On Apr 9, 4:25 pm, "noel.wade" wrote:
While I congratulate that team on a fine engineering accomplishment, I
really have to question the whole Fuel-Cell thing.

The problem is Hydrogen. It is abundant in nature, but it *loves* to
bond to everything. So you have to reclaim it from other things and
separate it out. That takes time and energy to do.

In fact, it can take a *lot* of energy to break the chemical bonds
that hydrogren has with many things. And what about the environmental
aspects of removing Hydrogen from the ecosystem?

I made a post about this awhile back on RAS (regarding tow-planes) -
but really the only cost-effective solution with today's technology is
to use Nuclear power to generate really cheap electricity, and then
use electrolysis to separate Hydrogen from Oxygen in water (like the
ocean or a large fresh-water sea).

How many Nuclear plants will the public allow to be built? My dad has
worked as an engineer at a Nuclear power plant for 25+ years so I am
totally comfortable with the system... But the American Public, at
least, has been motivated by fear and ignorance on this topic for
decades.

Even if you get Nuc plants built for the electricity and the
electrolysis, you still have only solved the production side of the
equation. What about storage and shipping and distribution? Gasses
are inherently less dense than a solid or a liquid, so you either have
to expend energy to cool and condense the gas; OR you have to
transport it inefficiently in a gaseous state. And the material and
systems to keep an explosive gas safe during transport add a lot of
weight and complexity to the situation.

As you can see, every single step along the production & distrubution
line "costs" you energy and materials. Sure you have a non-polluting
system at the very end of the chain - but how inefficient is the
system in total?

You are *already* generating a lot of electricity at the very early
stages of the sequence I described above. Why not use efficient
electrical distribution networks (which we already have), and
efficient electric motors (which we already have), and run things that
way?

The weak link is the battery technology - but that is seeing steady
improvement, and there have been some genuine breakthroughs lately.
Lots of hype, too - but a few things have been truly world-changing
recently... For example, how about this new twist on Lithium-Ion/
Lithium-Polymer batteries:

http://news-service.stanford.edu/new...re-010908.html

They think they are only 2 - 3 years from mass production, and even if
the batteries are only half as effective as the prototypes, that would
still increase capacity by 5 times the current levels. Wow! To put
that in perspective: An Apis-E (electric-launch Apis 15m glider)
battery pack would go from weighing over 100 lbs to weighing maybe 20
lbs, yet could still provide enough power for a couple of 3000'
launches. OR, the Tesla Roadster (www.teslamotors.com) could go
1000 miles per charge, instead of 200. ...And remember, I'm quoting
conservative numbers based on 50% effectiveness of mass-production
models.

I'm not saying that electric power is here _now_ or that its the
ultimate solution for the world; but for many applications it is just
as close (if not a whole lot closer) to being a suitable large-scale
solution than fuel cells are!

Take care,

Noel


With my post, I was not promoting hydrogen as a magic bullet for the
world's energy needs as you seemed to have reacted to it as. I really
do think it is a good thing that alternative methods are being
developed in the arena of aviation. Even if Boeing never gets it past
this phase, it sets a tone that other manufacturers/independent
inventors can follow; the doors are opening. It's one thing when
relatively unknown companies (Aerovironment, Lange, Apis, Sonex, etc)
dabble in electrics, but when a big name like Boeing gets in on it it
reduces the risk of such ventures for other designers to follow suit.
An electric motor in a motorglider is not cool enough because it also
has some obsolete technology? I'm sure glad the Wright brothers
continued with their experiments with inefficient, crude, unrefined
etc flying contraptions, paving the way for proper aircraft. Walk
before you run right? Boeing's fuel cell demonstrator provides another
platform for knowledge on electric aircraft to be amassed. Do you not
see that as a byproduct, bugs are being worked out of electric flight?
The electric power source on that plane can be changed to whatever the
energy of the month is, and it would probably still have the same
motor/prop/wiring/etc, which in this process also becomes more
refined. Yes, of course getting the silicon nonowire batteries on the
market will be a revolution, so much so that the powers that be
probably will not allow us to have such technology, since it's
revolutionary enough to actually threaten the power structure of the
world's energy monopolies whom seem to have an awful lot of say in our
lives, but that's another story...Anyone/group spending money that
could be spent on other things to try to find a sustainable future for
aviation has MY respect at least.

Paul Hanson