39 replies to this topic

[Mike McCarthy]

It's like a battery: you put energy in, you get energy out, and it's zero sum game.

A battery with 100% charging efficiency (not to mention other losses in charger, etc.) is a remarkable thingy.

So you understand that hydrogen is not a fuel, but rather a storage thingy?

(And yes there are losses in any charge/discharge process, so 100% is never on the table.)

The point I'm making -- and nimblebear doesn't understand -- is that hydrogen is not laying around waiting to be harvested (like oil and coal). You gotta make it, and making it takes more energy than you get out of it.

For example, take 1000 BTUs of energy (from some real source like coal or solar or nukes) and apply it to water. By doing so you can separate hydrogen from oxygen and harvest the hydrogen.

Now, burn the hydrogen (ie, re-oxidize it). How many BTUs do you get? Less than 1000. It's impossible to break even.

If you want 1000 BTUs from hydrogen, you gotta use MORE than 1000 BTUs (and that's gotta come from somewhere else, like from coal, nukes, etc.

Hydrogen is not a fuel, it's a less than 100% efficient storage thingy.

I fully understand what H2 is and how we will use it.

Its abundance IS TOTALLLY relevant. Efficiency only matters in the cost of the technology or stuff needed to get it, and the size. You can get H2 from a multitude of sources. That is the point. H2 is about storage, being a carrier, about abundance, about its natural occurance, and about its use as a fuel. And you can use it without COMBUSTING it, which it appears YOU don't understand, or appreciate what that means.

If you want to debate me on the use of H2, or fuel cells, be my guest. I worked for a fuel cell developer, and a company who funded the development of fuel cells since the '70's.

P.S. where doo you get the "oxidization' or 'burning' garbola ? Did you just make that up, or did you read it somewhere from the "reliable" info on the internet ?

P.S. I'll give you 50% correct. There is a oxidation half reaction. And there is a reduction half reaction. This gives you a cell reaction. 2H2 +O2 ---> 2H2O. You can't have one reaction without the other. Oxidation half reaction: It is a process where a chemical species changes to another species with a more positive charge due to the release of one or more electrons.

PPS A fuel cell is 2 to 3 times more efficient than an internal combustion engine.

PPPS. A battery is also an energy conversion device. Both battery's and fuel cells are are electrochemical conversion devices.

There is NO COMBUSTION (or 'burning') involved in either fuel cells or batteries.

Fuel cells advantages over batteries are:
smaller size
lighter weight
quick refueling (vs. re-charging)
longer range

The energy from this:
2H2 + O2 ---> 2H2O

CANNOT be more than the energy from this:
2H2O ---> 2H2 + O2

Splitting water into H2 and O2 takes AT LEAST the same amount of energy as you can later get from H2, whether from subsequent combustion or from a fuel cell (and that's not counting the ordinary costs of the conversion -- ie, the costs of production).

The basic chemistry, reduced to its elemental pureness, is zero-sum.


Again, if you want 1000 BTUs of energy from hydrogen you have to put AT LEAST 1000 BTUs into water (plus the costs of production). THINK about that, Understand that.

H2 is a battery, not a fuel. What you get out of it is always less than what you put into it Whether you burn H2 as a gas or use it to produce fuel cells the math is the same: NO gain, only recovery of some percentage of whatever energy was used to produce it.

Natural gas? That's a fuel. Mother Nature captured solar energy and stored it in natural gas eons ago. Same with coal. Same with oil. Those are all captured solar energy.

Nuclear is diffferent: matter itself is converted directly to energy.

Solar (and wind) are simply real time capture technologiies, grabbing current solar energy.

Hydrogen is NONE of those. It is not energy. It is a means (via electrolysis or other methods) where the energy from true fuels is stored. Invest 1000 BTUs in producing hydrogen and at best you get less than 1000 BTUs back. By definition you can never get more than what you put in it, just like a battery.

[espresso]

Ok ok, we know fuel cell is just a devise, though a green (compared to combustion) lightweight device! But what about : "don't forget you now have a h-bomb sitting behind your seat that is under 10,000 psi pressure. At least if u go, you won't need an urn or a casket. You'll just be vaporized"?!? It's true that's risky?!?

[Mike McCarthy]

Ok ok,
we know fuel cell is just a devise, though a green (compared to combustion) lightweight device!
But what about :
"don't forget you now have a h-bomb sitting behind your seat that is under 10,000 psi pressure.
At least if u go, you won't need an urn or a casket. You'll just be vaporized"?!?
It's true that's risky?!?

The "device" is only as green as the fuel used to charge the device. Burn dirty coal or burn fuel oil to make the electricity to charge the device and you aren't being green at all. You might be very dirty.

The entire "what is the best battery" question is interesting and complex. Hydrogen? The many different chemical? They all have different efficiencies, cradle-to-grave costs, risks, etc. Plus, almost all the technologies are young.....who knows what improvements and even breakthroughs are coming. I doubt there will be one-best-battery answer.

Just my opinion, but I'm not worried about the ignition risks. A tank of gasoline on a car, or a tank of propane in a back yard, can make a very big boom, too. I expect hydrogen could be deployed safely. It's my observation that we typically get "safety" dialed in well before a technology comes to market; otoh we don't do a very good job of dealing with toxicity until well after a technology is already deployed.

[espresso]

Well the European plan is to go to hydrogen only with new green source of energy. It is a real green plan. To substitute all the combustion cars with hydrogen harvested with green source! Of course the energy needed for all the rest is out of question yet!

[Mike McCarthy]

Well the European plan is to go to hydrogen only with new green source of energy.
It is a real green plan. To substitute all the combustion cars with hydrogen harvested with green source!
Of course the energy needed for all the rest is out of question yet!

Nothing wrong with green source, but 40-50% of the energy used in the US is for transportation (it's 50% in CA). Is there any way to get even 20% of our energy source green any time soon? It would take massive deployment of wind and solar to make even a green dent in transportation needs.

Knowing that, battery operated cars -- hydrogen or chemical -- are inevitably going to use coal and nukes as source. Most of them, for a long time.

We'll have to wait and see if there's any buyer's remorse over moving in that direction (there sure has been a lot of buyer's remorse with bio-fuels, and for the same reasons: from soup-to-nuts they aren't more efficient, and may turn out to be less efficient).

[colion]

> I was only noting that the "zero sum" thought was off the mark and was not addressing
> the nature of hydrogen vis-a-vis coal, nuclear, etc.


No. That is not the comparison, and suggesting that comparison completely misses the point.

Coal or nuclear or natural gas or solar all have losses associated with production or collection. Maybe you have to invest $10 in costs to recover $100 in energy for coal, and maybe you have to spend $30 to get nuclear, and maybe you have to spend $20 to get solar. Those numbers are interesting, and important, because they obviously help you decide which is the better way to go. And certainly you should do the entire soup-to-nuts analysis (including every relevant cost) so you can determine what the true costs of the life cycle of any source or energy.

Hydrogen is different, though, because it is NOT a source. It's a storage medium, it's a battery. With hydrogen the number is 120%, or 140% or whatever. You have to add 100% to the costs because hydrogen is NOT a fuel: it's a means to store energy from other fuels. It's like a battery: you charge it (use energy to create it) and you discharge it (burn it). You always get less than you started with. There is NO reason to create hydrogen except that it's portable.. There is no reason to take 1000 BTUs of energy and turn it into 800 BTUs except to make that 800 BTUs portable.

That's why the "zero-sum thought" is right on the mark. You've got to realize that -- in a perfect world with no inefficiencies -- the costs to generate 1000 BTU of hydrogen are 1000 BTUs. IOW, you start out with zero-sum, and go down from there. That's not true of coal, nuclear, e(tc.


Final example:

You have a pile of coal sitting on the ground in front of you. It cost you $10 to dig it out of the ground and transport it to your house.. How much energy can you recover? Let's say 1000 BTUs. Light a match, and 1000 BTUs are released. For $10 and a match you get the entire 1000 BTUs.

You have a drum of water sitting in front of you. It cost you $10 to get a drum and fill it with water. How much energy can you recover? Let's say 1000 BTUs. How? You can't just light a match: it's water, it doesn't burn, it's not ready to go. Here's what you have to do: you've got to spend another 1200 BTUs on electrolysis to recover the 1000 BTUs in your drum. Or maybe there are better technologies that mean you only have to spend 1100 BTUs, or 1050. Regardless of how good you are, you can't just light a match. You've got to spend ALL 1000 BTUs, and then some, to end up with 1000 BTUs of hydrogen. It's a zero-sum game.

Your initial remark (many messages back) that I commented on was "It's like a battery: you put energy in, you get energy out, and it's zero sum game." That ignores losses and is incorrect outside of a "paper and pencil" world which led to my comment. Based on your examples above, you now appear to shift gears and define zero sum in terms of a total, real world energy balance, including input, output, and losses, as I suggested doing before. If so, then at this point we are in agreement as far as zero sum goes. If not, then we must agree to disagree.

As for hydrogen versus coal, nuclear, etc., I did not comment on the nature (yes that is the comparison) of hydrogen versus coal, nuclear, etc. However, I do think that the discussion lacks definition of terms (e.g., battery, fuel, storage, etc.) which can lead to endless, circular discussion because people use the terms somewhat differently and is why I chose not to get involved. Given proper definition of terms, I think the debaters will find that there is more to agree on than not. This stuff ain't rocket science so define terms and I'm sure that most of the disagreements will evaporate.

Enuf ced.

Edited by colion, 17 June 2008 - 10:38 AM.

[Mike McCarthy]

> I was only noting that the "zero sum" thought was off the mark and was not addressing
> the nature of hydrogen vis-a-vis coal, nuclear, etc.


No. That is not the comparison, and suggesting that comparison completely misses the point.

Coal or nuclear or natural gas or solar all have losses associated with production or collection. Maybe you have to invest $10 in costs to recover $100 in energy for coal, and maybe you have to spend $30 to get nuclear, and maybe you have to spend $20 to get solar. Those numbers are interesting, and important, because they obviously help you decide which is the better way to go. And certainly you should do the entire soup-to-nuts analysis (including every relevant cost) so you can determine what the true costs of the life cycle of any source or energy.

Hydrogen is different, though, because it is NOT a source. It's a storage medium, it's a battery. With hydrogen the number is 120%, or 140% or whatever. You have to add 100% to the costs because hydrogen is NOT a fuel: it's a means to store energy from other fuels. It's like a battery: you charge it (use energy to create it) and you discharge it (burn it). You always get less than you started with. There is NO reason to create hydrogen except that it's portable.. There is no reason to take 1000 BTUs of energy and turn it into 800 BTUs except to make that 800 BTUs portable.

That's why the "zero-sum thought" is right on the mark. You've got to realize that -- in a perfect world with no inefficiencies -- the costs to generate 1000 BTU of hydrogen are 1000 BTUs. IOW, you start out with zero-sum, and go down from there. That's not true of coal, nuclear, e(tc.


Final example:

You have a pile of coal sitting on the ground in front of you. It cost you $10 to dig it out of the ground and transport it to your house.. How much energy can you recover? Let's say 1000 BTUs. Light a match, and 1000 BTUs are released. For $10 and a match you get the entire 1000 BTUs.

You have a drum of water sitting in front of you. It cost you $10 to get a drum and fill it with water. How much energy can you recover? Let's say 1000 BTUs. How? You can't just light a match: it's water, it doesn't burn, it's not ready to go. Here's what you have to do: you've got to spend another 1200 BTUs on electrolysis to recover the 1000 BTUs in your drum. Or maybe there are better technologies that mean you only have to spend 1100 BTUs, or 1050. Regardless of how good you are, you can't just light a match. You've got to spend ALL 1000 BTUs, and then some, to end up with 1000 BTUs of hydrogen. It's a zero-sum game.

Your initial remark (many messages back) that I commented on was "It's like a battery: you put energy in, you get energy out, and it's zero sum game." That ignores losses and is incorrect outside of a "paper and pencil" world which led to my comment. Based on your examples above, you now appear to shift gears and define zero sum in terms of a total, real world energy balance, including input, output, and losses, as I suggested doing before. If so, then at this point we are in agreement as far as zero sum goes. If not, then we must agree to disagree.

As for hydrogen versus coal, nuclear, etc., I did not comment on the nature (yes that is the comparison) of hydrogen versus coal, nuclear, etc. However, I do think that the discussion lacks definition of terms (e.g., battery, fuel, storage, etc.) which can lead to endless, circular discussion because people use the terms somewhat differently and is why I chose not to get involved. Given proper definition of terms, I think the debaters will find that there is more to agree on than not. This stuff ain't rocket science so define terms and I'm sure that most of the disagreements will evaporate.

Enuf ced.

That's exactly what I'm trying to do: define terms.

What is a source, what is a storage technology. There is point in discussing efficiencies until basic concepts are understood.

[espresso]

Well the European plan is to go to hydrogen only with new green source of energy.
It is a real green plan. To substitute all the combustion cars with hydrogen harvested with green source!
Of course the energy needed for all the rest is out of question yet!

Nothing wrong with green source, but 40-50% of the energy used in the US is for transportation (it's 50% in CA). Is there any way to get even 20% of our energy source green any time soon? It would take massive deployment of wind and solar to make even a green dent in transportation needs.

Knowing that, battery operated cars -- hydrogen or chemical -- are inevitably going to use coal and nukes as source. Most of them, for a long time.

We'll have to wait and see if there's any buyer's remorse over moving in that direction (there sure has been a lot of buyer's remorse with bio-fuels, and for the same reasons: from soup-to-nuts they aren't more efficient, and may turn out to be less efficient).

Let's say we start with all the public transport where possible (hydrogen bus), then we produce a small hydrogen city car (our habits are already much different from the americans), then we've already made a big dent!
Energy sources can come from solar in the Sahara desert or south Europe, wind from North Europe etc. etc.
Then let say we''ll have reduced 40% of the transport to a total green energy!
The cost of energy will probably be more expensive then now, but we need to move to a total efficiency bringing down the costs procapita.
The air will be more clean, people will be more happy!!!

[Mike McCarthy]

> Let's say we start with all the public transport where possible (hydrogen bus), then we produce a small > hydrogen city car (our habits are already much different from the americans), then we've already made a big > dent! Where do you get the energy to make the hydrogen? If you want to make a big dent, you are going to have to produce big energy. Can solar be the source? Can wind? Maybe, but the numbers are staggering. Transportation use is massive. We are nowhere near being able to generate enough solar electricity to power fleets of urban vehicles. Have you done any of the math? Where do you get your 40% number? How many square miles of solar panels and how many windmills would it take to convert 40% of transportation needs to green energy? I'm asking. If you have any numbers please post.

[espresso]

> Let's say we start with all the public transport where possible (hydrogen bus), then we produce a small
> hydrogen city car (our habits are already much different from the americans), then we've already made a big
> dent!

Where do you get the energy to make the hydrogen? If you want to make a big dent, you are going to have to produce big energy.

Can solar be the source? Can wind? Maybe, but the numbers are staggering. Transportation use is massive. We are nowhere near being able to generate enough solar electricity to power fleets of urban vehicles.

Have you done any of the math? Where do you get your 40% number? How many square miles of solar panels and how many windmills would it take to convert 40% of transportation needs to green energy?

I'm asking. If you have any numbers please post.

Sorry for the late answer i was away.

The 40% is my projection based on what i've read, there are many projects including self made electricity to sell back into the grid.
I don't remember where i read all but it was The european plan.
If you add the progress to be made in 40-50 years, i think have all the transports running green is factble.
I really hope so!

Edited by espresso, 17 June 2008 - 01:57 PM.