jw, on the referenced table (the same source I used) take the gallons used by passenger sources divided by the gallons used by all other highway and transit vehicles + the passenger sources. Second, that is only highway useage. I refer to it as land because I was not including air or sea but then again I didn't include rail so that is not entirely accurate.

(million gallons, latest data)
Passenger car and motorcycle... 76,208
Other 2-axle 4-tire vehicle... 62,626
Subotal - cars, motorcycles, light trucks... 138,833 (77.7% of total)

Single-unit 2-axle 6-tire or more truck... 9,263
Combination truck... 24,705
Bus... 948
Transit, Diesel... 749
Transit, Gasoline and other nondiesel fuels... 47
Rail, Class I (in freight service)... 4,059
Amtrak... 75
Subtotal - other surface transportation... 39,847 (22.3% of total)

Total... 178,680

Water transportation is another 7,835 million gallons.

even if hydrogen isn't used for transportation, it may still be a useful way of storing excess energy produced by uncontrollable renewable energy (wind, run of the river hydro, tidal, wave, solar, etc)

Group "Other 2-axle, 4 tire vehicle" with the other category. They are not passenger vehicles.

76,208 for passenger and motorcycles. (43.661% of total)

62,626 + 9,263 + 24,705 + 948 + 749 + 47. Like I said I had omitted rail transit. Sub total 98338. (56.339% of total)

You can't assume that every non-passenger vehicle is a pickup truck piloted by billy bob for his daily commute as there are many, many commercial vans & trucks with 2 axles and 4 tires in use by contractors, delivery, commercial entities, etc. Really I'm not sure how to divide that number up but honestly, since those vehicles get alternative means of fuel economy requirements and emissions requirements substantially lower than that of passenger vehicles I do not consider them to be passenger vehicles of any sort and should be considered as commercial.

Group "Other 2-axle, 4 tire vehicle" with the other category. They are not passenger vehicles.

"Other 2-Axle 4-Tire Vehicles which are not passenger cars. These include vans, pickup trucks, and sport/utility vehicles."
http://www.fhwa.dot.gov/ohim/hs01/vm1.htm#foot2

They're passenger vehicles. They are not passenger cars.

You can't assume that every non-passenger vehicle is a pickup truck piloted by billy bob for his daily commute as there are many, many commercial vans & trucks with 2 axles and 4 tires in use by contractors, delivery, commercial entities, etc. Really I'm not sure how to divide that number up but honestly, since those vehicles get alternative means of fuel economy requirements and emissions requirements substantially lower than that of passenger vehicles I do not consider them to be passenger vehicles of any sort and should be considered as commercial.

All light trucks (ie, half of all light vehicle sales) should be considered commercial? That certainly is a unique viewpoint. Yes, you are correct - some light trucks get used commercially. That doesn't mean you just take the sum total for the entire category and pretend that your neighbor Phil and his PT Cruiser (which is technically a light truck) is a commercial driver.

The bottom line is that your original assertion, that basically meant that normal, private driving only accounts for 43% of "land transport" energy use is WAY off the mark. Keep in mind that most of the energy use of commercial trucks are going to be in the "single-unit 2-axle 6-tire or more" and "Combination truck" categories.

One way to try and wash out commercial use from the light vehicle data is to use National Household Travel Survey Data. Self-reported household vehicle miles were 21,171 miles in 2001, and the actual odometer readings were about 1.07 times that. Average efficiency of light vehicles that year was 20.2 mpg and the number of households was 110 million. Run the numbers and that comes out to 123.6 billion gallons of fuel. Compare that with the total from that BTS chart for passenger cars and light trucks for that year (taking out the roughly 190 million gallons used by motorcycles), and you get 127.1 billion gallons. So, 97.3% of the total for the light vehicle data is household use.

So, using that data, it shows that personal vehicles account for 74% of ";and transport" liquid fuel energy use -- far closer to my original estimate than to yours.

"achieved up to 80% efficiency" 80% of what?
Electrolysis can never be a NET ENERGY SOURCE.
That's immutable thermodynamics.
Sure you can make money, coal powered electricity is DIRT CHEAP.

"achieved up to 80% efficiency" 80% of what?

I believe the term you're looking for is "conversion efficiency".

"Electrolysis can never be a NET ENERGY SOURCE.
That's immutable thermodynamics.
Sure you can make money, coal powered electricity is DIRT CHEAP."

Well, if you want to make hydrogen from coal, you use the water shift reaction instead.

Nick, you ask good questions, too bad no one takes the time to answer them.

1. You could sell the oxygen and it would provide revenue.

2. Yes, a fuel cell is more efficient.

HI just to share, DME developments in China:
Since DME has an advantage of decomposition at lower temperature than methane and LPG, R&D for hydrogen source for fuel cell has been carried out. DME has a potential of feedstock for chemicals. DME to olefins is under development in Japan.

If you would like to know more on the latest DME developments, join us at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:

DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
By:
National Development Reform Commission NDRC
Ministry of Energy for Mongolia

Production of DME/ Methanol through biomass
gasification could potentially be commercialized
By:
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.

Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe

Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation

For more information: www.iceorganiser.com

DME developments in China today:
Since DME has an advantage of decomposition at lower temperature than methane and LPG, R&D for hydrogen source for fuel cell has been carried out. DME has a potential of feedstock for chemicals. DME to olefins is under development in Japan.

If you would like to know more on the latest DME developments, join us at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:

DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
By:
National Development Reform Commission NDRC
Ministry of Energy for Mongolia

Production of DME/ Methanol through biomass
gasification could potentially be commercialized
By:
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.

Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe

Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation

For more information: www.iceorganiser.com

If you where to use these electrodes produced by qsi in an auto the electricity would be supplied from the auto. Using this electricity to produce the hydrogen to be added to the fossil fuel can improve gas mileage. I've done this myself using platinum tubes as electrodes. I used nearly half the gas in one month that I normally would. The hydrogen and oxygen produced at the electrodes are mixed and fed to the air intake. This goes directly into the gas/air mixture creating a bigger 'explosion' behind the piston. This bigger explosion propels the piston harder. Using this less gas is required to travel a distance.