Re: Solar-hydrogen home power system?

From: Gymmy Bob (nospamming_at_bite.me)
Date: 10/21/04 

Date: Thu, 21 Oct 2004 18:32:06 -0400

Ohhh? What was the "H-Bomb" composed of?

"Ray Drouillard" <cosmicpam2@comcast.net> wrote in message
news:2torp6F22ijp1U1@uni-berlin.de...
> In what way? Because I don't believe that hydrogen is economically
> feasible right now? If you look at the top of the thread, you'll see
> that my first post said exactly that.
>
> I may agree with the conclusion, but I see a whole lot of bad science
> used to prove the point. I am trying to correct the bad science. The
> biggest blooper is the one where someone equated a hydrogen chemical
> explosion with an H-bomb. That was a real howler.
>
>
> Ray Drouillard
>
>
>
> "Gymmy Bob" <nospamming@bite.me> wrote in message
> news:jeGdnT953d4RkurcRVn-hA@golden.net...
> > Sounds like a backpaddle for the "speak too soon foolish"
> >
> > "Ray Drouillard" <cosmicpam2@comcast.net> wrote in message
> > news:2tofefF21iggsU1@uni-berlin.de...
> > >
> > > "Dan Bloomquist" <EXTRApublic21@lakeweb.com> wrote in message
> > > news:4176DEE2.2040003@lakeweb.com...
> > > >
> > > >
> > > > Ray Drouillard wrote:
> > > > >
> > > > >
> > > > > 40% Is a whole lot better than the "less than none" that Don
> > > Lancaster
> > > > > keeps quoting. As a matter of fact, I'm beginning to believe
> that
> > > he
> > > > > has the whole spiel stuck in a text file for quick addition to
> his
> > > > > prose.
> > > >
> > > > Capital cost needs to be considered. On the other hand, Mr.
> Lancaster
> > > > has wave his hands around about wind and PV being energy sinks.
> Past
> > > > research has shown otherwise.
> > >
> > > Capital cost is economics, not engineering.
> > >
> > > Effeciency is engineering, not economics.
> > >
> > > They can be related, but the person expressing that relationship
> needs
> > > to be explicit.
> > >
> > >
> > > >
> > > > I went and fetched Grahams post for you:
> > > > > > This is it:
> > > > > > 41 percent (of delta 'G' of hydrogen oxidation to water
> vapour)
> > > > > > for the fuel cell spec'd at
> > > > > > http://www.ballard.com/resources/powergen/NexaSpec***.pdf .
> > > > > >
> > > > > > Raising specific power -- only 1.2 kW over 13 kg --
> > > > > > to levels adequate for a car prime mover drops the
> efficiency,
> > > > > > I guess, by a third. Then there are inverter and motor
> losses,
> > > > > > and we're down to 20 percent.
> > > >
> > > > However, I don't agree to his 50% hit in the implementation. The
> EV
> > > side
> > > > of the power train can easily do 85-90% net. There are source to
> wheel
> > > > traction systems that run 90% to 97% over most of thier
> power/speed
> > > range.
> > >
> > > Agreed.
> > >
> > > With 65%+ efficient fuel cells, and 90%+ motors, a vehicle can turn
> > > hydrogen into motion very efficiently. The main bugaboo is storing
> the
> > > stuff (an issue that has been debated hotly in this thread).
> > >
> > > There are now 60%+ efficient methane-fuelled fuel cells. I know of
> none
> > > that are commercially available, unfortunately. If they do become
> > > available, they would be ideal for running an ev because the methane
> > > storage technology already exists. It still isn't as energy dense
> as
> > > gasoline, but it's a lot more dense than hydrogen. It also has the
> safe
> > > ty advantage of dissapating and floating away in the unlikely event
> of a
> > > pressure tank rupture.
> > >
> > > Thirdly, it's a real fuel -- not something that is derived from a
> fuel.
> > > It can be mined, or very easily created from biomass.
> > >
> > >
> > > >
> > > > >
> > > > > I still want more details about that 40%. I'm hearing figures
> > > anywhere
> > > > > between 60% and 90% for both electrolysis and fuel cells. Where
> is
> > > the
> > > > > hard data?
> > > >
> > > > Crunch the numbers for your self, on that PDF above for that
> mighty
> > > > pricey PEM unit, if you don't believe Graham.
> > > >
> > > > > Yes, I can google until I'm blue in the face and crippled
> > > > > from carpel tunnels, but some of those quoting the efficiencies
> > > ought to
> > > > > have real data somewhere.
> > > > >
> > > > > If we have electrolysis going at 80% efficiency, and a 70%
> efficient
> > > > > fuel cell (just to throw in some reasonable numbers). you have a
> > > total
> > > > > efficiency of better than 50% (allowing for some modest storage
> > > losses).
> > > >
> > > > Electricity to wheels. Electrolysis 80%, storage 90%, PEM 40%,
> vehicle
> > > > 85%. So you net 25% of your electrical input. There are EVs in
> > > > production that net better than 50% now. Also, compare the capital
> > > cost.
> > > > Hydrogen, rough guess, will run some 5 to 8 times an EV commuter.
> > >
> > > It pretty well goes without saying that making hydrogen from grid
> > > electricity is a no-win situation.
> > >
> > > As far as comparing a hydrogen system to a battery system -- well, I
> > > expect the battery system to win when you consider efficiency. The
> > > biggest obstacle for EV transportation is the lousy range of even
> the
> > > best vehicle. It would be worth it to some people to give up some
> > > efficiency just to get more range.
> > >
> > > Getting back to the original post, though -- he was talking about a
> > > totally fixed application. The electricity --> hydrogen -->
> electricity
> > > idea had occurred to me, too. I was pondering what to do with cheap
> > > solar cells of those much-promised organic semiconductor cells
> become
> > > available at a reasonable price. At the time, I lived in the city,
> and
> > > was limited to the area of my (small) roof. Therefore, storage to
> pick
> > > up the slack in the winter would be a necessity. Since we also had
> > > natural gas piped in, I planned on generating any additional
> electricity
> > > needed using a natural gas fuel cell. The waste heat would be used
> to
> > > heat the house.
> > >
> > > Now that we live on a nice ten acre parcel, I'm not nearly so
> limited
> > > when it comes to the area that I can cover with solar cells. That
> makes
> > > it more feasible to get enough area covered to produce a day's worth
> of
> > > electricity on even the shortest day. That cuts the storage
> > > requirements considerably -- both in quantity and time. Hydrogen
> > > wouldn't be necessary at all.
> > >
> > > Of course, all of the above depends greatly upon the much-promised
> cheap
> > > solar cells, as well as the availability of relatively inexpensive
> fuel
> > > cells.
> > >
> > > Then, of course, there are things like inverters and/or DC
> appliances.
> > > The ceiling fans would have to be ripped out and sold. I would also
> > > have to find something to replace the compact fluorescent lamps that
> we
> > > have used to replace almost every incandescent light in the house.
> I
> > > would probably use regular red, yellow, green, and blue LEDs in
> fixtures
> > > that allow the light to mix because that is more efficient than
> using
> > > white LEDs (for very good quantum physics reasons).
> > >
> > > Incidentally, the cheapest way to save energy right now is to
> replace
> > > all your incandescent lights with fluorescent lighting. Soon, LED
> > > lighting will be more available.
> > >
> > > So, my next realistic step is to make a digester to turn organic
> garbage
> > > into methane. I don't expect to find an affordable methane fuel
> cell
> > > any time soon, so if I get more methane than I can burn in my
> appliances
> > > and vehicles, I'll use it to fuel a standard CNG generater, and use
> the
> > > waste heat to heat the house. Lots of research has to be done
> before
> > > getting anywhere near that far, though.
> > >
> > >
> > >
> > > >
> > > > >
> > > > > If you want to compress the hydrogen to store it, and if the
> energy
> > > cost
> > > > > of that is significant, you can recover some of the energy by
> using
> > > an
> > > > > 'air engine' to decompress the hydrogen before it is fed into
> the
> > > fuel
> > > > > cell.
> > > >
> > > > Capital cost and energy density.
> > > >
> > > > >
> > > > > Also, in a solar energy system, you are going to be getting more
> > > energy
> > > > > in the summer than in the winter. That means that you will be
> using
> > > the
> > > > > fuel cell in the winter if your solar array is sized such that
> you
> > > need
> > > > > to store power in the summer for use in the winter. In that
> case,
> > > the
> > > > > heat that is generated by the fuel cell can be used to heat the
> > > house.
> > > > > In that way, you can use 100% of the energy that you have stored
> in
> > > your
> > > > > hydrogen tanks. Any inefficiencies end up heating the house, or
> > > maybe
> > > > > even cooking the meals (depending on how 'retentive' you want to
> be
> > > when
> > > > > designing the system)
> > > >
> > > > It will never ever make sense to use hydrogen in a terrestrial
> > > > application. Just run some numbers and compare them to the
> > > alternatives
> > > > that are presently applied.
> > >
> > > I won't argue that point. Before I buy the equipment needed to
> > > generate, store, and use hydrogen, I will build a big water tower
> and
> > > use my excess energy to pump the water uphill, and use a turbine or
> > > water wheel to get the energy back. As a bonus, I'll also have
> either a
> > > swimming pool or a fishing pond.
> > >
> > > I might argue with the people who are scared to death of hydrogen,
> or
> > > those who say "less than zero", but I have already throught through
> the
> > > hydrogen-as-a-fuel situation to have a good handle on what it would
> take
> > > to make that practical. On a large scale, off-shore nuclear energy
> > > would make it a good option. On a small scale, it would take a very
> > > specific set of conditions to make it worthwhile.
> > >
> > >
> > > >
> > > > >
> > > > > Certainly, the cost of photovoltaics makes the system
> uneconomical
> > > now.
> > > > > But, this is rec.arts.sf.science, so speculation of future
> advances
> > > in
> > > > > the art are definitely on topic.
> > > >
> > > > Sure, we could see thin film at a buck a watt. Still not cheap.
> I've
> > > > been reading about it for years and I still don't see it
> happening.
> > >
> > > I'm talking about organic semiconductors, which may very well be
> made
> > > very cheaply. Still, I'll believe it when I see it. I'm hopeful,
> but
> > > far from convinced.
> > >
> > >
> > >
> > > > > If I could go out and buy a bunch of plastic sheeting that
> converts
> > > > > light into electricity with an efficiency of about 8% for a few
> > > cents a
> > > > > watt, what would I do with it? Putting it on the roof would be
> a
> > > good
> > > > > start. Storing power in batteries short-term for use at night
> would
> > > > > also be a good idea. In fact, I can save on the cost of an
> inverter
> > > if
> > > > > I use a bunch of batteries in series and store it at 180V, then
> just
> > > use
> > > > > some MOSFETs to generate a pseudo sine wave output -- no
> > > up-converting
> > > > > switching regulator, no muss, no fuss.
> > > >
> > > > As a past poster would say, 'If we only had some ham, we could
> have
> > > ham
> > > > and eggs, if we only had some eggs...'
> > > >
> > > > Inverters are $.50/watt, off the shelf. No muss, no fuss.
> > >
> > > They will probably be cheaper once electric cars come more into
> > > production. Right now, high-power switching transistors and fast
> > > high-power diodes keep the prices up.
> > >
> > > >
> > > > Qusetion, why hydrogen?
> > >
> > > Because it's cool?
> > >
> > > Remember, I'm not advocating the hydrogen solution. I have thought
> it
> > > through, and share the conclusion of some or the people I am arguing
> > > with. I don't share their reasoning, however.
> > >
> > >
> > > Ray Drouillard
> > >
> > >
> > >
> > > >
> > > > >
> > > > > Ray Drouillard
> > > >
> > > > Best, Dan.
> > > >
> > > > --
> > > > http://lakeweb.net
> > > > http://ReserveAnalyst.com
> > > > No EXTRA stuff for email.
> > > >
> > >
> > >
> >
> >
>
>

Quantcast