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The Energy Challenge 2004 - Hydrogen

11.30.04

Murray Duffin, Retired

Much has been written about the hydrogen economy (HE), and much misunderstood. In fact the label itself is probably a misnomer. Many in the USA believe that the Administration's hydrogen initiative is just a way to postpone doing anything useful about energy for as long as possible. If so it has backfired. Widespread research on all aspects of hydrogen production, storage, transportation and use is evident, not just in the USA, but worldwide, and technological advances are appearing at a bewildering rate. The subject is so large that only a few highlights will be touched on here.

Regrettably, a relatively small number of skeptics have been given undue publicity, presenting inaccuracies, distortions, errors and outright falsehoods, even in respectable peer reviewed journals. Misleading papers have appeared this year in Science, The Scientific American, and Solar Today to name just a few. It is important to try to present a more balanced view, especially as the future of the electrical industry will be shaped to no small degree by the evolution of the "hydrogen economy".

Skeptics
Anti-hydrogen published papers all suffer from some or several of the following thought/analysis weaknesses:

  • A failure to see the nature and evolution of the HE in practical terms and in the context of the total energy picture, including obvious alternatives.
  • Postulating a near 100% switch to hydrogen, implying renewable electricity generation, conversion to hydrogen, transport of hydrogen to region of energy need, and then reconversion into electricity.
  • Incorrect figures for efficiency of hydrogen generation and compression.
  • Wrong infrastructure assumptions, primarily relative to hydrogen transport.
  • Storage density assumptions that are much worse than is already being achieved.
  • Analyses based on old technology, with the implicit assumption of no technological progress.
  • Consideration of hydrogen production only by electrolysis.
  • Cost comparisons done per unit of energy contained instead of per unit of service provided.
  • Failure to consider whole system implications when estimating energy efficiencies and costs.
  • Grossly exaggerated safety issues, and failure to consider the natural safety features of hydrogen.

One of the most frequently quoted references is a paper1,2 by Bossel and Eliasson which has the appearance of being quite scientific, but is in fact largely wrong, due to both direct errors and wrong thinking.

Quick research
Any of the authors that have misrepresented the practicality of the HE could have discovered the following facts with an hour or so of googling:

  • Stuart Energy sells prepackaged alkaline electrolysis systems with 85% cell efficiency LHV, and 73% system efficiency compressed to 5000 psi, using unheated feedwater.
  • Fully absorbed cost of hydrogen at 10% after tax IRR, with electricity at average industrial cost of 4.83cents/kwh, would be $5.60/kg for such a system as a forecourt supply, and at today’s capital cost. Electricity is 88% of this cost.
  • Such cells can reach near 90% efficiency with 100+ deg. C feedwater
  • Successful experiments have been conducted with ionic activators to raise the efficiency of alkaline electrolysis by 10%.
  • PEM electrolysers operate at 80 - 85% efficiency, and have a theoretical upper limit of 94% if we can develop high temperature membranes. Progress on high temperature membranes is promising.
  • Solid oxide steam electrolysers have reached 90 -95% efficiency in the lab, but are not yet commercially available.
  • Hydrogen can be compressed to 5000 psi at >90% efficiency and 95% efficiency with electrolyser precompression.
  • The oxygen "byproduct" of electrolyzing water can be used in many processes to raise the efficiency and lower the NOX of those processes. Oxygen enhanced combustion raises combustion efficiency by 25-30%.
  • PEM air fuel cells are already at 45-50% efficiency. PEM direct oxygen FCs are at 59% efficiency at rated load and 69% at 20% load. Up to 80% is expected in the future.
  • Through 2002 almost all fuel cell design/improvement was empirical. Only in 2003 did advanced computer models become available to accelerate progress.
  • Microturbine/SOFC hybrid FC systems are at 53% electrical efficiency installed, and modeling during 2004 has shown the path to 67%. The goal is 70% by2010.
  • Hydrogen can be generated during off peak hours to operate coal and nuclear generators at max. efficiency 24/24. Waste heat from the generators will improve electrolysis efficiency. Nighttime electricity can be profitably provided at <4 cents/kWh.
  • Targeted worst case storage density for automotive fuel tanks is >5.5% of hydrogen by weight, and 11% at 5000 psi has already been achieved in conformable tanks that exceed requirements for overpressure and cycling, and 11.4% in lithium nitride.

When these facts are factored into anti-hydrogen papers, the papers become nonsensical. New equipment that uses all of the efficiency advances listed above, can reach >84 efficiency for hydrogen compressed to 5000 psi, and given energy credit for the oxygen generated, total system efficiency can reach at least 90%. Hydrogen cost would then drop to $4.60/kg. Electricity to hydrogen to electricity efficiency (e.g. for wind turbine buffering) will reach >60% efficiency, double what is assumed now.

What is the Hydrogen Economy?
The primary uses of hydrogen will be replacement of dwindling supplies of petroleum derived transport fuel, and buffering of intermittent renewable electricity sources. Hydrogen appears to be the best choice for the transport task, but critics feel that batteries or battery/FC stores like zinc/air fuel cells will prove to be viable alternatives. Quite possibly all 3 will prove feasible.

With NG also in decline, we have to look at how it is used. 8% is used today as a source of hydrogen, and almost 90% of the hydrogen is used to produce gasoline, and ammonia for fertilizer. As NG prices rise in the USA ammonia production is being moved offshore. As petroleum availability declines, the need for hydrogen for gasoline will decline. NG cost is already at a level to make hydrolysis competitive with NG reforming. This is the likely path to large-scale commercialization of hydrolysis.

More important is the 22% of NG used for residential purposes, mainly home heating, and 23% used for electricity generation. Some of the electricity generation is CCGT with efficiencies near 50%, but the bulk is older SCGTs with <25% efficiency. Globally the efficiency is probably <30% today. If the residential gas was consumed in an efficient SOFC with waste heat captured for heating and cooling, the NG could be used about 70- 80% efficiently (instead of the centralized <30%). The fuel cells exist, but are still expensive. However as NG prices rise, and carbon penalties enter the scene, gas suppliers or electric utilities will probably get into the home fuel cell business, instead of building more centralized generating plants. This is already happening in Japan. RMI sees the secondary aspect of the HE as building cogeneration, with NG being a bridge to the hydrogen economy. Certainly such a step can at least double the efficiency of NG consumption, and is therefore desirable, but the benefit with hydrogen is not clear.

How much hydrogen?
The main purpose of the HE is to use hydrogen to replace petroleum as a portable fuel for vehicles. For cars the key is to have lightweight, efficient FC vehicles, e.g. "hypercars" with fuel cells. The present car fleet averages 24 mpg. The Prius HEV already gets better than 40 mpg, and is not lightweight. A hypercar version of the Prius would get 80-90 mpg, and a full size family car would get at least 70 mpg. If we then replace the ICE with a FC we will more than double tank to wheel efficiency, giving us >140 mpg equivalent. In trucks and buses there is not much room to improve rolling efficiency, but better FC saving is possible, probably close to factor 3. Overall factor 5 is probably achievable. (Note-PEM fuel cells are already being used to power submarines). The approximately 28 quads of petroleum used in the USA for road transportation can be replaced in the next 25 to 30 years by efficiency plus < 6 quads of hydrogen. Buffering 15 quads of wind at 2010 expected efficiencies can be done with less than 3 quads of hydrogen. A mere 10 quads of hydrogen will go a long way to powering the so-called hydrogen economy. If batteries and/or metal/air fuel cells prove out, even less hydrogen will be needed. Another alternative to hydrogen for transport is likely to be oil generated from the thermal depolymerisation of agricultural waste, scrapped tires and municipal sewage. If this technology is widely deployed during the next 2-3 decades it could provide 1-2 Gb of diesel oil equivalent, or perhaps 20% of our current annual oil consumption, replacing at least 1 quad of the above estimated hydrogen.

Where do we get the hydrogen?
It has been estimated that conversion of current USA waste biomass could supply 2.7 quads of hydrogen. The 15 quads of dispatchable wind described in “The Energy Challenge 2004 – Wind”, would produce enough excess energy to generate 4 quads of hydrogen above that needed for buffering. Clean coal electricity generation byproduct would supply another significant increment. There are several other potential sources, including photolysis from waste water treatment plants or algae, solar thermochemical water splitting, and industrial process byproduct. We probably need additional electricity for no more than 1-2 quads of hydrogen. This amount can be supplied from the present electrical infrastructure on less than 6 hours per night.

Cost considerations
The 2005 cost of hydrogen by electrolysis given above is $5.60/kg with electricity at 4.83 cents/kWh and 73% efficiency. At 3 cents/kWh and 80% efficiency this would translate to $3.45/kg. Hydrogen from NG reforming, with NG at $6.00/Mbtu and electricity at 3Cents/kWh has been estimated by Amory Lovins as $2.50/kg. Hydrogen from waste biomass is estimated at $2.80/kg. It seems safe to count on a hydrogen cost =< $5.00/kg, with some probability of reaching $3.00/kg average. As 1 kg of hydrogen is comparable to 1 gal. of gasoline on an energy basis this cost still appears uncompetitive. However, recall that it is the cost per unit of service, not per unit of energy that counts.

At a before tax cost of $1.50/gal. and 25 mpg, gasoline costs 6 cents/mile. At a cost of $5.00/kg and 140 mpg equivalent, hydrogen costs only 3.6 cents/mi. At $3.00/kg the hydrogen powered car would only have to deliver 50 mi/gal equivalent to equal gasoline at today’s price. This is much less than the FreedomCAR goal, and the FreedomCAR does not consider low rolling resistance design. Hydrogen is not just competitive, it is sufficiently attractive relative to rising gasoline prices, to drive a free market economy switchover during the coming years. However an intelligent energy policy could accelerate the transition, and make it smoother rather then letting it be crisis driven.

Interestingly, given credit for the byproduct oxygen produced, hydrolysis would be competitive with reforming NG at a NG price of <$7.00/Mbtu, and we are already there. Critics have suggested that the oxygen credit is insignificant because oxygen is priced at about 10 cents/kg today, or $.80 of oxygen per kg of hydrogen. This criticism misses the point that oxygen today is a byproduct of producing nitrogen, and is not produced in enough quantity to support a use like oxygen enhanced combustion on a useful scale. Produced in sufficient quantity, e.g. as a byproduct of hydrogen production, oxygen would have a considerably higher value because of its contribution to combustion efficiency, making hydrolysis even more attractive.

The other key issue is fuel cell cost. In 1990 the estimated high volume production cost of PEM fuel cells was $3000/kW, dominated by platinum at 20 grams/kW. In 2004 platinum is down to 0.8 grams/kW and the estimated high volume FC cost is $225/kW. A FC car is estimated to need 50-80 Kw and the target price for FCs is $30.00/kW by 2015, but this does not take into a count a super efficient hypercar. The hypercar needs closer to 20 kW, so $100.00/Kw would be good, and that may be achieved before 2010.

What about infrastructure?
For filling station forecourt generation of hydrogen, energy will be transferred to point of use as electricity, using the existing infrastructure. For locally sited building cogeneration NG will be transported by the existing infrastructure. The major need for new infrastructure will be the forecourt hydrolysers. The technology already exists but large refueling stations would need scaled up units. The cost of converting the needed filling stations over a 30 year period is estimated to be 100-200 billion dollars, much less than the petroleum industry puts into E&D and infrastructure over a similar period (or less than the war in Iraq in a much shorter period).

Of course there is always the chicken and egg problem of which comes first, the vehicles or the infrastructure, and without some volume how do we get the infrastructure cost down. The cost problem is likely to be solved by Japan and China, both of whom are pushing ahead very rapidly. Japan has hydrogen FC cars on the road and China has ordered 10,000 hydrogen fueled buses to be delivered in time for the 2008 Olympics. This problem will get solved, whether by us or not.

As NG becomes scarcer it can be supplemented with hydrogen to make town gas for many uses, and finally, much of the NG pipeline network can be lined with a polymer barrier and used for hydrogen transmission. Salt caverns have already been used successfully for large-scale storage. A large share of the hydrogen needed for wind buffering can be stored under pressure in the wind turbine towers.

Hydrogen safety3,4
RMI has produced a few foils nicely addressing this issue. The main points deal with the inherent characteristics of hydrogen that make it safer than gasoline. Hydrogen is 8 times lighter and 4 times more diffusive than methane and 12 times more diffusive than gasoline fumes. It dissipates quickly and cannot accumulate unless trapped by e.g. a ceiling. In air, exposed to a flame or spark, it burns long before it reaches an explosive concentration, and is 22 times less explosive than gasoline. It burns upwards in a narrow plume and emits very little radiant heat. You almost have to be in the flame to be burned. Tanks designed to contain hydrogen have survived 50 mph crash tests without rupturing.

Transition to the HE
NG production in North America is likely to be halved before 2015. It is likely that onshore production plus LNG imports can then maintain 10 Tcf or so of supply for a couple of decades after that. Much of the early NG shortfall will be compensated by efficiency improvements and demand destruction. Large-scale hydrogen replacement will be 1-2 decades away. If petroleum availability declines at 5%/yr, it will take 26 years to get to of the present supply. Very early on, rising gasoline prices will stimulate the shift to more efficient cars, and finally fuel cell cars. One leading market research firm has estimated that HEVs will be 20%+ of North American auto production by 2010, and that without incentives. Hydrogen FC cars will likely appear shortly thereafter, but demand will grow gradually. Without energy policy incentives car fleet replacement is unlikely to be complete before 2040. A government “feebate” policy to encourage replacement of gas guzzlers with efficient vehicles could accelerate this process. Wind energy growth is also likely to be a 30-year proposition.

Conclusions

  • The driver of the HE will be declining NG and petroleum supplies.
  • The primary need is efficiency, especially more efficient FCs and cars.
  • The primary problem is still cost, mainly of FCs and storage tanks, but the major cost issues will be resolved by a combination of research and volume production.
  • Supporters, in addition to skeptics, are suffering from important misconceptions, e.g.:
    • The government is spending major sums to drive down FC cost below what would be necessary with more efficient cars. Focusing on more efficient cars would be more productive.
    • RMI sees NG as a bridge, rather than a problem and driver.
  • The electric utility and gas industries need to start looking at distributed FC cogeneration, urgently.
  • Large-scale electrolysis, raising the return on off-hour generation, is a major profit opportunity for electric utilities.
  • The transition to the HE will be a rapid evolution, not a revolution, and it is already well under way.

References:
1) http://www.efcf.com/reports/E02_Hydrogen_Economy_Report.pdf

2) http://www.hyweb.de/News/LBST_Comments-on-Eliasson-Bossel- Papers_July2003_protected.pdf

3) hgovttp://www.rmi.org/images/other/Energy/E03-15_H2FutureOfEnergy.pdf

4) http://www.hq.nasa.gov/office/pao/History/SP-4404/ch8-6.htm H2

Other Sources:
http://www.eere.energy./hydrogenandfuelcells/pdfs/35948.pdf

http://www.eere.energy.gov/hydrogenandfuelcells/annual_report03.html

http://www.eere.energy.gov/hydrogenandfuelcells/pdfs/iid1_milliken.pdf

http://www.eere.energy.gov/hydrogenandfuelcells/pdfs/separ_02_intro_anderson.pdf

http://www.fuelcellseminar.com/pdf/2003/Davis.pdf

http://www.protonenergy.com/index.php/html/gasproducts/datacharts/index.html

http://www.sciencenews.org/articles/20041030/bob10.asp

Readers Comments

Date Comment
Len Gould
11.30.04
Murray: Another good article. Those are dramatically lower figures for platinum requirement than I've seen before. Also no mention of the difficulties of operating a PEM FC at below freezing temperatures. I assume lack of space dictates the failure to address the issue of a need for a factor of five increase in life of the NAFion PEM membranes which currently don't live beyond 1000 hrs. and are the subject of much investigation. And I'd like to see some evaluation tests of eg. 250 bar H2 fuel tanks as terrorist explosive devices. Would you allow one into the basement of your apartment building?

I also find the Ovonics fuel cell very interesting, essentially a NiMH battery adapted to pump H2 into the cells to supplement the H2 normally stored in it when operating as a battery. Uses no platinum catalyst. Tested to -20 deg. so far. Eliminates the 2 min. startup time of PEM's and can recover, store and return the regen braking energy in the fuel cell. Very rational at first view. http://ovonic.com/sol_srv/3_2_fuel_cell_sol/fuel_cel_solutions.htm

Ideal cycle for efficiency, however, is still the boron / oxygen engine.

Len Gould
11.30.04
Sorry, of course I meant to say 330 to 660 bar H2 fuel tanks, not the 250 typical of CNG.

Murray Duffin
11.30.04
Thanks for the url on Ovshinski's latest Len. I had not gone there because Ovshinski has hyped so many things in the past that never quite got there that I have been turned off. It looks like he may have it this time, if Texaco is willing to invest heavily. I didn't find any data on storage by weight so would guess that there is srill some problem, but overall it looks promising. I didn't get into PEM temperature and lifetime issues because the technology is moving so fast that what you KNOW today will be wrong tomorrow. They don't put PEM fuel cells in a submarine with 1000 hr lifetime. Yeah, I'd allow a 5000 psi tank into my basement. The whole issue of storage by adsorption or absorption could take up another paper, and isn't really a subject matter for EnergyPulse. Murray

Roger Arnold
11.30.04

Roger - I admit I largely buy the RMI "koolaid", but not without reason. The Prius is already a large part of the technology. Lotus has built lightweight fiber composite cars for years and sold them affordably (albeit expensively) even with hand layup. The only thing keeping carbon fibre cost high is lack of really high volume production. Mazda has a new Miata concept car almost ready to roll out with a carbon fibre composite body shell. Daihatsu had a concept car at the Jan. 2004 Tokyo motor show with a light weight body, hybrid drive, and claimed 140 mpg. Even though the starting raw material for a fibre composite body is much more expensive than sheet steel today, by the time the steel is cut, formed, cleaned, welded, and painted the body shell cost is pretty close to a fibre composite body with the color baked in, and the capital cost for the fibre composite body is much less than for the steel one. RMI has had their projections validated both by retired American auto engineers and by Lotus engineering. The big obstacles are entrenched thinking of current auto engineers and managers, who are a very conservative bunch, and the existing capital sunk cost. When the Japanese start selling the next generation lightweight hybrids in the USA, and the waiting lists are again long, Detroit again will reluctantly move in the right direction. It will probably take at least another 10 years, but the hand writing is on the wall. Murray

Murray Duffin
12.1.04
Roger - I admit I largely buy the RMI "koolaid", but not without reason. The Prius is already a large part of the technology. Lotus has built lightweight fibre composire cars for years and sold them affordably (albeit expensively) even with hand layup. The only thing keeping carbon fibre cost high is lack of really high volume production. Mazda has a new Miata concept car almost ready to roll out with a carbon fibre composite body shell. Daihatsu had a concept car at the Jan. 2004 Tokyo motor show with a light weight body, hybrid drive, and claimed 140 mpg. Even though the starting raw material for a fibre composite body is much more expensive than sheet steel today, by the time the steel is cut, formed, cleaned, welded, and painted the body shell cost is pretty close to a fibre composite body with the color baked in, and the capital cost for the fibre composite body is much less than for the steel one. RMI has had their projections validated both by retired American auto engineers and by Lotus engineering. The big obstacles are entrenched thinking of current auto engineers and managers, who are a very conservative bunch, and the existing capital sunk cost. When the Japanese start selling the next generation lightweight hybrids in the USA, and the waiting lists are again long, Detroit again will reluctantly move in the right direction. It will probably take at least another 10 years, but the hand writing is on the wall. Murray

Murray Duffin
12.1.04
Oh yeah - one more point. Even if the initial cost for the lightweight car is high, I think that cost can be brought down much mote readily than can the cost of the fuel cells and the hydrogen storage. There are no technological issues, only financial and psychological ones. Murray

Richard J. McCann
12.1.04
Your discussion of the criticisms of the new "hydrogen economy" misses several key aspects: - Using natural gas or coal as the fuel stock and/or electricity source defeats the primary motive for conversion--reductions in GCC related gases. As pointed out in the many of the articles, emissions could actually RISE. As for production form nuclear power, that production is already claimed and there is little prospect for significant new capacity. As for renewables, its unlikely that we'll add enough new capacity to meet our current growing electricity demand, much less adding the entire equivalent implied capacity of our transportation fleet. For comparison, the entire truck fleet of California totals more equivalent MW (60,000+) than all of the state's current electricity generation (45,000 MW), and that does not include the smaller automobiles and Class I and II light trucks. - Using automotive batteries for transportation is now an acknowledged dead end as projected production cost savings and life extension were not sufficient to make them economic except under extreme conditions. - Your presumption that FC costs will fall almost 90% to $30/kW are unrealistic. The huge implied increase in demand will send platinum prices skyrocketing (and leave us entirely dependent on only 2 nations for production--Russia and South Africa--so much for energy independence). Even today's diesel engines cost about $100/hp, and turbines cost $300/kW. - NRC has looked at the costs of increasing fuel economy substantially and found that the assumptions used by RMI, ACEEE and others are unrealistic. Politicians like to quote these optimistic numbers to that they can claim to be "green", but the truth is that they are economic pie in the sky. It's not just engineering interia that limits these technologies--economic history (learning by doing) tells us that the high initial costs are reflective of expected future costs. (And not to mention the toxicity issues related to substantial carbon-fiber production.) It is for these and other reasons that the skeptics have poked holes in the hydrogen dream.

Graham Cowan
12.1.04

Repeated references to "hydrolysis", meaning splitting of water, are grating. Things that dissolve irreversibly in water are hydrolysed, i.e. broken by water. Breaking of water is beyond the range of meanings that word can usefully have. "Water-splitting" is a good expression to use, or if by electricity, water electrolysis.

I agree Bossel and Eliasson are too dismissive of liquid hydrogen, in effect knocking over a compressed-gaseous-hydrogen strawman. This is obviously a hazardous procedure!

Over the years many hydrogen cars have existed in the lab (cf. the hydrogen car timeline) and, to the best of my knowledge, no aluminum-burning ones.

But that just means aluminum-burning cars in real-world service are equally numerous with hydrogen cars so serving. Aluminum would be lighter and safer, and already is produced on a large scale using renewable energy.

--- Graham Cowan, former hydrogen fan
Boron: A Better Energy Carrier than Hydrogen?

Robert Hoffman
12.1.04
Thanks for a great article and perspective on hydrogen as an energy medium. Coming from an independent power and deregulated energy perspective, I am intrigued by hydrogen's potential. I am confident hydrogen will be part of a long-term solution to our energy needs. From my perspective, hydogen is not an energy resource, but rather is a medium to transport energy, much the way steam is an energy transporter using water as a medium. The fact that it takes other forms of energy and associated environmental impacts to produce hydrogen is not necessarily a bad thing if the sum of all components results in a net positive benefit (cleaner air and increased overall energy resource efficiency). I think there is more to the Hydrogen Economy than we fully appeciate. Chapter 8 of Jeremy Riflin's book "the Hydrogen Economy" struck an important chord in his reference to a "Hydrogen Energy Web" where fuel cells paired with hydrogen production are part of a network of distributed generation and hydrogen sources, working with existing utility distribution infrastructure to exchange electric energy to and from a network, much like the the way internet is a network to exchange information. While costs may be high today, the real frontier for hydrogen is development of a viable storage process. Another challenge we face is to bring hydrogen in line with other energy applications. The economics of most energy processes are measured on a energy conversion heat rate (BTU/kWh or kJ/kWh), $/MMBTU (or $/kJ) variable cost, and $/kW fixed cost basis, regardless of whether for power generation, transportation, or thermal (heat) process. A gallon of gasoline has about 155,000 BTU/gallon (HHV) which at $2.30/gallon (I live in California), works out to about $15.00/MMBTU. I realize there is more to hydrogen than a simple energy conversion, but it would be great to have some numbers or analysis expressing hydrogen energy processes on a net heat rate (BTU/kWh), $/MMBTU, and $/kW basis.

Bob Hoffman Energy Dynamix Corporation

Murray Duffin
12.1.04
Ah Richard, I do love those who know what can't be done. Interestingly the cost of wind energy fell about 90% in a decade or so. No big deal. The cost of a bit of DRAM memory has fallen 5 orders of magnitude in 30 years. There are dozens of universities and corporations and hundreds of very clever people busily beavering away to do precisely those things that you know can't be done. Who do you think will be right in the end? I'll bet on the very clever people. Please read my prior articles and watch for the next couple. You will be amazed! Murray

Len Gould
12.1.04
Richard: Statements like "And not to mention the toxicity issues related to substantial carbon-fiber production." just completely discredit your entire thesis. Do you also believe silicon transistors will never be developed simply because the process may involve some toxic processes? And, the last time I checked, no-one else ever mention toxic process in the producing of carbon fibers. Producing poly-acrylic-nitrile fiber base should be no more toxic than producing the materials in most clothes. Alternatives based on pitches use mainly carbon wastes from petroleum processing or coal dust. Producing composites is a long matured industry used currently to manufacture everything from bathtubs to lawn furniture, and I don't see why auto bodies should be any more of a problem.

Of course, you auto engineers may know some secret reason why it is better to leave development of solutions to future problems to the Japanese or Europeans (or Chinese).

Len Gould
12.2.04
Murray: It is an interesting coincidence that just today an announcement which I noticed on PhysOrg website but can no longer find, relevant to thermal electrolysis, eg see INEEL Hydrogen Website stated that they have demonstrated a 50% net thermal efficiency in producing hydrogen from high temperature electrolysis tests in a system which can be used with a nuclear reactor (apparently a gen IV type, not the current ones). Assuming they can get this operating and scaled up, I'm thinking the debate on "Where's the hydrogen Going to Come From" will be about done.

Len Gould
12.2.04
Actually the reason I couldn't find it on PhysOrg was because it was on E4Engineering, at E4Engineering Article

"We've shown that hydrogen can be produced at temperatures and pressures suitable for a Generation IV reactor," said lead INEEL researcher Steve Herring. "The simple and modular approach we've taken with our research partners produces either hydrogen or electricity, and most notable of all achieves the highest-known production rate of hydrogen by high-temperature electrolysis."

On re-reading, it appears they may not have actually progressed as far as I'd thought. Still, getting there.

Thanks GRL Cowan at Boron Blast - Boron a Better Energy Carrier for tips on posting links.

And I still think the boron / oxygen cycle engine beats hydrogen.

Jim Beyer
12.2.04
If one assumes carbon dioxide (CO2) is the optimum carrier for hydrogen, then almost everything you have written is true, but the final portrait would look much different. Combining 4 hydrogen molecules with 1 carbon dioxide molecule in a Sabatier reactor (nickel or ruthenium catalyst) produces 1 methane molecule and 2 water molecules that can be recycled to reduce your electrolysis water needs by 50%. I suppose one could also entertain ammonia instead (using N2), but though denser than hydrogen, it is still an awkward fuel that has no infrastructure either. Maybe we can consider ammonia if we can't find enough available CO2.

The methane retains 80% of the original energy content of the 4 hydrogen molecules. Compared with the efficiency of electrolysis, this is a greater improvement in energy density for the energy expended, so it should definitely be done if the CO2 is available. A two-pipe system of CH4/CO2 (moving in opposite directions) moves energy more efficiently than a single pipeline of H2 because the molecule count is reduced by 50%, but the energy stored is reduced by only 20%. Because the gas behavior is dominated by particle count, not weight (remember PV = nRT ?), the heavier system of CH4/CO2 still takes less energy to move than the bulky H2.

There is plenty of CO2 for now, and more will be available later. Biofuel production alone produces enough byproduct CO2 (that is easily captured and carbon-neutral) to support millions of methane-driven vehicles. We just need the hydrogen. In the future, all the pure O2 that is a by-product of electrolysis can be used to facilitate CO2 capture at stationary plants (I can explain that more if anyone is curious).

The reason this will supplant any effort to building a pure H2 economy are threefold: infrastructure is already in place, the medium is 3.2 times denser energetically than H2, the system can co-exist with natural gas supplies.

H2 is a horrible fuel medium for vehicles. Even if a FC was 100% efficient (LHV), the storage requirements for hydrogen vs. methane would still be larger, even if the methane is burned in an engine that is only 33% efficient (LHV). So, all things being equal, a FC car will have less volume available to the customer. Efficiency improvements for vehicles are far more effectively accomplished with plug-in hybrids, which bypass the whole fuel creation issue entirely. Since a plug-in still has fuel powering it also (and thus range), it shares virtually all the benefits of an all-electric vehicle (including energy efficiency) with none of the drawbacks. All an automaker needs to build is a plug-in hybrid that can run on methane. Heck, maybe a small gas tank too. That's it. No fuel cells. No hydrogen. No infrastructure changeover.

At the risk of sounding patronizing, the problem with energy studies is that if just one piece of information is out of place, one needs to rewrite a whole strategy. Such is the case with hydrogen. If energy storage via carbon is the best strategy based on billions of years of evolution, who are we to question it? The answer seems clear to me (unless, of course, I've missed a piece of information).

-Jim

Graham Cowan
12.2.04
Who are we? We're what billions of years of evolution produces when it "wants", so to speak, to tame fire and make heat engines. That's who.

Arguing from the authority of Nature will, if done consistently, take you some places you probably don't want to go.

--- Graham Cowan, former hydrogen fan
Boron: A Better Energy Carrier than Hydrogen?

Murray Duffin
12.2.04
Jim - I'm not knocking your idea, because I haven't previously thoight about it and don't fully understand it. My first problem is with the infrastructure. We don't have 2 way pipelines. However we do have a complex network so it would be possible to transfer CO2 one way and methane the other using different pathways, at least for some source/destination combos, but only after we no longer use these paths for NG. Getting the CO2 to the hydrogen, and the methane to the point of use is not obvious with the existing infrastructure. Then let us start with 10 quads of electricity ro generate hydrogen at 90% efficiency. Then combine the hydrogen with CO2 ro make methane that can be burned with 80% of the energy in the hydrogen. We now have 7.2 quads available as methane which we burn in an ICE at 33% efficiency providing 2.4 quads ro the drive shafts and maybe 2 quads to the wheels. We use methane for 70% of the travel and battery power from the plug in hybrid for the other 70%, with let us say 85% battery efficiency. We have 66% combined efficiency ideally, pretty close to what we can expect from the hydrogen system in a few years. However if we used hydrogen in a FC in place of the methane the 30% would be at close to 60% efficiency instead of 20 % and our combined efficiency would be 78%. Also we can use the existing electrical infrastructure to bring the energy to the point where we need the hydrogen, so no 2 way pipeline and no conflict with natural gas. If the source of CO2 is burning coal for electricity, I'm not sure we would have enough. I'm not a chemist and don't know how to work out the amount of CO2 we would get from 23 quads of coal, and how much hydrogen we would need to combine with it, and how many quads of methane would result. We would need at least 6 quads of methane to replace 30% of 28 quads of petroleum used for transportation now. If batteries are not problematic in other ways I can see the plug in hybrid having advantages, but I don't see how methane would be as good as hydrogen, especially after we run out of coal and don't have the CO2 source. It seems to me you are trying to cross a chasm in 2 jumps. Murray

Jim Beyer
12.2.04
Thanks for your comments. I agree that using methane as an energy medium is counterintuitive. There is an article in www.evworld.com that touches on this.

Regarding infrastructure, the two pipelines would not need to be set up extensively in practice, only in a few select areas. As an example, consider the wind resource of the Dakotas, a good potential energy source for hydrogen production and which would be expensive to access via the electrical grid. If this hydrogen source was fed CO2 produced from biofuel plants located around and near that area, then only a few hundred miles of CO2 pipeline is needed. The existing NG infrastructure could pipe the produced methane out of that area to points west, east and south.

By your own calculations, FCs net 18% more efficency than methane if plug-in hybrids can be employed. But you need to be careful to base both systems on HHV, not LHV. The LHV for hydrogen is only about 82% of its HHV, compared with about 90% for methane (LHV/HHV). So if you are assuming 90% (LHV) efficiency on your fuel cells, this would translate into 74% (HHV). If I am following your calculations correctly, this puts the net efficiency of the FC back to 50% (instead of 60%) and lowers the combined efficiency to 75%. On the other hand, SOFCs (burning methane) could bring the methane vehicle up to 40% (HHV), for a combined efficiency of 72%. So this whole hydrogen infrastructure may only net us 3% more efficiency for our vehicles, certainly not the 2-3X efficiency improvement that some are claiming. I know Bossel-Eliasson rattled some cages, but their comments on the LHV/HHV issue are very important.

I understand this seems to be placing a burden on getting plug-in hybrids to work, but given the market introduction of regular hybrids, this seems a more likely bet than the near-term introduction of fuel cell vehicles. As an aside, the recent NAS study on hydrogen vehicles completely omitted plug-in hybrids entirely. I cite this as evidence of how dynamic this area is at present.

Finally, there is probably enough carbon-neutral CO2 to go around. There is potentially 15 quads of biomass available in the U.S., by some estimates. Only about 3 is used now, so let's assume we could get to 7 quads, just to be safe. If used to produce biofuel, that would produce 7 quads of fuel plus enough CO2 to support 7 more quads of methane. Probably enough to go around. Plug-in hybrids would help with this, as they would reduce the amount of energy (as fuel) needed by our vehicles.

Thanks for the discussion! I'd much rather be shown to be wrong than to remain wrong-thinking, so I think it's important to keep interrogating each other until we can figure this all out.

-Jim

Graham Cowan
12.2.04

I think this was in the news a year ago. I don't recall just where the methane was supposed to get burned, but if it was in cars, there are some details that were, as far as I recall, only implied. I fill them in thus: to get back to the Sabatier reactor, carbon dioxide from a combustor exhaust port (through which it passes in fairly dilute form) is cooled to a temperature very near ambient, so cool that perhaps liquid CO2 condensation is possible (temperature well below the critical one of IIRC 31 Celsius). That would allow some degree of separation from nitrogen.

Kept in an onboard tank, the CO2 can be swapped for methane at a refuelling point, and from there travel through the return pipeline to the power station.

There are already a few thousand cars with compressed methane tanks. How would the onboard CO2 tanks compare in volume? I may get around to this arithmetic if no-one else does.

--- Graham Cowan, former hydrogen fan
Boron: A Better Energy Carrier than Hydrogen?
Everyone knows the one true answer. Maybe they can agree this is the second choice?

Murray Duffin
12.3.04
I think that adding to the existing electric grid is less expensive than building pipelines. Taking the electricity to where the Hydrogen is needed, and generating the hydrogen on site has to be easier than than moving CO2 to the hydrogen and methane back. Also we have significant parts of the country not served by NG pipelines, but almost the entire country served by the electricity grid. On the other side, using oxygen enhanced combustion, and the latest flue gas clean up technologies we can get a very highly concentrated CO2 stream for coal sourced CO2. I'm pretty doubtful about collecting CO2 on the vehicle for recycling. That seems too complex, and the simplest solutions are the best (Occam's razor peraphresed). Murray

Dursun Sakarya
12.3.04
"The cost of a bit of DRAM memory has fallen 5 orders of magnitude in 30 years." I love your can-do attitude!! Perhaps in 30 years we can turn hydrogen from a net energy sink to a net energy source. However I won't be holding my breath.

Jim Beyer
12.3.04
You don't need any CO2 collection on vehicles. Vehicles account for only 18% of our CO2 emissions (U.S.) and nearly every other emission source would be easier to capture than from a moving vehicle. See the Keith-Farrell paper in the July-03 Science. We need to be concerned about CO2 emissions from cars only when our other emission sources have been fixed. They are all lower hanging fruit. With respect to methane instead of hydrogen, you just emit the CO2 from the car. By definition, it is either carbon neutral (if derived from biomass sources) or at worst twice-used (such as from a coal-fired electric plant stack). Either way, you aren't making anything worse, and you are able to use a fuel that is 3x denser than hydrogen and already widely used in our economy.

Regarding electric-based grid distribution of hydrogen -- that's fine, assuming the grid is always going. But if we wish to move to more renewable electricity, the grid may NOT always be going, at least to the extent needed to support vehicle fuel in addition to our electrical needs. If that's the case, you either need electrical storage or massive bulk hydrogen storage to accommodate the daily and even seasonal variation in our renewable energy sources. We obviously get more sunlight during the summer months, so if we wish to take advantage of this resource, we need some way to store it. Not for hours or a few days, but months. Since electrical storage (batteries) would be far too expensive, that leaves hydrogen gas, and a lot of it, much more than you could store at individual gas stations. Given that, finding, and perhaps moving a bit of CO2 is not so bad, because it would reduce THAT storage by a factor of 3 as well.

-Jim

Jim Beyer
12.3.04
Harrumph!

Regarding Dursun Sakarya's comment, of course making hydrogen (from electricity) is a net energy sink. It always will be. It will NEVER be an energy source, only a medium.

The point is STORAGE and TIME. If you want to use energy that was accumulated in the past, you need some way to store it. Hydrogen (or methane) is a convenient way to store energy, at least compared with electrical charge, or even chemical batteries.

This convenience comes at a price. Only 70 or 90 percent (or whatever) of the electrical energy remains in the hydrogen. But the storage cost is much lower, so depending on how long you need to be able to store the energy indicates how wise it is to create the hydrogen in the first place.

People seem to have no trouble understanding that a laptop computer should cost more money than a desktop computer of equal capability. With energy, the situation is the same. Higher density is more convenient and thus more valuable. Under the right conditions, making hydrogen from electricity can be a value adding operation.

-Jim

Len Gould
12.3.04
I think a lot of the discussion is clouded by a lack of stating clearly what time frame is being discussed. Murray's article, I think, is directed to the very near term eg. what is possibe in the next 10 to 20 years, whereas part of the debate is directed much further out, eg. what will happen when fossil carbons are no longer ever used as energy fuels, a very different though inevitable proposition.

Discussing whether bi-directional methane/CO2 systems make sense in terms of the energy distribution infrastructure of today or the next twenty years is fairly pointless, it won't happen on a widespread basis. In 200 years? Who knows, maybe. But given todays pace of scientific development and extrapolating that far, I'd guess it's simply an academic exercise. Chances are that by then any energy requirement you can't collect from the globally available harmless microwaves beamed down from power satellites designed to mitigate the onset of the next ice age, can be gotten from your pocket fusion reactor / garbage recycler as necessary.

It's like asking George Washington to predict the optimum energy distribution infrastructure for powering the computers and cellphones of 2005, though even that understates the likely level of change given todays rate of communication and organization in scientific and technological research.

One thing that is fairly predictable is a large penalty for allowing carbon atoms to combine with oxygen. The way carbon nanotube developments are heading, i'd guess by then pretty much everything from your personal transporter to your 3D video display will be manufactured largely from pure carbon. Hopefully the price of the nanotube can be brought down for current $85,000 / kg.

Roger Arnold
12.3.04
While it's true that one can make methane from hydrogen and CO2, one can just as easily make methanol. (Maybe a little easier). Methanol doesn't carry quite as much energy per molecule as methane, but it's liquid at room temperature. That's a very significant difference. CNG vehicles have been around for a long time, but have never become popular--even though NG was until recently a very cheap fuel. Two problems have been the bulk and weight of the CNG tanks, and the time and inconvenience of refilling them. I.e., the same problems, on a more modest scale, that compressed hydrogen faces.

Since methane and methanol are equally suitable as fuel for an IC engine, or for reforming and fueling a high temperature SOFC, my question for Jim is why advocate methane rather than methanol?

Jim Beyer
12.3.04
Len Gould: I don't think this is an academic subject at all. A lot of money seems to be being spent to try to get hydrogen fuel cells to work. A lot of talk is going on about how to build a hydrogen infrastructure to support these vehicles. The recent CARB ruling in California (completely ludicrous, in my opinion) limiting CO2 emissions in vehicles is real, not academic. These are all affecting people and some businesses in real ways. Not academic at all.

Maybe we don't need CO2 (or hydrogen) pipelines at all. Maybe plug-in hybrids are enough and we can just use foreign oil for the remainder.

Maybe global warming is worse than we thought and we can't even do that.

Maybe plug-in hybrids won't work, so producing fuel from renewables IS important after all.

Who knows? But I think it is important to at least try to think some of these things through. If only to keep politicians from wasting more of our money.

But I do know that even if we do have fusion reactors or solar power satellites, we will still desire a dense, energetic fuel for some uses. But maybe by then, we'll have enough energy to just make JP-8 and be done with it ! :)

-Jim

Jim Beyer
12.3.04
Roger Arnold: I have no trouble with methanol at all. I think reasonable people can see the advantages and disadvantages of either choice. If we do wish to use more methanol in our vehicles, however, it's important that we don't reform our existing (and dwindling) domestic natural gas to make it. We must either make it the hard way (out of electrolyzed hydrogen) or perhaps import it from Qatar or some other NG rich area that can reform it there and ship it over on a tanker. Or maybe pyrolize biomass, but that seems a little brutish to me.

It is kind of a crummy fuel though, about twice as bulky as gasoline, very poisonous, hard to keep the NOx and formaldehyde emissions down. I'm not saying it's liquid form doesn't trump these concerns, but I think there may be a reason why it hasn't been enthusiastically embraced to date.

If I remember correctly, converting from methane -> methanol or methanol -> methane both leave about 80% of the energy left over, so if you ARE making it from scratch it would be beneficial to figure out which one you want and to stick with it. Since our existing infrastructure does have some high efficiency combined-cycle gas turbines (58% efficient), there is probably a use for at least some methane. The obvious convenience of a liquid fuel can't be overlooked, however. I'm not (yet) impressed with methanol fuel cells -- a recent vehicle demonstration in Germany could only produce about 1.5 kwatts.

On the other hand, it is possible that with liquid fuels, there is no free lunch, and you are paying even for that. For example, consider ethanol vs. methane as a fuel product from biomass. Ethanol, being liquid, is obviously a more convenient fuel. But the fermenting process produces ethanol in a water mixture, so a drying step is needed, which can be up to 30% of the energy content of the fuel produced. If this step can't be improved, or perhaps implemented with a waste heat source, then the "cost" of this convenience (the fuel being a liquid) could be another 30% of energy needed. Based on that, a pressurized tank might pay for itself in a just hundred fillups or so. Methane, on the other hand, is more easily separated (energetically) CO2 if the biomass is subjected to methanogenesis by methanogens instead of fermentation by yeasts. Only about 5-10% of the energy content is needed for the separation of methane from CO2. There may be some issues with methanol in the same way, but I'm not sure. (I'm not 100% sure of this "liquid-fuels-are-not-a-free-lunch" thing, just a hypothesis....)

I think in general, if we can understand how to live with smaller chain hydrocarbon fuels, at least in theory, we will be less surprised if oil depletion accelerates in the future and forces our hand.

(probably talking too much......)

-Jim

Roger Arnold
12.3.04
Jim, I quite agree about not using our existing natural gas supplies to produce methanol. There may be exceptions, e.g., in cases where a gas well is small and remote. If it's uneconomical to build a pipeline to the well, it might still be economical to convert the gas to methanol, rather than flaring it. It could then be shipped out by tanker truck. That's one GTL approach. Another is to makes synthesis gas, and use FT synthesis to form heavier hydrocarbons. I think both approaches are under development and maybe being used in various places.

Do you have any opinion about the ZECA approach to gasification? It starts out by "burning" any carbon or hydrocarbon fuel in a hot hydrogen atmosphere to produce methane. The methane is then reformed with CaO and water, producing CaCO3 and at least twice as much hydrogen as used to make the methane. The CaCO3 is then calcined to regenerate CaO and a pure stream of CO2.

What's interesting to me about that process is that it should work well with oil shale as the hydrocarbon input. We have lots of that around. If we combined it with electrolytically generated hydrogen from renewable sources, it would stretch pretty far.

It seems like there's a wealth of good possibilities. Fighting wars over dwindling oil supplies is criminally stupid.

Roger Arnold
12.3.04
A short "PS" about saving methane for power generation in high efficiency CCGTs: I don't believe there's anything magical about methane as a fuel for these systems. In fact, the turbine stages actually work better on liquid fuel, because the fuel doesn't have to be compressed. The rise of CCGTs using NG is an accident of history: gas was cheap and had "no better use". Liquid fuels were (and are) more valuable for use in vehicles than for producing power. But if a renewable energy economy produced liquid fuels naturally, they wouldn't need to be converted to methane in order to fuel a CCGT for power.

Jim Beyer
12.5.04
I forgot. Another argument for methane over methanol is storage. If one can accept the 'value' of CO2 as a carrier for hydrogen bond energy, then one would collect it and send it back to energy sources. But if the time of energy use varies widely from the time of energy production, you may be dealt with a significant CO2 storage issue. Since CO2 is a gas (and always will be) then if the fuel itself is a gas, you could perhaps make dual use of this storage and transport mechanism. (Like Mr. Duffin said, perhaps a single pipeline could transport CO2 to an energy site for one part of the year and CH4 back during another part of the year.) Currently large amounts of CH4 are stored in underground geologic structures. They could be used to store CO2 as well. If you made methanol, you still need all the CO2 storage and transport, but in addition you'd need storage and transport for the liquid fuel. Agreed, since it is a liquid, this would be a more modest investment, but given the concerns about MTBE, people might not be thrilled to have underground tanks of methanol around either.

From what I can figure out, methanol is not nearly as bad as MTBE, because it does decay naturally and quickly in the enivronment, but it is not all that wonderful either. If your toddler drank a tablespoon of gasoline, she would get sick. But if it was methanol, she would either die or have permanent serious injury. Methanol in higher concentrations also does NOT break down naturally because it kills the microbes that would normally feed on it.

We also DO have the existing NG infrastructure. I just tore the old oil tank out of my basement, so it would be annoying if they decided to heat homes with methanol instead. :)

-Jim

Jim Beyer
12.5.04
Roger:

According to their own website, the ZECA system does not produce hydrogen that is pure enough to be used in PEM fuel cells without degrading their catalysts. Ridiculous! Using hydrogen is IC engine is the worst of all worlds : poor fuel density, poor efficiency, they even have no-so-great NOx emissions.

In general, the notion of hydrogenating to remove C-C and C-O bonds from a hydrocarbon is a good idea. It improves the ratio of energy/CO2 produced from combustion. In terms of what ZECA is doing on both the methane production side and the CO2 capture side, I'm not sure how efficient they really are. Both seem to require substantial heat input, which has to come from somewhere.

I'm more of a fan of hydrogenating biomass, because you still get a good fuel (methane, methanol, perhaps even a kind of biodiesel) and the result is carbon neutral. The ZECA system is a little vague about how the CO2 sequestering is going to work.

I think we really need to be honest with ourselves and put all our cards on the table.

Are we considering the move to hydrogen because of the concern about oil depletion or global warming?

If it is oil depletion, then we should look to fuels from biomass or coal, such as methane, methanol, and biodiesel (we probably can't make a LOT of this stuff). We should look at improving efficiency with hybrids and plug-in hybrids. If we can reduce our oil use by just 10% (with a glare that we can reduce it another 10%) that would send enough shocks to the supply side of the oil industry to settle things down for another 20 years or so. But no hydrogen is needed in this equation. As for our electrical needs, just keep building coal plants.

If it is global warming we are concerned about, we need to limit emissions from our coal plants. Vehicle CO2 emissions are a small part of the equation, and not the thing to be looking at. We need to figure out how to integrate renewable electric in our grid and build more infrastructure for this. At least enough to forgo additional coal plant construction (This is the Joe Romm belief.) We need to consider nuclear power again, and gauge the risk/reward of that versus global wamring. We need to conserve electricity. There is probably at least 10-20% hardship-free reductions in electrical consumption that could be instituted if we focused on this. It is mostly an educational effort, as a home or business is always interested in saving money on their power bills. Again, no hydrogen here either.

In my opinion, the best, safest, and cheapest method of carbon sequestration is to burn less coal, and leave the solid chunks of near 90% carbon in the ground.

Len Gould
12.5.04
Jim: Your last sentence has certainly hit one nail on the head. By far the wisest method of carbon sequestration is to leave coal in the ground. US citizens should intend to be very upset with politicians and company management if in the next twenty or so years if it is decided they need to reduce CO2 emissions given the present attitude to coal-electric generation. Good luck.

Murray Duffin
12.5.04
Jim, it is not either /or. For me the main driver is declining supplies of NG and petroleum, not global warming. However, in the medium run the 2 are synergistic. We will burn more coal, and it is better to do so as cleanly as possible, but the result will be declining coaL AVAILABILITY ALSO IN LESS THAN 50 YEARS. That's what I meant about crossing a chasm in 2 leaps. Using coal in the short run is only the first leap, and doesn't get you across the chasm. There are a couple of reasonably economic ways to clean flue gases and leave relatively pure CO2, as well as generating some hydrogen. For me the best part of your thesis is to then use this CO2 and the hydrogen, plus probably supplemental hydrogen to make methane to serve the present NG infrastructure/demand and stretch the NG supply as far as possible, allowing more time for the ultimate transition to hydrogen. I haven't thought my way through this yet, but there is promise in the idea. Murray

Len Gould
12.5.04
Murray: I don't quite buy it. Collecting CO2 and H2 at an IGCC coal plant, combining them into methane, then piping it out into the natural gas infrastructure is (almost) entirely pointless. The only potential gain is energy storage as NG rather than as coal, and the reuse of the then-nearing-obsolescence NG infrastructure. This is of course assuming the conversion process is about as energy efficient as electricity generation. Storing energy as coal is far more efficient than as methane, and transporting energy as electricity has far more potential for efficiency, convenience and co-operation with other more environmentally smart energy sources than as methane. Think developing superconductors, super highvoltage DC.

Given that the fossil carbons still wind up being dumped, and methane itself is a far more worrisome GHG than CO2, I just don't see the balancing benefit.

Jim Beyer
12.6.04
Murray, if you are mainly driven by declining NG and oil, then we should further develop hybrids and plug-in hybrids. If we can get plug-in hybrids to work, then even renewable electric at 10 cents per kWhr is cheaper than the gasoline it would displace. Vehicle fuel is definitely easier to displace economically than coal-generated electrical power.

I agree with Murray that coal won't last as long as people think, especially if it is used more aggressively. With respect to a fuel, you are better off just making methane from coal, and using that. Assuming you sequester the CO2 from the methane production process (NOT during the methan USE) you still save about half the CO2 that the coal would otherwise produce. You could replace that CO2 emitted (from the methane use) by sequestering a like amount of CO2 obtained from biofuel production. The potential for biofuel from cellulose is hopeful, and since the process produces much carbon-neutral CO2 as well, biofuel production can serve to utilize fossil fuels in a carbon neutral way further. Assuming large scale CO2 sequestering works. I'm a little skeptical about that. If you have one wellhead split open, you could kill a few thousand people downwind with a CO2 leak. That would give CO2 sequestering all the public confidence of a nuclear power plant.

I realize proposing to turn our cars over to NG sounds crazy, given our current shortage. But we have more NG around than we do hydrogen, which doesn't exist at all, and which is most commonly obtained from NG in the first place.

I'm trying to figure out what the two leaps are. I think the first is domestic energy independence, and the second is no carbon emissions. Is that close?

Electrical grids are not cheap, are only really economically practical for lengths under 300 miles or so, and depend on 24/7 use. We tried to size a grid needed to get the wind power from the Dakotas to Chicago. It's really hard. You either end up throwing away a bunch of electricity during peak times, or way oversizing the wires, making the transport of electricity ridiculously expensive. Another thing that people don't seem to understand is that renewable energy is completely different than our current system. Fundamentally so. Not necessarily worse, just different. It has to do with their intermittent nature, which is totally anti-thetical to the grid as we presently perceive it. But if we can learn to live with this, our ability to integrate these resources will be much easier for us.

Methane is not that much worse than CO2 as a GHG. True, it is much more heat absorbing, but it break s down (into CO2) after about 10 years. So over the life of the molecule, CH4 is only about 5X worse than CO2, not the 20X that people say. (That was another thing CARB got wrong.) Since CH4 is useful, presumably people will work harder to capture and use it rather than let it drift away.

I think a good experiment would be to develop some of the wind resources in the Mid-Central states. Use the energy to make hydrogen and then methane and probably some ammonia too. (Ammonia is the lowest hanging fruit for electrolyzed hydrogen, and producing it would reduce some of the methane use from that industry.) The CO2 is fed from nearby ethanol plants. (I'm not a huge fan of corn-based ethanol, but they are good sites to test out the process.) Congress just approved a massive NG pipeline to come down from Alaska, so the system could pipe into that. Depending on how much wind we capture, we'd end up producing a centrally-located, but very disperse methane source that would never run out. All of this would cost money, of course, but since so little gas would be initially produced, the overall price of NG would not go up very much.

In the short term, we need to conserve energy more and add smaller renewable energy sources locally that people can use. Plug-in hybrids are good for this because they can be plugged in perhaps 20 hours per day, so they have a good chance of getting charged from an intermittent source. We need to resist the urge to build more coal plants, because that's a 50 year committment of infrastructure to emit more CO2.

If our government is working to make us safer, it is hard for me to understand how spending another dollar on defense accomplishes this, versus spending that dollar on either increasing domestic energy production or increasing our energy efficiency.

-Jim

Len Gould
12.6.04
Jim: The "two leaps" referred to are first, replacing petroleum with coal-based systems, then eventually replacing that coal-based system when the coal runs out. Is definitely pointless if the "second leap" technology is already known.

Your statement "electrical grids are not cheap... " etc just doesn't hold up. Compared to what? Anf you guys need to stop evaluating AC electrical as the only possibility (300 miles). HVDC at modern voltages can transport energy more economically than rail or pipeline and the greater the distance the greater the advantage. With articles such as F. Mack Shelor's at The Arguments for a National Direct Current Transmission Grid , or the proposal for a continental DC grid by Black and Veatch, and many others having been around for years, there is simply no further excuse for not fianlly bringing the grid into the 21st century and resolving all these issues. Or see my own proposal, the Active Electrical Transmission System

The limits of North-South NG transmission are already filled by Canadian production so building the pipeline from Alaska proposed by congress (only to the canada border) will either require an additional huge investment to get the gas from the Alaska-Yukon border into the markets or displacement of currently available production. Neither makes sense. This one should be held off until canadian production has fallen enough to allow it to use existing pipes. Problem is, that would require some creativity in how to expand energy production in the mean time. BTW, Canadian NG resources fell almost 5% last year despite record drilling.

Jim Beyer
12.6.04
The only problem with the "first leap" being the leap to coal, is that if it turns out we have more coal than atmosphere, we may never get to the second leap.

I am suggesting electrical grids are not cheap compared with pipelines. I am not suggesting to make a fuel from electricity, pipe it somewhere, and then convert it back to electricity in a power plant. That wouldn't be wise. What I am suggesting is that some electrical power could be 'stranded' which might be better off converted to some kind of fuel instead. And then use the fuel in a vehicle.

The problem with any type of electrical transmission grid (AC or DC) is that electricity can't be stored in it. A pipeline can accommodate different pressures to allow for some storage as well as storage in geologic structures, etc. If we wish to embrace renewable electric (sun, wind) then we need to think about the grid more carefully. The grid at present relies on flexible capacity to match demand changes. If the future grid is to accommodate renewable electric, it will have both the supply AND demand sides changing somewhat randomly. I don't think they are prepared for that. That's why utilies are reluctant to assign wind farms any percentage of base capacity. This is a much more serious problem than whether we should have DC vs AC transmission lines, in my opinion.

It may make sense for some amount of the power to come out of the Dakotas as electricity, but it would have to be a small percentage of the peak power production, well under 30%, I would think. Otherwise the transmission capacity would be wasted.

I thought they had approved funding for the entire pipeline, not just that section. My mistake.

Murray Duffin
12.7.04

Jim, believe me the entire NG pipeline network can't vary the pressure enough from min to max ro make much difference in storage. It might be 1% of annual consumption. You havent read the paper I published on wind. Intermittancy is not a problem in a geographically large well integrated grid, with modest back up storage. The storage can be hydrogen, or pumped hydro where that is possible. yeah, I am all for hybrids, and for plug in hybrids if batteries are not problematic (which I am not yet convinced of). Hybrids are a very important bridge to the HE as I thought I made clear in my paper. Murray

 

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