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December 12, 2006



Excellent! Now do this same analysis for SOFC/plugin hybrids.

The fabulous (as in the root word, fable) hydrogen economy!

The biogas/SOFC vehicle/solar collector algae/biofuel economy. That's the one to do a study on, Ulf.


Here are further studies on the efficiency of a hydrogen economy:

European fuel cell forum



Well, you have a good portion of the plug-in hybrid information already there, i.e. power plant -> wheels. I found a power plant efficiency presentation via Google. It could be GIGO (garbage-in garbage-out), but it's a starting point.

Here's their fuel->electricity efficiencies for a range of plants:
- Gas Combined Cycle: ~57%
- Gas Steam Turbine: ~39%
- Coal Steam Turbine: ~39%
- Fuel-oil Steam Turbine: ~38%

So, to back up their tables and be optimistic:
Fuel: 100 kWh
Power Plant->Electricity (57%): 57.0 kWh out
Electricity Transmission (90%): 51.3 kWh out
AC->DC + Battery (85%): 43.6 kWh out
Car+Regen Breaking (90%): 39.2 kWh out

Or be pessimistic:
Fuel: 100 kWh
Power Plant->Electricity (38%): 38.0 kWh out
Electricity Transmission (90%): 34.2 kWh out
AC->DC + Battery (85%): 29.0 kWh out
Elect Motor+Regen Breaking (90%): 26.2 kWh out

So far, I've had little success finding efficiency information for ICE engines or the associated fuel processing steps.



Bossel is essentially correct. Hydrogen is a dead end and is a gimmick for certain interests to freeload on the taxpayer. The future belongs to nano-phosphate iron lithium batteries (e.g. A123 Systems).

The only issue I would take is that electrolysis is more efficient than 75% (about 85 to 90%), and the amount of water needed is miniscule. I am not sure why he thinks we will run out of water !!!


Ethanol is by far a better storage medium than hydrogen. Ethanol ICE is about 30% efficient, and ethanol diesel engine can be as high as 40%.

Does anyone know if there is an easy way to obtain ethanol from hydrogen and carbon dioxide?


Beek wrote: Does anyone know if there is an easy way to obtain ethanol from hydrogen and carbon dioxide?


GRLCowan said... A few years ago I added methanol to this table.

Although it is more toxic than ethanol, I believe it's not a cumulative toxin. One's liver converts it to formic acid just as it converts ethanol to acetic acid. The difficulty is that formic acid is a stronger acid. Very likely there's more to it.

Nuclear methanol could be polymerized into nuclear gasoline. The starting point likely would be nuclear hydrogen. Hydrogen has been produced from water by thermal processes, so large amounts of electricity would not necessarily be involved.

A 1-megabarrel-per-day nuclear gasoline plant would likely need a 200-thermal-gigawatt reactor, or, I suppose, an octet of 25-GW ones; but there seems to be no good reason not to build such reactors.

--- Graham Cowan, former hydrogen fan
B: internal combustion, nuclear cachet

3/03/2006 8:44 AM


Thanks Nucbuddy. If according to the article, 6.7 KWh converts to 1 litre of methanol, then 1 million barrels of methanol a day (almost as good as gasoline, given the higher octane rating of methanol) will take a 20 GW nuclear plant (or 10 2 GW plants) to produce. (1 barrel of oil converts only to 21 gallons of gasoline).

Methanol being toxic and corrosive, it would be better to produce ethanol, which has higher energy density (by about 20%).

Is there an easy way to produce ethanol from hydrogen and carbon dioxide?




The Hydrogen Economy will never sence? I beg to differ. Water is broken down to O2 and H every day with just sunlight. It is called Photosyntsis. If nature can do it so can we. I am not saying it is possible at this time but if we fund the research it should be avaliable in the next Fifty to Hundred years.


It's an interesting way to look at the total system Mike.

How to account for solar, wind, and water electric power? I say start with those sources as 100% fuel efficient since they use no fuel.

Under that analysis the electric car gets 69kwh to the wheels out of every 100kwh. But over a battery range of say 40 miles, a serial SOFC/microturbine hybrid needs fuel to keep going. That fuel is turned into electricty at 75% efficiency.

In that mode it gets 75kwh to the motor of the vehicle for every 100kwh worth of fuel. A large percentage of that gets to the wheels.

Biodiesel fuel for this can come from a renewable source, algae in solar collectors. And backup electricity would come from biogas or powdered algae cellulose used in this same type fuel cell at 75% efficiency.

Since these biofuels are renewable energy that comes from waste and solar energy, once again assume that product, the biodiesel is 100% fuel efficient in production. So for every 100kwh of biodiesel fuel you get 75kwh of electricity to the battery system in the vehicle.

The thing is that once there is enough capacity to dispense with fossil and nuclear fueled sources, the analysis kind of breaks down. Renewable energy systems need no fossil fuels so do not lend themselves to this sort of analysis.

An ICE vehicle is aproximately 14% fuel efficient. Oil recovery and refining burns 20% of that oil up. Only a fraction of oil can be turned into motor fuel. It's a dismall puicture, efficiency wise.

The plugin serial hybrid with sOFC/microturbine backup would average 10% or less of the fuel use and cO2 emissions of an ICE vehicle.


The automotive (e.g. Delphi) SOFC's currently in development aren't 75% efficient, they just recently hit 49%.  I doubt they'll ever see 75% because of limitations on weight and other factors required for a vehicle.

Not that this matters much.  With PHEV-60's, internal combustion engines will do fine for extended range and still yield up to 80% liquid-fuel savings.  Even if on-board fuel cells NEVER work, the system as a whole could eliminate petroleum.


Well poet, I meant solid oxide fuel cell/microturbine backup generation, which has reached 75% efficiency.

And it will fit just fine in a car, so far the microturbine design has been installed in a bus.

Smaller systems for cars are in development. ICE serial hybrids have already beat ICE paralell hybrids in terms of gas mileage and efficiency.

But continuing to use ICEs for transportation energy at 14% efficiency is about as good an idea as burning oil to generate grid electric power. An idea you proposed elsewhere that is too ridiculous to even comment on.

The other big reason to switch to serial hybrids using this sOFC/microturbine system is that 100s of millions of these vehicles plufgged into the grid and biogas could replace aging, filthy, dangerous fossil and nuclear power plants and make trillions in grid upgrades unecessary.


amazingdrx -

Do you have any links or references for your efficiency stats? I've been playing with this topic on my own for a bit, but kept getting stymied by ICE and refining efficiencies.



I will try to retrieve them Mike. I think most are on my blog.

But these bits and pieces seem to be absorbed into the brain and the links aren't. We need google implanted in the brainpan! Hehehey.

I tried to post on your blog but it didn't take for some reason.

Here's another encouraging figure! 15 to 30% of US CO2 emissions are absorbed by conservation land. Increase that effect by 4 times, with a new Prairie National Park (and huge wind farm) and more reserve cropland and organic farming, then by decreasing CO2 emissions with renewable energy, and we could actually reverse the uS contribution to global climate disaster. Removing past cO2 emissions from the astmosphere so the concentration actually drops.

The 14% ICE vehicle efficiency figure and 20% of oil burned in recovery and refining figure are so far back it might take awhile. I've been using those estimates for years.

Paul Dietz

Is there an easy way to produce ethanol from hydrogen and carbon dioxide?

Yes, there are Fischer-Tropsch-like catalysts that can do this. I think MoS2 is one of them. You can also produce mixed alcohols this way. But why not make hydrocarbons?


Paul, I am not sure what the advantages of mixed alcohols are. Why would that be more advantageous than Et? There is already an infrastructure in place for Et distribution and consumption. Also hydrocarbon generation is not as efficient as Et generation, and flex fuel cars can run on E85.

Paul Dietz

Paul, I am not sure what the advantages of mixed alcohols are. Why would that be more advantageous than Et?

Higher energy density, and (from syngas) they might be easier to produce than pure ethanol.


Also greater miscibility with petroleum, lower water solubility (allowing pipeline transport) and lower distillation energy requirements.


Beek and buddy,taking GRL as a reference source might be a bit risky. Check out his Boron energy website.


"It is also one of the most efficient means for generating electricity and usable heat.As simply cycle power generator, it can convert more than 55% of the energy in itsfuel source to electricity (conventional coal plants, for example, operate at efficien-cies of 33%-35%). When the quality waste heat from the electrochemical processis used, overall efficiencies could reach 85%. When utilized with a gas turbinein a combined power system, efficiencies over 70% can be achieved."

A DOE solid oxide fuel cell/microturbine project Mike.


"Capstone MicroTurbine used in the world’s first successful road test of a microturbine-flywheel powertrain for autos, and installed in an HEV bus and 2 HEV cars."

And a microturbine for cars.


Dr. X wrote: taking GRL as a reference source might be a bit risky. Check out his Boron energy website.

What is wrong with Graham Cowan's boron energy website?


Besides not being thermodynamically efficient, the sheer electrical energy to convert our private vechicle fleet to hydrogen is staggering. Our private fleet of cars, light trucks, and SUVs travel 2.3 trillion vehicle miles per year at an average mileage of about 21 mpg. IF -- and that's a big if -- all those vehicles were switched to hydrogen and IF the effective mileage when to 100 mpg, then nearly 200 new 1400 mega-watt nuclear power plants would be required for hydrogen production via water electroysis. (There are only 109 nuclear power plants in this country now.) Ain't gonna happen.


Correction: I meant "thermodynamically inefficient" on the first phrase of my preceeding post.


Freedom of speech, the great legacy of our founders. Illuminates the darkness. Sheds a glow into strange corners.

But to each his own, buddy.


I'm not saying it is not worth reading, as with accounts of atomicrod's nuclear powered buses it is excellent reading!

Just the sheer Jules Vernesqueness of it alone makes it fascinating.

I prefer the Fuller floating geodesic city fantasies myself, less toxic! And solar powered.

Simon Jones


to be fair, a good portion of the required energy could be sourced from the idle capacity of existing plants.

See http://www.pnl.gov/news/release.asp?id=204 which summarises the possibilities for EVs, which IMNSHO beat the pants off the hydrogen fantasy on every measure.

Matt Earley

Don't understand why there is a 10% loss assumption for compression of the hydrogen. Perhaps you are taking into account the cost of such compression .... thought you suggest waste is the issue.


Simon, thanks for that link. I am in no way in favor of hydrogen. In fact I get incested that very high up officials are pushing it. It makes no sense on so many levels. I like the calculation of hundreds of nuclear plants to illustrate the immense scale of transportation energy used in this country. The next issue might be is there enough raw materials to produce millions of high-tech batteries.


Harrison, lithium is one of the most abundant raw materials and in the form of the hydroxide LiOH, which is used in lion batteries, it is very cheap. Besides, lion batteries are eminently recyclable.

So are phosphorous and iron, etc.

There are absolutely no doomsday scenarios or 3rd world colonialism/imperialism scenarios with lithium ion batteries, to the chagrin of the post-colonials - fortunately. Praise be on Allah for siding with the west in this case.


Matt, hydrogen has very high compression energy requirements because it has relatively little energy per molecule/volume (methane has twice as much HYDROGEN, and far more energy, per molecule than H2) and the high pressures required to get reasonable energy densities drive compression requirements up even further.

Paul Dietz

Harrison, lithium is one of the most abundant raw materials

Well, not really. It's not enormously rare, but it isn't terrifically abundant, either. Having said that, I suspect they can extract it from seawater if the demand gets high enough. The oceans contain 200 billion tons of the element at a concentration of roughly .17 ppm. The Japanese and some others have been researching materials that selectively adsorb Li from dilute solutions, and have some interesting candidates.


There is enough lithium in brine pools and flats that you don't even have to tap salt water.

A 50 kWh battery pack has about 20 kg of lithium element - and this is 100% recyclable.

600 million cars on earth if all converted to lion, will require 12 million tons of lithium.

That is probably less than 2% of what can be found in brine flats and 0.006% of what is in the ocean.

So lithium is quite abundant and there is absolutely no chance that we will ever run out.

If you think we will run out, then we should limit population to 1.5 child per family. There is no such thing as a right to procreate. Only roaches have such rights.


Beek, Your last paragraph about population control is really the heart of the matter. Since 1900 (or basically the start of the oil age) the population of the world has increased 4-fold. It tracks nearly perfectly with the annual increase in world oil use. Every increase of 6.3 barrels of oil production per year supports one net person on the face of the earth. It won't last. Let the cock roaches rule.


The best argument against the hydrogen economy - besides Bossel's work - is that G. W. Bush - yeah that guy! - is busy promoting it.
Chances of Bush success in any of his plans: 0%



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