Hot Air? Not Really

Cool.

This is a link people can follow to read about the technology.

http://en.wikipedia.org/wiki/Air_engine

Some engines use also liquified nitrogen that expands in the piston chamber and outputs power.

I'm not holding my breath to see many of these cars on the road. Compressing air remains an inherently lossy process, so regenerative braking will be less efficient than it is in an electric hybrid: more heat will be released to the environment.

The real hurdle, however, is that compressing and storing air requires more energy than required for charging batteries in an electric car, (or simply burning fuel directly in a petrol powered car). Even if that energy is from windmills, it would be better applied to charging batteries than to compressing air.

Air- or electric-powered cars, plug-in hybrids, hydrogen powered vehicles, etc. are anything but non-polluting. There will perhaps come a time when all electricity used to compress air, charge batteries, electrolyse hydrogen, etc is generated without pollution -- but that time is along way off. So, environmentally and economically, the fewer energy conversions, the better. Compressed air, like hydrogen power, adds a conversion that is not required in a fossil fuel vehicle and that is far more efficient (AC to batteries) in an electric car.

On the other hand, the relatively free air conditioning provided by the expanding air would be a real plus of this technology: running the air conditioner in current hybrid cars significantly lowers fuel efficiency.

But my crystal ball tells me that electric cars will be what we will drive in the future. The hurdles are falling fast, with battery and supercapacitor technologies advancing quickly. And perhaps most importantly, the infrastructure is in place. Where do you go to buy 10,000 psi air?

I agree electric cars are the future. Their concept is cleaner, with a lot less moving parts, they have everything to grow, at least until a new source of power is discovered.

Unfortunately, I'm affraid petrol companies will not allow it while they're making money... they just don't care about global heat. According Bush, no one has proved to him that the global heat is a problem...

get off this conspiracy kick!!

The plain and simple reason gas power rules is cheapness and power density.

Oil is cheap because we find it in a hole in the ground. like coal, and all we face are drilling and distrubution costs at first. So we used it to the exclusion of all other for that reason.

Now oil is running out. Canada could flood the world with oil from tar sand it if made huge extraction facilities to bring the cost down. It cannot get the cost down the Arabia's cost of less than $1/barrel. Tar sands need a lot of mechanical digging and processing to get the oil out. They say it is on the order of $20/barrel

this gives you and overview.

http://en.wikipedia.org/wiki/Tar_sands

If oil was $200/barrel a host of other wats to run vehicles would appear, and as oil gets higher and higher they will replace oil.

In time we will have no oil, 500 years? as the rate of consumption will drop dramatically as it gets to $250/barrel and people will not simply burn it any more.

Rising oil prices will drive better house insulation as we now waste 90% of the heat we use in houses. A well insulated house can operate on occupant heat from body, cooking and lighting. It needs a total vapor seal and countercurrent air exchangers for ventilation that trap heat and they use all electric light and cooking facilities. Model houses have been build. It costs an extra $30,000 for an average house to be built to this spec. With burned oil costing $1000/year for heating a common lesser insulated house the 30 year payback does not work. At $4000/year for heat it pay to do it.

As this time badly insualated houses cost $4000/year to heat now and the insulation business thrives in Canada to insulate old houses. All new houses must be built to the lesser standard now. In time they will go to the R2000 standard and beyond.

R2000 is now 20 years old

http://oee.nrcan.gc.ca/residential/personal/new-homes/r-2000/About-r-2000.cfm?attr=4

http://www.sk25.ca/default.aspx?DN=99,93,16,1,Documents

they now have the so called "super insulation" where the wall is a vacuum with radiant baffles as in a dewar flask. A super insulated house needs only body heat and counter current air exchangers to keep the oxygen level breathable and not lose heat by vents.

http://www-de.ksc.nasa.gov/dedev/projects/mechgse/docs/superins.html

http://biz.yahoo.com/prnews/070215/lath035.html?.v=92

Remember Lovins' (and probably others' also) suggestion that we match the intensity of the energy source to the intensity of energy need, so space heating is done from low-intensity sources, etc.

The style of home construction and its energy-conserving envelope have to be matched to its local environment. In Canada where Aurizon lives, this could be quite high, but in a great many places, the cost is much lower. Cooling and removal of humidity become major factors in many places.

It is easy to mislead ourselves into believing that because something is available we have a socially-justified need for it--witness the insanely huge homes being built and sold in the USA and other markets, and compare them with what is truly needed for health, safety, and modest aesthetic and cultural values. We can layer our clothes for far less costs than to layer our homes with extra insulation.

Back to air-powered cars. At a Kansas City Energy Expo around 1980, an air-powered vehicle was being driven all day from one end of the hall to the other. Certainly, the quietness, lack of pollution, and low cost of an air-driven piston have merit in many locations. Have we as engineers forgotten to KISS (Keep It Simple, Stupid)?

Unfortunately, the current levels of energy consumption are designed and built into our physical, social, and legal environment. It takes 30-80 years for changes in zoning, transportation type, home design and insulation levels, marketing and distribution, and all else to become substantially effective. Planning that far ahead is not something that we are noted for being good at. The present business cycles seem to expect a Return On Investment in as little as one year, with stock holders penalizing companies whose performance is poor for even a quarter.

Prophetic leadership tends to be dangerous, because we martyr anyone who tells us to shape-up. But, that is what we need, even if it is what we won't heed.

JMM

Compressed air as a source of power for any application is a matter of economics, convenience, safety, portability, etc.

As a plant wide utility it is expensive to compress, cool, dehydrate, and distribute to points of use. It therefore is used only where other means are inadequate. Chemistry labs require it as do dry atmosphere glove boxes and to cool the gloves and remove perspiration from operators hands via small supply tubing inside the gloves.

As motive power for vehicles it is a dead loser other, again, for special purposes. Eastman Kodak in Rochester, NY had an air powered railway locomotive. Deemed necessary in the vicinity of the film manufacturing facilities to minimize cinders and smoke contamination of the film products and production areas.

A pneumatic automobile - - - Phweew!

Here we go with the "If only it wasn't for the evil conspiracies ....."

I do agree that electrics ultimately offer more promise than compressed air ever will, but as we so often do, we are ignoring what's here now, and the fact is that a modern hybrid car, for all its faults is typically less polluting than generating the equivalent amount of power in a utility plant to charge batteries, with all the inefficiencies of the grid, charger and batteries themselves. Until we bring down the average pollution per kWh of our sources of electric power for the grid, electric vehicles will do nothing for reducing pollution.

Greg

I have a real problem with using compressed air as a general purpose motive force for traction. The reason being approximately 90% of the energy to generate the compressed is dissipated as heat. This is the same for positive displacement or dynamic compression. Furthermore my experience of air motors to convert the compressed air back into torque is one of inefficiency, noise, limited life & a messy oil mist in the exhaust, this applies to both vane & piston type.

Even if the system was closed with an initial charge of say dry nitrogen, the doubling up of pipework & effect of inevitable leakage would make the economics of the system questionable!

In addition storage requirements, especially at elevated pressure for optimum power density would pose an 'interesting' accident risk?

L MacKellar

8 March 07

The answer is processed and granulated politicians. Keep them in a sealed container and use the hot air for propulsion,.

This is as close to a perpetual motion machine as we can get. It has been postulated that they eventually cease production, but no proven instance has ever been documented...