[Aaron]

It might be useful to know what percentages of total consumption per region breaks down into. (ie. Commercial | Military | Consumer Transportation | Industry etc...)

So we can see how things like more fuel efficient cars for example, actually affect the depletion model. Since many alternatives are "specific use" technologies, like imagine a hydrogen powered tank for example, it's a mistake for us to assume across the board reductions or application.

[gg3]

Aaron, is that your actual picture there?

Re. military applications:

Compressed gas as a fuel has one drawback that may be significant. Toward the end of each "tankfull," pressure reduces and engine performance declines somewhat. I am aware of a CNG application for road sweepers, where the operators report that the machines become somewhat "sluggish" at the end of a tankfull. These are machines that require a lot of horsepower to operate the sweeping equipment, so even though they run at low road speeds, the performance drop is noticeable. It seems logical that hydrogen would have a similiar problem.

Tanks per se serve an infantry support role in combat, so they're constantly moving and have to be as nimble as possible; I don't think compressed gaseous fuels are adequate for that purpose. Same case for other front-line vehicles. The place where compressed gaseous fuels would be applicable is to vehicles that operate at the rear or aren't subject to active maneuver conditions. For example mobile rocket launchers, certain types of long-range artillery platforms, etc. These are moved in convoys and then set up in one place and basically stay there.

Question is whether we want to burden the military with the logistical complications of handling multiple fuel types. Ideal case is one standard fuel for all applications, and in that case it would have to be in liquid form. Diesel has huge advantages over more volatile fuels since it's intrinsically resistant to casual accidental ignition. Best case is a fuel that has similar characteristics to existing diesel, e.g. biodiesel sounds like a logical candidate, and has the advantage of having potential for local supplementary feedstocks.

A close friend of mine in the Army is very much interested in sustainable technologies; I can check with him about the appropriate applications for various renewable fuels.

[DoctorDoom]

Thanks, Aaron. Yes, this is exactly why I think it's important to have a good breakdown of usages, because I do think some level of both savings and substitution is possible, but it's not equally applicable. I think it would be useful to break down civilian versus military consumption, and to break down civilian into transportation verus heavy equipment, passenger versus freight, etc.

[DoctorDoom]

Reposting your graph from the other forum so I won't lose track of it:

http://www.energyquest.ca.gov/story/ima ... of_oil.jpg