two-
thirds to allow for the inefficiency of oil-fuelled power stations
(yeah I'm skipping the different energy density of petrol vs. whatever
an oil station really burns) and that gives you a conservative energy
saving of around 12,000MJ, which is enough to produce 50kg of virgin
(not cast, which is mainly recycled thus much cheaper) aluminium,
which as you may know is *incredibly* energy instensive to produce
(most al smelters are sited next to hydro dams or nuclear
powerstations, or both!). I don't know how much energy is needed to
build a Prius battery (mass around 100kg) but I imagine it must be
less than it takes to make aluminium. Yellow Cab of Vancouver have
taken their Priuses to 200,000 on the original batteries, and afaik
are still going. Therefore I personally reckon the whole-life cycle
cost of a hybrid is beneficial, and the only way to claim otherwise is
to pretend that the alternatives will last three times longer, which
is what CNW did, which is bull.

However the context has to be understood. The future of the automobile
is hydrogen as oil is a finite resource - all the car companies are
developing hydrogen-powered cars for the very long term (who says
capitalism is only about a quick buck?). Where hybrids fit in is the
short-term - the next decade or two where oil prices will rise, but
not so much that hydrogen is competitive. The alternative to the
hybrid is the diesel, which is what the Germans and French are
developing. A few companies are introducing "mild" hybrids for
marketing purposes. (There were also electric cars. I haven't seen
that film about the scrapping of the GM EV1, which is probably some
great big conspiracy theory, but at a guess the reality is probably
that battery technology simply doesn't have the fundemental potential
to be competitive with the fuel cell.)

Bottom line: hybrids get the best gas mileage at present. Diesels are
close behind and may always be a bit cheaper to buy, but not quite as
good for mileage, and also have issues with pollution. Ultimately -
decades ahead - hydrogen is the future. Where the energy to produce
the hydrogen comes from is a whole other ball game :-).

*Personally* I drive a medium-size petrol as the low mileage I do -
about 5,000 a year - means that the extra purchase cost of a diesel
isn't economical. To save the planet (and my heart) I cycle where-ever
possible.


Dan