[washington mac user]

I'm glad we are getting closer to having hydrogen powered cars; hydrogen could drastically cut down pollution.

http://www.sciencedaily.com/releases...1204093524.htm

Now scientists at the University of Bath have invented a material which stores and releases hydrogen at room temperature, at the flick of a switch, and promises to help make hydrogen power a viable clean technology for the future.

What does everybody else think about this advancement?

[drewprops]

From what I recall there seems to be a lot of academic pessimism about the practical creation of a hydrogen distribution system (taking scientific pessimism with the grain of salt it deserves after having been proved wrong again and again.... manned flight, computing power, etc, etc).

[billybobsky]

A hydrogen economy will be the worse planned environmental catastrophe possibly ever.

[joveblue]

From what I've heard, hydrogen is a terribly inefficient method of storing energy - it requires a lot of energy to seperate out of water and you only get a small fraction of that energy back from hydrogen feul cells. This will only be a step forward environmentally if we can use green power to create the hydrogen, which isn't going to happen any time soon really...

[AsLan^]

Originally Posted by billybobsky A hydrogen economy will be the worse planned environmental catastrophe possibly ever.

Now that's quite an assertion!

Seriously though, what's wrong with storing energy in hydrogen?

I understand that it takes quite a lot of energy to make hydrogen but isn't that what nuclear is for?

[Banana]

Why not take out the middlemen and actually put in a mini-nuclear reactor under the hood?

[joveblue]

Nuclear has a whole raft of problems associated with it, I really don't think it's the answer to global warming...

Originally Posted by Banana Why not take out the middlemen and actually put in a mini-nuclear reactor under the hood?

I'm assuming this is a joke...

[AsLan^]

Okay... I'll take back my nuclear example. Lets just assume there is a way to generate clean safe electrical power but the infrastructure required restricts it to large facilities rather than say in your car.

What is the problem with storing this energy in hydrogen?

[billybobsky]

Originally Posted by joveblue From what I've heard, hydrogen is a terribly inefficient method of storing energy - it requires a lot of energy to seperate out of water and you only get a small fraction of that energy back from hydrogen feul cells. This will only be a step forward environmentally if we can use green power to create the hydrogen, which isn't going to happen any time soon really...

Biological catalysts have very high efficiency, but we don't have good ways to take advantage of them now.

[billybobsky]

Originally Posted by AsLan^ Okay... I'll take back my nuclear example. Lets just assume there is a way to generate clean safe electrical power but the infrastructure required restricts it to large facilities rather than say in your car. What is the problem with storing this energy in hydrogen?

Hydrogen has a very short lifetime in the atmosphere most accidentally released will escape into space causing the earth to become more oxidizing than it already is -- this isn't a good thing...

[joveblue]

Originally Posted by AsLan^ Okay... I'll take back my nuclear example. Lets just assume there is a way to generate clean safe electrical power but the infrastructure required restricts it to large facilities rather than say in your car. What is the problem with storing this energy in hydrogen?

If there was, there isn't really a problem. But at the moment, most of our electricity comes from non-renewable sources. If the electricity used to create the hydrogen was matched by an increase in the supply of green power (in addition to increases not influenced by this), then I'll be spearheading the campaign to make the transition to hydrogen. But I can't see how that would work. The government(s) would have to mandate that hydrogen plants could only use green power or something I guess...

EDIT: I'm not especially familiar with what's going on in terms of power supply in the US and other countries

[AsLan^]

Originally Posted by billybobsky Hydrogen has a very short lifetime in the atmosphere most accidentally released will escape into space causing the earth to become more oxidizing than it already is -- this isn't a good thing...

See, nobody ever mentioned that before.

Say a motor vehicle is involved in an accident and its fuel cells are compromised, does this hydrogen just leak out of the cells and into the atmosphere?

Also... wouldn't escaped hydrogen just float off the planet? which I believe is the reason why its not common on Earth to begin with.

EDIT: Wait! I didn't think this through, wouldn't the hydrogen bond with another element before it escaped our atmosphere? and create water or some other such molecule. Is there a harmful molecule it could create?

[joveblue]

Originally Posted by AsLan^ See, nobody ever mentioned that before. Say a motor vehicle is involved in an accident and its fuel cells are compromised, does this hydrogen just leak out of the cells and into the atmosphere? Also... wouldn't escaped hydrogen just float off the planet? which I believe is the reason why its not common Earth to begin with. EDIT: Wait! I didn't think this through, wouldn't the hydrogen bond with another element before it escaped our atmosphere? and create water or some other such molecule. Is there a harmful molecule it could create?

But:

Originally Posted by Wikipedia Another characteristic of hydrogen fires is that the flames tend to ascend rapidly with the gas in air, causing less damage than hydrocarbon fires. Two-thirds of the Hindenburg passengers survived and deaths were from falling or from gasoline burns.

[Majost]

Originally Posted by AsLan^ See, nobody ever mentioned that before. Say a motor vehicle is involved in an accident and its fuel cells are compromised, does this hydrogen just leak out of the cells and into the atmosphere? Also... wouldn't escaped hydrogen just float off the planet? which I believe is the reason why its not common Earth to begin with. EDIT: Wait! I didn't think this through, wouldn't the hydrogen bond with another element before it escaped our atmosphere? and create water or some other such molecule. Is there a harmful molecule it could create?

Exactly. It would probably react before reaches the upper portion of our atmosphere. Also, remember that the only reason that hydrogen rises is due to a difference in density. As the density of air decreases, so will the buoyancy of hydrogen.

Also, you were wondering about the inefficiency of hydrogen. Any time you change storage forms of energy, there is a loss associated with it. Green power is typically mechanical (hydro, wind, etc) or heat (thermal, solar, etc). That gets converted to electricity, which gets pushed through water to convert it to gasses, which are used as a fuel cell for electricity, which pushes a mechanical motor (or are combusted to become thermal energy, which is used for mechanical energy again). That's a rather long chain, and when you consider all the lost, unrealized potential at each step, it becomes rather staggering.

As long as we're daydreaming, it'd be absolutely ideal to use some of these new "SuperCapacitors" to grab the electric potential from the second step, and use that directly. At least then we don't lose quite so much to stupid changes in potential energy. And the electric infrastructure already exists... we'd use quite a bit of energy building these new hydro pipelines and shipping hydrogen to the right places.

[AsLan^]

Originally Posted by joveblue But:

Yeah, I was just going through that page ;P

I don't think fuel cells will really carry that much hydrogen!

Perhaps though, that would actually be the way to make fuel cells environmentally friendly. Embed something into casing so that any escaping hydrogen is ignited which should just leave H2O. There might be a way to do this safely.

That being said, I haven't seen anything about environmental hazards posed by releasing hydrogen into the atmosphere. Also, I am not a scientist, chemist, or other person who knows about these things so I don't really know where to look. I am interested though

[joveblue]

Just remembered I saw a story a while ago about scientists developing a solar-cell that directly converts solar energy into hydrogen... Well, I mean that's obviously impossible but solar energy + water = hydrogen + oxygen...

[AsLan^]

Originally Posted by Majost As long as we're daydreaming, it'd be absolutely ideal to use some of these new "SuperCapacitors" to grab the electric potential from the second step, and use that directly. At least then we don't lose quite so much to stupid changes in potential energy. And the electric infrastructure already exists... we'd use quite a bit of energy building these new hydro pipelines and shipping hydrogen to the right places.

That's the problem though and the reason we are discussing it in the first place. Our current energy source is not sustainable which makes the accompanying infrastructure irrelevant in the long term. We need a new energy source and a new distribution system. At the moment, hydrogen seems to be what everyone is focusing their research on.

[washington mac user]

Not just hydrogen, bioconversion, gasification, bioethanol.

[Banana]

Originally Posted by joveblue Nuclear has a whole raft of problems associated with it, I really don't think it's the answer to global warming... I'm assuming this is a joke...

But there is a truth to it- After all, fossil fuels, hydrogen, hydropower and whatever all ultimately traces to nuclear reaction. (e.g. Sun's fusion of hydrogen into helium) Fossil fuels and hydropower are very convenient in that there is little inital energy spent in activating the reaction and unreleasing the stored energy, but they're not quite ecologically friendly. Fuel cells may be more "eco-friendly" but they're ineffective.

Nuclear reaction, all things considered, is actually most environmentally friendly. Why, instead of putting radioactive waste in steel drum and burying it only to dig up whenever there's leak, you could put them in a breeder reaction or whatever to harness the potential. Not to mention that there are discoveries for creative use of radioactivity, including a 10-years laptop battery.

The real barrier is the FUD that comes with the nuclear energy. *shrugs*

[billybobsky]

H2 is quite stable in the atmosphere... you need a source of spark, which doesn't exist readily...

[Banana]

Except that if I understand it correctly, a concentration of H2 more than 17% in a given volume would explode without any presence of spark?

# Flammablity Class: Highly flammable gas Auto Ignition Temp: 773K 500°C 932°F Explosive Limits Lower (LEL): 17% Upper (UEL): 56% Flammable Limits Lower (LFL): 4% Upper (UFL): 75% Flash Point: 20K -253°C -423°F Theoretical (there are no oxidizing materials i.e. oxygen in the gas state at this temperature, which is necessary to support combustion.)

Source

EDIT: Never mind- did some more digging, and found that explosive limit only refer to quantity required to continue an explosive reaction, not necessarily an explosion without ignition. I did thought H2 readily reacts with 02, but guess I was wrong.

[AsLan^]

Also, if it's stable, wouldn't it then just float away?

[joveblue]

Without going into the advantages and disadvantages of nuclear power in general, hurtling miniature nuclear reactors down a freeway at each other at 110km/h doesn't sound like a good idea to me...

[Moogs]

Even if it were easy to store, there's the little problem of getting every gas station in America and elsewhere to retrofit all of their equipment (not to mention all the tankers) to provide Hydrogen. It'll never happen; greed will see to that.

[billybobsky]

Leaking hydrogen generally won't catch fire without a spark; hydrogen released in an accident near hot metal or sparks will burn, but in a very well defined way, like a jet of fire (invisible) coming out of a pin hole and rapid leak...

[Moogs]

Great so every car accident could end up looking like a Formula 1 race where the drivers appear to be fine after an accident and then end up rolling around and being doused because of the invisible fire that's on them. Good times!

[billybobsky]

Except hydrogen isn't a liquid like methanol... An accident would occur and a bunch of burned corpses would appear to be in a pile; when you go to investigate, the pile just gets bigger.

[Moogs]

So you're saying it's kind of dangerous then?

[Banana]

Whereas an accident involving an nuclear powered car would only involve steam burn, an increased dosage of your daily radiation exposure. Much more safer!

/rimshot

[Moogs]

Yah but what if lead-lined clothing becomes all the rage in the future? The extra calories we have to burn wearing them all day could be a health benefit by itself! I'm all about the Plutonium-mobile. Hook me up!