AutoblogGreen

Do valentin technology have started to build a prototype of their hydrostatic car? They needed some money invesment if i remember.

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Why the obsession with the air car? It's bad, eco-*UN*friendly tech. Air compressors like you'd find in your garage are like 10-15% efficient. Factor in generator and transmission, and you're looking at ~3-5% efficiency (vs. ~20% for gasoline). I.e., many times more pollutants emitted. Compressed air storage also has poor energy density. And it's only cheap because it's made by Tata, which doesn't say much for its quality.

Just let it die.

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"Anyway, why are YOU not excited about a cheap, air powered car with that kind of range :D"

For the same reason I'm not excited about Hummers: because they're *bad for the environment*. Only, a Hummer is *better* for the environment than this air car. Just because the air that comes out is clean doesn't change the fact that that to get that clean air to come out of the vehicle, there's a power plant that's spewing half a dozen times more pollutants into the atmosphere than you'd have if you just drove a normal car. And even *IF* your electricity was "renewable" (which ours isn't -- not even close), you'd be using many times more land and have many times more of the pollution involved in making the renewable power source than if you used a BEV. I.e., say hello to large swaths of desert occupied by solar, many more dams destroying our rivers, wind turbines covering every bit of wilderness, and so on, as well as saying hello to the steel mills needed to make those turbines, the factories and mines for the solar, the concrete and steel operations for the dams, etc.

Bad Efficiency = Bad Idea, and this is the epitome of bad efficiency.

The range comes from a fuel-burning range extender. Nothing green about that, either. Ironically, however, thanks to the horrible inefficiency of compressed air, it's probably a whole lot greener than the air engine.

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I see the same 2 people constantly making the same comments about the air car. Their logic is seriously flawed and the numbers they use are meaningless. All that really matters is you can charge this car up for the same amount of electricity as most electric cars and it has the same range(unboosted) as most electric cars. Add to that the fact that this car does not have a very expensive and very toxic battery pack and it is more green than some electric cars.

Power companies capture a lot of their emissions and a single source of power generation is always more efficient than millions of internal combustion engines on the road so the argument that you will spewing more pollutants into the air is ludicrous.

From experience I can tell you that the compressor you would need to fill this car up can easily be powered by a solar cell and if you so choose a small battery bank.

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"Air is not running out."

That's not the issue; it's not about things "running out". It's about power plants spewing vastly more pollution into the air to run the air car than you'd spew from a gasoline car.

"I would be happy to cover the other electric cars coming out next year but none are coming out for YEARS"

What are you talking about? The Aptera starts rolling off the line at the end of this year. The iMiEV is targetted for release between 2008 and 2010. 3000 R1es hit the street this year. I can keep going if you'd like.

"My main point is it's here VERY soon"

And the Hummer is here *now*. And it's better for the environment than the Air Car. This is AutoBlog*Green*; why are you focusing on something which is *bad* for the environment?

"I have seen government studies that say off shore wind could power the entire US. It might impact the environment but oil already does."

Yes, turning our entire coasts to wind farms could provide our existing electricity. *Not* the electricity we would be using if we used vehicles that were horribly inefficient as well.

But hey, let's just pretend that it could. Cape Wind (ideal location)'s turbines are 3.8 MW each in peak conditions. Capacity factor for wind farms is typically around 25%, so let's say 1MW for each 440 foot tall turbine. Let's say, after generator and transmission losses and the compressor, we're looking at an incredibly low system efficiency -- say, 30kW. A typical light vehicle at a reasonable speed expends something 200Wh of energy per mile. Assuming the averge of 12,000 miles per year, you're looking at each *turbine the size of a 50-story building* running only 110 cars. The US has ~250 million cars. Thus, you're looking at almost *3 million skyscraper-sized turbines to be built*, each containing *several hundred tons* of steel and perhaps a *thousand* tons of concrete. This means *tens of thousands of tons* of CO2 each, as well as huge amounts of SO2 and particulate matter.

Let's keep going with this, shall we? With a 30 year lifespan on a turbine and 110 vehicles per turbine, assuming only 15k tons of CO2 in manufacture, that's around 4.5 tons of CO2 per vehicle per year. A typical 30mpg gasoline car going 12000 miles per year *only releases 3.55 tons of CO2 per year*. So even with *Renewable Power*, you're still releasing *More* CO2 by using an air car than an *gasoline burning* car.

Even when power is renewable, it is NOT free of environmental consequences. Certainly, it's better than coal, but it is *not* pollution-free over its lifecycle. When you multiply the amount of pollution by vehicles with appalling efficiency, like air cars, you are *destroying* the environment, not saving it.

"Their logic is seriously flawed and the numbers they use are meaningless. All that really matters is you can charge this car up for the same amount of electricity as most electric cars and it has the same range(unboosted) as most electric cars."

Look, you're free to deny reality all you want. But small air compressors *ARE* very inefficient. Anyone who tells you you can use the same amount of electricity to take an air car the same distance as an EV is either ignorant or scamming you.

http://www.p2pays.org/ref/32/31312.pdf

10-15% is the standard for air compressors. If it's a cheap compressor, it may get even worse than 10%. Only huge, ridiculously expensive industrial air compressors with a waste heat regeneration cycle can get even remotely reasonable efficiency numbers.

"Add to that the fact that this car does not have a very expensive and very toxic battery pack"

No, EV battery packs are not toxic. The ever-popular A123 batteries, for example, have a corrosive electrolyte but no persistant toxins or heavy metals or anything of the sort; a plastic separator; a graphite (pencil lead) anode; and a lithium iron phosphate (nontoxic) cathode. Also, battery packs have much higher energy density than compressed air. Mind you, even if they *were* lead-acid, the main type of "toxic" battery, there's a 97% recycling rate on them.

"From experience I can tell you that the compressor you would need to fill this car up can easily be powered by a solar cell and if you so choose a small battery bank."

At 10-15% efficiency in the compressor, sure. Want me to repeat my above wind calculations for solar?

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"You can clean up power plants rather easily, so the argument sorta makes sense"

See my calculations about wind power above. When you're that horribly inefficient a user of energy, even renewables are no longer that green.

"I meant a normal looking, affordable car the average family with 2.5 kids would buy."

Like the MiEV? Certainly at least as normal looking as the Air Car. And if you want to talk about schedules, perhaps you'll recall that the air car has been to be released "any day now" for the past decade.

"It's really about choices. Think of this like organic farming, the air car is an organic veggie "

Assuming you don't actually drive it, wherein it turns into a energy-gobbling, massive-pollution-causing monster. Production of vehicles is almost always dwarfed by pollution involved in their operation.

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I'd just like to see the crrash test data on the X-prize cars....

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KarenRei: I don't much care for air cars either, but I'm a bit confused about your numbers:

"Let's say, after generator and transmission losses and the compressor, we're looking at an incredibly low system efficiency -- say, 30kW."

The 3.8MW (and 1MW) output is already post generator losses. If wind farms are located on the east coast (where most of the population is) transmission losses will be negligible, and if air cars are popular, "gas" stations will have efficient air compressors.
So at 10% efficiency you're getting 100kW worth of compressed air out of a turbine.

I haven't gone through the rest of you numbers as carefully as I probably should, but I notice you also use a "30mpg car" to defend an argument you made about a Hummer. I don't know what an H2 gets, but if we use 15mpg (which I think is generous) it makes a nice neat factor of 2.

So with a factor of 2 increase for the ICE and a factor of 3 decrease for the air car, the numbers come out to

1.5 tons of CO2 per air car per year.
7 tons per Hummer per year.

I still think that you're right, compressed air is a dreadful way to power a car (or store energy for any task), but unless I missed something wind-2-air is still be a lot better than the big FUVs.

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KarenRei: The numbers may be even worse than you figured. Standard air compressors max out at only 200 psi, but the "Air Car" requires up to 4,500 psi, from a special compressor. Since increased pressure means more energy lost to waste heat, that special 4,500 psi compressor must be considerably less efficient than a standard 200 psi compressor.

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MDI is a scam. No published report for anyone driving much more than around the block. The 125 mile range on compressed air has never been verified. The carbon fiber tanks? Just recently saw a carbon fiber tank that was tested to failure - big and violent catastrophic failure, not the seeping failure mentioned. This company has been around for years attracting investors, fails to deliver and then it goes underground. Per Wiki no car has ever been produced. Was on Discovery where they suggested perpetual motion: use the forward momentum to drive air compressors on board and then use that air to run the motors. No shit, and the Discovery narrator made no comment.

Previous comments about compressor efficiencies are on target, but they omitted that air motors are inherently inefficient too. All in all the numbers don't add up. Other technologies have a much better chance.

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Yes, a hummer emits more pollution than an air car powered by wind. But it easily beats an air car powered by normal grid power.

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@lots of people above me
Before jumping on the bandwagon of the air car polluting more than a Hummer, I think we need some hard numbers. The video mentions $2 for 125miles. Assuming that they were referring to offpeak energy (2.5cents/kWh), that's 80kWh for 125 miles. That's 640Wh/mile; okay not good, since even a much heavier (2700lb), faster, safer Tesla roadster gets 310Wh/mile. 640Wh/mile means 52.66mpge plug to wheels. Factor in 32.5% efficiency for most coal plants and that's 17.11mpge fuel to wheels. Okay before saying see, see, remember as for all other grid powered vehicles, we must remember 100% coal is pretty much the worst case (remember even place in US that uses the most coal is 73%) and also factor in off peak energy. And by Hummer, I assume you guys mean the H2; that gets 13mpg at the best. So overall, don't think the air car is worst than a Hummer. But without hard numbers, it's hard to judge b/c the result would be a lot better if they were talking about normal energy @ 10cents/kWh.

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Hello !

Hey! Wake up ! Reciprocating compressors are definitely old-fashioned ! ;o)

With new types of compressors, designed by engineers from the famous "Ecole Polytechnique Fédérale de Lausanne"(EPFL, Switzerland), it's absolutely possible to compress air with an excellent efficiency (>80% !) thanks to liquid pistons or air-oil interfaces that allows an almost isothermal process. Today, best reciprocating industrial compressors have an efficiency of 50-55%.

Sylvain LEMOFOUET, a young engineer that made his thesis on the subject, has just created a startup to bring this new invention to the market.

See:
http://www.bfe.admin.ch/php/modules/enet/streamfile.php?file=000000008102.pdf&name=240050.pdf

or search his name on the web to see all his publications.

That offers a efficient way to store renewable but intermittent energy
(windmills, solar panels...).

Moreover, this improve greatly the global efficiency of the air car
and brings it nearer electric cars.

Free bonus ! :o)

Here is a very interesting report (.pdf in a .zip file: 1.7MB) from International Energy Agency about evaluation of different existing storage devices.

http://mdi.cats.free.fr/Img/Evaluation_of_energy_storage_devices.zip

It shows that compressed air has its place ! :o)

Regards,

Marsupy.

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Two interesting forums to go into detail:

English Yahoo! group dedicated to MDI air car:
http://autos.groups.yahoo.com/group/mdiaircar

French + english (readable without registration)
http://air-car-concept.bb-fr.com/

Regards,

Marsupy.

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Unfortunately, we will not be attending the New York auto show. We are on a tight budget; both money and time are short. We are instead focusing our limited resources on our vehicle.

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[Clarification] - Team IMW (Illuminati Motor Works) will not be appearing at the New York auto show.

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