Questions about a Hydrogen Economy; Scientific American

[Ivan Seeking]

I wanted to point out a great article about our up and coming Hydrogen Economy. This article comes from the May 2004 issue of SciAm and it gives nice snapshot of the state-of-the-art.

Not available for free AFAIK, here is an internet link and brief.

In the fall of 2003, a few months after President George W. Bush announced a $1.7-billion research program to develop a vehicle that would make the air cleaner and the country less dependent on imported oil, Toyota came to Washington, D.C., with two of them. One, a commercially available hybrid sedan, had a conventional, gasoline-fueled internal-combustion engine supplemented by a battery-powered electric motor. It got about 50 miles to the gallon, and its carbon dioxide emissions were just over half those of an average car. The other auto, an experimental SUV, drove its electric motor with hydrogen fuel cells and emitted as waste only water purer than Perrier and some heat. Which was cleaner? [continued]

http://www.sciamdigital.com/browse.cfm?sequencenameCHAR=item2&methodnameCHAR=resource_getitembrowse&interfacenameCHAR=browse.cfm&ISSUEID_CHAR=CB826BAE-2B35-221B-6E2587F29CF2C88A&ARTICLEID_CHAR=CB9BE5E6-2B35-221B-6F2461DEF9B52B9C&sc=I100322

 

[jdavel]

Ivan Seeking said, "I wanted to point out a great article about our up and coming Hydrogen Economy."

Isn't it a little misleading to call what this technology could make possible a "hydrogen economy"? That term seems to imply that hydrogen is an energy source in the same way that the petroleum we get out of the ground is. But that isn't true. We're going to have to make the hydrogen, and doing that requires more energy than the hydrogen provides once it's made!

The advantage is that the energy can be produced in electric power plants and then easily distributed (in the form of electricity) through a conventional power grid to hydrogen production plants. But we're still going to need an energy source (coal?) to make the electricity that makes the hydrogen.

So, where we're really headed (maybe), is toward an economy based more on coal than our economy is currently. Since we've got lots of coal in the US, that's good, but it's hardly a "hydrogen economy".

 

[Janitor]

And of course coal is infamous for carbon dioxide (greenhouse) and sulfur (acid rain) and mercury (freshwater fish contamination) emissions.

If it gets to where the average citizen of India and China lives the middle-class lifestyle of a typical Westerner, I shudder to think what our air and water may become.

 

[Matt-235]

I remember hearing there's a decent sized initiative in the nuclear inductry to become one of the prime players in the production of hydrogen, which would be a lot better on the environment than coal would be.

I link to the DoE's Nuclear Hydrogen Initiative: http://www.nuclear.gov/infosheets/hydrogenfactmarch2003.pdf

 

[Ivan Seeking]

Ivan Seeking said, "I wanted to point out a great article about our up and coming Hydrogen Economy."

Isn't it a little misleading to call what this technology could make possible a "hydrogen economy"? That term seems to imply that hydrogen is an energy source in the same way that the petroleum we get out of the ground is. But that isn't true. We're going to have to make the hydrogen, and doing that requires more energy than the hydrogen provides once it's made!

How this will finally pan out is anyone's guess. Yes, H2 is an energy carrier, not an energy source. That is H2 101, day 1. There is much, much more to this than you may realize. There are at least 2 dozen different approaches to H2 production that include biological approaches, such as by using H2 producing bacteria, and that involve many previously untapped resources. Coal does play a role, and frankly, the article is a little less positive than our friends at the National Hydrogen Association,

http://www.hydrogenus.com/

but a lot of good information is found in the SciAm report. Please see also an earlier discussion where I made my best arguments for all of this.

https://www.physicsforums.com/showthread.php?t=4127

 

[Ivan Seeking]

Here is a link to some NPR interviews about Iceland which promises to serve as a test bed for H2 technologies.

http://www.loe.org/ETS/organizations.php3?action=printContentItem&orgid=33&typeID=18&itemID=204&User_Session=63e33af74b5bc33216035afa351f1a58

 

[Ivan Seeking]

I wanted to add that many good links are provided thoughout this thread.

https://www.physicsforums.com/showthread.php?t=4127

Please review this thread completely if you have any interest here. I did my best to provide much of the key information.

I should also add that the SciAm article does significantly play down the energy cost of fossil fuels - well to tank - as I have tried to argue. I recognize this without conceding the argument. It would take some time to find out if we are really comparing apples to apples.

 

[jdavel]

Ivan Seeking,

Thanks for the links. I read some, and I'll get to the others later. They're pretty encouraging, at least with respect to how close we are to having the technology.

I can't believe I've gotten on the wrong side of this "argument" with you. I'm a fanatical believer in our need to do whatever is necessary to end our dependence on oil, both for environmental and political reasons. If hydrogen is the solution (or part of the solution) then we should push it hard. I just think the term "hydrogen economy" implies a little more than it really means.

 

[Ivan Seeking]

Hey, no wrong side or right side here.

I just wanted to make sure that you and everyone else realizes that more exists here than most people know. It is easy to be too quickly dismissed. For years I thought the 2nd law pretty much made this all a moot point but I now believe this not true.

As for the term "Hydrogen Economy", this may be a glorification of the idea. I really don't know if any strict definitions of economics may apply, but the key concept is that H2 will act as a base, as the energy carrier for most other energy options. In this sense we would switch from a fossil fuel economy to an H2 economy. In the most hopeful sense, H2 might be viewed as the new currency for energy. Remember also that fossil fuels are no different than H2 in that fossil fuels are also energy carriers for solar energy. Same for hydropower and wind. So this can all get to be a matter of where we draw the line or how we choose to define things.

 

[russ_watters]

Remember also that fossil fuels are no different than H2 in that fossil fuels are also energy carriers for solar energy. Same for hydropower and wind. So this can all get to be a matter of where we draw the line or how we choose to define things.

Yeah, but there is of course a difference - an important one. For oil/coal the sun and Earth already did 99% of the work to make it - with H2, we have to do all of the work to make it.

 

[jdavel]

russ_watters said, "For oil/coal the sun and Earth already did 99% of the work to make it - with H2, we have to do all of the work to make it."

Exactly!

For all intents and purposes, petroleum and coal are energy sources. In the form in which hydrogen is available, (H2O) it's not an energy source. More energy will be used to turn it into an energy source than it will produce as an energy source. That's not much to base an economy on!

 

[Ivan Seeking]

Yeah, but there is of course a difference - an important one. For oil/coal the sun and Earth already did 99% of the work to make it - with H2, we have to do all of the work to make it.

We don't do the work; nature does by solar powered chemical, biological, or even chemically powered mechanisms such as chemosynthesis. The same for fossil fuels.

Look guys, no one argues that H2 must be produced. AFAWK, we have no ready made reserves for H2 available as we do fossil fuels. Anyone who feels that this argument needs to be made really needs to do a lot of reading. No serious advocate of H2 technologies would question this point.

Is it anyone's position here that we should not pursue renewable technologies?

 

[Ivan Seeking]

I remember hearing there's a decent sized initiative in the nuclear inductry to become one of the prime players in the production of hydrogen, which would be a lot better on the environment than coal would be.

I link to the DoE's Nuclear Hydrogen Initiative: http://www.nuclear.gov/infosheets/hydrogenfactmarch2003.pdf

Fission and/or Fusion power can easily co-exist symbiotically with H2 technologies.

 

[russ_watters]

We don't do the work; nature does by solar powered chemical, biological, or even chemically powered mechanisms such as chemosynthesis. The same for fossil fuels.

In other words, burn more fossil fuels to make hydrogen? How does that help anything?

Is it anyone's position here that we should not pursue renewable technologies?

Certainly not - I'm just not sure what hydrogen has to do with anything in this context. I think you probably understand the issue, but to the general public, they hear the politicians talking about a hydrogen economy and picture the hydogen materializing at the gas pump. Politicians (the people driving the issue) for the most part completely ignore the issue of manufacturing the hydrogen. And that's a dealbreaker for the whole idea. Its like talking about landing a man on the moon without first discussing how to get one in orbit around earth.

Realistically if Bush or Kerry (both have picked up the issue) succeed in getting a million hydrogen powered cars on the road in 10 years and a hundred thousand hydrogen fueling stations, where is that hydrogen going to come from? Realistically. My bet is it'll come from hydrogen manufacturing plants that either take their coal-fired electricity straight from an already overloaded grid or make their own power using oil-fired gas turbine generators. Net result: more pollution, more dependancy on domestic coal and foreign oil, and a bigger energy crisis.

 

[Ivan Seeking]

A review of the links given in the Hydrogen thread addresses the many methods explored for producing H2.

Russ, I think your concerns are completely valid. You and I have already hashed this out pretty well in the thread linked and I realize that we disagree on questions of production. I will only say that this is a core issue being addressed on many fronts, and that many scientists feel that this is not a show stopper; but that much work is still needed.

By no means is this a done deal. To "Go Hydrogen" could still mean many different things depending on how the technologies pan out.

Finally, I make no bones about my motives here. I think we need many brains filled with thoughts of Hydrogen. Politically, economically, scientifically, and environmentally, H2 strikes me as our best hope to finally end our addiction to oil. The political motivation is now more obvious than ever. Bye bye OPEC!

 

[russ_watters]

My opinion is the same as before as well: we need to focus on our power grid first, fixing a primary issue before a secondary (and tertiary?) one.

 

[Ivan Seeking]

Realistically if Bush or Kerry (both have picked up the issue) succeed in getting a million hydrogen powered cars on the road in 10 years and a hundred thousand hydrogen fueling stations, where is that hydrogen going to come from? Realistically. My bet is it'll come from hydrogen manufacturing plants that either take their coal-fired electricity straight from an already overloaded grid or make their own power using oil-fired gas turbine generators. Net result: more pollution, more dependancy on domestic coal and foreign oil, and a bigger energy crisis.

I should add also that to some extent the SciAM article referenced supports your position better than mine. On this point my response is that many key issues are addressed, but some of the important issues are not addressed.

This is a very broad subject. This in fact is a key feature of H2: Decentralization of the energy supply.

Unfortunately, this also demands that the range of solutions is very large. I don't know if I have even heard of all possible options for production. I see references occasionally that imply that even more can be found.

 

[Cliff_J]

This is a very broad subject. This in fact is a key feature of H2: Decentralization of the energy supply.

And I think this is the main stumbling block/selling point beyond the glassy eyed notion that H2 can work only with exclusive fuel cells produced by hand in the lab. The ICE is here to stay short-term, and the additional costs to equip/retrofit to FFVs that could handle H2 would be pretty insignificant long-term.

After that, the notion of producing mass quantities of H2 from burning coal or natural gas is so illogical that it could only come from government members who are motivated by the individuals that can directly benefit from such a decision. At least Carnegie and Rockefeller were obvious targets to control, much less clear today. In the future we could call the Enron of H2 production from fossil fuels some sort of Hindenburg moniker, I can already hear great sound-bites and see the visuals...

Maybe rebirth of the "flower-power" days will hit when the SUV goes the way of the muscle car and the VW van is replaced with a H2 compatible car. It'd be interesting to see which oil distribution companies make the journey or completely miss the target like the number of ice-box manufacturers and ice processing companies who embraced the refridgerator. (zero)

Cliff

P.S. Anyone have information on how much power eletrolysis requires to produce a given quantity of H2? Would it be as low as 10kW/1L?

 

[russ_watters]

And I think this is the main stumbling block/selling point beyond the glassy eyed notion that H2 can work only with exclusive fuel cells produced by hand in the lab. The ICE is here to stay short-term, and the additional costs to equip/retrofit to FFVs that could handle H2 would be pretty insignificant long-term.

That would be a deal-breaker due to H2's efficiency as a storage medium when you recover the energy in an ICE vs fuel cells (30% vs 90%). I don't think there is any question that fuel cells can be mass produced - that they haven't is simply a matter of demand.

P.S. Anyone have information on how much power eletrolysis requires to produce a given quantity of H2? Would it be as low as 10kW/1L?

The simple answer is 'the same amount of energy you get back when you burn the hydrogen.' Meaning, I don't think its really an important number - it just determines how big storage tanks need to be but doesn't affect generation costs. But in any case, its 285 kJ/mol. You can convert the units to whatever...

 

[zoobyshoe]

P.S. Anyone have information on how much power eletrolysis requires to produce a given quantity of H2? Would it be as low as 10kW/1L?

This book:

Fuel from Water
Address:http://www.lindsaybks.com/bks/hydrogen/index.html

Goes into extensive detail about that. The energy requirements vary considerably with the design of the electrolysis cells. One interesting thing he mentioned is that the voltage requirement tops off for any kind of cell at about two volts. It never takes more than that. The current depends on the materials of the electrodes, their distance from each other, the means used to isolate the electrodes, the size of the cells, and considerations like that. He does say that the smallest amount of energy needed to electrolyse one mole of water is 63.3 Wh at 25C (77F).

 

[Ivan Seeking]

H2 allows wind, solar, and nuclear power to be "carried" to automobiles, aircraft, and large industrial vehicles.

 

[zoobyshoe]

H2 allows wind, solar, and nuclear power to be "carried" to automobiles, aircraft, and large industrial vehicles.

It is unlike generating electricity with wind and solar, because there is no need for a smooth steady rate of production. Overall volume is important, but since we're talking about a storage situation here, there is no need for a minute to minute steady rate, and the daytime-only production by solar power is no problem.

 

[Janitor]

Interestingly, zoobyshoe's 228 kJ/mol is a bit less than Russ's 285 kJ/mol. I wonder why the discrepancy.

 

[zoobyshoe]

Interestingly, zoobyshoe's 228 kJ/mol is a bit less than Russ's 285 kJ/mol. I wonder why the discrepancy.

Apparently the process is not accomplished by electricity alone and depends on heat taken in from the surroundings as well, which is why my author gave that figure at that specific temperature.

 

[Ivan Seeking]

This would also mean that the transportation infrastucture for power, such as oil tankers, can eventually be [mostly] dismantled. Power can be produced semi-locally using the best options for each region.

National security benefits greatly. The political and economic value of energy autonomy is hard to even imagine.

The environmental benefits are obvious and vast.

Health benefits can be estimated but I don't have that information readily available. What is the health benefit, for example, in dollars, in eliminating fossil fuel powered vehicles?

 

[Ivan Seeking]

Just a reminder of some options explored previously

for producing hydrogen:
-------------------------
Direct production from whole biomass

Gasification

Thermal/Steam/Partial Oxidation

A technical note by Williams (1980) (USA) makes a case for efficient hydrogen production from coal using centrifuge separation of hydrogen from other gases following steam gasification at 1100-5000°C. Recent advances in new materials developed by the aerospace industry made it appear possible to develop such a gaseous centrifuge.

A large number of single research studies have appeared from 1981-2000, from researchers in many countries around the world. Brief notes follow. McDonald et al. (1981) (New Zealand) proposed extracting protein from grass and lucern and using the residue for hydrogen production (among other fuels). Saha et al. (1982, 1984) (India) reported using a laboratory-scale fluidized-bed autothermal gasifier to gasify carbonaceous materials in steam. Further studies with agricultural wastes were planned. Cocco and Costantinides (1998) (Italy) describe the pyrolysis-gasification of biomass to hydrogen. More-or-less conventional gasification of biomass and wastes has been employed with the goal of maximizing hydrogen production. Researchers at the Energy and Environmental Research Center at Grand Forks have studied biomass and coal catalytic gasification for hydrogen and methane (Hauserman & Timpe, 1992, and Hauserman...

Hydrogen from Biomass-Derived Pyrolysis Oils Laboratory work using this approach has been conducted at NREL (USA), starting in 1993 (see Chornet et al., 1994; Wang et al., 1994; Wang et al., 1995; Chornet et al., 1995; and Chornet et al., 1996 a, b, c). Early papers present the concept of fast pyrolysis for converting biomass and wastes to oxygenated oils. These oils are subsequently cracked and steam-reformed to yield hydrogen and CO as final products (Mann et al., 1994). The 1995 Wang report presents the chemical and thermodynamic basis of this approach, the catalysis related to steam reforming of the oxygenates, and the techoeconomic integration of the process...

Six progress reports in 1996 and 1997 document the systematic exploration of the pyrolysis oilto-hydrogen process. In Chornet et al. (1996a) bench-scale experiments determined the performance of nickel-catalysts in steam reforming of acetic acid, hydroxyacetaldehyde, furfural, and syringol. All proceeded rapidly. Time-on-stream experiments were started. In Chornet et al., (1996b), Czernik et al., (1996), and Wang et al. (1997a), the approach of using extractable, valuable co-products with the balance of the oil converted to hydrogen is explored.
---------------------------------

Small scale reformer technologies
-------------------------------------

Four types of solar photochemical hydrogen systems have been identified: photochemical systems, semiconductor systems, photobiological systems and hybrid and other systems. Asurvey of the state-of-the-art of these four types has been presented. The four system types (and their sub-types) have been examined in a technological assessment, where each has been examined as to efficiency, potential for improvement and long-term functionality. Four solar hydrogen systems have been selected as showing sufficient promise for further research and development:

1. Photovoltaic cells plus an electrolyzer
2. Photoelectrochemical cells with one or more semiconductor
electrodes
3. Photobiological systems
4. Photodegradation systems
------------------------------------

Photoelectrolytic and Photobiological Production of Hydrogen
-----------------------------------------------------

Hydrogen by Catalytic Decomposition of Water:
Researchers at DOE’s National Energy Technology Laboratory and Argonne National Laboratory have patented a "Method of Generating Hydrogen by Catalytic Decomposition of Water." The invention potentially leapfrogs current capital and energy intensive processes that produce hydrogen from fossil fuels or through the electrolysis of water. According to co-inventor Arun Bose, "Hydrogen can be produced by electrolysis, but the high voltage requirements are a commercial barrier. The invention provides a new route for producing hydrogen from water by using mixed proton-electron conducting membranes." Water is decomposed on the feed surface. The hydrogen is ionized and protons and electrons travel concurrently through the membrane. On the permeate side, they combine into hydrogen molecules.
--------------------------------------------------------

DENSE CERAMIC MEMBRANES FOR HYDROGEN SEPARATION
------------------------------------------------------

HYDROGEN FROM COAL

 

[Cliff_J]

That would be a deal-breaker due to H2's efficiency as a storage medium when you recover the energy in an ICE vs fuel cells (30% vs 90%). I don't think there is any question that fuel cells can be mass produced - that they haven't is simply a matter of demand.

We seem to have no reservations at blissfully wasting away limited natural resources. I see no reason why we couldn't do the same with a renewable one if the production demands could be met.

I thought that mass production was very difficult, akin to large silicon chip production where extreme cleanliness, low margin of error, and high failure rate was common. But if there's a demand great enough then someone will do a costs/benefits analysis and do it, I agree.

The simple answer is 'the same amount of energy you get back when you burn the hydrogen.' Meaning, I don't think its really an important number - it just determines how big storage tanks need to be but doesn't affect generation costs. But in any case, its 285 kJ/mol. You can convert the units to whatever...

I was going to add "minus losses associated with electroylsis" in my mind but from that other posts it sounds like the process is assisted by heat from environment. Interesting, wonder how accurate that is?

But as far as generation costs, one website on renewable energy did the math on how large a solar farm would need to be to generate the equivalent of the US electrical consumption. Using current PVs only and assuming the daytime generation could be used at night (stored as H2 ) the farm would only be 125x125 miles. Massive? Yes, but how large is just the resivor from the Hoover dam? Oversimplified? For sure, but an interesting thought experiment nonetheless.

What is the issues with the power-grid. Am I better off ignorant to the problems so I can just assume that when I flip the light switch the lights will come on? I'd hope the recent NE blackout would have the wheels in motion to resolve all that, but that's likely way too optimistic once budgets and politics comes into play...

Cliff

 

[zoobyshoe]

We seem to have no reservations at blissfully wasting away limited natural resources. I see no reason why we couldn't do the same with a renewable one if the production demands could be met.

Excellent point.

I was going to add "minus losses associated with electroylsis" in my mind but from that other posts it sounds like the process is assisted by heat from environment. Interesting, wonder how accurate that is?

I was hoping someone who was well informed about electrochemistry would sort this out. I am only vaguely aware that there are endothermic and exothermic chemical reactions (some reactions require heat imput, others have heat as a byproduct ) but this is the first time I have run into it being connected with electrochemistry.

But as far as generation costs, one website on renewable energy did the math on how large a solar farm would need to be to generate the equivalent of the US electrical consumption. Using current PVs only and assuming the daytime generation could be used at night (stored as H2 ) the farm would only be 125x125 miles. Massive? Yes, but how large is just the resivor from the Hoover dam? Oversimplified? For sure, but an interesting thought experiment nonetheless.

The periphery of the Salton Sea here in Southern California would be an excellent place to spread a 125 square mile solar plant out. This massive brine lake was created by accident early in the 20th century and people have been trying to make something out of it ever since. You have: low population density, large water supply that is being used for nothing else, and intense desert sun. You could generate electricity, hydrogen, or both. Potential problem: couple of wildlife/bird sancutaries to stay away from, not insurmountable.

 

[russ_watters]

It is unlike generating electricity with wind and solar, because there is no need for a smooth steady rate of production. Overall volume is important, but since we're talking about a storage situation here, there is no need for a minute to minute steady rate, and the daytime-only production by solar power is no problem.

That is a pro for hydrogen (or any other form of storage) - it allows for utilization of some otherwise wasted capacity by doing more of the production during off-peak hours. In Philly, there is a reservoir that's used as an energy storage facility: water is pumped up a hill at night and runs turbines during the day.

Interestingly, zoobyshoe's 228 kJ/mol is a bit less than Russ's 285 kJ/mol. I wonder why the discrepancy.

Dunno - could be temperature. I googled it...
... come to think of it, its possible that mine was just heat of fusion of H2O, which wouldn't include the energy required to split H2 and O2 into 2H and 2O.

Apparently the process is not accomplished by electricity alone and depends on heat taken in from the surroundings as well, which is why my author gave that figure at that specific temperature.

Not quite. Every reaction has an energy level (temperature/pressure) associated with it. So if you are (for example) freezing water, the energy required depends on the starting temperature - first you cool the water to 0C, then you freeze it. So the higher the starting temp, the more energy associated with the total reaction. Similarly, there is a specific temperature/pressure at which a molecule of H2 splits into two atoms of H. Activation energy is the energy it takes to get there from where-ever you started.

We seem to have no reservations at blissfully wasting away limited natural resources. I see no reason why we couldn't do the same with a renewable one if the production demands could be met.

Its not an issue of waste, its an issue of cost: Most people spend $600 or so a year fueling their cars. Assuming H2 cost the same per mile as gas (big assumption), you'd have a choice between buying a car that costs you $600 a year to fuel or one that cost you $200 a year to fuel. It would also triple the startup cost for this "hydrogen economy" because you need triple the generation and triple the transmission infrastructure. Fuel cells would end up cheaper.

But as far as generation costs, one website on renewable energy did the math on how large a solar farm would need to be to generate the equivalent of the US electrical consumption. Using current PVs only and assuming the daytime generation could be used at night (stored as H2 ) the farm would only be 125x125 miles. Massive? Yes, but how large is just the resivor from the Hoover dam? Oversimplified? For sure, but an interesting thought experiment nonetheless.

Lake Mead is 247 square miles and isn't covered with panels that cost $10/square foot. Some more math: that's $4 trillion dollars worth of solar panels. That said, it still may be worth doing over the next 50 years.

What is the issues with the power-grid. Am I better off ignorant to the problems so I can just assume that when I flip the light switch the lights will come on? I'd hope the recent NE blackout would have the wheels in motion to resolve all that, but that's likely way too optimistic once budgets and politics comes into play...

I know to someone with a scientific mindset, ignorance is not bliss, so I'll answer... The problems with the transmission side of the grid are more critical than those on the generation side. To avoid more NE (and NW a few years ago) blackouts requires a few hundred billion dollars right now. Then we'll need to double the capacity of the high voltage part to support hydrogen production...

I was hoping someone who was well informed about electrochemistry would sort this out. I am only vaguely aware that there are endothermic and exothermic chemical reactions (some reactions require heat imput, others have heat as a byproduct ) but this is the first time I have run into it being connected with electrochemistry.

Endothermic vs exothermic is talking about net energy of the reaction. The final product. Again, water: an ice cube sitting on the table gains energy from the environment when it melts - its endothermic. A glass of water in the freezer gives energy to the freezer: exothermic.

The periphery of the Salton Sea here in Southern California would be an excellent place to spread a 125 square mile solar plant out.

There are lots of places to put a massive solar plant, but distribution isn't a trivial thing: better to spread them out. And that's 125 miles squared (15,625 square miles), not 125 square miles.

 

[zoobyshoe]

So the higher the starting temp, the more energy associated with the total reaction. Similarly, there is a specific temperature/pressure at which a molecule of H2 splits into two atoms of H. Activation energy is the energy it takes to get there from where-ever you started.

Explanation clear. Thanks.

Lake Mead is 247 square miles and isn't covered with panels that cost $10/square foot. Some more math: that's $4 trillion dollars worth of solar panels.

I'm into parabolic reflectors for all things solar, myself.

Again, water: an ice cube sitting on the table gains energy from the environment when it melts - its endothermic. A glass of water in the freezer gives energy to the freezer: exothermic.

Understood I can see how this is not connected to the ambient temperature during electrolysis. Thanks.

There are lots of places to put a massive solar plant, but distribution isn't a trivial thing: better to spread them out.

Here's my reasoning: I think it would be easier to solve the problem of getting the hydrogen to Minnesota from Salton Sea than it would be to generate it in Minnesota. There aren't many days of full on sun there per year, and the windmill-busting winters would put a damper on that tack.

Regardless, your point about spreading things out is a good one. I suppose all the other methods of generation cited by Ivan would become the most viable for places like Mn.

And that's 125 miles squared (15,625 square miles), not 125 square miles.

Er...I knew that!

 

[Ivan Seeking]

The key issue with electrolysis is not that a new source of energy is found, it is that sources once limited to the production of electricity, such as fission or [hopefully] fusion power, in addition to solar, wind, and hydro, can now be used via H2 as a fuel source for nearly any application. This, in addition to the many non-electrolytic approaches to H2 production broadly diversifies the energy base for transportation.

 

[zoobyshoe]

The key issue with electrolysis is not that a new source of energy is found, it is that sources once limited to the production of electricity, such as fission or [hopefully] fusion power, in addition to solar, wind, and hydro, can now be used via H2 as a fuel source for nearly any application. This, in addition to the many non-electrolytic approaches to H2 production broadly diversifies the energy base for transportation.

This may be true, but hydrogen has no appeal to me on this basis. The ability to broaden nuclear power to run cars, in fact, bothers me. I like hydrogen because it can be generated with solar and wind and then stored, and because when you burn it all that results is water.

 

[Ivan Seeking]

ssssshhhhhh. It is still a nice carrot for the pro-nuclear crowd.

Even on fission my mind is still open.[edit: hey, that's kind of funny] We have a family member who is a retired, high ranking [GE] nuclear engineer who remains active in the industry in various ways. He is quite sold on fast flux reactor technologies. Also, methods that make melt down impossible are now explored - such as by using ceramic encapsulated Pu beads for a core. I have been anti-nuclear for about twenty five years now, but on this point of new technologies I try to remain open.

Fusion may be great! We will just have to wait and see.

 

[zoobyshoe]

ssssshhhhhh. It is still a nice carrot for the pro-nuclear crowd.

_{Whoops! Sorry!}

Also, methods that make melt down impossible are now explored - such as by using ceramic encapsulated Pu beads for a core. I have been anti-nuclear for about twenty five years now, but on this point of new technologies I try to remain open.

I thought I had heard that this non-meltdownable thing was already up and running in Canada.

Regardless, I'm very much less concerned about meltdowns than about disposal of the waste.

 

[Ivan Seeking]

Regardless, I'm very much less concerned about meltdowns than about disposal of the waste.

This is my main objection as well. On this point I am told that the French do a pretty good job of recycling. Still, I am no advocate for nuclear power. I really wish I could be. High hopes for fusion still.

Tokamak, Tokamak, Tokamak!

 

[Janitor]

Elaborating on the energy requirement issue-

I found a table which said bond energies in kJ/mol are:

H-H 436
O=O 499
O-H 463

So in order to approximate the energy requirements for 2 H20 --> 2H2 + O2, figure 4*463 to tear apart two water molecules, then get back 2*436 for the recombining hydrogen atoms plus 499 for the recombining oxygen atoms. The net energy required is thus 1,852 - 872 - 499 = 481. But a single water molecule would only require half that, 240.5 kJ/mol, to be split. This number is between the two numbers already given in this thread. This calculation ignores subtleties, such as that the O-H bond energy listed above would not apply exactly when the O already has another hydrogen attached to it.

 

[Ivan Seeking]

According to the Scientific American article, in practice, electrolytic production of H2 results in a 22% efficiency- as required to create the H2. H2 production by steam reforming techniques can be over 60% efficient.

This steam reforming option [cracking natural gas with steam], when combined with hydrogen fuel cells, is claimed to yield the best source-to-wheels effiiency of all options - about 22%. This is better than gasoline internal combustion, diesel combustion, compressed natural gas, compressed H2 for combustion, gasoline hybrids, diesel hybrids, gasoline fuel cell, methanol fuel cell, ethanol fuel cell, or H2 by electric; which all land around 12% to 16% for a source-to-wheels efficiency.

 

[Ivan Seeking]

Note that this does not address electrolysis combined with catalytic materials, or some of the more advanced techniques being explored.

 

[zoobyshoe]

In the other thread I posted about the process of dissociating water into hydrogen and oxygen by high temperature created with a parabolic mirror from sunlight. Efficiency is moot with this, since the energy is free. The problem, they say, is developing materials for the equipment that can withstand the high temperatures.

Water spontaneously dissociates at 2,730C (4,946F). This isn't that hard to achieve with a parabolic reflector: it's a matter of size. In the 1700s they ground a 20ft dia glass lens that would instantaneously vaporize stones placed at the focal point. So, I think a mirror about that size is probably what we're talking about to dissociate water by heat.

The hydrogen and oxygen would be lead to a water quench and then separated by gravity. I'm very fond of this idea.

 

[Ivan Seeking]

Not to be negative since work is definitely going on here, but efficiency is a consideration as a function of the cost of production per square foot of light incident area, the total mass rate of production of H2 as a function of this area, and the maintenance and lifespan of the system. This all affects the final cost of energy per watt, to the consumer - in whatever form it may take. So, from what I have seen and only as a hypothetical example, at some point it might make more sense to fill the Mojave Desert with solar panels and wind generators as opposed to light focusing systems. Likewise, focusing technologies may be more practical in Death Valley.

The cost of photoelectric panels is supposed to drop precipitously as production techniques improve. I have seen some really encouraging reports in the tech news in recent years.

On the high temp, focused light side, I have seen some neat work being done. I think that that liquid lithium is used in one system to generate steam.

 

[Ivan Seeking]

Something that I am just learning about now...with reforming technologies in mind.

Methane Hydrates -
The Gas Resource of the Future...

...Worldwide, estimates of the natural gas potential of methane hydrates approach 400 million trillion cubic feet -- a staggering figure compared to the 5,000 trillion cubic feet that make up the world's currently known gas reserves. [continued]

http://www.fe.doe.gov/programs/oilgas/hydrates/

 

[BCRion]

This is my main objection as well. On this point I am told that the French do a pretty good job of recycling. Still, I am no advocate for nuclear power. I really wish I could be. High hopes for fusion still.

Tokamak, Tokamak, Tokamak!

There are some interesting technologies using transmutation to convert the particularly bad fission products into more stable products that are much easier to handle and have less disposal time. The advancements in the past five years have been quite encouraging, although the economics still need work.

Keep in mind that only 1-2% of spent fuel is actually fission product waste. The rest is Plutonium and other Actinites (2%) and good old U-238 (96%). This is potentially a valuable fuel in the future.

As far as the issue of waste disposal, at least it can theoretically be disposed of. Fossil fuels really do not give us this option. There is simply way too much waste. It's a trade off. Everything has costs.

DT fusion has serious materials problems to commercialization. The neutron damage to the reactor vessel could prove to be uneconomic as it would require constant replacement. Also, Tritium can be some pretty bad stuff especially in the GigaCurie quantities. Perhaps D-3He fusion would be more economic. However, we would need to go to the moon for that. 3He-3He would be great...nuclear power with no nuclear waste.

 

[Cliff_J]

Our tranmission grid is in a state of affairs where it needs hundreds of billions to get it fixed? Wasn't this deregulated just a few years back in the 80s? The History channel program "Modern Marvels" on the power grid mostly focused on challenges with power generation and glossed over the issues with transmission. They did cover the NY blackout in the late 60s, the CA issues, and the NE blackout and its roots. They talked about the challenges of monitoring transmissions as being the 'key' to avoiding problems in the future. Is this what you're referring to, or to the actual transmission lines and routing, or something more substantial like redundant lines to mitigate single-point failures?

The 4 trillion dollar PV farm is to me like asking if we could scrounge auto salvage yards and pick up old motors with their generators and make a megawatt powerplant. Possible, but horribly inefficient. But I find it facisnating that we could farm out a few sq miles of dessert in the SW and produce enough energy to effectively 'run' the country. From a producers point of view, how long before the we could get the technology to the point where the yield from H2 production could exceed the profit from growing crops? Even better is using land not currently in a production capacity and without much environmental impact. The Marlborlo man on horseback image replaced with an image of a PhD drinking Starbucks riding an electric scooter while making sure the array is fully functional.

Personally I think it makes more sense to keep the costs centralized because even at 3x the capacity the expense should be fractional (large fixed small variable costs model) or as a worst case scenario exponential, but regardless far easier to implement first. Similar to Arnold's ambitious "...build it and they will come..." proposals. Hopefully with better success than GM had with their EV1 car. $400 a year doesn't really pay for the cost of the fuel cell in the near future, and a big set of government subsidies on cars that will depreciate quickly seems wasteful instead of infrastructure investments that the general public could access after a retrofit to their existing autos.

Lots of interesting things in store though, hopefully sooner than later. I just want to setup a small PV cell hooked to an electrolysis still, and buy another lawn mower to attempt a H2 conversion on a little Briggs & Stratton engine. Low cost, low risk...maybe next year.

Cliff

 

[Ivan Seeking]

One thing that scares me a bit is the idea that land use for food might come into competition with land use for energy, but typically it seems that solar is best where food does not grow well, such as in deserts, and wind generators do not really compete for land directly as do PV panels. Biomass need not be anything useful, and coal is coal.

As for the chicken and the egg problem, what I see as one possibility is that in addition to small test programs, industry will apply H2 technologies in such a way that small test communities will emerge. For example, let’s imagine that Weyerhaeuser discovers that they can produce H2 as a byproduct of some process used in the production of paper. All of the company cars could then be converted to run using H2 as a fuel source. I have seen this done for years in other applications. My uncle worked for Richfield [now ARCO] for forty years. He drove a natural gas powered company vehicle for as long as I can remember.

So, along with engineered test communities that are created through various means, such as through research, private funding, and government test programs, my hope is that industry might lead the charge through the practical application of existing technologies. In some cases at least, simply adding a few steps to an existing process can yield an untapped supply of energy that was sometimes even lost as waste. Also, I would assume that certain large population centers that have an H2 advantage, say for example Phoenix or Vegas [with PV in mind], will see the economic justification for H2 fueling stations and local H2 production before most other places. Maybe we will even see auto dealers selling H2 to get things started.

As with anything new, there will have to be a bleeding edge.

 

[Ivan Seeking]

Again, on a related note

Far more natural gas is sequestered on the seafloor—or leaking from it—than can be drilled from all the existing wells on Earth. The ocean floor is teeming with methane, the same gas that fuels our homes and our economy.

In more and more locations throughout the world’s oceans, scientists are finding methane percolating through the seafloor, bubbling into the water column, collecting in pockets beneath seafloor sediments, or solidifying in a peculiar ice-like substance, called methane hydrates, in the cold, pressurized depths of the ocean.

Massive deposits of methane hydrates could prove to be abundant reservoirs of fuel. But in the past, these massive storehouses of methane also may have “thawed” suddenly and catastrophically, releasing great quantities of climate-altering greenhouse gas back into the atmosphere [continued]

http://oceanusmag.whoi.edu/v42n2/whelan.html

Also:

METHANE FUEL PUTS PLANET IN DANGER: Scientistswarn of global warming catastrophe in hunt for new energy. IT HAS been hailed as the fuel of the future, a source of energy that could powerour planet throughout the next century. But now scientists have warned thatthe world’s largest untapped energy reserves—huge deposits of methane gaslocked under the ocean floor–could trigger a catastrophic bout of atmosphericwarming that would cause global devastation. [continued]

http://216.239.51.104/search?q=cach...thane.pdf+Worlds+known+methane+deposits&hl=en

 

[Ivan Seeking]

For a list of who’s who in Hydrates?

Who Studies Gas Hydrate?
http://woodshole.er.usgs.gov/project-pages/hydrates/who.html

 

[russ_watters]

I'm not sure about methane. Its certainly preferable to other forms of hydrocarbons, but it is still a hydrocarbon. Whether you convert it to hydrogen to burn in a hydrogen fuel cell, use it as methane in a fuel cell, or burn it, the chemical reaction is about the same and as a result, the pollution is about the same.

 

[Ivan Seeking]

On this point it is argued that clean, carbon based technologies are practical on a large scale but not on a small scale; such as on a car by car basis. It is within our reach, some say, to build large, clean, H2 reforming plants that use carbon based fuels as the primary energy source. This includes reforming coal for H2. In the most ideal sense this is a transitional technology that addresses the practical concerns about an energy base. Also, Methane -> H2 -> Fuel cell is now the most efficient option from source to wheels. In principle, if we could convert instantly to fossil fuel fired H2 production from methane, and then if we used this H2 in fuel cell powered cars, we would instantly require about 2% less energy in total - according the Sci American data [Edit: note that I had said 5%, the correct number is about 2.5%+-0.5% from what I can see]. Allegedly this includes the efficiency of production of the H2 as well as the efficiency of the auto; from energy source to fuel cell to wheels.

Note also that the total of greenhouse emissions through this channel is about 140 grams of gh gas per mile. This compares to 380 grams per mile for autos burning fossil fuels directly. Apparently this does not assume clean, carbon based H2 production, so this might be a worst case only estimate - i.e. if this happened today with established technologies.

BTW, I'm not convinced that this is the best path but this seems to be the state of the consensus for now. I still think we may ignore huge energy losses in the production of fuel cells and in the efficiency of the fuel chain for gasoline and diesel. I will provide related information as I'm able. It also possible, God forbid, that my previous evaluation of this issue is wrong :surprise: but I'm not buying into that just yet.

Minor edits for clarity.

I should add that the article stresses that this issue is very complex.

 

[Ivan Seeking]

The NHA's Hydrogen Commercialization Plan
http://www.hydrogenus.com/commercializationplan.asp

A sustainable hydrogen energy industry - an energy system based upon the extensive use of hydrogen as an energy storage and transportation medium - must be established if an environmentally and economically sustainable world is to be left to our children and grandchildren. Few doubt that the hydrogen energy industry will eventually evolve. Many debate the timing of such a development. Only by defining the nature of a future hydrogen energy system, by identifying the path to such a system, and by actively taking the first steps along that path will we, as a world society, achieve that goal in time to avoid serious environmental and economic disruptions.

The National Hydrogen Association, in conjunction with the U.S. Department of Energy, is embarking upon the process of defining the path and beginning the journey. The NHA believes that this journey will only be successful by working together in an industry/government partnership. [continued]

The NHA's Hydrogen Implementation Plan
http://www.hydrogenus.com/implementationplan.asp

The 1999 Implementation Plan provides a path to achieve the near-term goals of the NHA’s Hydrogen Commercialization Plan.

The Hydrogen Commercialization Plan, as first drafted in 1996, challenged industry and others to show their commitment to making hydrogen a major “energy carrier” in three major markets — autos, buses, and power generation. Industry, government, and other sectors are responding to this challenge through the development of hydrogen products with aggressive milestones and field tests. The Implementation Plan lays out a strategy which, if followed, would achieve the near-term goals of the Hydrogen Commercialization Plan. Achievement of these goals will also establish niche markets or a market presence important for hydrogen energy systems. [continued]

 

[Ivan Seeking]

I should have included this in the quote from the Implementation Plan above.

Roles:

...Academia

The key role of academia is to increase public awareness and acceptance through education of high school and college students about hydrogen systems, and informing the public of the true cost of fossil fuels, far more than simply the price at the pumps.

In addition, academia can solve long-term technical issues for future generations through research and development. This may be accomplished through government and industry support.