The Ford Global Challenge - A Green Car That Runs On Air?

The challenge set by Ford Global Technologies is to design a Model-T for the 21st Century - an inexpensive, innovative and sustainable car. Deakin University is the only Australian university and one of only five worldwide invited to participate in the Challenge, part of the celebrations for the 100th anniversary of the fabled Model T; the car that changed the 20th Century.

Deakin University's 'under wraps' design for the Ford Global Challenge left for Detroit on 29th August carried by Deakin's Tim de Souza (Chief Design Engineer) and Stuart Hanafin (Portfolio Coordinator). Deakin's project is code-named T2 ('TSquared').

Forget petrol, forget electric... how about air?: Hanafin and de Souza believe their model, which has an engine powered by the release of compressed air, fits the bill.

"Fitting the compressed air technologies into cars of today which are quite heavy and large is infeasible," de Souza told 2GB's Jason Morrison. "Whereas the concept we've come up with is a really small, lightweight vehicle that can make use of this type of technology."

Although the idea of a compressed air engine suggests it wouldn't last long without needing a 're-fill', de Souza insists his model would have real staying power.

"One of the conditions [of the competition] is that it had to have a 200 kilometre range. So we've engineered it to make sure we have that range," he said. "It's a slightly tweaked system where we re-heat the air... which gives it a bit of a boost. If you just used plain compressed air you'd probably get 60 to 70 kilometres."

There were announcements late last year that IT MDI-Energy was to setup manufacturing facilities for air-powered cars in Australia. You can read more from TOD about that in The Air Car - A Breath Of Fresh Air Or A Waste Of Breath? and Q & A With Louis Arnoux of IT-MDI.

We hope to bring you the results of the Ford Global Challenge soon..

Does anyone know the current status of the Tata Motors / MDI CAT car?

I found this dated January 2008 saying that Tata will start pre-production this year

Nègre's company, Moteur Developpment International (MDI), has been working on the vehicle since the early 1990s, showing concepts at alt-energy conferences and collecting dozens of patents. The car has been produced in prototypes called the Minicat for in-town driving and the Citycat with a longer driving range thanks to an additional diesel or ethanol tank on board. It uses an electric motor paired with compressed air of the type used by deep-sea divers. The pressurized air makes the car's pistons move — and the pistons compress the air into a reservoir that lets it keep working.
The plan is to offer refills of the compressed air at service stations. Tata has invested nearly $30 million in the project and reportedly will start pre-production of the CAT car this year. How it stacks up next to Tata's own just-introduced Nano, the $2,500 "people's car," should be interesting. The CAT car is expected to be priced closer to $6,000. Nègre has an answer for that in the OneCAT concept, which would come in a "basic and cheaper" version with no backseats — and no top or windows.

NYT in July says next year

Mr. Negre’s engine will be offered as an option in Tata Motor’s new production model, the Nano, next year. The Nano, a minicar with an ultralow price tag, was introduced in January and is primarily aimed at the Indian market. Mr. Negre said a full tank of compressed air would cost about $3 and provide about 200 kilometers, or 125 miles, of driving. The tank could be filled by gas station compressors used for inflating tires, or a built-in compressor powered by plugging in to an electrical outlet, he said.

The "air car" has been just over the horizon for many years now - I wouldn't hold my breath waiting for one to appear from a commercial production line.

I saw an announcement from Tata this week that they will be producing electric vehicles using lithium-ion batteries for sale in Norway "within a year". If this occurs I'd bet the air car never gets built by Tata. Maybe I should do a follow-up interview with Louis and see what the current forecast is...

Good grief! The 'Air Car'! Why not an 'Air Helicopter' or an 'Air Cruise Ship'? The only way an air car can be 'green' is if the manufacturer paints it green.

I have some 'fuel' for an air car. It comes out of a hole in my butt ...

the solution to the automobile problem is the junkyard.

Actually, I think the idea of returning to blimps and zepplins is not so far fetched. Think of all that surface area for solar PV to drive their engines. Sure they would be slow but faster than a ship I think and have the advantage to go straight to their destination.

OK as long as they use hydrogen, not helium, which is a really critical irreplaceable resource which is being scandalously wasted.

It is so light that it rises straight to the top of the atmosphere, and is swept away by the solar wind.

It is vital for many engineering uses.

Certainly technology to handle hydrogen has advanced since the days of the Hindenburg. Is this a viable option now? Also, I was wondering what those engineering uses of helium are that would not also work with Argon?

There is a big 'fear factor' involved in the use of hydrogen, but the Hindenburg incident seems to have been caused more by the materials used than directly by the use of hydrogen.
In many respects the flammability of hydrogen is less of a problem than that of kerosene, as the kerosene being heavier pools.

Substituting argon means that you are using one rare element for another, and anyway is unsuitable in supercooled applications:

It doesn't make sense to waste a truly irreplaceable element, and hope that you can somehow do without.

Actually argon is not particularly rare at all, it's about 1% of the atmosphere. Of course, it's slightly heavier than air, which is why it's still with us, so it's of no use in airships or party balloons.

I always thought that the only 'smart' application in an H2 economy would be flying. I would imagine very large Zeppelins circling the planet on fixed routes in high altitudes; never landing, always at full speed, being accessed by smaller shuttles carrying passengers and cargo from and to the ground. Solar energy would be the propellant and collected from the cloudless sky via a thin film PV skin. H2 would provide buoyancy and at the same time serve as energy carrier for day and night operation. Traveling above 300km/h would provide additional lift and controllability. The longer travel times would be compensated by comfort and convenience known from large cruise ships. I would be the first to use such an infrastructure for my long distance traveling! r

PS: whenever I have the opportunity I visit the Zeppelin museum in Friederichshafen just across the lake - and I'm always fascinated walking around in the 1:1 model of the Hindenburg (

I actually had a few shares in CargoLifter, and would love to take a trip in one of the new Zeppelin NT ships.

Just need to go for a visit some day.

Airships can't fly in bad weather.


That's the point of Rolf_w's comment fly above the weather. As it is, all air craft get grounded in severe weather as they can't take off, but having a network of what is in effect a fleet of low orbiting blimps/weather balloons is technically feasible. There is also the idea of having these things covered in pvs and 'moored' to ground power take off points. As they are above cloud cover and atmosphere, they become much more efficient, + distribution looses are just the length of connecting/mooring cable (carbon fibre/composite something light and strong) - the added thing is that at the edge of the troposphere temperature is a cool -55 Deg.C adding further to electrical efficiency - possible superconductivity etc. But hey, no harm in fantasising eh?


They can fly over the weather. they just cannot take off and land so easily in bad weather. I suppose one could run out of champagne if aloft too long. Now, that would be a tragedy. ;->

Winds at that altitude can reach 100 mph. Just figuring out where they are would be a challenge:)

Considering the the German´s managed world wide flights in them with early 1900´s technology, I think we might manage quite well with GPS and modern weather tracking. Computers should be able to put those winds to good use.

Agreed. A number of 'outdated' forms of technology need to be revived. New technology can ionterface with the old. to make the old work better, safer:

- Trains
- Streetcars
- Sailing ships
- Blimps and Zeppelins
- Shipping canals

A lot of 'old fashioned' jobs need to be rediscovered, too. People need interesting things to do, besides work in a store in a mall ... or sit in an office sending emails back and forth to others doing the same thing.

"I think the idea of returning to blimps and zepplins is not so far fetched"

As a card carrying member of The Chums of Chance I would have to agree.

Ref: Against The Day by Thomas Pynchon

P.S. As to blimps, any schmoe with a 22 could take one out IMO as the glide ratio is rather weak.


I remember being excited about the compressed air car something like 6 or 8 years ago.

They were claiming that breaking returned a large % of energy via on board compressor brakes or some such thing, making it the most efficient car ever.

Also claimed that the exhaust air was cleaner than intake air therefore a large fleet would have the net effect of cleaning city air.

A win win eh? LOL

Compressed air cylinders often EXPLODE

Scuba shops recharge air tanks with them submerged in troughs of water. This is to keep the tank cool as it fills, and to contain shrapnel in case of tank failure. This is not unusual, and typically will shred the tank and destroy any adjacent masonary walls. Compressed air tanks are like balloons - they swell under pressure and shrink when they're empty. They can't be filled hundreds of times without risking explosions.

Ford currently makes the (European) Focus and Mondeo. Cars that, over there, knock it out of the park. Unfortunately, American management doesn't feel Americans would like a well made, tight, efficient, car.

They'd better come up with a world beater. It's the only thing that could save Ford from Ford management.

Compressed air? Didn't this website crunch the numbers on this idea recently and give it the boot? How light does this car have to be? What kind of terrain can it traverse? Let's face it, a car run on compressed air will need to super light, accelerate from 0-60 in a minimum of 3 minutes, and driven on flat terrain with smooth, new ashpalt. The whole time you'll be hypermiling it while attentively glued to an array of feedback displays. If you pass, it must be downhill on a long straight-away going past a car doing a consistant 45 mph.

Where's the beef?! People want gurgle, pop, and zing. They want to punch it past a slower vehicle in turbo charged nano second. Crank up the AC and stereo, while talking on a blue tooth munching on some fast food. Get real!

it may only haul horse jockeys.

A compressed air vehicle is not "powered by air." It is powered by electricity. The electricity compresses the air.

You might as well say that a conventional car is "powered by pistons." It is powered by gasoline. The gasoline drives the pistons.

The news media is clownshoes. So much money, so many lives, so much energy. All in the service of nonsense.

Didn't this website crunch the numbers on this idea recently and give it the boot?

I did some rough calculations, yes. It came out that going on their figures, and knowing how much energy is required to compress air, assuming a small city car travelling 200km (the maximum stated range for the air cars),

- petrol costs $26 and causes 46.4kg CO2e in emissions
- air compressed by coal-sourced electricity costs $2.85 and causes 34.9kg CO2e in emissions
- air compressed by wind-sourced electricity costs $3.99 and causes 0.84kg CO2e in emissions

Since I did those calculations, the price of petrol has gone from A$1.30 to A$1.50, and coal-sourced electricity from A$0.1355/kWh to A$0.1555/kWh, with wind still $A0.05/kWh greater. However this doesn't really change the relative costs of petrol and the air car.

I made some other comments about its practicality and plausibility which I needn't repeat here, except for the conclusion,

"it looks like another example of Science! at work. We're forever being promised some wonderful new technology, and it's always "just a few years away from commercial sale." I'm glad to see innovation, but I'll believe it's practical when I see it for sale in the shops."

I wonder how long the car industry will survive the 1st phase of peak oil (bumpy crude oil plateau since 2005).

British Car Market Runs Out Of Gas
New car registrations in Britain fell 18.6% in the year to August, signalling the weakest market since 1966.

Once the 1st physical fuel shortages arrive at the filling stations and shelves in shops start to be empty, our focus will turn on how we can maintain food production and distribution as well as basic services, not which cars we drive. Car pooling will allow us to keep going for a couple of years, provided there is no big bang in the Middle East. Read here how the strategic situation has changed during and after the war in Georgia:

The Medvedev Doctrine and American Strategy

Russian units raid Georgian airfields for use in Israeli strike against Iran – report

Kazakh oil and gas worries

Iranian Trump Card. Russia Can Take Control of Persian Gulf

And we can expect dramatic, yet unknown, climate change events in the next years, possibly connected to the disappearnace of the Arctic summer sea ice.

September 4, 2008
Record ice loss in August

Maslowski calculated this event may happen in 2013
Causes of Changes in Arctic Sea Ice; by Wieslaw Maslowski (Naval Postgraduate School)

Once the Arctic summer sea ice is gone, disintegration of glaciers flowing from the Greenland icesheet will accelerate and when this process goes beyond the grounding line, sea level rises wil start immediately.


Then it will dawn on all of us that we'll have to abandon coal much earlier than previously thought. So where will the carbon free primary energy come from to drive millions of cars? This is not a technology but an energy problem.

#1 priority will soon be to replace and/or retrofit our EXISTING coal fired power plants. There is no room for any new demand for electricity for cars.

I recommend to re-tool our car factories and parts suppliers to mass-produce components for the renewable energy industry. This chance was already missed when Mitsubishi closed, a company also manufacturing generators for wind farms.

Forget your car dreams. In urban areas, time is running out for all Capital cities to adopt the Transperth solution, electric rail on freeways:

B series departing Murdoch bound for Mandurah

Excellent post Matt, thank you. My up and down buttons are not working today.

It should be noted that Henry Ford was little more than a crank wandering Detroit with a cranky idea and a design scrawled on a napkin....until he met John and Horrace Dodge.

Horrace scrapped Ford's entire drive train, redesigned it from scratch and John agreed to supply them on credit, over $10,000 worth on the initial run. Once the Dodges bought into it, others stepped in and Ford the Great was born.

A car in every pot. A bird that is coming home to roost.

I'm as into defaming Ford as the next guy, but I'd be curious to know where you got that information. Before becoming associated with Dodge, Ford had already produced several cars with different sets of backers -- including the famous 999 racecar driven by Barney Oldfield with the money of Tom Cooper, a champion bike racer -- and before that Ford was the chief engineer at the Edison station in Detroit. Furthermore, when the Dodges were hired to make trannies for Ford, that particular incarnation of the Ford company had already been formed with the money of Alexander Malcomson, a coal baron. Or not?

Robert H.

A car of this type requires a vastly different cost structure to build and be profitable for the manufacturer, I think.

It's a very good idea since it has the feel of appropriate technology to it (it could be a neighborhood vehicle, for instance), but it's an idea that I think needs to surface post-collapse, once the labor and material costs have adjusted to the new economic context.

I don't see it being profitable until then, but I'm open to being shown to be mistaken.

it could be a neighborhood vehicle, for instance

We already have one of those--a golf cart. Why reinvent the wheel? :)

Indeed we do...however, please see my posts later in the thread about battery availability.

As others say, the idea [as described] is a non-starter.

Something which could be useful [which I posted in TOD years ago] is the expansion motor [eg steam/air engine] driven by dry ice. This could be frozen from other waste combustion sources by intermittent renewable energy. You are effectively storing [in refridgeration to ~ -40C] intermittent renewable energy sources in concentrated transport form, so conversion losses are less crucial. This would give far more range than compressed air but would still work best for planned scheduled transport like ships, trains or rail transport [similair limitations as coal driven].

It's nice to think about new technology. However, the old technology still works pretty well. And it is very cheap.

The tata-nano runs 50 mpg (20 km/l) if not better and costs US$ 2500. Even if oilprices triple (!) it would still be cheaper to buy a car like this iso any new-technology-based-car.

And if that is too expensive for you, then you can always ride a solex.

Very old technology (from after ww2!) It gets you around 100 mpg or better.

So if you use a nano if there are more of you or for longer distances (or the train if available & practical) and a bike or a solex for cruising through town, you basically have cut your petrol use with 75%.

And if you need to do some shopping or get your kids to school, then this one will be just perfect:

Where do I find the trike for hauling? Is it geared to maximum human energy and an earlier post here described?

I'm not sure about that particular trike, but I saw an xtracycle in Houston (, and it can carry a lot. I think having all the weight between the wheels is good for ease of riding.

Air pollution and safety laws mean the Tato may not be street legal in the U.S.

Ralph Nader brought safety lawsuits against the auto industry that may have resulted in energy inefficiency. Now there are ultra large SUV's that were safer in head on collisions with cars. While SUV drivers were more likely to survive such collisions, they were more likely to kill people in accidents because of the large size and crash impact potential. These large vehicles had a much greater required stopping distance and in the hands of some drivers were "unsafe at any speed."

I heard about a friend of a friend who had injured someone in a vehicle accident. The person got a letter from his insurance agency informing him the cost of medical care to the party he injured was expected to exceed the insurance limits and the policy holder would be responsible for any further medical bills.


It's not about the Nano, from the Tata company. If this car is not street legal in the US, then there are others. The Daihatsu Cuore gets more than 50 mpg, and there are many more.

This technology is very old. Cars that run 50 mpg were (more or less) the norm after ww2 in Europe. Take for instance the Citroen 2CV

This car was originally designed in the 1930's, targeted at the French rural population. France does not have any oil, so it had to be efficient. And it is (was actually, it's no longer in production)

The point I'm trying to make is that it's rather easy & straightforward to cut your oil use in half, or better. It doesn't require any new technology, let alone a Manhattan project (of which a lot op PO'ers are big favorites)

You want a car that does 75(!) mpg? Here it is:

It's the VW Lupo 3l. It runs on diesel. There is one parked right across the street from my home as we speak.

I agree with your points entirely. Here in the US, we would be far better off to simply bring vehicles like these - already designed, developed and manufactured - to market ASAP, and spend our real efforts on electric light rail. Instead of connecting towns and villages with rail, which would even allow salvaging of many suburbs, we do nothing while dreaming of all the wonderful new technology that will allow us to prolong the car culture forever. Which is of course doomed to fail.

If the projections given here are anything like right for fuel availability, then just doubling mileage will not do the trick.

By around 2018 fuel available for passenger cars will be very low indeed, so why buy a car you will barely be able to use?
You are better off running your present car very, very occasionally, and using a bike the rest of the time.
A new petrol car is just throwing money away, and in any case if they use the lease system for batteries as expected, a pure EV would cost less to run than a petrol car.

I don't disagree with that, and I have no intention of buying a new car. My main point was to move away from the car and back to the train, and to not waste time/money/development effort on new automotive fantasies. That includes replacement of infrastructure and upgrading of the electrical grid for EVs.

Well, whether or not passenger EV's take off, the fact that they are trying to get them to work is what is paying for the progress in batteries which will enable moving goods from the railhead to the shops.

We would be pretty stuffed without that, not to mention emergency vehicles and so on, so perhaps it is a pretty useful fantasy.


This one is Dutch. (Actually it is Turkish made, if I am correct) The website is, but it is in Dutch.

There are many brands everywhere in the world, just ask around. The Chinese alone should have a few factories lined up!

Anyhow, I have actually one of these. They are ok to drive. You can get up to 15 mph, but that is rather fast. Usually about 8 or so. If you are in reasonable shape, then a 5 miles hike should be no problem. And if you have one, then you get in shape anyhow. I go for a ride with my 3 kids on sunday for a few hours and that's all laughs all the way. Or tears if the kids start beating each other ;-)

This is a Dutch bike, to be found on
They actually also sell abroad in Germany, Belgium, Denmark, Japan and the US (Chicago).

We are all about focusing our technology on war, folks. Trinkets like the Tata and the alleged air car and solar cars and the like keep some folks distracted. That serves some purpose for the war effort. Luxury SUVs do the same for another market segment.

Ford and GM are both run by npeople who know better than to think that affordable transportation for the masses is really an issue now. Most of us are "the masses" and are simply too expensive to keep around for much longer.

I drive a Zap Xebra PK -- electric. It is a good experiment for me in a particular direction toward sustainable transportation. I may go back to walking and biking within five years or so, if I'm still around.

I no longer see solutions for us all. Different people try out different things, but we are mostly making the planet far more toxic and far more violent each day. Our appetite to consume resources, create pollution, and destroy life seems to grow exponentially.

Ford's public relations machinations do not change the fact that they are a Corporatist entity completely embedded in the fascist war machine.

Of course Tata Motors is no different. The political and business leadership of China or Russia or Europe or Australia or wherever are into the same game for full spectrum global dominance.

Our species devotes our big brains to killing and consuming and dumping waste. Look at how much better we become at killing large numbers of our own species every day, and on purpose, too. Then look at how much better we are at killing large numbers of all the living species each day. This is called progress.

I wish the air car boosters success in experimenting with air cars. The nonsensical hype surrounding it is much like the nonsensical hype surrounding every "Green" product or service I've seen so far in my life. Plenty of hot air from Wizard of Oz-like PR hacks combined with realities that simply are not at all what was promised.

It is all about War. Now more than ever. We focus our economy on being able to kill more, consume, more, and dump more waste. We focus on creating Hell on earth for the next generation: more violence, more toxins. Thast is what we do, as opposed to the hype sold by educators, pharmaceutical companies, car manufacturers, energy companies, and environmental nonprofit groups. "It's the War, stupid!" is our most honest motto.

Can the air car be made into an up-armored Humvee? That's the key question. Otherwise, it may transport a few stupid, distracted happy idiots to and from their jobs engineering better cluster bombs Monday-through-Friday, and then to church, mosque, synagogue, or secular recreation on whatever Holy Day may or may not work for them.

That's a tough point, Beggar, and one we must not forget. Glad you said it.

But we're not powerless, either. We just have to decide where our power lies. (Unintentional Double-entendre'..)


“My optimism rests on my belief in the infinite possibilities of the individual to develop nonviolence.... In a gentle way you can shake the world.” M Gandhi

Thanks Bob -- I'm going to remember those comments. They are funny in a way: "we are not powerless" and "...our power lies," but also true in interesting ways.

The Ghandi quote is spot on.

I wish the experimenters and the folks who try different things all the best. We need to explore all the infinite possibilities for nonviolent change.

One never knows when good surprises may happen, and it can keep us from dissolving into a puddle of misery as time goes by.

The air car is interesting, but it -- like many of our technologies -- is ultimately an energy user.

We suck in that energy and we use it to do stuff.

The efficiency of various ICE's is not great in the big picture either, it is just that gasoline has been so darn cheap that it makes us feel like the ICE is efficient.

Isn't that last observation about ICE's fairly accurate?

I may be missing something, but on its face this seems like a net energy loser.

For every action there's an equal and opposite reaction - so if it cost zero energy to compress the air in the first place, the system would be in balance.

But that cost isn't zero, so when you add the compression energy cost, you end up with a negative EROEI.

Or am I missing something?

There is nothing wrong with negative EROEI as long as it is for an energy vector instead of an energy source,

Many of the sustainable energy sources like wind and solar can't be put in a fuel tank for vehicles. But if they can be transformed into a transportable vector, they can still power vehicles. Of course the law of physics are that the conversion into a vector always involve energy losses.

Guy Negre's air car concept has changed considerably since the first prototype.

Whilst the engine will run on the stored energy from a compressed air cylinder, the range and speed is very limited. Negre is very cagey about how far the prototype actually ran, that data was covertly removed from the MDI website, about the same time that he started talking to Tata.

To get more range and power, Negre developed a liquid or gaseous fuel burner, which heats the air before expanding it in the engine. The vehicle is thus propelled by the heat energy from the fuel rather than solely by the stored compressed air.

Two conclusions:

Compressing air for vehicle propulsion would put a significant burden on the electricity grid. Compressing air is a very inefficient process - IIRC 7hp are needed to compress air to provide 1hp of power.

Using fuel to heat the air, converts the engine to an external combustion engine, and the overall efficiency of this in an automotive application is questionable.

You are down to the same old energy sources for vehicle propulsion, the electricity grid and liquid/gaseous fuels. There is no such thing as a free ride.

This makes it sound like a parallel hybrid with a grossly inefficient battery technology and no ability for regenerative braking.

Hi Russ,

Yes, in some sense it is a net energy loser. But just like any machine that obeys thermodynamics (be it an IC car or an electric car).
And indeed it does not have negative EROEI. You put some energy in, some of it is used to move you around and most of it is wasted in heat.
In this case you spend either electric energy to pump the air in, or you spend some fuel (biofuel, diesel, or any other) to run the mechanism that refills the air tank, and then the stored air (or its energy) is used to run the pistons (with a given efficiency). At city speeds you get 150 miles/gallon (that is per gallon of fuel that helps refill the air-tank). [they are hoping to get to 300 mpg ~ 1liter/100km)

The idea got a start because compressed air was used in the starter motor in race cars, and there is considerable experience with this.

It is not nearly as efficient as using a battery, but saves on that substantial cost, and so with many years when battery technology was stuck looked quite attractive, but the technology is moving forward nicely now, and if it is got going is a niche player, for instance France could use them, re-charging when they have surplus nuclear power as city run-abouts.

It's probably an idea whose time has passed though.

Hi Dave,

As this blog has previous;y said, Its largely an EROI problem. When the heat of compression and the cool of expansion is taken in the equation and then the energy required for the physical compression it is not a very efficient system.

The weight and danger of high compression storage tanks does not help much.

Maybe if we put the air through a one horsepower electrical turbine we would be closer what is feasible.

All of us are still hung up on the false construct of personal transport. We want 0-60mph times, we want long distance endurance times we want family comfort.

My dad as a child used to go to the beach, 30 miles away in an ox-wagon. It took a whole week-end and they were very grateful of it.

I took out a friend's 1150CC BMW motorbike yesterday for a "burn". It was totally orgasmic and thrilling. My regular daily transport is 150CC Chinese piece of junk. My overall impression is that somewhere along the line, BMW has forgotten why they started to make bikes. Any single one of the 60 horses in that BMW could transport me equally well.

We will never be able to find an alternative to the modern false construct of what a vehicle is.


Hi reindeer,
I don't see present ownership and use patterns of transport continuing either, mainly for financial reasons rather than technical.
However, that does not mean that a very fair level of personal mobility shouldn't remain, as we can do things a lot smarter.

Light rail, pedestrianisation and re-zoning etc to move work and home closer are some of the obvious moves, but initiatives like one in Paris are also entirely practical:

this is entirely practical, as it just duplicates and already running scheme in La Rochelle.

The main reason I am interested in EV cars is as they will advance battery technology, making this sort of thing practical so that you can pick up bulky purchases and so on without undue hassle.

It also advances the use of battery technology so that electric delivery vehicles can become the norm - you have to have some way of moving things from the railhead:
English electric trucks heading to America | Diesel Progress North American Edition | Find Articles at

My favourite initiative is this one:
Taxibus | Intelligent Grouping Transportation

In combination with electric bikes, trikes and scooters in urban areas at least a very fair degree of mobility should be possible at a fraction of today's cost and energy use.

It is rather tougher in rural areas, but there is the world of difference between a rural community which owns and runs a couple of ten-seater buses and trucks, perhaps hybrids using biofuels, and one which is entirely isolated.

The compression side of compressed air cars is not that bad.
It's about 37% efficient and the storage medium is cheap. Also heat could be recovered from the compression side.

Compressed air storage is cheaper than batteries, environmentally friendly and long lasting. The tank space requirement is no worse than some kinds of batteries, so it would match a short range battery car.

Another big advantage over most battery technologies is fast-recharge, so as long as you stop often you can go as far as you like, as long as charging points are available.

majorian -

While in principle it is possible to recover a portion of the lost heat of compression by means of multi-stage expansion with heat exchangers between stages, it would appear to me that such an approach would be far more suitable for a stationary power system rather than for a vehicle. After all, this air vehicle is supposed to be super light and simple, and going with a complex arrangement of expanders and large interstage heat exchangers would appear to be neither light nor simple.

Most torpedos of the WW II era had some form of fuel-based heating system to counter the rapid cooling effect of the expanding air and to pump more energy into the expanding gas and thereby extend the torpedo's range. But I think as was stated somewhere up thread, this would effectively turn the air engine into a sort of external combustion engine.

It's very hard for me to see this air car concept going anywhere.

I expect that compression would be in a stationary system (e.g. gas station). Expansion is local to the vehicle. Drive it on hot days to get free A/C.

That said, recovered waste heat at the compression station has no practical use, unless used as low grade building heat.

chemE -

What you say is true.

However, in this case what I am referring to as 'recovering' the heat of compression is something a bit different. Some of the heat of compression is inititally dissipated to the atmosphere via the hot surfaces of the compressor and also the storage tank, as the latter cools down and drops in pressure. If you employ interstage air-air heat exchangers, then some of the heat in the atmosphere is temporarily transferred to the cold expanding gas, thus increasing its energy. This I suppose is a rather roundabout use of the term 'recovery', but I'm not sure what else I should call it.

True enough - could work for on-site elec. generation for example. Unfortunately, even in that application one would expect that compression and energy recovery via expansion will be separated by time. Therefore a heat storage mechanism would be required for storage of that low grade heat (in the sense of the second law of thermodynamics) - as you know that adds cost, complexity and inefficiencies.

Compressed air storage is cheaper than batteries, environmentally friendly and long lasting. The tank space requirement is no worse than some kinds of batteries, so it would match a short range battery car.

It's for these reasons I think this idea should be pursued until enough people have looked at it enough times before pronouncing this technology DOA.

I'm not assuming batteries will be plentiful and cheap. At best they will be expensive and "available if one has the money," particularly some of the more exotic chemistries. Thus, an alternative to storing energy in a battery is a worthwhile thing to pursue, even if it gets us only a neighborhood passenger vehicle or a work trolley of some sort.

I'd agree that it is worth giving compressed air a go.

However, it is hardly correct to say that 'at best' batteries will be expensive, since a number of technologies have the potential to be cheap and are made from readily available materials.

Of course, it is possible that incomes will decline even faster, so that they are still relatively unaffordable, but the statement that you have presented a best case is not sustainable.

With this sort of forward-looking statement, I operate on the following assumptions:

  • average incomes will indeed decline, making everything less easy to buy
  • items we merely want will become cheap until they are no longer made (discretionary/luxury items like a game console, for instance); items we really need will become very expensive, like batteries
  • a failed currency will make trade difficult -- what medium of currency will the battery factory take?
  • a rush for supplies will cause scarcity early in any collapse scenario I can see; it will take some time for supply to catch up to demand and for many items it's entirely possible that it will never catch up

Any one of the above factors is enough to push batteries beyond the reach of the average person, two or more and it becomes more difficult and may be impossible to get the batteries one wants.

There was a list floating around of the items that became scarce during the Kosovo war, I can't find it but I think I recall batteries being one of the most valuable items to have and trade.

Given the above, I think the statement that batteries will become dear is easily supportable.

You may be right, and that is one possible scenario, but that still does not make it the 'best case.'

Unfortunately, we shall soon find out.

If your scenario (abundant and relatively affordable batteries) turns out to be true, I'll happily drive over in my battery car to bring you a good bottle of your favorite liquor.

If my scenario turns out to be true, maybe you can send me a bottle by the USPS.


Well, aangel, again that is not really accurate, as I have not presented a scenario, still less an optimistic one!
I tend to think in the same way as business's now plan, or the IPCC does it's projections - I don't know what is going to happen, but I see a range of possibilities, some more optimistic than others.

My crystal ball is cracked, and the variables are too great to be definitive IMHO.

My 'best guess' would not be too far from yours, as it happens, but I don't know that that is how it will pan out.

I would never have believed that the finance world could create such a ponzi scheme as they have, so my expectations could always be falsified again - as a neophyte to the world of high finance, a certain modesty in being too absolute in predictions would seem to be called for.

On the slightly safer ground of technology, it seems possible although not certain that lithium batteries can be reduced in cost from the present $1-1.5k per kwh through $500 to around $200, and obviously that has very different implications to one where those efforts are less successful.

I also don't know whether the compressed air car will be practical, so in many respects the future remains mysterious.
It is clear though that oil use will have to drastically decrease, but that is about all that is totally clear, the rest is an exercise in probabilities.

" lithium batteries can be reduced in cost from the present $1-1.5k per kwh through $500 to around $200"

Current costs for conventional li-ion, per Tesla, are about $400 per kwh. That's for small format, cobalt based li-ion: iron-phosphate li-ion batteries such as A123systems should be less expensive in large volume, as large formats are cheaper, and the materials are cheaper too.

Battery costs fall relentlessly every year due to increasing manufacturing experience by 7-10%: Toyota's NIMH batteries have fallen sharply in cost, and Tesla expects to get their replacements at 5 years out at roughly 40-50% lower cost.

$200 per KWH is very reasonable to expect in 5 years. Also, don't forget lead-acid, the neglected stepchild of PHEV batteries: Firefly's are likely to be around $125/KWH this year (for weight and energy density performance very close to li-ion), and, of course, will also fall in cost.

Frustratingly for those of us who want info, GM is exaggerating costs to justify an initial early-adopter premium, and lobbying for tax credits (or possibly they're just being very conservative...).

It should be noted here that the price decreases you both are counting on are also dependent on a scenario, namely business-as-usual.

During economic crises, scarcity (whether from inability to pay or reduced production) and higher costs are the order of the day, not reduced costs.

After the wave of company consolidations (and bankruptcies) that occur at the beginning of every recession/depression, we will next start receiving reports of previously announced products being cancelled.

The companies will start saying they need to:

  • "concentrate on core markets" or
  • "lower costs by lowering the number of product lines we carry" or
  • cancel xxx due to the "inability to raise funding to continue product development"

and such. I saw this first-hand while raising money for a venture during the dot com era. Money is about to get very, very tight.

I for one would be enormously surprised given what I expect to occur if these numbers of yours pan out. But as I note elsewhere on this thread, we shall very soon find out.

You do seem to frequently re-write what is actually said to suit your preconceptions.
When you say 'both' I could not have made it any clearer that I was making no price predictions, instead stating what the targets were if it worked out, and I also made clear that the figures were indicative of likely technical improvements, and would also depend on the financial environment.

Please try not to read in meanings which are directly contrary to what I actually say!


you may be correct...or perhaps you're being a bit sensitive? We're just having a conversation; neither you nor I are being graded.

I wasn't having a go at you - it's all perfectly civil on both sides.

Don't be too sensitive when it is pointed out that you have misrepresented what I was saying - I obviously could not leave that as a fair representation of what I actually said since it was in direct opposition to that!

"the price decreases you both are counting on are also dependent on a scenario, namely business-as-usual."

No, though it would help to avoid a deep depression. I would note that there is no evidence for the likelihood of a deep depression. I've seen the crash in SUV and pickup sales given as evidence, but isn't that what we would want? Car sales are stable, and manufacturers can't make enough fuel-efficient vehicles to satisfy demand at the moment.

The scarcer liquid fuels are, the faster PHEVs will arrive. Transport electrification would accelerate even with oil production at 50% of current levels (and no one is predicting that in 10 years) - the US, at least, could run the essentials of it's economy with 50% of current oil consumption. It wouldn't be easy or comfortable, but it could be done very straight forwardly - envision every highway 100% HOV. Don't forget, the world economy has grown more than 40% in the last 5 years on essentially flat oil consumption - it's not btu's that's the problem for the US, it's the current account deficit.

Now, is it possible for the world's economic system to crash? Sure - we know that any economy (including that of Meerkats, to Mesopotamian agriculture, to modern credit economies) is potentially unstable. Could oil exporters shoot everybody in the foot by crashing the dollar? Probably, but why would they? No, the likelihood is that we'll muddle through.

You might want to take another look at my discussion of the flaws in Hirsch's analysis.

"During economic crises...higher costs are the order of the day"

I'm not following you there - could you give examples?

"we will next start receiving reports of previously announced products being cancelled"

Sure. OTOH, Toyota and GM are making hybrids and PHEVs the core of their business strategy. Increasing oil scarcity will only strengthen that.


Hirsch never claims in his paper or in interviews more than an order of magnitude correlation and you seem to read into what he says quite a bit more than that. I think you are misreading him.


Well, I'm glad to hear it - I only included that because it was the only argument that I was aware of for a depression. If you feel that Hirsch isn't arguing for that...then...I see even less support for the idea of a looming depression.

So: I don't see evidence for a likely financial crisis. Do you agree?

Yes, I agree that you don't see evidence of a likely financial crisis. But it is there to be seen if you look around. Fossil fuel-dependent sectors like the airlines and car companies are already requesting government bailouts in the tens of billions to stay afloat. I think the executives in those companies would consider this a financial crisis even if you don't.

As for Hirsch, the point of his paper is to get a sense of the impact on the economy of declining oil availability. He does that by bracketing the range of impacts and saying that it will fall somewhere in between. On one side he uses the correlation of the Arab oil embargo:
% change in US GDP / % change in oil supply
-3% / -4.4 ~ 0.7

and the Iranian Revolution:
% change in US GDP / % change in oil supply
-3% / -5.4 ~ 0.6

to establish the low end of the range.

On the upper end he uses the correlation of the economy and oil from 1995 through 2006:
% change in world GDP / % change in oil demand = 2.5

Thus he has ruled out a 1 to 10 ratio as too small and a 10 to 1 ratio as too large.

Based on the above, he adopts the following premises for the remainder of the paper:
"(1) when world oil supply declines on a sustained basis, the resulting shortages will cause world oil prices to escalate and world GDP to decline, and (2) a sustained percentage decline in oil world supply will cause an approximately equal percentage decline in world GDP."

Then he examines three scenarios:
Best Case Maximum world oil production is followed by a period of relatively flat production (a plateau) before the onset of a decline rate of 2–5% per year.
Middling Case World oil production grows to a relatively sharp break maximum, after which it goes into a monotonic decline (2–5% per year).
Worst Case A sharp break worsened by oil exporter withholding, leading to rapid declining world oil production (potentially greater than 2–5% per year). The timing of withholding is not predictable, but it could easily occur before the peak in the Middling Case.

And in establishing those cases he uses phrasing like "extremely damaging" and "economically devastating" and "An annual decline rate of 5% or higher would likely be devastating."

Hirsch does not say which of the scenarios he leans towards in that paper, but it is clear (to me at least) in listening to him that he is extremely concerned about the economy.

Since I tend to think events are going to spiral out of our control (the worst case scenario), I think we're headed for "devastating impacts."

I am unlikely to continue this conversation with you beyond this point, so please forgive me if I break off at this point.

We seem to be going in circles. I'm sorry you may not answer, as we've gotten to the brink of dialogue in the past, and you've shied away as well. I'd love to actually follow a dialogue through to some kind of progress.

"Fossil fuel-dependent sectors like the airlines and car companies are already requesting government bailouts in the tens of billions to stay afloat. "

No, not the whole sector, just individual companies, just as Chrysler did decades ago, due to legacy costs and product mixes. Southwest Air and Toyota are doing just fine. That's not to say I think the airline industry, or Detroit, will do all that well in the upcoming years, but they're not indicative of the overall economy: Detroit's truck and SUV sales have fallen 40%, but the US GDP was still growing at a 3.3% rate in the 2nd quarter.

"I think the executives in those companies would consider this a financial crisis "

No, not for the whole economy.

As for Hirsch, you say: "a sustained percentage decline in oil world supply will cause an approximately equal percentage decline in world GDP."

Well, that's exactly how I read him. I'm puzzled that you said above that I misread him.

So: Is this realistic?

No. We can see this from economic history: in the US, oil consumption fell by 19% from 1978 to 1983 and yet GDP grew slightly (I'm baffled as to where the stats above for the "Iran crisis" of '79 come from). Similarly, world oil consumption has been flat for the last several years, but GDP growth has been quite strong, stronger than for the US (which itself has grown 8% in the last 3 years, with flat oil consumption).

Hirsch seems to have looked at the relationship between oil and GDP over the last 20 years, noticed that the ratio of oil increase to GDP increase has dropped from the previous 1:1 to roughly 1:2.5 (an analysis which he attributes to the DeutcheBank, but which can be derived straightforwardly from IEA statistics). In other words, in previous decades as the economy grew, oil consumption grew as quickly, while lately less oil has been needed. Hirsch drew the very strange inference that GDP has become more dependent on oil, rather than less.

An important and relevant researcher here is Robert Ayers . We see that he showed that GDP is related to applied energy (exergy), and only very loosely linked to energy, let alone to oil consumption. The research indicates that BTU's only explain 14% of GDP,and that the source of those BTU's can change (coal to oil to wind, for instance). Both energy efficiency and energy intensity can change. Further, oil is only one source of BTU's. Oddly enough, many energy commentators seem to misunderstand Ayre's research, and think that it supports the idea of a strong causal connection between oil consumption and GDP.

US (and world) GDP would grow much more quickly than it's energy consumption (even including electricity). The best example of this is California, which has kept per capita electricity consumption flat over the last 25 years, while growing it's GDP relatively quickly.

Ayres used "exergy services", which are not "very close to BTU parity". Exergy services are work performed. So, for instance, a Prius performs the same work as a similar vehicle with half the MPG, but uses half the BTU's. Strictly speaking, a Prius can perform the same work as a Hummer (transporting people), and use 20% of the BTU's. An EV also does the same work as a Hummer, and uses about 1/3 of the BTU's as the Prius, and 1/15 of the Hummer's...and so on.

So, Andre, I looked at yourblog, and found it simply accepts Hirsch's arguments. It
discusses both Hirsch's findings as well 3 other reports. Oddly, two of those other reports actually disagree with Hirsch's thesis of a strong causal connection between oil and GDP - this analysis seems to misunderstand Ayres in the manner that is discussed above.

This is unrealistically pessimistic: "oil is peaking or will soon peak. I don't quibble over 2012 or 2020 — either date is a disaster for humanity because we can't get ready in time." source: . A difference in timing of 8 years makes an enormous difference.

You said "Hirsch does not say which of the scenarios he leans towards in that paper" but in public comments he said: "So then if one calculates a range of 2 to 5 percent, some people think the number may be larger, 2 to 5 percent per year increase in oil shortage, one comes up with a rather disastrous indication world GDP will decline by 2 to 5 percent a year in tandem with increasing oil shortages." So, clearly he's going with the "disastrous" interpretation.

"I tend to think events are going to spiral out of our control "

But why? Is this based on Hirsch, or something else? I think I've shown that Hirsch is misinterpreting the evidence. If you see other evidence, or see a way to rescue Hirsch's arguments, please say so.

Ayres' paper is totally weird, peppered with his own new theoretical constructs. It was probably published by the IEA as a cover for their inactivity.

He limits the analysis to the USA which has been shedding manufacturing like mad over the last 30 years.

Oil is needed worldwide. Oil is critical to global trade which keeps US GDP and everyone else growing.

Hirsch is right that a decline in world oil production will cause a decrease in world and therefore US GDP. And 8 years won't make any difference because the problem is too big.

Aren't things spinning out of control fast enough for you now?

"Ayres' paper is totally weird, peppered with his own new theoretical constructs. "

hmmm. I often see people on TOD relying on it, including Aangel, and I have to say, it makes sense to me. What in it do you think is weird?

"He limits the analysis to the USA which has been shedding manufacturing like mad over the last 30 years."

I think if you look at US manufacturing, you'll see that production jobs have declined dramatically, not output. There's certainly been outsourcing, but much of the decline is increasing labor productivity - the majority of those jobs would have been lost in any case. Have you noticed how much Asian auto assembly has moved to the US, in states like Tennessee? More importantly, we can test the "oil-consumption outsourcing" idea by looking at the whole world: we see that world GDP has grown dramatically in the last 4 years, even while oil consumption has been flat: oil just isn't the essential causal ingredient for economic growth that some have suggested.

"Oil is critical to global trade "

In the short term, a modest amount is essential, but it isn't as much as you think, and can be reduced more than you think. For instance, container ships can cut their diesel consumption by 50% by reducing speed by 20%. In the long run, oil isn't needed: ships could run on wind, solar and batteries.

"Hirsch is right that a decline in world oil production will cause a decrease in world and therefore US GDP."

Then why hasn't flat oil production stopped world GDP growth? It's been growing as fast as ever.

"Aren't things spinning out of control fast enough for you now?"

US GDP grew 3.3% in the last quarter. Both oil prices and the dollar:Euro have stabilized. In what ways are things spinning out of control?

"Ayres' paper is totally weird, peppered with his own new theoretical constructs. "

"hmmm. I often see people on TOD relying on it, including Aangel, and I have to say, it makes sense to me. What in it do you think is weird?"

All that silly algebra for one, typical economonist crap. Exergy and emergy for another. There are simply no substitutes for light oil. Unconventional oil is coming online too slowly and timidly to make a difference. It's silly to compare economics in the Cheap Oil past with Peak Oil economics of today. No mention of geology either; the man's a cornucopian.

"He limits the analysis to the USA which has been shedding manufacturing like mad over the last 30 years."

I think if you look at US manufacturing, you'll see that production jobs have declined dramatically, not output. There's certainly been outsourcing, but much of the decline is increasing labor productivity - the majority of those jobs would have been lost in any case. Have you noticed how much Asian auto assembly has moved to the US, in states like Tennessee? More importantly, we can test the "oil-consumption outsourcing" idea by looking at the whole world: we see that world GDP has grown dramatically in the last 4 years, even while oil consumption has been flat: oil just isn't the essential causal ingredient for economic growth that some have suggested.

Labor productivity is rising but it hasn't keep employers from moving offshore because offshore labor productivity is rising even faster.
Auto plants are being built in the South because local governments subsidize them and they are all non-union.

GDP of a single country isn't the best gauge of growth because capital flows are involved.

Regardless, the EIA for the US calculates that though the energy use per capita is constant the energy use per dollar GDP is falling at about 1% per year. Over the last 4 years that's a small amount and we have witnessed demand destruction in the last year. A 1% growth in energy to GDP productivity just can't offset a decline in supplies and in fact US energy consumption is down about 1% this year.

"Oil is critical to global trade "

In the short term, a modest amount is essential, but it isn't as much as you think, and can be reduced more than you think. For instance, container ships can cut their diesel consumption by 50% by reducing speed by 20%. In the long run, oil isn't needed: ships could run on wind, solar and batteries.


"Hirsch is right that a decline in world oil production will cause a decrease in world and therefore US GDP."

"Then why hasn't flat oil production stopped world GDP growth? It's been growing as fast as ever."

No, the world is in a recession and consumption declines in the US and OECD are being absorbed in the Third World.

"Aren't things spinning out of control fast enough for you now?"
US GDP grew 3.3% in the last quarter. Both oil prices and the dollar:Euro have stabilized. In what ways are things spinning out of control?

That's bullcrap and everyone knows it. The US government sent everybody $600 checks. If you don't realize things are getting bad, then you're not listening. And if China is seriously slowing you know that the whole world is in recession.

"There are simply no substitutes for light oil."

Electric motors are better than ICE motors. Batteries are good enough.

"Unconventional oil is coming online too slowly and timidly to make a difference. "

The best alternative is electrification.

EDit, with more:

"Labor productivity is rising but it hasn't keep employers from moving offshore because offshore labor productivity is rising even faster."

I haven't seen that - do you have sources for rising offshore labor productivity? AFAIK, jobs are moving offshore because of wage differentials.

"Auto plants are being built in the South because local governments subsidize them and they are all non-union."

I agree. They're still here, though.

"GDP of a single country isn't the best gauge of growth because capital flows are involved. "

It's a pretty good gauge of production (and the growth of production), and that's what we're talking about.

"the EIA for the US calculates that though the energy use per capita is constant the energy use per dollar GDP is falling at about 1% per year. "

No, the EIA projects that energy use per dollar GDP will fall by 1.7%. Do you really want to rely on EIA projections??? They won't help your case...

"in fact US energy consumption is down about 1% this year."

Precisely my point: GDP is up 3.3%, and energy consumption is down (by much more than 1%, for oil).


uhm....that's not very specific. Would you like to show some solar surface area to engine KW comparisons, perhaps? Or, just google windpower and shipping??

"the world is in a recession"

Could you show any UN or US government source that agrees? Perhaps the World Bank? The Fed?

"That's bullcrap and everyone knows it. The US government sent everybody $600 checks."

Sure, and it worked, at least for the moment. They'll probably have to do it again.

" if China is seriously slowing you know that the whole world is in recession."

Do you really want to rely on a Falun Gong publication? Using indirect numbers like a manufacturer's purchasing index?

How can you say with a straight face that the GDP is growing? Growth in GDP is only a result of a long transparently obvious cascading chain of doctored numbers.

"Growth in GDP is only a result of a long transparently obvious cascading chain of doctored numbers."

I disagree - it's not hard to measure the increased exports that were the primary cause. Now, increased exports don't increase US consumption, but they do increase US production, which is what we're talking about here.

It's a very long debate.

For a good analysis, look here:

I wonder if this technology would be a good energy storage system for transient power supplies like wind, especially in rural areas with no grid connection or in countries that do not as yet allow net metering? One could compress the gas at home and use the engine to make electricity when there is no wind. Additional storage tanks would not be all that costly if they were needed. I wonder how much electric output these engines have?

Of course once you go through all the trouble of compressing air, the question becomes...why not just go ahead and liquify it by cryogenic cooling:

I have been following and doing research on this for years, and have come to the conclusion that it is not well suited for transportation alternatives, but may have a future in stationary energy storage applications to help solve the "variability" problems of wind and solar. Cryogenic air is a better energy storage option than the so called "hydrogen economy" and can rival batteries in stationary storage. I recently did a longer essay on this subject that has some fascinating math on the issue of conversion efficiencies, which are as good or better than most alternatives, but the devil is still in the details, because exactly how components are arranged and at what cost they are procured means everything. This one is an engineering problem, as the thermodynamics seem sound.


If it was marginally viable seems like the idea of storing solar energy in a suitable phase change material as a supplement may be something to explore. Chloroaluminate melts at 160 C, that would add maybe 40% to the deltaT. Extra engineering challenges though.

I'd like to see you conclusions on the conversion efficiencies, I was under the impression that the cryo or compressed air engines were simply heat engines and therefore would have difficulty reaching even 50%.

This isn't a heat engine, it's the reverse--net work is input makes heat rather than net heat makes work as in a heat engine. The expansion turbine phase in the air car is actually very efficient(84%) so it can be ignored in the cycle.

For the compressor, we get a mechanical efficency of ~50%, that is ~40% of the energy input is ejected as the heat of compression, some friction and the rest of the work remains as pressure.

The NET thermal efficency is (assuming Qc/Tc = Qh/Th), you get
Wnet + Qc [i.e. Qh*Tc/Th] = Qh or Wnet/Qh=(1- Tc/Th)where Tc=530R
Using a four stage compressor has four stages at 3.76 pressure ratio, i.e. 3.76^4=200bar
That is 31% thermal efficency for adiabatic compression or 1-530/774=.31).

Since Win is ~twice Wnet, the OVERALL 'thermal efficiency' of Win/Qh would be ~62% so the more correct measure, coefficent of performance 'heating'(COP) would be ~1.61, which is a lousy heat pump but that is not the purpose of an air compressor.

Can the heat energy of compression be used by a heat pump? This would give the ability to both heat and cool would it not?

Sure, however heat pumps do require electricity
to move heat about, though they can raise the temperatures to make the heat more useful.

Imagine inputing 1 kw to a compressor producing .5 kw of heat of compression and .5kw of mechanical energy(pressure). Now use that .5 kw of mechanical energy(pressure) to run an air motor to run a heat pump to take that .5 kw of heat of compression and boost its output heat to 1kw(COP of 2), so overall you trade 1 kw of low temperature heat for 1 kw of refined electrical energy, which is basically a waste.

The problem with using heat of compression to run a heat engine is that the temperature of the heat is rather low, 300 degrees F for which the maximum theoretical(carnot) efficiency is low, for example 1-(530)/(460+300)= 30% andthe practical efficency of <16%.

I think a better use is to make hotwater which is one of the best storage mediums on earth at an efficency of 75% or greater.

Actually, heat pumps DO cool and heat just by reversing the flow of the heat transfer medium(refrigerant) by (wait for it)...a 'reversing' valve.

Reply to css1971

One of the best set of tables and calculations I have seen

Recall that the application being considered is a transportation power converter/storage system. This means that all of the tools of the thermodynamic trade cannot be used, due to the need to consider weight and volume (space taken) of the system being absolutely primary considerations. Cost is a consideration, but it would be in a stationary application also. Space and weight would be far less of a consideration unless the system became large and heavy beyond the point of reason (no one ever complains greatly about the weight or the space taken of a Combined Cycle natural gas power plant for example). In a stationary system extra insulation and reheating stages could be considered that cannot be in a transportation system.

The cryogenic system described in the pdf file is given as 3 times greater in specific energy than compressed air, and 5 times greater in specific energy than lead acid batteries.

There is a sentence in the PDF given a conversion factor, the sentence being structured this way:

"Since there are several different concepts which can provide quasi-isothermal performance, the work output of a crogen energy conversion system having a quasi-isothermal expander will be estimated as 85% the isothermal work." There are also plenty of equations and charts to mull over.

There would surely be other losses in a transportation sytem (such as fans or pumps) thus reducing the conversion efficiency to say 75%, but if that number could be held, it would be a very good number.

The greatest potential of such a crogenic energy converter/storage system may be, ironically, in the area of heavier vehicles where space and volume of the system would be a lower percentage of the total weight and size of the vehicle, for example tractor trailer trucks and towing vehicles. On this very string, the issue of an energy system for heavier vehicles has been discussed in a very interesting post by PriorityX and followed on by Davemart.

One could picture a heavy vehicle designed for towing that would use a crogenic drive system, either alone or in combination with a fossil fuel energy source (such as Diesel or natural gas) which would use waste heat in a heat exchanger type system to improve the reheating phase discussed in the pdf. All of this becomes an old fashioned conversion exercise that any graduate level thermodynamic engineer could have a field day with! The basics are actually very simple: How efficiently can you remove heat from air? How efficiently can you put the heat back in? How fast?

Thanks for the interest,


I'm no scientist, but if all our cars were to run on air, would that affect our oxygen supply at all, especially with deforestation. And how long would it take to develop technology like this, 10-20 years for a prototype? I'm a fan on getting all cars to run on Natural Gas like Mr. Pickens' plan. It's good to see that the car companies are finally seeing an upside in developing new technology so not to rely on oil anymore. It's too bad we won;t be around to see what the world will be like in 100 years. I'd imagine it would be very clean...

Burning coal and forests for agriculture has been the big agent for oxygen depletion, and may be approaching dangerous levels.

There have been prototypes of these compressed air cars running around for ages, and is supposedly just about ready for release - but then we have heard that before.

Anyway, here is a look at it:
BBC News video: Air Car out "by end of year," in Europe, for 3,500 Euros - AutoblogGreen

Is the depletion of oxygen itself really a big concern? We're at about 380 ppm of CO2 after all the carbon we've dumped in the atmosphere, we're around 210,000 ppm for oxygen. That seems enough to burn everything above and below ground and still not seriously affect oxygen levels.

Compared to prehistoric times, the level of oxygen in the earth's atmosphere has declined by over a third and in polluted cities the decline may be more than 50%.

Much of this recent, accelerated change is down to human activity, notably the industrial revolution and the burning of fossil fuels.

I find oxygen so useful!


I believe you have misunderstood something about this thread.

Mr. Pickens talks about Natural Gas as part of his Water/Electricity/Nat Gas plan. Natural Gas is a specific type of Hydrocarbon IE Hydrogen atoms bonded to Carbon in a specific geometric pattern with perhaps less than 1% trace other elements. There are other gaseous fuels that are used; Ex is Propane which is easilly compressed to a liquid then burnt in engine that is nearly identical to Gasoline engines.

This entire discussion is about a very different type of 'Gas Engine' This discussion is about compressed Oxygen + Nitrogen used in a motor similar to an Internal Combustion Engine...the difference is there is ZERO combustion in this type of motor. If you do a websearch of Oildrum you will get lots of technical info RE 'AirCar' that enlightened me on this technology.

I was going to post this when the topic of electric vehicles came up. But this same logic applies to the concept of air cars.

One energy fact that is a constant thread throughout TOD is the incredible scope of the problem in replacing transportation fossil fuels.

One partial solution often discussed is electric vehicles. Usually the vehicles are sub-compact or compacts. While these vehicle types are what we are most familiar with and the easiest to understand, there is a lack of data which gives the perspective required to properly understand how electric vehicles can integrate into our transportation mix.

I don't have the data, what I have are questions which might lead to others doing the research and sharing it with us:)

My question is what percentage of ground transportation fossil fuels (we can leave air transportation out) are used for each vehicle class? The transportation industry has standardized vehicle classes based on the gross vehicle weight rating (GVWR) This class starts with light trucks and goes all the way up to the largest over-the-road tractors.

Here is a great description of the truck types and classes.

The truck classes start with class one and go up to class 8. The vehicle types we typically discuss are lighter than class one. Let's call them class zero, which covers the sub-compact and compact vehicles.

Next, we need to factor in off-road vehicle classes. Examples of these are farm tractors and construction equipment (bulldozers, backhoes etc). Then we can move onto specialty transportation classes such as trains and ships. My commute includes a ferry ride and the rates go up rapidly in lockstep with the cost of diesel fuel.

Commercial vehicles are only cost effective to operate if they drive/operate/run a large number of miles per day. Unlike personal use, class zero vehicles, a high percentage of commercial vehicles operate 8 or more hours per day. They obviously have a substantially lower average MPG. Class zero vehicles are primarily commuting vehicles and have the highest average MPG. There are many more class zero vehicles than the other classes combined. What we don't know is ratio of class zero vehicle fuel use to the fuel use of all other transportation classes combined. It is as if we are shooting at a target and don't know where the bulls eye is.

Another aspect of this discussion is the limitation of electric vehicles types due to the ratio of battery weight to vehicle weight, and the average trip miles or operating hours required by the various vehicles classes. It seems likely that there is a weight break point where battery powered vehicles become untenable due to the total vehicle weight, thus limiting their application in the total ground and water transportation vehicle type mix.

I think we will may find that class zero vehicles use a surprisingly small percentage of transportation fossil fuels. (Yes, I know, thinking is not the same as facts:) If that is true, then electric vehicles are not a significant solution to solving the problem of decreasing oil and natural gas used for transportation. Another question is demand destruction. Do class zero vehicles have a greater rate of demand destruction than all other transportation types and classes? If they do, the impact of electric vehicles is reduced even more.

If class zero vehicles use a small percentage of total transportation fossil fuel, and current battery technology limits their use to class zero vehicles, are we going to discover that electric vehicles will have an impact similar to solar and wind energy. There is a niche for them, but they won't be primary solutions.

So, that's the challenge. Do we have the data to support the investment in electric vehicles? Could those investment dollars be better spent on other potential solutions? I'm not asking yet about the charging infrastructure, battery efficiency/cost, and the types of electricity generation/transmission required to support electric vehicles. I'm trying to come to grips with the contribution percentage electric vehicles will make in reducing the total amount of fossil fuels used in ground and water transportation.

Any takers:)

You can proxy that pretty well if you want to, by checking the use of diesel in American transport to petrol, as passenger diesel cars are not common there, so the figures should be fairly directly comparable.
Alternatively, you can look on the BERR website for the UK, which if you want to wade through it will doubtless have the figures for the UK - figures for Europe are often difficult to come by, as they tend to be national, and in several different languages at that.

- OK, I have done some Googling
Here are the car and light truck figures for the US:

that comes out to around 130bn gallons a year

And here is some info on heavy truck trailers:
As you can see, they put a 10% saving at 1 billion gallons, so total use would be around 10 billion gallons.

This does not include some uses classes of vehicle, or things like agricultural equipment, but it is clear that the answer to your fundamental question is that yes, going electric for passenger vehicles and light trucks would save enormous amounts of fuel.

Delivery vehicles also work perfectly well with electric, and heavy use providing you are not covering great distances:
World's Most Powerful Electric Truck : TreeHugger

As long as the range does not have to be too great, it is perfectly possible in an industrial context to keep vehicles active either by fast charge technology with the latest batteries, or by swapping the batteries - in dock areas, for instance, heavy equipment to swap batteries is just fine.

For agricultural use biofuel production should be suitable for their heavy equipment, and that limited use would not unduly strain food production - much could be achieved just by converting animal waste, which presently pollutes the water, into fuel.

Heavy long distance trucking is not currently possible with battery technology, but trains will do that just fine anyway - you just have the added expense of loading it onto electric trucks for delivery from the railhead, but on the other hand you have eliminated much of the damage to roads, which rises vastly with heavier vehicles
New national poll shows Americans dislike larger, heavier trucks on U.S. highways. «

We have the technology to switch transport to vastly more efficient electric systems, if we generate the power to do so.
(cough) nuclear...(cough)....

Thanks for the bulls eye:)

Superb points, DaveMart.

I do think it is useful to look at the "Cradle to Cradle" energy and material implications of various technologies.

Using ICE vehicles feels great as long as petroleum is cheap and in abundant, uninterrupted supply. But the ICE engine and the infrastructure we've set up around it is not very effective or efficient from the perspective of overall impacts upon our habitat.

Electric and other options need to be thought through with the wisdom gained from our experiences thus far.

I do not see any "freebies" out there in terms of transportation technology.

There is hope in the fixed energy costs of cars too, as we are getting close to the point of being able to use carbon composite body shells:

It is particularly interesting that this sort of technology is much easier to implement for small companies.
In that connection it should be noted that pure electric cars are way simpler than ICE vehicles, as you can throw away a lot of the parts.
People who have built there own say they need hardly any maintenance - even the brake-linings last ages, since most of it is used regeneratively.

Concerns that lack of asphalt will destroy all roads should also be mitigated by the possibility of using concrete, which without so many heavy lorries pounding it will last way longer.
It might even be able to absorb carbon:
Green cement may set CO2 fate in concrete

Now none of this should be taken as indicating that I feel that we are in for anything but a very rough passage, but this is mainly for financial reasons rather than due to inadequacies of transport technology.

We have good possibilities of maintaining good mobility, but in my view in some respects the fact that we are unlikely to be able to finance a straight switch to EV cars may be a good thing, making us re-think neighbourhoods to be more friendly to pedestrians, bikes, electric bikes and so on.

I don't see (I hope) most owning their own car, and being so car-based as now - it is already unfashionable for young people in Japan - but using a variety of means to have adequate transport at far lower cost than today.
This idea seems one of the new ways forward:
Green Car Congress: Manganese Bronze and Tanfield to Produce Electric London Taxis by 2009

I can hang on 3 minutes for a ride!
And if it is a carbon composite car, running on electric on roads which have done their bit to absorb CO2, as may be possible by around 2020, then I think we will have got a result.

If that sounds Panglossian, these are not predictions, but an attempt to describe what the technology should allow, and at reasonable cost, lower than we pay for transport at the moment.
Whether we get there depends on political and economic factors more than technological, as does generating adequate energy.

Thanks for these posts, Dave.

I can't help but read them and shake my head....I start by thinking, "if only we had started two decades ago" but then remember that without also reducing our population and thus overall resource use, no amount of technology would have saved us.

We would simply have expanded our numbers to use the extra resources we gained via the super-efficient, whiz-bang technology.

Hi Aangel,
The wasting of oil resources doesn't have much to do with population or population growth, after all US and Australia are using about x10 times the average per capita oil use of less developed countries.What would be better for sustainability, 300Million Americans driving PHEV's averaging 200 miles/gallon of gasoline use, or 100Million driving SUV's getting 22 mpg??

Its about technology and in this case clearly about the technology that has been served up by the major vehicle manufacturers(light trucks,SUV's). EV cars have been around for a lot more than two decades but its only now that companies like GM are realizing that the ICE only powered vehicle is a dead end technology, post PEAK OIL and that hydrogen fuel cells are not going to work in time and will be too expensive.
I don't see the 40K price being a problem for the first 1Million buyers of serial PHEV's and if waiting lists start stretching to years, you can be sure a lot of closed SUV plants will be re-tooled for Chevy Volt like vehicles, with a range of prices and options, including perhaps smaller and larger batteries and EV only ranges. If GM doesn't do it properly then another manufacturer will. I am hopeful, because any manufacturer can come out with a parallel PHEV, as is shown by the announcements of the other auto manufactures, but the serial PHEV is on the path to NO gasoline.
The savings in gasoline use can be very large once a significant proportion of new cars sold are serial PHEV's, but more importantly, the rather in-elastic response of gasoline consumption to price will be come very responsive, because with only a little inconvenience, PHEV's can be uses almost exclusively as EV's.

Hi, Neil.

I think fossil fuel availability makes a big difference both with population and population growth, but in different ways depending on the economy of the country. Your example looks just at transportation of individuals, but fossil fuels efficiency directly impacts food productivity, refrigeration and more.

The net effect is a larger population globally. Here is one take on it:
Population and Fossil Fuels

Efficiency alone does not do the job. Curtailment leading to an absolute reduction in usage must be present, also.

If you are saying that energy availability leads to a higher population, then why does India have 1Billion people and yet use very little energy.?
Many things are responsible for a high population, the very productive Agriculture regions of China and India have allowed a large population to grow with very a relatively low energy use, over the last 5 Centuries.
If energy availability was to decline eventually that would limit food production and thus population.
The world has many viable options to develop energy from nuclear and non-FF sources, such as wind, solar and geothermal.
This would allow a much higher population, but that doesn't mean that population growth is going to continue. Almost all high living standard countries have less than replacement population growth without net immigration, and China also has less than replacement birth rates. We would hope that as third world countries share in prosperity, they will also have a declining birth rate.
I think your graph is meant to illustrate that coal and oil is supporting a higher population than was in 1750. If so, I think this is totally wrong, the increase in population especially since 1900 has been due to medicine and public health, before that time cities had trouble growing because of the high mortality due to disease in crowded cities, requiring continued immigration from the healthier countryside. The green revolution did depend on more fertilizer availability, but really what the green revolution did was improve the nutrition and prosperity of rural poor. Vaccinations, cleaner water was what stopped most infant deaths, neither really energy intensive infrastructure.

I am not sure what is the difference between driving 100 miles in a SUV and using 5 gallons of gasoline and either driving 50 miles in the SUV(curtailment) or driving 100 miles in a fuel efficient vehicle using only 2.5 gallons? Both are equally using less fuel, I would argue that the more efficient vehicle is better because that can support a more productive use( ie going to work 4 days a week rather than 2 days a week).

One energy fact that is a constant thread throughout TOD is the incredible scope of the problem in replacing transportation fossil fuels.

That's because we're looking at the problem backwards. We look at all the fuel we burn for transport, and we think we need to replace the fuel. We don't. We don't want fuel, we want transport.

We're confusing ends with means, goals with methods. Our goal is not to burn stuff, our goal is to transport ourselves from A to B. There are many ways to transport ourselves, some of which involve burning a lot of stuff, some burning very little, some burning nothing at all.

So if we use (say) 100 million barrels of oil to transport 100 million people, when we are forced to or decide to stop burning oil, we don't need 100 million barrels of ethanol or air or natural gas or whatever to replace the oil, we need to transport 100 million people. Which does not necessarily require 100 million cars, it could be achieved with 100 million pairs of shoes, 100 million bicycles, 4 million buses, 2 million train carriages, and so on - or some combination of all those.

What it comes down is that if whenever you go somewhere you insist on schlepping around a tonne of metal and plastic with you, it's never going to be very energy efficient, whatever you're getting your energy from.

Remember, our goal is not to burn stuff, our goal is to get from A to B - burning stuff is just one way of doing it. Let's not confuse methods with goals, that confusion causes us a lot of distress as we crap ourselves about peak oil, or turn food into fuel, and so on.

I have been interested in compressed air cars for a while because I work with compressed (bio) methane for vehicle fuel.

If it is possible to run an air engine purely on the energy of releasing the stored gas then why not use methane instead of air and have the added advantage of a combined heat source rather than carrying liquid fuel like so many 'air powered' cars seem to.

Probably for a number of reasons. Kerosene is easier to transport in an airplane, methane requires a heavy tank to hold the compressed methane. Also, it involves more complexity. Jet engines evolved over years and years. If you started developing methane fuel for jet aircraft if might be workable after some number of years. Who will pay that development cost?

Compare the energy in a tank of methane compared to the energy required to compress it. Extracting energy from the decompression recovers a fraction of the energy spent in compression, but most of the energy spent in compression is lost.

This is the bit I don't get, why use air with very little energy when you can use methane with heaps of energy, and you can make it so easily. To me it makes a mockery of a kerosene-fired 'air powered' car and all the research monies being poured into them right now.

It should be approximately the same energy input to compress air as methane (0.25-0.3kW/m3 1>250 bar) so why not carry all that energy for no extra compression cost and forget about the liquid fuel?

Here's a brief look at how the CAV's (Compressed Air Vehicle) engine will run:

Low speeds: When the car is traveling 35 miles (56 km.) per hour or less, the engine runs only on air compressed to 4,500 pounds per square inch (31,028 kilo-newtons per square meter). The compressed air is stored in reinforced carbon-fiber tanks, which have a capacity of about 80 gallons (304 liters) and are attached below the chassis.

Higher speeds: When the driver accelerates above 35 miles (56 km.) per hour, the CAV's computers automatically kick on a small fuel burner positioned between the motor and the compressed air tank. Fossil or bio fuel will power that heater, but not through traditional internal combustion. Instead, the heat generated by the burning liquid fuel is the central element in generating greater speed. Heat automatically adds pressure to compressed air. So any boost in acceleration means higher pressure in the air that drives the engine's pistons. Voilà, more power.

Compressed air for cars is a non-starter. Has it been investigated for fixed site buffering of electric power? You could build the compressed air tanks underground and insulate them well so that only a little heat was lost. This would vastly raise the efficiency. If you only need to store the power a few hours (afternoon to late evening) then the insulation should work well to retain the heat. I haven't thought this through. Perhaps the temperatures get too high for the materials to retain their strength?

I'm not sure how many of you guys have read "The long Emergency", but I am going to guess at least a few. My question is really this: how many of you guys sort of romanticize the effects of peak oil, and maybe look forward to them? Sometimes I find myself excited about certain possible outcomes, like using horses to get around, fishing with nets off of small sail boats, and trading goods along the coastline (I live in a small port town in CT). Other times I am sickened by my own excitedness, because I remember all of the other likely hardships that will come also, like population declines, global resource wars, poverty, starvation, political meltdown, etc. I think many of you fall into the same boat as I do, in that you are possibly excited for the "settled" period, but not really so much for the transition. I don't wanna get killed "Road Warrior" style, I just want to live like Bilbo Baggins and go on quests. haha... good thing I have a katana and am sick at making stuff with simple tools.

Has anyone heard about the Air Force trying to switch its fleet to run on coal to liquids fuels? Seems like they know something...


Sure, on the surface it builds images of being one of the lucky ones to survive. To have hunkered down with some good company, enough stuff for many months while the world goes nuts and the population declines precipitously. Afterwords there are far fewer people, much less stress to make various monthly payments, and a sense of independence from the regular rigors of the previously set lifestyle. A certain sense of adventure.

The reality will probably be much less interesting. A slow downward trek to a much lower standard of living. Pulling a bandaid off quickly is one thing, but this will probably be a long, slow, arduous ratcheting down from a rather interesting, exciting life, to one where you really do have the time to watch the grass grow, but get really bored doing so.


Never mind the Air Force, I think if the rest of the world knew what the US military has in mind for the bulk of the remaining oil, we would all wet our pants.

The Military is 100% dependent upon oil both directly, as well as indirectly for its high tech programs. No oil, no military. Native tribes with bows and arrows would defeat them.

At my age, and my now lower testosterone, has made me see the insanity of what we have created and I actively await its demise. My children still see no evil in it but enjoy its craziness.


I have read both of Kunstler´s recent books. It is probably correct to feel both ways. Things are breaking down and that is depressing. But we get to build it again with the hope of doing it properly, that is in harmony with our environment and each other. We have to get rid of the notion as humans as conquerors of nature by realizing we are part of that nature. By trying to conquer nature we destroy ourselves.

If the Air Force is thinking coal to liquids then they are a lot dumber than I thought they were. The idea is only slightly less insane than Canada using up its supply of relatively clean natural gas to produce an oil like material from their tar sands. Then they ship the product to the U.S. while keeping all the toxic water in Alberta for domestic comsumption. It boggles the mind.

My thought is that we should stop buying cars and instead buy the service, ie from rental companies. Rent a small car for driving to work, the socccer field and store. Exchange the small ICE/EV for the SUV or minivan for trips.

I personally have a diving compressor aboard our Research Ship. It is a German built Bauer Junior. It has three pistons operating in sequence and produces pressures up to 135 Bar (3600 psi).

It is run by a 5 hp Honda single piston petrol engine and uses about 1 liter of fuel to fill 3 SCUBA tanks, size 100.

Like all things mechanical this unit operates at an efficiency less than 100%, actually far less..... approximately 80% or so.

Regardless of whatever motive power is chosen, compressing air to run a vehicle involves losses due to inefficiencies.
The Thermodynamic Cycle
An explanation of a few basic thermodynamic principles is necessary to understand the science of reciprocating compressors. Compression occurs within the cylinder as a four-part cycle that occurs with each advance and retreat of the piston (two strokes per cycle). The four parts of the cycle are compression, discharge, expansion and intake. They are shown graphically with pressure vs. volume plotted in what is known as a P-V diagram (Figure 3).

Figure 3. Intake

At the conclusion of a prior cycle, the piston is fully retreated within the cylinder at V1, the volume of which is filled with process gas at suction conditions (pressure, P1 and temperature, T1), and the suction and discharge valves are all closed. This is represented by point 1 (zero) in the P-V diagram. As the piston advances, the volume within the cylinder is reduced. This causes the pressure and temperature of the gas to rise until the pressure within the cylinder reaches the pressure of the discharge header. At this time, the discharge valves begin to open, noted on the diagram by point 2.

With the discharge valves opening, pressure remains fixed at P2 for the remainder of the advancing stroke as volume continues to decrease for the discharge portion of the cycle. The piston comes to a momentary stop at V2 before reversing direction. Note that some minimal volume remains, known as the clearance volume. It is the space remaining within the cylinder when the piston is at the most advanced position in its travel. Some minimum clearance volume is necessary to prevent piston/head contact, and the manipulation of this volume is a major compressor performance parameter. The cycle is now at point 3.

Expansion occurs next as the small volume of gas in the clearance pocket is expanded to slightly below suction pressure, facilitated by the closing of the discharge valves and the retreat of the piston. This is point 4.

When P1 is reached, the intake valves open allowing fresh charge to enter the cylinder for the intake and last stage of the cycle. Once again, pressure is held constant as the volume is changed. This marks the return to point 1.

Comprehending this cycle is key to diagnosing compressor problems, and to understanding compressor efficiency, power requirements, valve operation, etc. This knowledge can be gained by trending process information and monitoring the effect these items have on the cycle.

Not included in the above are frictional losses...

Since the favored approach involves Electromotive power provided by the grid overall efficiency is about as follows:

Generation ~ 35%
Distribution ~ 95%
Motor ~ 90%
Compressor ~ 75%

Air motor ~ 80%

Over all ~ 18%

So what makes more sense?

Ultra Capacitors......

They are ~ 95% efficient, last more than 100,000 cycles.. are solid state... and are installed in busses now, and are currently in sizes suitable for electric bicycles, and micro cars... eg the HyperCar ala Lovins.

Also, it must be accepted that nothing improves efficiency as much as shifting from personal mobility to mass transit. While my truck has a 100 hp engine, the 35 seat bus has 250 hp, and hauls 7 times more people, were we using light rail the power requirement for 35 people would drop to 50 hp or less.

Since ~ 90% of fuel use is for transportation, it is vital that we inculcate the lessons learned from the nationwide rail electrification project which showed that electrifying and double tracking 36,000 miles of the US rail network, combined with a mass shift from trucks to rail, would save 6 Mbbl/ day in domestic consumption. If mass transit for commuters, or shifts to living locally occured, we'd save far more.

This would go a long way to reducing the trade deficit, and would obviate the necessity for controlling the planet to secure fuel to run the economy.

Given that Iran will likely cease to export ~ 2012, Russia ~ 2015, and KSA shortly thereafter see latest updates on ELM... changing the US appetite profile is not an option, but rather a given.


Dr. George W. Oprisko
Executive Director
Africa GeoPower, Ltd.

The efficiency of public transport is not nearly as great as you imply.
A 35 seat bus does very well at rush hour when it is full, but for most of the day in many areas you are then trundling around a rather large vehicle, and paying a driver, with comparatively few people in it.
The same applies to trains, where you are frequently moving a truly huge weight for a very light payload.

Even an ICE car, especially if you have a passenger or two, frequently surpasses the efficiency of a bus or train most of the time.

Check this out for much more efficient transport - smaller vehicle size means that you can pull vehicles and drivers off the road more easily when they are not so busy, and the capital costs are far lower:
Taxibus | Intelligent Grouping Transportation

In urban areas they would also be able to pick you up and drop you off where you actually wanted, and when you wanted, unlike buses and trains!

I lived in Japan for nine years. During rush hour the trains run as often as every three minutes or so. As it takes nearly a minute for the train to stop, exchange passengers and depart this was an extremely tight schedule. Often you could see the next train waiting a few hundred meters away as the current train was departing. Later in the morning they would reduce the schedule to as little as one train per hour depending on demand. They also could reduce the number of cars on the train.

The trains are also quite efficient. Riding in the front car you can watch the readings on the ammeter as the train would accelerate, coast and decelerate. Between stations the trains use almost no electricity unless they had a hill to climb. I don't know if they did this but they had the potential during deceleration to recapture some of that energy and feed it into the grid.

I am not knocking trains, and see them as the main means of both goods transport and long distance passenger transport, and it is particularly suitable for high density areas like Japanese cities and their links.

My point though is that the efficiencies should not be exaggerated, and that a whole range of other options are available with modern technology beside the traditional bus and train, and in the right context they may be more efficient and convenient.

We can do pretty well for transport without most people owning a car, and without great inconvenience, providing our economy holds up enough for us to do so - but it is way cheaper than present methods.

What I find discouraging about this thread is that the underlying paradigm is business as usual. My guess is that BAU will have died long before they could have made a difference.



Challenge this: 1990 Geo Metro. 54 mpg highway, 46 mpg city. The fanciest bit of technology in this vehicle is the computerized engine controller. Except for brakes, no power anything. Our "air conditioner" is a spray bottle filled with water.

Claims that busses and trains run empty most of the day, are rubbish.

They rely upon a belief that the system cannot and will not adapt to traffic patterns. This may be true in AUS and NZ where the 1 meter gauge imposed by the UK still rules, but everywhere else, the gauge is 1.5 meters and not only do trains carry freight, they carry passengers at high speeds.

There isn't enough fuel available for AUS - NZ to continue driving from Whangarei to Auckland along side a perfectly maintained, but unused railway, or whatever is the equivalent in AUS.

I did not set exact efficiency targets for busses, and if you don't like the 36 seat version, IVECO makes a very nice 22 seat version with a 3 Liter turbo diesel that gets 8 km/ liter. Perhaps Aus - NZ don't have these, but backward Namibia has dozens... all run by entrepreneurs....

There will be no alternative... it is either mass transit or the ox cart.


Claims that busses and trains run empty most of the day, are rubbish.

Well, it depends on the system. When I travel on the weekend on a bus running once an hour, I find it only has five or six people on it. When I travel on the train to and from the city at any time from 7am till 7pm when it runs every 5-15 minutes, I will be lucky to actually be able to get on and stand somewhere during peak hours, and lucky to have a seat the rest of the time.

Public transport is like any other business. If your service is frequent, reliable and pleasant relative to alternatives, people will line up for it. If your service is infrequent, unreliable and unpleasant, people will avoid it.

In my own city of Melbourne, petrol price rises and congestion in recent years have made private vehicle traffic so unreliable and unpleasant that even the infrequent, unreliable and unpleasant train system looks better to many commuters.

In case the math escapes you 22 seats at 8 Km/ liter equates to 2 seats, (the norm with a personal car) at 88 Km / liter or 216 mpg.

The 36 seat bus gets 6 km/ liter which equates to 265 mpg

MPG figures given for 2 pax personal vehicle equivalent required to match the seat-mile performance.

Lest we forget, eliminating 11 cars in favor of one IVECO mini bus, or 18 cars infavor of one bus, will eliminate traffic jams, and attendant fuel wastage.


It doesn't matter how inneficient the road vehicle is, when it's the only thing between you and walking, most people will choose the easy way out.

What is very apparent is the return for investment that is the whole crux of making a people carrier, be it for 22 people or just one person.

People will ALWAYS want to go where they want to go, not where the public transport nearly gets them eventually.

When all the oil is gone or just too hard to economically produce, then the next player will step up to the platform and if it is a hay burner using waste hay from the food industry, then so be it, people power will always justify the means, trust me.

Supposing the air car was the preferred means of transport, and the inter heater was fueled by Ethanol, this just leaves the compression of air to be catered for by wind/solar/photo voltaic or whatever method dominated on the energy playing field.

Nothing is improbable when it comes to transport, and the 0 to 60 MPH in 4 seconds is just as impractical as living to be 110.