To clarify ... hydro, wind, solar energy could be used to create the
hydrogen. And it's looking like natural gas, swamp gas, you name it may be
used as well without the combustion side effects associated with getting
energy from gas.

The sticky point with hydrogen is that it takes so much energy to
produce. Where are we going to get all this energy, which we're already
short of?

OK, a little chemical reality here...

First, if creating the electricity to electrolyze water by "hydro,
wind,solar energy" were economical today, then it would also be true
that creating electricity for ANY use (including water electrolysis)
would be economical today. In the US, pretty much all the economical
hydro power has been tapped already (or is unavailable for other
reasons, eg. damming up the Colorado in the Grand Canyon is
unacceptable), and wind and solar are still considerably more expensive
than (depending on the location) burning natural gas, oil or coal to
make electricity. As soon as it becomes economically feasible to tear
down the coal-, oil- or gas-burning power plants and replace them with
windmills and/or solar cells, it will be done.

Second, obtaining hydrogen from "natural gas, swamp gas, you name it" is
already the current primary production methodology. The end product is
CO2, which comes from the carbon in the hydroCARBON source (exactly the
same amount of CO2 is produced as when the hydrocarbon is burned in a
power plant), and hydrogen. And of course, the amount of energy
contained in the product hydrogen is considerably less than what was
contained in the feed hydrocarbon. And no electricity is produced.


dons asbestos suit, getting ready for flame war

bob



bowgus wrote:
To clarify ... hydro, wind, solar energy could be used to create the
hydrogen. And it's looking like natural gas, swamp gas, you name it may be
used as well without the combustion side effects associated with getting
energy from gas.


The sticky point with hydrogen is that it takes so much energy to
produce. Where are we going to get all this energy, which we're already
short of?

There's still a lot of problems to be overcome with using hydrogen, or swamp
gas, or biogas... or any other non-petroleum based fuel... in vehicles.

First and foremost, there's the energy density problem. All of those gases
have far less energy content per unit volume than any petroleum product.
Ergo, it takes lots of gas to create the same horsepower. Where are you
gonna put all that gas in a vehicle? You have to compress it and put it
into some kind of storage tank. Compressing anything takes more energy.
How are you going to create the hydrogen or other gas? You don't just
gather it up. It has to be manufactured, which takes more energy. Some
methods allow you to use passive energy such as solar, but take a long time
to generate the quantities required to be useful. Other methods require
energy input from... petroleum fuels... to create the "clean" gas. Ack.

Second, with hydrogen there is a huge storage issue. Hydrogen molecules are
tiny, the tiniest molecules around. They're even smaller than helium
molecules. Ever watch a helium balloon deflate over days? It leaks THROUGH
the balloon, not out the knot. Same thing would happen to a pressurized
hydrogen storage tank. Gradually the molecules would seep out and the tank
would empty. Not good. So, people are working on storage techniques using
metal hydrides to bind with the hydrogen, then release it upon demand.
Unfortunately, the "release" part requires more energy input.

Third, let's assume that we're talking about using a fuel cell approach to
convert hydrogen into energy. Fuel cells produce electricity. This means
electrical motors for a boat, and possibly larger battery banks. Ever
priced 100hp electric motors, not to mention 300hp ones? Wonder what the
power plant for a trawler consisting of a 200kW fuel cell, a bank of
batteries, two 100Hp motors, the associated electronic controllers, and the
huge inverter(s) for AC consumption onboard might cost? Ack. How about
what it would weigh?

Fourth, let's assume that we're not generating our own hydrogen or biogas or
swamp gas on our boats. How long do you think it will be before every
marina and fuel dock in cruising waters has a hose marked "hydrogen"? I
think the longterm answer will be some sort of sequential machine: hydrogen
generator feeds fuel cells which feed electric motors, or something. You'll
make your own hydrogen (or swamp gas, or ...) on the fly using sea water,
sunlight, and Special Sauce, then feed the gas you produce right into the
"engine". Hopefully, the "Special Sauce" will be cheap and available.

If I ever get into the cruising game, and I intend to - thus I'm lurking in
groups such as these - I'll try to employ alternative fuels. I just don't
think affordable diesel is going to last all that long into the future.
But, per my research, practical alternative fuels are ways away. Don't
believe me? Go to some of the web sites that promise such wondrous
technology. See how many have a commercial, viable product. Folks like to
talk about what can be done, but there are a LOT of technological and
economic hurdles yet to overcome before these alternative fuels are a viable
reality.



"bowgus" wrote in message
...
To clarify ... hydro, wind, solar energy could be used to create the
hydrogen. And it's looking like natural gas, swamp gas, you name it may be
used as well without the combustion side effects associated with getting
energy from gas.

The sticky point with hydrogen is that it takes so much energy to
produce. Where are we going to get all this energy, which we're
already
short of?

"Dene" dene@(nospam) ipns.com wrote in message
...


I'm looking into my crystal ball and envisioning being a liveaboard on a
40
foot powerboat, 8 months out of the year, likely stationed in Savannah.
We
dream of touring the ICW, Gulf, Caribbean, and the Great Lakes.

Then we calculate today's fuel costs into the picture and gasp! Will
H-boats being standard in 10-15 years? Will fuel costs drop as supply
demands drops? Will a powerboater will be able to cruise all day for $50?

Discussion.

-Greg

From what I've seen most scientist think realistic fuel cell
technology...including the distribution factor in the equation, is at least
20-30 years out. Another big sticking point is the unknown -- if you believe
in the human induced global warming theory then we must be concerned with
fuel cell technology. The primary emission of a hydrogen powered engine is
water vapor; of the "greenhouse gases" water vapor is the most prominent
followed by CO2. So, what happens if we begin releasing millions/billions of
pounds of previously unreleased water vapor...will it exacerbate global
warming? Unintended consequences? As we all know, the road to hell is paved
with good intentions.

Dene wrote:
I'm looking into my crystal ball and envisioning being a liveaboard on a 40
foot powerboat, 8 months out of the year, likely stationed in Savannah. We
dream of touring the ICW, Gulf, Caribbean, and the Great Lakes.

Then we calculate today's fuel costs into the picture and gasp! Will
H-boats being standard in 10-15 years? Will fuel costs drop as supply
demands drops? Will a powerboater will be able to cruise all day for $50?

Discussion.

-Greg



Only if he is willing to cruise at about 3 knots, on account of the
hull speed rise in drag. At really low speeds, boats can be very
efficient. At high speed, forget it, you would need a nuclear
reactor if regular fuel won't do.

At economical speed, you may as well calculate on sails, and patience.

Unless....

If you had a huge, low pressure fuel tank, say, sewn into the
inflated sails, that was able to carry the boat so it was mostley
out of the water, an airship with a sail and a low weight
dynamically erect or towed leeboard / centreboard, and solar cells
to make H2 at sea....

One advantage is that to make water, all you have to do is burn H2.
to power or heat the boat. This would save weight, too.

Hmmmmm.

Terry K

On Sun, 20 Nov 2005 10:23:27 -0800, Dene wrote:

I'm looking into my crystal ball and envisioning being a liveaboard on a
40 foot powerboat, 8 months out of the year, likely stationed in
Savannah. We dream of touring the ICW, Gulf, Caribbean, and the Great
Lakes.

Then we calculate today's fuel costs into the picture and gasp! Will
H-boats being standard in 10-15 years? Will fuel costs drop as supply
demands drops? Will a powerboater will be able to cruise all day for
$50?

You can still do it today with a modest single screw diesel trawler.

It's unfortunate that the mainstream recreational power yacht these days
is a semi-displacement fuel hog. Just say no! There are alternatives.

Is the anchorage 100 miles away really any better than the one half that
far? Life's just as good at 8kt, vs. 15. Also, people will chug around
all day using 50-100% more fuel, not to mention put up with double the
maintenance, just because docking is easier with twin screws. This is
absurd. Learn to drive, and set yourself free...

Matt O.