Hooray! A reply already! =D I was elated to find that this discussion has ALREADY begun to take place within the permies forums, but apparently I wasn;t using the correct keywords to search for it. The compressed air powered vehicle you linked to is WAY outdated and there is a WONDERFUL new rotary engine that has been invented in Australia which is WOEFULLY under-reported, simply search for the keyword "Engineair", and check out this VERY cool video about it:
https://www.youtube.com/watch?v=-X6oWZe0QTc
As for "volume" issues for compressed air and the ALLEGED dangers of exploding compressed air tanks (all intentional propaganda in my humble opinion), there are all sorts of options for containers from "traditional" steel and aluminum holding tanks (including even old propane and other pressurized gas tanks) to using old tractor trailer tires that still have pressure holding integrity, just lack a usable tread to this concept I described about AIR BAGS made from carpets with the nap on the inside and purposely kept WET so that the surface tension of water clinging to the fibers could (theoretically) be constructed that would become STRONGER UNDER PRESSURE. The likelihood of an air tank "exploding" seems low to me. If anything, a hole may develop and a loud noise may occur as the pressure is released, but as for them becoming a "bomb" with shrapnel flying all over, we're not talking about HUNDREDS of PSI being forced into small places but MANY vessels holding relatively small amounts of pressure. Pressure relief valves are widely available that would prevent explosions and besides, wouldn't we rather have inert atmospheric gasses being discharged in a breach rather than some sort of FLAMMABLE or poisonous gas?
I can envision rigging a household with WALLS made of compressed air tanks and just about every appliance that we currently run from electricity being converted to ON DEMAND pneumatic power instead INCLUDING refrigeration units. Just IMAGINE the new industries that could be created building pneumatic appliances or in simply building replacement motors for existing appliances using scaled down versions of these new ROTARY air motors shown in the link!
Now imagine using one of these new motors to power an ELECTRIC GENERATOR in every household so that people could even continue using their electric appliances? We could even use existing natural gas and/or water pipes to distribute and share a common compressed air source that people would have the OPTION of adding pressure or consumiing it AS WELL AS using their own electric generators to add to the existing electrical grid! There are just SO MANY OPTIONS that would open up under this new, improved "grid" that would allow people to either be completely self-sustaining or generate INCOME from their own compressed air and/or electricity. The key in generating compressed air is going to be in bringing back the good old FLYWHEEL and I have some interesting concepts about improving upon this very simple basic machine principle including filling tires with WATER instead of air to create what I call a "fluidic flywheel" that would start rotating easily as the water remains momentarily stationary, and then inertia increases as the water catches up to the vessel speed, and then is difficult to STOP rotation as the water attempts to maintain the inertia.
Another idea I have is to use the HOLDING TANKS themselves as sources of inertial energy, like rigging air tanks to the perimeter of a playground carousel that charge up and GAIN WEIGHT which would enable the same amount of force to build higher and higher pressures, similar to the example that I believe is being shown in that "alien lightbulb" machinery. Here is a link to my latest project which is actually a VASTLY simplified version of other prototypes I've been working on (mostly before my bout with meningitis that has left me virtually bedridden and possibly a bit brain damaged. I have some other older examples on my YouTube channel as well along with a plethora of other urban permaculture projects.
https://www.youtube.com/watch?v=rOhBQDYTVuQ
I have some serious catching up to do in the other forums to discover how far other people have taken this concept and again I am OVERWHELMED to discover that others have indeed not only discussed this concept but have BUILT THEIR OWN MACHINES and have been using them since at least 2006 which is almost the EXACT time that I began "tinkering" with this stuff myself. Incidentally, I have also built machines that merely float on moving water sources tethered to the shore and convert the kinetic energy of moving WATER into compressed air. I can envision this concept being scaled down to harness the power of RAINFALL running through downspouts and storing the energy as compressed air right within the compressed air wall structures of homes (that would incidentally add INSULATIVE properties as well).
I do hope others find this discussion and chime in and/or perhaps we can revitalize the pre-existing discussions because I really do see some MASSIVE potential in this reversal of the notion that "cars don;t run on thin air" mentality! =D