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#26 2004-11-20 11:58:48

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: Fuel Cells - A viable power source?

Exhaust Gas Recirculation (EGR) for internal combustion engines has been around for ages.  It just doesn't do enough.  You still need a massive amount of oxygen.  Do the math and you will see.  Going over these same old arguments is like pounding away at the same door for years and years, never realizing it's not a door at all.

The space shuttles fuel cells weigh 250 lbs and constantly produce 7kw each with a surge capability of about 12kw.

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#27 2004-11-20 12:44:29

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Fuel Cells - A viable power source?

Since Hydrogen and Oxygen are oxydized into water by both;
The arithmetic is the same for fuel cell and combustion engine.
Two parts Hydrogen to 16 parts Oxygen, by weight.

Strikingly different is the power per kilogram of engine weight.
And that gives great advantage to the Quasiturbine.

http://www.freedom-motors.com/]Horsepower per pound
http://www.osengines.com/engines/osmg1400.html]Even in small size.

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#28 2004-11-20 17:25:29

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: Fuel Cells - A viable power source?

Internal combustion engines also produce nitrogen oxides, carbon monoxide, and hydrocarbons whereas fuel cells produce pure water.  How are you going to clean the water?

The arithmetic for fuel consumption is NOT the same.
You simplifiy things to an amazing degree.  Even sentences. 

Ignoring very important side effects.
It's bad medicine.

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#29 2004-11-20 20:05:43

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Fuel Cells - A viable power source?

Everything should be made as simple as possible, but not simpler. 
~Albert Einstein

Internal combustion engines also produce nitrogen oxides, carbon monoxide, and hydrocarbons whereas fuel cells produce pure water.  How are you going to clean the water?

If you only feed the internal combustion engine Hydrogen and Oxygen,
then it will only produce water.

Power generation should be modular; there might be ways that one method is superior to the other. For racing, internal combustion give the most bang for the weight. For long term endurance, solar cells combined with batteries.


http://www.google.com/url?sa=U&start=1& … e=9872]The chart inside this pdf is very good.

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#30 2004-11-20 22:27:35

Austin Stanley
Member
From: Texarkana, TX
Registered: 2002-03-18
Posts: 519
Website

Re: Fuel Cells - A viable power source?

Yes dook, we have been over your calculations, and your method for arriving at them is simply wrong.  ICE engines (rotary or otherwise) are less efficent than fuel cells (only about 40% efficent), but still a workable alternative.  And as mars dog points out they can generate nearly 5 times more energy per unit of engine weight than a fuel cell can.

You are also incorrect about the gasous byproducts of a martian closed cycle engine.  Without nitrogen in the combustion atmosphere, no energy is wasted in the formation of nitrogen oxides, and in a closed cycle engine the formation of other products of incomplete combustion is very small.

I won't go back over all my arguments in favor of them again, but you can see them http://www.newmars.com/forums/viewtopic.php?t=3495]here


He who refuses to do arithmetic is doomed to talk nonsense.

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#31 2004-11-20 22:50:07

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Fuel Cells - A viable power source?

Of course, the most likly arrangement for a Mars rover will be an electric drive vehicle, where a combustion engine would require a generator and a fuel cell would not. A small gas turbine engine has the potential to be even lighter then a piston or wankel engine and possibly more efficent, and you could use ISRU produced Methane directly.

I also wonder how much the powerplant will weigh versus the fuel it carries; I bet that a fuel cell system, the powerplant and the fuel weight, will be lighter then a comperable ICE or turbine arrangement because of the lower fuel consumption.

Fuel cells also have the potential for higher durability and lower failure risk, since they have so few moving parts and no high mechanical or thermal loading in any of the componets.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#32 2004-11-20 23:53:06

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Fuel Cells - A viable power source?

Ocean liners do not use fuel cell power.
Neither do http://millennium-debate.org/tel14aug03.htm]model aeroplanes.

Somewhere in between, fuel cell powered buses might become common.
http://www.abqjournal.com/AED/143263bus … 4.htm]Even train locomotive with fuel cell operation.
Seems like a good way to reduce pollution.

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#33 2004-11-21 07:50:49

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: Fuel Cells - A viable power source?

Finally GCN is coming around.  My point exactly.  Sure using an ICE on mars is possible but when compared to fuel cells it is just not as desirable for many reasons.

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#34 2004-11-21 07:55:49

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: Fuel Cells - A viable power source?

Ocean liners do not use fuel cell power.
Neither do http://millennium-debate.org/tel14aug03.htm]model aeroplanes.

Ocean liners?  That's a tough one to argue with.  Yes indeed I just can't argue with that kind of logic.  I've changed my mind completely.  We should launch ocean liners to mars and use them to explore the planet.

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#35 2004-11-21 08:17:58

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: Fuel Cells - A viable power source?

http://web.mit.edu/newsoffice/2003/hydr … o-friendly cars must travel long road to reality


"In the context of portable power, fuel cells are not a technology, they're a laboratory curiosity."

pictures.gif

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#36 2004-11-21 09:44:35

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Fuel Cells - A viable power source?

Well, somebody warn Honda then, their prototype fuel cell fleet cars are now half as expensive as the General Motors prototype from just a few years back.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#37 2004-11-21 16:10:53

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: Fuel Cells - A viable power source?

Fuel cells have been around for a very long time, one was on the Apollo missions and two are aboard the space shuttle.  The technology is proven and dependable.  In all the space missions only once has a fuel cell failed. 

Fuel cells replacing ICE in vehicles is a different matter, one that has little to do with a fuel cell powered vehicle on mars.  The primary problem is that our entire infrastructure is designed to build ICE vehicles and supply fuel for internal combustion engines.  If you had a fuel cell vehicle where would you go to get hydrogen fuel?  The costs will come down as fuel cells replace ICE.

Just wondering who that quote was from and when?

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#38 2004-11-21 23:30:01

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Fuel Cells - A viable power source?

From the linked article!

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#39 2005-04-27 11:56:17

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Fuel Cells - A viable power source?

Well it has been a while since thoughts of fuel cells were in the main stream but with the rising gas price I am sure that it will be front page news once more.

The harnessing of bacteria in a Microbial fuel cell: High yield hydrogen source and wastewater cleaner

Using a new electrically-assisted microbial fuel cell (MFC) that does not require oxygen, Penn State environmental engineers and a scientist at Ion Power Inc. have developed the first process that enables bacteria to coax four times as much hydrogen directly out of biomass than can be generated typically by fermentation alone.
This MFC process is not limited to using only carbohydrate-based biomass for hydrogen production like conventional fermentation processes. We can theoretically use our MFC to obtain high yields of hydrogen from any biodegradable, dissolved, organic matter -- human, agricultural or industrial wastewater, for example -- and simultaneously clean the wastewater.

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#40 2022-02-05 19:10:17

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,750

Re: Fuel Cells - A viable power source?

Bump hydrogen fuel cell use

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