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looks like I have been upstaged again, all the elements of the fuel cell/hydrogen battery produced by a British company:
I suppose it shows we are working on the right lines. The PDF leaflet does look vaguely familiar, but I saw the working system on the local TV news today, so it is clearly practical. I would be very interested to find the weight per stored Kw compared to conventional Lithium Ion, or other metal-based systems.
Jan
On 22 Jun 2009, at 23:22, Ueli Scheuermeier wrote:
Well, methane certainly sounds like a better way to store hydrogen than H2.
But folks, what is this shaping up to be?
Craft baths in bright sunlight near the sun and splits water to then store hydrogen and O2.
Then travels far out, taking all that mass with it.
Out there where the Sun is dim, the fuel cells produce the electricity for operating the METs and the water for reaction mass to do the boosting out there.
Is that what we're talking about?
But then I guess the question is how far out are we talking about here. If it's just into the asteroid Belt and back, then I imagine it would be cheaper and less delicate to simply tack on reflective foil to the PV panels to reflect sunlight on them, rather than go through all the hassle of lugging all that mass out - ahm, wait a minute... no, of course that mass would have to come out anyway as water for shooting out the METs, so might as well split it before we do that?
Hm, does that mean any craft would always be using its PV panels, and any surplus electricity is always immediately stuck into splitting water? So the water becomes both battery AND reaction mass for the METs? Wow, that's elegant! Hm, interesting balancing act on excentric solar orbits!
But folks, what is this shaping up to be?
Craft baths in bright sunlight near the sun and splits water to then store hydrogen and O2.
Then travels far out, taking all that mass with it.
Out there where the Sun is dim, the fuel cells produce the electricity for operating the METs and the water for reaction mass to do the boosting out there.
Is that what we're talking about?
But then I guess the question is how far out are we talking about here. If it's just into the asteroid Belt and back, then I imagine it would be cheaper and less delicate to simply tack on reflective foil to the PV panels to reflect sunlight on them, rather than go through all the hassle of lugging all that mass out - ahm, wait a minute... no, of course that mass would have to come out anyway as water for shooting out the METs, so might as well split it before we do that?
Hm, does that mean any craft would always be using its PV panels, and any surplus electricity is always immediately stuck into splitting water? So the water becomes both battery AND reaction mass for the METs? Wow, that's elegant! Hm, interesting balancing act on excentric solar orbits!
Ueli
From: EOS Mars Program <eos.mars.program@ btinternet. com>
Subject: Re: [NEAmines] I want to hear from you // electric power sources
To: NEAmines@yahoogroup s.com
Date: Sunday, June 21, 2009, 9:23 PM
Subject: Re: [NEAmines] I want to hear from you // electric power sources
To: NEAmines@yahoogroup s.com
Date: Sunday, June 21, 2009, 9:23 PM
Ueli,
despite the recent inconclusive exchanges on electric power, and
taking your point on Mass/Kw ratios, I have been wondering about ways
of achieving 'darker' missions at aphelion, where there is a drop in
available solar energy
One thing I considered is that production of liquid hydrogen and
oxygen from water in orbit, is relatively straightforward closer to
the sun and this can act as a form of storage battery when carried
onboard a freighter.
When in darker regions, even if just returning on a cyclic solar
orbit, this stock can be used to provide electrical power in fuel
cells that drive the METs, and the byproduct (pure water) also fed to
the jets for the working fuel, until the solar arrays can deliver
full wattage. This may prove to be less massive than metallic-based
batteries for supplementing distant missions, but would not
necessarily replace these entirely.
This still uses one type of engine, so keeping weight down (which
otherwise would be a very high overhead and negative factor if using
properly shielded nuclear drives). A nuclear engine that failed would
also be unapproachable, with possible terminal consequences for
someone, or everyone, whether attempts were made to fix it or not.
This is why replaceable METs have many advantages. There is also the
possibility of using many available working fluids other than water,
if such sources are discovered on NEAs, like frozen and then
liquified gases.
Jan
despite the recent inconclusive exchanges on electric power, and
taking your point on Mass/Kw ratios, I have been wondering about ways
of achieving 'darker' missions at aphelion, where there is a drop in
available solar energy
One thing I considered is that production of liquid hydrogen and
oxygen from water in orbit, is relatively straightforward closer to
the sun and this can act as a form of storage battery when carried
onboard a freighter.
When in darker regions, even if just returning on a cyclic solar
orbit, this stock can be used to provide electrical power in fuel
cells that drive the METs, and the byproduct (pure water) also fed to
the jets for the working fuel, until the solar arrays can deliver
full wattage. This may prove to be less massive than metallic-based
batteries for supplementing distant missions, but would not
necessarily replace these entirely.
This still uses one type of engine, so keeping weight down (which
otherwise would be a very high overhead and negative factor if using
properly shielded nuclear drives). A nuclear engine that failed would
also be unapproachable, with possible terminal consequences for
someone, or everyone, whether attempts were made to fix it or not.
This is why replaceable METs have many advantages. There is also the
possibility of using many available working fluids other than water,
if such sources are discovered on NEAs, like frozen and then
liquified gases.
Jan
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