I will believe the Saudis don't see any upcoming problems with Ghawar when they cancel one of their projects due to low oil prices. If they continue to be full steam ahead with increasing their capacity then I think they are aware that Ghawar may not be as robust in 5 years time as they would like us to believe.
Joined: Aug 15, 2006 Posts: 282 Location: 'bout 15 miles from EU's eastern border (thankfully on the inside)
Posted: Sat Apr 21, 2007 1:18 pm Post subject: compressed air car
I recently read an article in a magazine i can no longer find about a european prototype for a car based on an engine working on compressed air. autonomy is about 200 km, and the recharge is electric. Does anyone know anything about this kind of technology? I found a site talking about an advanced version: http://www.theaircar.com/
However this refers to a "hybrid" fossil fuel - compressed air version. I'm interrested in the air only car, especially the way the engine works...
Joined: Feb 06, 2006 Posts: 166 Location: passaic, new jersey
Posted: Sat Apr 21, 2007 3:13 pm Post subject: Re: compressed air car
thanks for posting, i really enjoyed the youtube video - looks interesting, as a PO optimist i'll be checking this technology, i hope it's not one of those technologies that promise a lot but you never hear about it later
Since it is necessary to produce electricity to recharge them, are your vehicles really clean?
Effectively, there is no technology that permits for completely pollution free vehicles. We feel that the creation of electricity and compressed air in rural areas is more ecologically friendly than the combustion of fossil fuels in urban areas. Therefore, our current objective is not to produce a completely pollution free car, but rather, to produce a car that emits the minimum amount of pollution possible.
to me they look pretty honest, let's wait and see if they can deliver their promises
Joined: Mar 18, 2006 Posts: 1258 Location: Off with the Fey Folk
Posted: Sat Apr 21, 2007 3:23 pm Post subject: Re: compressed air car
Compressed air is a really interesting means of power storage - also of transmission if you get the technology right. It's used extensively today, in engineering workshops and also the mining industry.
Perhaps the best-known historical application was Brunel's 'Atmospheric Railway' which used a vacuum-pipe to suck the trains along. He had major problems with the infrastructure (over 150 years ago, mind) but I think most of these problems could be solved with modern materials.
JPL _________________ I see a dark sail on the horizon
set under a black cloud that hides the sun.
Bring me my broadsword and clear understanding.
Bring me my cross of gold as a talisman.
Posted: Sat Apr 21, 2007 8:50 pm Post subject: Re: compressed air car
From their FAQ:
Quote:
How much will the cars cost?
In Europe the MiniCAT's will be put forward at a base price of 6 .860 Euros (without Iva) except in some options.
The CityCAT's will be put forward at a base price of 9 .460 Euros (without Iva) except in some equipped options. Taxes and subsidized options have not yet been calculated.
Sounds like this could make a dent in oil consumption, provided that the power grid could keep up.
Joined: Sep 29, 2004 Posts: 2330 Location: Pennsylvania, USA
Posted: Sat Apr 21, 2007 9:14 pm Post subject: Re: compressed air car
I'd give the comp-air car a better chance than the hydrogen fuel cell car, but that's not saying much. _________________ "That's the problem with mercy, kid... It just ain't professional" - Fast Eddie, The Color of Money
Posted: Sun Apr 22, 2007 8:59 am Post subject: Re: compressed air car
Aaron's right. Compressing air then decompressing it to run a motor is really inefficient. They also are way optimistic on their range estimates, they have not achieved anything close to that. _________________ The shovel with a wheel - The Wovel.
http://wovel.com/
Posted: Mon Apr 23, 2007 3:38 am Post subject: Re: compressed air car
JPL wrote:
Compressed air is a really interesting means of power storage - also of transmission if you get the technology right. It's used extensively today, in engineering workshops and also the mining industry.
Of course it is used. It is used in those places where you don't want any sparks, no matter how inefficient or cumbersome your alternate storage is. CAS was tried also on personal cars, but soon abandoned; it is way too inefficient and costly (all this high pressure and changing temepratures take their toll on equipment).
Quote:
Perhaps the best-known historical application was Brunel's 'Atmospheric Railway' which used a vacuum-pipe to suck the trains along.
He had major problems with the infrastructure (over 150 years ago, mind) but I think most of these problems could be solved with modern materials.
I'd rather think he had major problems with some fundamental principles of physics and engineering, and those are the same now. First of all, the energy density of vacuum-induced pressure is lousy, meaning that your acceleration will be very slow. Second, materials are available which can withstand continuous vaccum, but would cost dearly. Third, maintenance would be problematic; if there's a leakage or a simple malfunction, not only the single train won't move, but no train on this part of the railway. Fourth, operation of trains at track switches would be awkward at best. And last, the competition with electricity-driven trains kills the technology in the cradle.
Joined: Mar 18, 2006 Posts: 1258 Location: Off with the Fey Folk
Posted: Mon Apr 23, 2007 4:00 pm Post subject: Re: compressed air car
kolm wrote:
I'd rather think he had major problems with some fundamental principles of physics and engineering, and those are the same now. First of all, the energy density of vacuum-induced pressure is lousy, meaning that your acceleration will be very slow. Second, materials are available which can withstand continuous vaccum, but would cost dearly. Third, maintenance would be problematic; if there's a leakage or a simple malfunction, not only the single train won't move, but no train on this part of the railway. Fourth, operation of trains at track switches would be awkward at best. And last, the competition with electricity-driven trains kills the technology in the cradle.
If I remember my college notes, I think the biggest problem Brunel had was braking the damn things. They used to shoot right past the station with everyone shouting 'Woah!'
Issues like these are solveable. But I also agree with your point that a vaccum-pipe is limited to a pressure-difference of 15 PSI (atmospheric pressure). But I still think it's an interesting idea. Apparently the trains were almost totally silent and also very fast for their day (remember we are talking early 19'th century).
JPL _________________ I see a dark sail on the horizon
set under a black cloud that hides the sun.
Bring me my broadsword and clear understanding.
Bring me my cross of gold as a talisman.
Posted: Mon Apr 23, 2007 9:01 pm Post subject: Re: compressed air car
JRP3 wrote:
Aaron's right. Compressing air then decompressing it to run a motor is really inefficient. They also are way optimistic on their range estimates, they have not achieved anything close to that.
Depends on use I suppose. MDI explicitly states that the model are for use in an urban setting, meaning city and only city. And, supposedly, their range estimates match up with this type of vehicle use.
MDI wrote:
The development of our vehicles has been the result of thousands of hours of research. The engines and prototypes have been the object of countless tests and trials. The car's driving range has been tested under various conditions (different temperatures and payloads). All of this is what makes the utopia real. Numerous experts examined the car before agreeing to take part in the project and it has also been shown on television programs around the world. At the same time the car is available for viewing by anyone who wishes to see it.
It's efficiency is roughly half to a third that of an EV. On the other hand, it doesn't require costly periodic battery replacements, and is cheaper to produce. In countries like France, where they have stable and significant electricity production from fission, as well as export electricity, the air car would likely make for a nearly pollution free, economical form of urban transportation. _________________
Posted: Tue Apr 24, 2007 4:25 am Post subject: Re: compressed air car
yesplease wrote:
JRP3 wrote:
Aaron's right. Compressing air then decompressing it to run a motor is really inefficient. They also are way optimistic on their range estimates, they have not achieved anything close to that.
Depends on use I suppose. MDI explicitly states that the model are for use in an urban setting, meaning city and only city. And, supposedly, their range estimates match up with this type of vehicle use.
I really liked the idea when I first saw it, nice concept. But not more than that. Their range estimates are the only truly impressive usage of condensed hot air I saw on their pages. Read
Their protoype ran for 7.22 km. They designed a prototype, set in on the street with full 'tank', and the car would run (from the sketches I'd assume straightforward with at most two stops) for 7.22km. That's the hard facts they can provide. (By the way, this 'test' took place years ago, and they did not, repeat, did not, publish any improvements over this number.)
Then they do very suspicious number juggling and get the result that the 'corrected distance' (I'm not making this up) is 242.10 km.
Unless you care more about engineering fantasies than about the real world, you should take good distance from such 'corrected results'.
They don't even play on the same continent than EV now, and most probably they never will, appealing concept or not.
Posted: Sat May 05, 2007 2:15 pm Post subject: Re: compressed air car
Well, it really depends on the validity of their assertions, which would need to be evaluated individually. Engineering fantasies or not, I wouldn't hold my breath, but I also wouldn't knock them w/o much more concrete information. Engineering fantasies are generally viable, if the consumer accepts the limitations, which they usually don't. For instance, most people wouldn't want to drive a 3L Lupo even if it got ~80mpg combined because they don't consider the compromises made to get the car to ~80mpg acceptable, however, if oil were ~$100-150/bbl, more people would probably accept it. _________________
Posted: Sat May 05, 2007 2:48 pm Post subject: Re: compressed air car
That's precisely why aerodynamics should be significantly improved so we can shove a big farking V8 into a midsize car and allow people to still get 35+ mpg while allowing 0-60 mph < 5 seconds. And we could also have 80 mpg midsize cars with diesels that still do 0-60 mph in 11 seconds.
Consumers in the US would gladly embrace efficiency then, and both the above are feasible today. The only ones averse to the idea are those running the auto industry, completely unwilling to leapfrog their technology, wanting to sell everything in-between. This is the same industry that decided consumers shouldn't be able to buy EVs, even if they wanted them and even though the technoogy for long range has been here for 10 years, and thus mass EV adoption had been set back 15+ years(if it will ever occur at all). _________________ The unnecessary felling of a tree, perhaps the old growth of centuries, seems to me a crime little short of murder. ~Thomas Jefferson
Posted: Sat May 05, 2007 4:08 pm Post subject: Re: compressed air car
That is definitely not feasible today! If the auto industry starts building V8s that get ~35mpg combined, they may as well throw in the towel completely, because 150mile lead acid powered EVs at ~2 cents per mile are right around the corner with those rolling shells.
The auto industry builds inefficient cars for two reasons. Every inefficient car drives up the price of gasoline/oil because the stuff is incredibly inelastic, and when gas does go to $6+/gal, they'll be able to make "breakthroughs" in automobile efficiency. _________________
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