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Old January 15th 07, 06:32 PM posted to rec.aviation.piloting
James Robinson
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Posts: 180
Default Can Aircraft Be Far Behind?

Larry Dighera wrote:

Here's another link to information about GM's 'Volt prototype hybrid
automobile dated Jan. 7, 2007.


http://www.canada.com/topics/finance...48-a654-4000-8
b3c-aff0354600aa&k=45978&p=2
Lutz said the engineering development of the car itself is 18
months from being completed. The batteries are about 18 months
behind the rest of the car.

How many years would that put GM's product behind the Japanese? :-(


None.

All of the car manufacturers are waiting for battery technology to get to
the point where such cars can be practical. The auto manufacturers have
put electric cars on the market in the past, mainly because of
California's ZEV requirements, but they were quickly pulled when the
California regulations were retracted, since the vehicles were expensive
and the batteries had relatively short lives. Battery technology at the
time wasn't good enough to make the vehicles practical.

Battery technology has improved somewhat since then, with about double
the energy density, but they still have a long way to go before they can
compete with liquid fuels foe convenience and cost.

This is like the days when stereo equipment manufacturers were in an
ouput power race, or today's speed race with personal computer
manufacturers. Every time a new improved type of transistor came on the
market, or a new microprocessor, the builders of the final product would
quickly market the highest power stereo, or the fastest computer. They
were all pretty well at the same place in the market at the same time,
based on what was available.

The same can be said for hybrid vehicles, plug in hybrids, or all-
electric vehicles. The manufacturers need appropriate batteries to make
their products practical and cost-effective.

As far as practical aviation applications, using batteries for primary
power is nowhere near possible today, and given the huge gulf in weight
that has to be overcome, they will only be practical after a huge
technical breakthrough, making the energy density something like ten or
fifteen times what it is today. At the present rate of improvement,
assuming it can be sustained, that will take something like 50 years.

The original developer of LiIon batteries has stated that such
improvements will never happen. He feels that improvements of existing
batteries will be in safety, cost, and the ability to more quickly charge
or discharge them, but there will be little improvement in energy
density, which is what would be required for aviation application.