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  #61  
Old 11-05-2011, 10:21 PM
RayThackeray RayThackeray is offline
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Originally Posted by kerosene View Post
Nobody is questioning the fact that fuel cells exist and they work and that they are used in number of applications. What people question (rightfully so) is that you could produce enough H2 to run said fuel cell with less power than the output.
Fundamentally people need to understand that the act of producing hydrogen and using it to generate power elsewhere is just a form of energy transmission. Instead of sending electricity down cables for example, the hydrogen in tanks just releases stored energy.

There is always an inefficiency, which means that energy is LOST between producing the hydrogen and actually using it in a motor.

One might ask "Why do it then?" The answer is that in mass production, power generation facilities are considerably more efficient than your diesel or car engine, so from a system perspective, fuel cells can enable a theoretically more energy efficient system.
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  #62  
Old 11-06-2011, 10:53 AM
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Frog4 Frog4 is offline
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not a lack of understanding, power in minus inefficiencies = power out ...
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  #63  
Old 11-08-2011, 01:58 AM
Dave Gudeman Dave Gudeman is offline
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Originally Posted by Frog4 View Post
Remember, the scientific consensus was that the earth is FLAT, the universe revolves around the earth, the sun is IRON, the sun is Helium, the sun is Hydrogen, Phlogiston, Alchemy.

All of these and MORE without a single shred of EVIDENCE.
If I keep pointing out that this stuff is urban legend, do you think some day I'll stop reading it?

There was never any kind of consensus among scholars that the earth was flat. This is just urban legend. Scholars always knew that the earth was a sphere. Ancient Greeks actually calculated its diameter pretty accurately.

Also, there was never a scientific consensus that the universe revolves around the earth, because the end of this consensus pretty much corresponds with the beginning of science. However, even though the theory wasn't exactly scientific, there certainly was evidence for it --and very good evidence at that.

The other things you listed either were never actually the scientific consensus or there was good evidence for them at the time.

A lot of people have an unrealistic view of science, beleiving that as long as you go with the evidence you can't be wrong so they reason backwards from the fact that a theory was wrong to the assumption that there must not have been evidence. That is not sound reasoning.
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  #64  
Old 11-08-2011, 02:46 PM
Kay9 Kay9 is offline
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Your just not getting it. Yes a gas or diesel engine once started will run off of said fuel without batt input provided there is an alternator. Your arguement is your 5KW engine will power not only the 150w Alternator but also the 5KW engine once its going. The analogy dosnt hold up as the gas/diesel engine isnt "powered" by the alternator it is powered by the gas/diesel. Your 5kw fuel cell is powered by the H1. Your 5KW fuel cell cannot run and make fuel at the same time. Or it can but the loss will eventually = 0 at which point your Fuel cell will have no "FUEL" .

If I am wrong simply build one, drive up here and I promise to buy it from you for whatever you ask.
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  #65  
Old 11-08-2011, 03:27 PM
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Frog4 Frog4 is offline
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Originally Posted by Kay9 View Post
Your just not getting it.
I got it fine. Folks here are confusing combustion of H2 with the conversion of H2. Fuel cells do not have the inefficiencies of H2 ICE setups.

Quote:
Originally Posted by Kay9 View Post
Yes a gas or diesel engine once started will run off of said fuel without batt input provided there is an alternator.
Until it runs out of fuel, just like an H2 fuel cell.

Quote:
Originally Posted by Kay9 View Post
Your arguement is your 5KW engine will power not only the 150w Alternator but also the 5KW engine once its going.
Sure it will, just like our gas/diesel example. And "engine" should be replaced with "fuel cell" (no moving parts) entirely different technology. 150W (gas generator) supplies H2 (fuel) to the 5kW generator/reformer (engine). The input is from the 150W solar panel in my original project > 48VDC 105aH battery bank > H2 lab gas generator + RO/DI water > 5kW H2 fuel cell

Quote:
Originally Posted by Kay9 View Post
The analogy dosnt hold up as the gas/diesel engine isnt "powered" by the alternator it is powered by the gas/diesel.
and the project is "powered" buy the H2 fuel cell.

Quote:
Originally Posted by Kay9 View Post
Your 5kw fuel cell is powered by the H1. Your 5KW fuel cell cannot run and make fuel at the same time. Or it can but the loss will eventually = 0 at which point your Fuel cell will have no "FUEL" .
Solar feeds the 48VDC 105aH battery bank and the gas generator. The "fuel" is made/processed in the gas generator, which is fed into the fuel cell. All separate "systems". And YES, eventually it will run out of "fuel". No perpetual motion garbage ...

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If I am wrong simply build one, drive up here and I promise to buy it from you for whatever you ask.
I hate driving, and I'm not looking to sell anything. Only sharing info and ideas.
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  #66  
Old 11-08-2011, 03:32 PM
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Frog4 Frog4 is offline
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Quote:
Originally Posted by Dave Gudeman View Post
If I keep pointing out that this stuff is urban legend, do you think some day I'll stop reading it?

There was never any kind of consensus among scholars that the earth was flat. This is just urban legend. Scholars always knew that the earth was a sphere. Ancient Greeks actually calculated its diameter pretty accurately.

Also, there was never a scientific consensus that the universe revolves around the earth, because the end of this consensus pretty much corresponds with the beginning of science. However, even though the theory wasn't exactly scientific, there certainly was evidence for it --and very good evidence at that.

The other things you listed either were never actually the scientific consensus or there was good evidence for them at the time.

A lot of people have an unrealistic view of science, beleiving that as long as you go with the evidence you can't be wrong so they reason backwards from the fact that a theory was wrong to the assumption that there must not have been evidence. That is not sound reasoning.
Remember PLANET Pluto? How about nuclear fission (over unity)?
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  #67  
Old 11-08-2011, 03:42 PM
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Frog4 Frog4 is offline
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this is a REFORMER based system which uses H2O (carrier) + methanol (consumable):

Electrical inputs are (4) 12VDC batteries in series rated at 105aH = 48VDC @105aH

Reformer system draws 3A @ 48VDC from "battery bank" for 40-100+ hours into H2 reformer producing 5kW @ 48VDC/104A

ElectraGen™ ME System

There are similar systems which only use RO/DI water (carrier) thru an MEA fuel cell. The (consumables) in those are Platinum or Ruthenium and others under development.
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  #68  
Old 11-08-2011, 05:30 PM
kerosene kerosene is offline
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Originally Posted by Frog4 View Post
"reformer" was used in this example ...
it is NOT a requirement ...
a standard H2 lab gas generator will work the same ...

we CANNOT use any fossil fueled (gas, diesel, propane, LP etc) boat on restricted waters ... our alternative is a ton of batteries and/or solar and/or H2 ... or a friggin paddle, as a sail will not cut it ...

.
No fossil fuels but methanol is fine? And now its a reformer again?
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  #69  
Old 11-08-2011, 06:00 PM
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Frog4 Frog4 is offline
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Originally Posted by kerosene View Post
No fossil fuels but methanol is fine? And now its a reformer again?
it is an EXAMPLE ... wow ...

Use an MEA fuel cell with plain ole RO/DI water and you take out the whole "reformer" example ...
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  #70  
Old 11-09-2011, 01:17 AM
RayThackeray RayThackeray is offline
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Originally Posted by Frog4 View Post
this is a REFORMER based system which uses H2O (carrier) + methanol (consumable):
.
If you're using methanol, you're back to consuming fossil fuels.

I hereby bet you $1,000,000 that the systems you've been proposing will be no more efficient for propulsion than a common diesel engine. Now it's up to you to try to collect - but it'll take proof.

In the meantime, a conventional diesel/electric hybrid or use of hydrogen as stored energy should be more efficient within limits, and neither of these will break the laws of thermodynamics.
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  #71  
Old 11-09-2011, 08:14 AM
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Frog4 Frog4 is offline
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Quote:
Originally Posted by RayThackeray View Post
If you're using methanol, you're back to consuming fossil fuels.
You're correct. But we are not using fossil fuel, except on the front end, i.e. component manufacturing.

Quote:
Originally Posted by RayThackeray View Post
I hereby bet you $1,000,000 that the systems you've been proposing will be no more efficient for propulsion than a common diesel engine. Now it's up to you to try to collect - but it'll take proof.
Actually current systems are pushing 70% efficiency compared to ICE which are lucky to get 20%. As far as "proof", I'm not a Google/Research Mommy. I'll send my knuckle draggers over to bust kneecaps and break fingers

Quote:
Originally Posted by RayThackeray View Post
In the meantime, a conventional diesel/electric hybrid or use of hydrogen as stored energy should be more efficient within limits, and neither of these will break the laws of thermodynamics.
This system doesn't break any "laws".
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  #72  
Old 02-24-2012, 12:28 AM
Mick@itc Mick@itc is offline
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Gee this is going well...

I was hoping to read something about hybrid electric populsion for boats, not a long rather nasty discussion about fuel cells, etc. Can we get back to to boat propulsion and take this conversion into a new thread titled Fuel cell technology facts or maybe a seperate one on efficiency/effectiveness calcs for solar/hydrogen production.
Regardless, can we get some input from people on why the weight of the batteries seem to be the deal breaker in most proposed systems. There seems to be a cost/weight tradeoff that seems to be a killer. would love to hear some thoughts and facts on this.
Thnaks
Mick
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  #73  
Old 02-24-2012, 01:24 AM
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WestVanHan WestVanHan is offline
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Originally Posted by Mick@itc View Post
can we get some input from people on why the weight of the batteries seem to be the deal breaker in most proposed systems.
Mick
Seriously?

Ok,I'll tell you: they are full of lead and ARE TOO HEAVY.


Though I doubt this will kill discussion on the matter,here is the battery sizer from Lifeline:
http://www.lifelinebatteries.com/marinesizing.php

Enter in 48 Volts and say 300 amps to get you say 15 kW. At 5 hours reserve,so enough to get you ~40 miles in a decent sailboat,you will need 56 of these:
http://www.lifelinebatteries.com/marineflyer.php?id=8

They're 156 pounds and you'll need 56 of them.

Thats 8700 pounds.

End of story.
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  #74  
Old 03-23-2012, 01:39 PM
Kay9 Kay9 is offline
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Dont forget the 5 year replacement cost of the Batts and the Controller....Everytime I do the calculations its roughly what i would have spent on a new motor and the fuel to run it.
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  #75  
Old 03-23-2012, 02:54 PM
kerosene kerosene is offline
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this is from another thread for comparison

Quote:
Originally Posted by windboat
search on website"how many CO 2 emissions" , and the diesel boat use 5000 L per year
Lets see how that 5000 liters compares to what your boat can do. (his boat assumes following: battery: 108KWH ,i.e. 90 pcs deep cycle batteries (100Ah 12V)=3000KGs)


5000l * 800g/l (density) * 200g/kwh(diesel effciency) = 20,000kwh

so we get 20,000kwh from 5000l diesel. How many cycles on the batteries does that equal.

your battery is 108kwh nominal. Much over 50% depth of discharge will kill the lead acid batteries in no time but i will give you depth of discharge 66%. Also in these calculations I am not counting in any losses in your electric power train (at least 10-20% losses)

20,000kwh/(108kwh*0.66)=280.6 cycles

so your windboat would have to drain the batteries 280 times to equal same amount of energy as the diesel numbers you suggested.
-----
More sensible numbers for your boat would be a cycle a week. Which would be ~70kwh/week ~3600kwh/year. That would equal 900L of diesel/year.

I am not penalizing you for far less optimal boat shape and weight that would probably make significant difference in hull efficiency in favor of the diesel.

---


The drivel above is for "windboat's" boat which would (supposedly) get 14nm range out of his 108kwh battery pack. Just 20hp with 108kwh lead acid pack will runs dry in under 5 hours. (108kwh*0.66(depth of discharge)/ 20hp*.735(hp to kw)=4.8h).
3000kg of "fuel" to run small motor for 5h with nowhere to go when it runs out. Not so attractive. Also the batteries cost $15000+, so $3000-5000 /year.







the combination of factors makes electric only interesting or feasible in very small boats (row boat) or specialty applications where things like reduced noise are more important that financial/efficiency matters.
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