[JRP3]

I really hate all these air car BS stories, it's so friggin obvious how lame this is. First of all you have to generate electricity to power an electrical air compressor. An air compressor is basically an ICE without fuel, you have all the losses involved in an ICE and much of the mechanical complexity and moving parts. Then that compressed air has to be stored in a very strong tank that is costly to manufacture and not very energy dense. Then that compressed air is decompressed in what is essentially another ICE without fuel, again with the same inefficiencies, complexity, manufacturing costs, etc. Not to mention that no real world demonstration of this technology has shown any real range or power. Take the same weight vehicle with an electric motor and some batteries and the power and efficiency is much much higher, and the refueling infrastructure already exists at everyone's house and business.
Also, let me stop anyone who might be tempted to try and argue about batteries and disposal: Lead acid batteries are valuable and recyclable, and Lithium are the same, as well as being non toxic and much longer lasting.
Smaller lighter vehicles, automated lithium manufacturing, lowered travel expectations can make EV's quite viable. Changing the laws of physics would be needed to make air cars viable.

[yesplease]

Air cars on air are nice if there's extra electricity generation capacity in urban, and provide for urban transport at much reduced cost compared to BEVs because batteries are pricey. Unlike BEVs, they don't need another powerplant to get the range extension associated with fossil fuels, so... Whatever they lack in energy efficiency due to compressing air, they make up in cost.

[JRP3]

Whatever they lack in energy efficiency due to compressing air, they make up in cost.

No they don't. The tiny limited range punishment cars that have been used as air cars would be just as cheap to do with electric motors and batteries. An electric golf cart would perform as well as current air cars.

[yesplease]

Compare the cost of a small ICE drivetrain and storage tank to an electric drivetrain and periodic battery pack replacement. Batteries are just too expensive to compete with something like this unless the cost/mile comes down significantly.

[threadbear]

I really hate all these air car BS stories, it's so friggin obvious how lame this is. physics would be needed to make air cars viable.

Really. It's more apparent to me, that the arguments against any and all technologies that compete with gasoline are the lame ones. If it's such a lousy idea, why are major corporations overseas going to be implementing this technology?

Did you even read the Oil Drum interview?

[JRP3]

Compare the cost of a small ICE drivetrain and storage tank to an electric drivetrain and periodic battery pack replacement. Batteries are just too expensive to compete with something like this unless the cost/mile comes down significantly.

First of all we aren't comparing ICE vs. EV, we're comparing Aircar fantasy with EV NEV's.
Secondly you're trying to compare mass marketed ICE vehicles with small volume EV's. Mass produce Lithium batteries which will last the life of the vehicle and maybe beyond and your argument completely falls apart.

[JRP3]

I really hate all these air car BS stories, it's so friggin obvious how lame this is. physics would be needed to make air cars viable.

Really. It's more apparent to me, that the arguments against any and all technologies that compete with gasoline are the lame ones. If it's such a lousy idea, why are major corporations overseas going to be implementing this technology?

Did you even read the Oil Drum interview?

I'm all for competing technology to gasoline, that's why I'm in favor of EV's, so that's a stupid argument. This thread is entitled "Why is the Air Car not a viable replacement for fossil fuels", and I've been explaining why. The Oil Drum article goes into other uses for the MDI engine full of speculation and no proof. An electric motor is 80-90 percent efficient, proven, so they have a long way to go to equal this with the MDI.

[EnergyUnlimited]

I think, both EV and air vehicle are not going to be replacement for ICE.
Electric vehicle will fall fool of expensive battery technology.
There are some plans to bring EV called Volt within 3 years from now on, but price estimate is now in range $30-40k, at least according to one article which I recently have red.
On the top of this price tag it is likely that batteries will rather be leased then sold.
All this suggest that large scale production is unlikely.

On the other hand air car has far better prospect because of low price of components and easy mass production
However it likely to overload electric grid and contribute to further pollution.
Additional bonus is that it would provide free air conditioning, if used in India or other hot country. That is because of very cold exhaust air.

So overall air car is a cheap "more of the same" idea (lets drive and make pollution green ) and EV is pie on the sky idea due to unresolved battery problems.

It was claimed on this forum that turning transport electric would require increasing of electricity production by 20%, assuming EV.
So in the case of air car it would be necessary to increase electricity production by 60-70%.
That is assuming full global conversion and current level of car use.

[threadbear]

Why do I get the impression some of you people just make sh** up as you go along? Your objections are whiny and you're not backing them up with anything, other than dismissing, out of hand, every alternative proposed. What's the matter, the future doesn't look grim enough for you already?

[EnergyUnlimited]

Why do I get the impression some of you people just make sh** up as you go along? Your objections are whiny and you're not backing them up with anything, other than dismissing, out of hand, every alternative proposed. What's the matter, the future doesn't look grim enough for you already?

Well, there is no need to make some elaborate dismissals again and again.
There was threads dealing with air car or EV in the past.
It is enough to say that replacement of current car fleet with air car would require increase of electricity production by 60-70%, about 3 times more then in the case of EV.
That would be mainly coal based electricity.

The future would really be grim, if it is proven to be possible to apply some technofixes, carry on with happy motoring, growth economy and credit expansion for lets say next 200 years and only then pay a final bill to Nature with less then 1000 survivors (if any) left.

Fortunately that is not the case and the party is going to end up soon for benefit of all of us.
There is nothing grim here.
These are really good news.

[WisJim]

Industry uses LOTS of compressed air to power things. Factories don't worry about the weight of compressed air tanks, either. But, it is often considered that a typical compressed air system is less than 20% efficient. The compressed air to run a 1 hp air motor can take 7 or 8 horsepower, and that is in a large efficient system.

As has been mentioned many times, using compressed air as a motive force is not energy efficient.

Compressed air costs:
http://www.energystar.gov/ia/business/i ... d_air1.pdf

[threadbear]

Industry uses LOTS of compressed air to power things. Factories don't worry about the weight of compressed air tanks, either. But, it is often considered that a typical compressed air system is less than 20% efficient. The compressed air to run a 1 hp air motor can take 7 or 8 horsepower, and that is in a large efficient system.

As has been mentioned many times, using compressed air as a motive force is not energy efficient.

Compressed air costs:
http://www.energystar.gov/ia/business/i ... d_air1.pdf

And this is something that r&d can't easily get around? If it is so inefficient why is it being proposed to be developed en masse?

[JRP3]

And this is something that r&d can't easily get around? If it is so inefficient why is it being proposed to be developed en masse?

No, R&D can't easily get around the laws of physics!! Compressing and decompressing gas in an engine is very inefficient!
Lot's of things are being proposed to be devolped en masse, including non starters such as ethanol and hydrogen. Doesn't mean they can actually be implemented or sustained.

[JRP3]

Electric vehicle will fall fool of expensive battery technology.
There are some plans to bring EV called Volt within 3 years from now on, but price estimate is now in range $30-40k, at least according to one article which I recently have red.
On the top of this price tag it is likely that batteries will rather be leased then sold.
All this suggest that large scale production is unlikely.

The Volt is an overly complex hybrid, not a true EV. It therefore has unnecessary ICE components just so people can have the option to drive hundreds of miles without refueling, a completely unnecessary and mostly unused option. Further, batteries will not be leased unless they retain value beyond the life of the vehicle, which may be possible, (Altairnano), but is not so at this time.

On the other hand air car has far better prospect because of low price of components and easy mass production.

Again, an EV with the same performance as the Air car would be very cheap to produce and much cheaper to run.

[yesplease]

My bad about the ICE thing, I got mixed up. What I meant to say is the Aircar can run on liquid fuels as well...

Secondly you're trying to compare mass marketed ICE vehicles with small volume EV's. Mass produce Lithium batteries which will last the life of the vehicle and maybe beyond and your argument completely falls apart.

If we mass produce Lithium batteries supply starts becoming a problem at current prices, so any advantage from large format mass production would likely be wiped out due to supply issues. The only format I know of that wouldn't have this problem would be lead acid, and even then, we would need greater energy capacity than what we have now at reduced cost.

Lets assume we have the same glider, a small city car platform that used, on average, about 100Wh/mile. Like you and WisJim pointed out, compressed air is inefficient, and batteries are fairly efficient. Lets say batteries are five time more efficient than compressed air. Right now, at the extremes, lead acid batteries cost 7Wh/$, and will last around 800 cycles to 80% dod.[1]

With electricity at $.2/kWh, if the EV was 100% efficient, electricity costs would be $.002/mile. Given the 7Wh/$ price, 800 cycles at 80% dod, and 100Wh/mile range, the batteries would go 1 mile 800*.8=640 times, for $14. The cost over their lifetime is around $.0218/mile, and with electricity this is about $.022/mile. If the air car was five times less efficient and used five times more electricity to travel the same distance, it would cost $.01/mile.

Since the EV version will probably cost more as well, either electricity is gonna have to get really expensive, or batteries really cheap, or both to a lesser extent, for a BEV to be cheaper than a compressed air/liquid fuel vehicle.

If it is so inefficient why is it being proposed to be developed en masse?

Because batteries are expensive and electricity is cheap.

[1]http://en.wikipedia.org/wiki/Lead_acid_batteries

edited for errors

[yesplease]

It was claimed on this forum that turning transport electric would require increasing of electricity production by 20%, assuming EV.
So in the case of air car it would be necessary to increase electricity production by 60-70%.
That is assuming full global conversion and current level of car use.

I don't see how use could stay the same. An air car has only decent range in the city due to reduced energy requirements. Any more than that and it would have to switch over to a liquid fuel, so there's no way we would see a 60-70% increase in electricity production because there's no way air cars could travel that distance on compressed air.

[EnergyUnlimited]

I don't see how use could stay the same. An air car has only decent range in the city due to reduced energy requirements. Any more than that and it would have to switch over to a liquid fuel, so there's no way we would see a 60-70% increase in electricity production because there's no way air cars could travel that distance on compressed air.

Why not to fit compressor stations every 20 miles or so, as motorway goes?
About once per 60 miles you would have to take a charging brake and carry on.
Anyway, that's only theory.
Somehow I do not think that air car is going to be widely adapted.
We cannot sufficiently scale up electricity supply to carry on with that.
If air car is used mainly by commuters, I wonder what peak demand would actually result out of this mess.

[EnergyUnlimited]

Further, batteries will not be leased unless they retain value beyond the life of the vehicle, which may be possible, (Altairnano), but is not so at this time.

I think, it has something to do with value of Nickel ($30,000 per tone) used in Ni/MH batteries, the most likely battery candidate from technologies which already exist.
Few hundreds kg of Nickel per battery would be required.

[Frank]

If this is such a wonderful idea then why aren't there thousands of them running around? Is there a Youtube video of one? Is there a forum where we can ask questions to anyone who's ever used one? Just because someone's trying to develop an idea doesn't mean it's practical and efficient! After all we already know how to compress air, how to store it and how to make an air motor. Compressed air is EVERYWHERE! How could it be so hard?! I'm not from Missouri - but show me!

[WisJim]

The reason that I mentioned the industrial uses of compressed air, and its inefficiency, is that increasing efficiency of compressed air production and use is, and has been for decades, a major concern and focus of industry. They save money and increase profits by increasing compressed air efficiency, and they are doing the best they can already.